WMN All Units Notes

Unit I BASICS OF PCS AND GSM (12 Marks)
Evolution of Mobile Communications

• 1 G- Analog
• Voice Calls eg AMPS(Advanced Mobile Phone System)
• 2 G- Digital
• Voice calls +SMS
• GSM (Global System for Mobile Communication)
• CDMA (Code-Division Multiple Access)
• 2.5 G
• GPRS (General Packet Radio Service)
• 2.75G
EDGE(Enhanced Data rates for GSM Evolution)
• 3G
• UMTS(Universal Mobile Telecommunications System)
• CDMA2000
• 4G
Prepared by: Ms. M. S. Karande Wireless and Mobile Networks (Sub Code: 22622) Pg 1/ 39
WIMAX (Worldwide Interoperability for Microwave Access)
LTE (Long Term Evolution) VoLTE (Voice Over LTE)
• 4.5G
LTE-A (LTE Advanced)
• 5G
Cellular Telephony Network
CELL
❖ LARGER AREA DIVIDED

INTO SMALL NO. OF AREAS
❖ SHAPE IS HEXAGONAL
❖ EACH WITH ITS OWN

BASE STATION AND SET OF
FREQUENCIES.
GSM
Downlink
• Base Station (BTS –Base Transceiver Station)
• A fixed station in a mobile radio system used for radio communication with mobile
stations. Base stations are located at the center or on the edge of a coverage region
and consist of radio channels and transmitter and receiver antennas mounted on a
tower.
1.1. Personal Communication Service(PCS)

• The term Personal Communication Service (enabling communication with a person at
anytime, at any place, and in any form) include Various Wireless Access and Personal
Mobility Services.
• PCS is a wireless phone service similar to cellular
telephone service emphasizing personal service with extended mobility (more no of
antennas to assist mobility)
• PCS provides the user with an all-in-one wireless phone, paging, messaging, and data
service
• TDMA,CDMA and GSM along with 2G,3G and 4G are some technologies used for PCS
Application of PCS
1. Voice Communication
2. Messaging
3. Internet access
4. Location based services
PCS Architecture
• The PCS Network Architecture is a communication network structure in which

components communicate with one another to establish wireless communication.
• The PCS Network Architecture is divided into two sections:
• Radio Network
• Wireline Transport Network
Radio Network
• The radio network connects Mobile Stations (MS) and other network components via a
wireless network.
• MS connect with one another via the radio network's Base Stations (BS).
• The radio link protocols are handled by the BS in a radio network during
communication.
• Protocols are a collection of rules that must be followed to establish a connection.
• A cell is a radio coverage region that each BS in a radio network has.
• MS can converse with one another both inside and outside the cell.
• The BSC serves as a link between the radio network's BTS and the Wireline Transport
network's MSC
Wireline Transport Network
• The Base Station Controller (BSC) in the Radio Network interfaces with the Mobile
Switching Center (MSC) in the Wireline Transport Network.
• To provide wireline customers with communication services, MSC connects to the

Public Switch Telephone Network (PSTN).
• MSC also communicates with a mobility database, which keeps track of where moving
devices are in the architecture.
1.2. Global System for Mobile Communications

• The Global System for Mobile Communications (GSM) is a standard developed by the
European Telecommunications Standards Institute (ETSI) to describe the protocols
for second-generation (2G) digital cellular telephone network (known as a Public
Land Mobile Network, or PLMN) used by mobile devices such as mobile phones and
tablets.
Global System for Mobile (GSM) is a second generation cellular standard developed to
cater voice services and data delivery using digital modulation
GSM Architecture
Interfaces in GSM
Interfaces used for GSM network : (ref fig 2)
1)UM Interface –Used to communicate between BTS with MS
2)Abis Interface— Used to communicate BSC TO BTS
3)A Interface-- Used to communicate BSC and MSC
4)Singling protocol (SS7)- Used to communicate MSC with other network .
GSM network layout
GSM network areas
In a GSM network, the following areas are defined −
• Cell − Cell is the basic service area; one BTS covers one cell. Each cell is given a Cell
Global Identity (CGI), a number that uniquely identifies the cell.
• Location Area − A group of cells form a Location Area (LA). This is the area that is
paged when a subscriber gets an incoming call. Each LA is assigned a Location Area
Identity (LAI). Each LA is served by one or more BSCs.
• MSC/VLR Service Area − The area covered by one MSC is called the MSC/VLR
service area.
• PLMN − The area covered by one network operator is called the Public Land Mobile
Network (PLMN). A PLMN can contain one or more MSCs.
GSM Architecture
• GSM system consists of three major components:
1. Base Station System (BSS):

MS, Base Transceiver Station (BTS) Base Station Controller (BSC)
2. Network and Switching Subsystem (NSS)

Mobile Switching Center (MSC) Home Location Register (HLR) Visitor Location
Register (VLR)Authentication Center (AUC) Equipment Identity Register (EIR).
3. Operation Support Subsystem(OSS)

Operation and Maintenance Center (OMC)
1. Base Station System (BSS):

Base Station Subsystem is composed of parts that communicate across the
standardized Abis interface allowing operation between components made by different
suppliers.
This system consists of
i. Mobile Station (MS)

ii. Base Transceiver Station (BTS)
iii. Base Station Controller (BSC)
Mobile Station (MS)
The Mobile Station is made up of two entities:
1. Mobile Equipment (ME)
2. Subscriber Identity Module (SIM)
The ME is the only part of the GSM network which the subscriber will really see.
There are three main types of ME, these are listed below:
1. Vehicle Mounted
2. Portable Mobile Unit
3. Hand portable Unit
Subscriber Identity Module(SIM)
• The SIM is a card which plugs into the ME. The SIM contains several pieces of
information:
1. International Mobile Subscribers Identity(IMSI) –
– This number identifies the mobile subscriber. It uniquely identifies a given MS.
2. Temporary Mobile Subscriber Identity ( TMSI ) –
– It is an temporary identity that is allocated to an MS by the VLR when it is in roaming

and it is on temporary basis
– It is an alias of the IMSI and is used in its place for privacy
3. Location Area Identity ( LAI ) -
– Each LA in a PLMN has its own identifier.
– Identifies the current location of the subscriber.
• The SIM is a card which plugs into the ME. The SIM contains several pieces of
information:
4. Subscribers Authentication Key ( Ki ) –
– This is used to authenticate the SIM card.
5. Mobile Station International Standard Data Number ( MSISDN ) –
This is the telephone number of the mobile
Base Transreceiver Station (BTS):

• It is connected to MS via Um interface and it is also connected to BSC via the Abis
interface.
• The Um interface contains all mechanism for wireless interface (TDMA, FDMA etc.).
• The BTS is a radio equipment (transreceiver or antenna) needed to service each cell in
the network.
• Encodes, encrypts, multiplexes, modulates and feeds the RF signals to the antenna.
• Decoding, decrypting, and equalizing received signals
• Communicates with Mobile station and BSC
Base Station Controller (BSC)

• BSC provides all the control functions and physical link between MSC and BTS.
• BSC handles:
– Channel allocation for the duration of call
– Maintains the call
– Monitor Quality
– Handoffs
– Control the power transmitted by BTS or MS
– Control of frequency hopping
2. Network and Switching Subsystem (NSS):
NSS is responsible for performing call processing and subscriber related functions.
It also includes:
Mobile Switching Center (MSC)

Home Location Register (HLR)
Visitor Location Register (VLR)
Authentication Center (AUC)
Equipment Identity Register (EIR) etc
Mobile Switching Center (MSC)
• Heart of the network
• Manages communication between
GSM and other networks
• When provides interface between PSTN & BSS in GSM network then known as a
Gateway MSC(GMSC)
• Mobility management
- Registration
- Location Updating
- Inter BSS and inter MSC call handoff
• Billing information and collection
Home Location Register (HLR)

• It is a database for managing the mobile subscriber.
• HLR stores permanent data of subscriber which include subscribers service profile,
prepaid/postpaid, roaming restrictions ,supplementary services, location information and
its activity.
A home subscriber charges are less than the roaming subscriber
• Home location register (HLR) is a database used for mobile user information
management. All permanent subscriber data are stored in this database.
• An HLR record consists of 3 types of information:
1. Mobile station information
– IMSI used by MS to access network
– MSISDN
2. Location information
– Address of VLR and MSC where MS resides
3. Service information
– Service subscription
– Service restrictions
– Supplementary services
Visitor Location Register (VLR)

• The VLR is a database that contains temporary information about subscribers that is
needed by the MSC in order to service visiting subscribers
• The VLR is always integrated with the MSC
• When a mobile station roams into a new MSC area, the VLR connected to that MSC will
request data about the mobile station from the HLR.
• Later, if the mobile station makes a call, the VLR will have the information needed for
call setup without having to interrogate the HLR each time
• Assigns a TMSI to each MS entering the VLR area which keeps on changing.
• VLR information consists of 3 parts:
1. Mobile station information
– IMSI
– MSISDN
– TMSI
2. Location information
– MSC number
– Location area ID (LAI)
3. Service information
– Subset of the service information stored in the HLR
Equipment Identity Register
• International Mobile Station Equipment Identity (IMEI)
It is similar to a serial number. It is allocated by equipment manufacturer, registered by

network, and stored in EIR
• This database that contains information about the identity of mobile equipment that
prevents calls from stolen, unauthorized or defective mobile stations
• The EIR contains a centralized database for validating the IMEI.
• This database is concerned solely with MS equipment and not with the subscriber who
is using it to make or receive a call.
• The EIR database consists of lists of IMEIs (or ranges of IMEIs) organized as follows:
1. White IMEI: All known IMEI.
2. Black IMEI: All stolen mobile handset.
3. Gray IMEI: Handset that is uncertain
Authentication Center (AUC)
• The AuC is a processor system that performs the “authentication” function
• AUC provides authentication and encryption parameters to verify the users identity &
ensure the confidentiality of each call.
• Contains the algorithms for authentication as well as the keys for encryption.
• Protects network operators from fraud.
• It is normally co-located with the HLR as it will be required to continuously access and
update, as necessary, the system subscriber records.
• The authentication process will usually take place each time the subscriber “initializes”
on
(iii) Operation Support Subsystem(OSS)

Operation and Maintenance Center (OMC):
• OMC is connected to all equipments in switching system and to the BSC.
• It maintains operation of the GSM network by observing the handovers, system load,
blocking rates etc.
• OMC provides network overview and allow network engineers to monitor, diagnose and
troubleshoot every aspect of GSM network.
Features of GSM
• Improved spectrum efficiency
• International roaming
• Low-cost mobile sets and base stations (BSs)
• High-quality speech
• Compatibility with Integrated Services Digital Network (ISDN) and other telephone
company services
• Support for new services
• In GSM terminology, telecommunication services are divided into three broad

categories:
• GSM Services
1. Bearer services
2. Teleservices
3. Supplementary Services
1. Bearer services are also called as Data services.
• GSM allowing for data rates of up to 9600 bit/s or 9.6 kbps for non-voice services
• Include various data services for information transfer between GSM and other networks
like PSTN, ISDN etc at rates from 300 to 9600 bps or 9.6 kbps
2. Teleservices are telecommunication services that enable voice

communication via mobile phones
3. Offered services
1. Mobile telephony
2. Emergency calling
3. Videotext and Facsimile
4. Short Text messages
3. Supplementary services are additional services that are provided in addition to

teleservices and bearer services.
These services include
• Multiparty Service/Conferencing
• Call Waiting
• Call Hold
• Call Forwarding
• Call Barring
• Calling Line Identification
• Advice of Charge (AoC)
• Closed User Groups (CUGs)
• Supplementary services are additional services that are provided in addition to

teleservices and bearer services.
• These services include −
1. Conferencing − It allows a mobile subscriber to establish a multiparty conversation,
i.e., a simultaneous conversation between three or more subscribers to setup a
conference call. This service is only applicable to normal telephony.
2. Call Waiting − This service notifies a mobile subscriber of an incoming call during a
conversation. The subscriber can answer, reject, or ignore the incoming call.
3. Call Hold − This service allows a subscriber to put an incoming call on hold and resume
after a while. The call hold service is applicable to normal telephony.
4. Call Forwarding − Call Forwarding is used to divert calls from the original recipient to
another number. It is normally set up by the subscriber himself. It can be used by the
subscriber to divert calls from the Mobile Station when the subscriber is not available,
and so to ensure that calls are not lost.
5. Call Barring − Call Barring is useful to restrict certain types of outgoing calls such as
ISD or stop incoming calls from undesired numbers. Call barring is a flexible service that
enables the subscriber to conditionally bar calls.
6. Calling Line Identification Presentation − This service displays the telephone number
of the calling party on your screen.
7. Advice of Charge (AoC) − This service was designed to give the subscriber an
indication of the cost of the services as they are used. Furthermore, those service
providers who wish to offer rental services to subscribers without their own SIM can also
utilize this service in a slightly different form. AoC for data calls is provided on the basis
of time measurements.
8. Closed User Groups (CUGs) − This service is meant for groups of subscribers who
wish to call only each other and no one else.
GSM Frequency Spectrum

The GSM standard operates on three different frequencies which are as follows:
1. 900 MHz: It was used by the original GSM system.
2. 1800 MHz: It was used to support the growing number of subscribers.
3. 1900 MHz: It is mainly used in the US.
1. GSM 900:
• 890-915 MHz UPLINK
• 935-960MHz DOWNLINK
2.GSM 1800:
• 1805-1880 MHz DOWNLINK
3. GSM 1900:
• 1930-1990 MHz DOWNLINK
GSM Radio Aspects
• GSM utilizes two bands of 25 MHz which have been set aside for system use in all
member countries
• Two frequency bands 45 MHz apart have been reserved for GSM
– 890-915 MHz for uplink (mobile-to-base) frequency
– 935-960 MHz for downlink (base-to-mobile)
• The GSM uses time division multiple access (TDMA) and frequency division multiple
access (FDMA)
• Each of these bands of 25 MHz spectrum is subdivided into 124 carriers ( with no guard
band) of 200 kHz. This 200 kHz band is called ARFCNs(Absolute Radio Frequency
Channel Number)
• Each carrier in turn is divided into 8 time slots ( radio channels ).
• Each user transmits periodically in every eighth time slot in an uplink radio carrier &
receives a corresponding time slot on the downlink carrier.
• Thus, several conversations can take place simultaneously at the same pair of
transmit/receive radio frequencies.
• In each uplink/downlink bands there exists a guard band of 200 KHz
Each of these bands of 25 MHz is subdivided into 124 single carrier channels of
200 KHz band is called ARFCNs(Absolute Radio Frequency Channel Number
System Parameter Value (GSM)
Multiple Access TDMA/FDMA
Uplink frequency (mobile-to-base) 890-915 MHz
Downlink frequency (base-to-mobile) 935-960 MHz

Channel Bandwidth 200KHz
Number of channels 124
Users per Frame(Full Rate) 8
Frame duration 4.615 ms
Interleaving duration 40 ms
Modulation 0.3 GMSK
ARFCN Number 0 to 124 and 975 to 1023
Modulation Data Rate 270.833333 kbps

Time slot period 576.9 µs
Bit period 3.692 µs
Tx/Rx Frequency spacing 45 MHz

Tx/Rx Time slot spacing 3 Time slots
GSM CHANNELS
1. Physical channel –
Each timeslot on a carrier is referred to as a physical channel.
Per carrier there are 8 physical channels.
2. Logical channel –
Variety of information is transmitted between the MS and BTS. There are different
logical channels depending on the information sent. The logical channels are of two
types
i. Traffic channel
ii. Control channel
2. Logical channels (GSM)
BCH Channels( Broadcast channels)

1. BCCH( Broadcast Control Channel )
• Downlink only
• Broadcasts general information of the serving cell called System Information
• BCCH is transmitted on timeslot zero of BCCH carrier
• Read only by idle mobile at least once every 30 secs.
2. SCH( Synchronisation Channel )

• Downlink only
• Carries information for frame synchronisation. Contains TDMA frame number

and BSIC.
3.FCCH( Frequency Correction Channel )

• Downlink only.
• Enables MS to synchronise to the frequency.
Also helps mobiles of the n cells to locate TS0 of BCCH carrier
CCCH Channels(Common Control Channels)

1.RACH( Random Access Channel )
Uplink only
Used by the MS to access the Network.
2.AGCH( Access Grant Channel )

Downlink only
Used by the network to assign a signaling channel upon successful decoding of access
bursts.
3.PCH( Paging Channel )

Downlink only.
Used by the Network to contact the MS.
DCCH Channels(Dedicated Channels)

1.SDCCH( Standalone Dedicated Control Channel )
• Uplink and Downlink
• Used for call setup, location update and SMS.
2. SACCH( Slow Associated Control Channel )

• Used on Uplink and Downlink only in dedicated mode.
• Uplink SACCH messages - Measurement reports.
• Downlink SACCH messages - control info.
3. FACCH( Fast Associated Control Channel )
• Uplink and Downlink.
• Associated with TCH only.
• Is used to send fast messages like handover messages.
Works by stealing traffic bursts.
CALL PROCESSING IN GSM

• Once a Mobile Station initiates a call, a series of events takes place. Analyzing these
events can give an insight into the operation of the GSM system.
Following different types of call flow in GSM
• Mobile Phone to Public Switched Telephone Network (PSTN) – Mobile Call

Origination
• PSTN to Mobile Phone- Mobile Call Termination
• Mobile Phone to Mobile Phone
Mobile Call origination
1. The MS sends the dialed number indicating service requested to the MSC(via BSS)
2. The MSC checks from the VLR if the MS is allowed the requested service. If so, MSC
asks BSS to allocate necessary resources for the call.
3. If the call is allowed, the MSC routes the call to GMSC.
4. The GMSC routes the call to the local exchange of called user.
5. The LE alerts (applies ringing) the called terminal.
6. Answer back (ring back tone) from the called terminal to LE.
7. Answer back signal is routed back to the MS through the serving MSC which also
completes the speech path to the MS.
Mobile Call Termination
1. The PSTN user dials the MSISDN of the called user in GSM.
2. The LE routes the call to the GMSC of the called GSM user.
3. The GMSC uses the dialed MSISDN to determine the serving HLR for the GSM user
and interrogates it to obtain the required routing number.
4. The HLR requests the current serving VLR for the called MS for a MSRN(MS roaming
number) so that the call can be routed to the correct MSC.
5. The VLR passes the MSRN to the HLR.
6. The HLR passes the MSRN to the GMSC.
7. Using the MSRN, the GMSC routes the call to the serving MSC.
8. The MSC interrogates the VLR for the current location area identity (LAI) for the MS.
9. The VLR provides the current location for the MS.
10. The MSC pages MS via the appropriate BSS. The MS responds to the page and sets
up the necessary signaling links.
11. When the BSS has established the necessary radio links, the MSC is informed an the
call is delivered to the MS.
12. When the MS answers the call, the connection is completed to the calling PSTN user.
1.3. MOBILITY MANAGEMENT (MM)

• Mobility Management is categorized into 4 sections:
• Paging
• Location Update
• Handoff Mechanism
Roaming
Paging
• Paging is one to one communication between mobile and base station
• Paging is procedure that network used to find
Subscriber's location before actual call establishment.
• Paging is used to alert mobile station of incoming call.
• Paging is done by NSS (network subsystem) and it is based of location registration

information.
Roaming
• Roaming is the ability for a customer of mobile communications to automatically make
and receive telephone calls, send and receive data, or access other services while
travelling outside the geographical coverage area of the home network, by means of
using a network of another operator.
• Roaming can be either national roaming or international roaming.
• National roaming means that mobile subscribers make use of another network in
geographical areas, where their own operator does not have coverage.
• This is, for example, used by operators, who do not have complete coverage in a
country.
• International roaming is used when mobile subscribers travel abroad and make use of
the network of an operator in the foreign country
How Roaming is Performed
• If a service provider does not have a network coverage in a particular city or country,
then this service provider makes a roaming agreement with another service provider
having network in that city or country.
• As per this agreement, another service provider provides all the available services to
the roaming customer of first service provider.
• CDRs(Call Detail Records) generated in one roaming partner's area are collected and
rated by that roaming partner and finally they are sent to the actual service provider of
the roaming customer. Actual service provider charges the end customer for all the
roaming services provided based on their predefined service charges.
• Two roaming partners settle their financials on monthly basis by exchanging actual
roaming CDRs and reports based on those CDRs.
Handoff
• Handoff (or handover) is a control process initiated when a mobile moves from its
current cell to its neighboring cell.
• A user of a mobile phone will be moving continuously. In such a situation, the mobile
connection should also remain intact especially if the user is currently using the phone.
This transfer of connection from one cell to another should be quick and in such a
manner that user doesn’t actually realize that a handoff has happened
Why Handovers Required
➢ For Seamless mobility / connectivity to prevent call drop.
➢ If the traffic in the cell increases handovers may be required
➢ When mobile node move away from cell centre(tower/ BTS) towards cell edge, signal
level dropped. This can be continuously transferred through Measurement Reports to
BTS.
Hard Hand-Off
Soft Hand-Off
Intra-BTS Handover
1. Intra-cell handover:
Such a kind of handover is performed to optimize the traffic load in the cell or to
improve quality of a connection by changing carrier frequency.
1. Intra-BTS handover
2. Inter-BTS/Intra-BSC handover
3. Inter-BSC handover
4. Inter-MSC handover
2. Inter-cell handover:
• It is also known as Intra-BSC handover.
• Here the mobile moves from one cell to another but remains within the same BSC
• Here the BSC handles the handover process
3. Inter-BSC handover:
• It is also called as Intra-MSC handover.
• As BSC can control only a limited number of cells, we might usually need to
transfer a mobile from one BSC to another BSC.
Here the MSC handles the handover process
4. Inter-MSC handover:
• It occurs when a mobile moves from one MSC region to another MSC.
• MSC cover a large area.
It can be imagined as a handover from Maharashtra MSC to Gujarat MSC while

travelling
• Hard Handoff − In a hard handoff, an actual break in the connection occurs while
switching from one cell to another.
• The radio links from the mobile station to the existing cell is broken before establishing a
link with the next cell. It is generally an inter-frequency handoff.
• It is a “break before make” policy.
• Eg GSM
• Soft Handoff −
• In soft handoff, at least one of the links is kept when radio links are added and removed
to the mobile station.
• This ensures that during the handoff, no break occurs. This is generally adopted in co-
located sites.
• It is a “make before break” policy.
• Eg CDMA
GSM security
• Authentication (used for billing purposes)
• Confidentiality
• Anonymity ( used to identify users)
• Security services
ACCESS CONTROL/AUTHENTICATION
• user SIM (Subscriber Identity Module): secret PIN (personal identification
number)
• SIM network: challenge response method
CONFIDENTIALITY
• voice and signaling encrypted on the wireless link (after successful
authentication)
ANONYMITY
• temporary identity TMSI
(Temporary Mobile Subscriber Identity)
• newly assigned at each new location update (LUP)
• encrypted transmission
3 algorithms specified in GSM

• A3 for authentication (“secret”, open interface)
• A5 for encryption (standardized)
• A8 for key generation (“secret”, open interface)
GSM – Authentication
• Authentication is a process of exchanging information between a communications

device and the mobile network which allows the carrier or network operator to confirm
the true identity of the user (or device).
• This validation of the authenticity of the user or device allows a service provider to deny
service to users that cannot be identified.
• The authentication algorithm (A3) used in the GSM system is contained

in the subscriber identity module - SIM - card. The GSM authentication process can use
different versions of authentication.
• The GSM authentication process starts with the transmission of a random

number (RAND) from the base station.
• As part of a typical authentication process, a random number that changes periodically
(RAND) is sent from the base station.
• This number is regularly received and temporarily stored by the mobile radio.
• The secret number Ki is stored in both the mobile telephone and GSM system and it
is not transmitted over the radio link.
• This random number is used, along with other information including the secret data
value (Ki), to calculate a signed response (SRES).
• The authentication response is sent back to the system to validate the mobile radio.
• The system processes the same information to create its own authentication response.
• When the GSM system performs the authentication process, it compares the SRES it
calculates to the SRES returned by the mobile telephone.
• If both SRESs authentication responses match, service may be provided, the GSM
system allows call processing to continue.
GSM location Update

What is GSM Location update? (2M Explanation)
Location Area (LA):
• A GSM network is divided into cells.
• A group of cells is considered a location area.
• A mobile phone in motion keeps the network informed about changes in the location
area.
• If the mobile moves from a cell in one location area to a cell in another location area, the
mobile phone should perform a location area update to inform the network about the
exact location of the mobile phone.
• GSM "location update" is a part of registration.
• GSM networks keep track of the location area (LA) where the MS is operating.
• When receiving an incoming call, the MS is paged in all cell of its current location area.
When it occurred: (2M Explanation)
• The Location Update procedure is performed:
1. Updating on entering a new location Area:
• The Location Area Identity (LAI) is broadcast in system information message and stored
in mobile station memory.
• When a new received location area identity does not match with the previously stored
location area identity, then MS does a location update.
2. Periodic update:
• Whenever MS performs location update, it resets timer T.
• A timer has timeout value.
• As and when the timer expires, the MS does the location update.
3. Updating on deactivation and activation:
• Mobile equipment do this update and send IMSI DETACH message when it is
deactivated.
• The network marks that MS as a deactivated and does not send paging message to for
MS until it is activated again.
• MS send IMSI ATTACH message does a location update when it is activated again.
GSM location Update
1. MS sends location update to new VLR
2. VLR sends location update msg to HLR with address of new VLR and IMSI of MS
3. Service and security related data for MS is downloaded to new VLR
4. MS is sent acknowledgment of successful update
5. HLR request old VLR to delete data relating to relocated MS
Type Of Areas In GSM

There are three of area in GSM:
1.Location area
2.Routing area
3.Tracking area
1.Location Area
• A "location area" is a set of base stations that are grouped together to optimize
signaling
• Typically, tens or even hundreds of base stations share a single Base Station
Controller (BSC) in GSM.
• A location area is controlled by one or more BSCs, but only by one MSC.
• Each location area has an assigned unique identifier, made up of numbers, called a
"location area code" (LAC).
• The LAC is broadcast by each base station at regular intervals.
• Within a location area, each base station is assigned a distinct "cell identifier" (CI)
number
2.Routing Area
• The routing area is the packet-switched domain
equivalent of the location area.
• A "routing area" is normally a subdivision of a

"location area".
• Routing areas are used by mobiles which are

GPRS-attached.
3. Tracking Area
• A tracking area is a set of cells
• The tracking area is the LTE counterpart of the location area and routing area.
1.4. Network Signaling
Databases
– VLR (visitor location register)
– HLR (home location register)
– AuC (authentication center)
– EIR (equipment identity register)
• Used to maintain a list of legitimate, fraudulent, or faulty mobile

stations
• Works with HLR to block calls from illegitimate MS
Switches
– MSC (mobile switching center)
– GMSC (gateway MSC)
– SSP (service switching point)
Radio systems
– BSC (base station controller)
– BTS (base transceiver station)
– MS (mobile station)
The figure shows various network signaling protocols used by the entity interfaces in
GSM
• The software platform for implementing GSM network signaling protocol is GSM
MAP(Mobile Application Part)
• GSM MAP is used in B,C,D,E,F,G interfaces
• In terms of Network signaling, the GSM architecture can be partitioned into 3 parts
1. Databases 2. Switches 3. Radio System

1. Databases:
• GSM utilizes databases such as HLR, VLR and AuC.
• It also consists of EIR which is used to maintain a list of legitimate , fraudulent mobile
station(faulty)
• EIR is optional in GSM. AuC/EIR is a combined Node
• To accomplish mobility management, VLRs communicate using G interface and HLR to

VLR using D interface
2. Switches :
• The GMSC performs necessary switching functions for mobile stations within the
geographical area it controls.
• An MSC area is partitioned into several location areas. Each LA consists of many BTS.
For originating a call from MS to a wireline user , the MSC communicates with SSP in
the PSTN using SS7ISUP protocol
• To deliver a call from PSTN to MS, the originating SSP in PSTN with Gateway MSC
using SS&ISUP protocol
• In Intersystem Handoff, 2 MSCs are required to communicate through E interface
• To perform Mobility and call handling tasks, the MSC needs to communicate with HLR
using the C interface and with VLR using B interface
• To prevent Fraudulent handset usage, MSC communicates with EIR using F interface
3. Radio system
It consists of BSc, BTS and MS.
The BSCs connect to MSC through A interface.
BSC connects to BTS through A-Bis interface using ISDN link access protocol for D
channel(LAPD).
A BTS communicates with MS through radio interface Um
• Um – MS to BTS
• Abis – BTS-BSC
• A – BSC- GMSC
• B – GMSC-VLR
• C - GMSC-HLR
• D – VLR-HLR
• E – MSC-GMSC
• F - GMSC-EIR
• G - VLR-VLR
• H – HLR-AUC
Um
• The air interface is used for exchanges between a MS and a BSS.
• LAPDm, a modified version of the ISDN LAPD, is used for signalling.
Abis
• This is a BSS internal interface linking the BSC and a BTS, and it has not been
standardised.
• The Abis interface allows control of the radio equipment and radio frequency allocation
in the BTS.
• The A interface is between the BSS and the MSC.
• The A interface manages the allocation of suitable radio resources to the MSs and
mobility management.
• The Mobile Application Part (MAP) is an SS7 protocol that provides an application layer
for the various nodes in GSM and UMTS mobile core networks and GPRS core
networks to communicate with each other in order to provide services to users.
• The B interface between the MSC and the VLR uses the MAP/B protocol.
• Most MSCs are associated with a VLR, making the B interface "internal". Whenever the
MSC needs access to data regarding a MS located in its area, it interrogates the VLR
using the MAP/B protocol over the B interface
• The C interface is between the HLR and a GMSC.
• Each call originating outside of GSM (i.e., a MS terminating call from the PSTN) has to
go through a Gateway to obtain the routing information required to complete the call,
and the MAP/C protocol over the C interface is used for this purpose.
• Also, the MSC may optionally forward billing information to the HLR after call clearing
• The D interface is between the VLR and HLR, and uses the MAP/D protocol to
exchange the data related to the location of the MS and to the management of the
subscriber.
• The E interface interconnects two MSCs.
• The E interface exchanges data related to handover between the anchor and relay
MSCs using the MAP/E protocol.
• The F interface connects the MSC to the EIR, and uses the MAP/F protocol to verify the
status of the IMEI that the MSC has retrieved from the MS.
• The G interface interconnects two VLRs of different MSCs and uses the MAP/G
protocol to transfer subscriber information, during e.g. a location update procedure.
• The H interface is between the MSC and the AUC, and uses the MAP/H protocol to
support the transfer of short messages.
• The I interface can be found between the MSC and the ME. Messages exchanged over
the I interface are relayed transparently through the BSS.
MSBTE QUESTIONS
1. Enlist two application of personal communication services. (l -R)
2. Enlist any four GSM Services. (I-R)
3. Draw the architecture of GSM and explain function of each block. (l -U)
4. Explain authentication process in GSM.
5. Write the function for temporary identity subscriber.
6. Draw GSM architecture
7. List the supplementary services offered in GSM.
8. List any two functions of HLR and VLR.
9. Describe call processing in GSM.
10. Draw GSM architecture and list the logical channels in GSM.
11. Define the term:
i) Routing area ii) Location area iii) Tracking area
12. Draw the block diagram of the architecture of PCS (Personal Communication Services)
and explain.
13. Explain the Network signalling and radio interfaces in GSM (6M)
14. Enlist any two GSM services
15. Describe the mobile originated call in GSM with neat diagram.
16. Explain various types of Handoffs
17. Explain the various interfaces used in GSM.
18. What is GSM Location update? When it occurs?
GPRS and Mobile data communication
(12 Marks)
2.1. General Packet Radio System (GPRS) (2.5 G)

GPRS Stands for General Packet Radio Service developed by European Telecommunication
Standard Institute (ETSI) is one of the standards of Global System for Mobile communications
(GSM) Phase 2+ is designed as a packet switching system
Features of GPRS are:
Packet switching: GPRS uses packet switching to send and receive data, which means
that data is broken down into packets and transmitted over the network. This allows for
efficient use of network resources and enables faster data transfer rates.
Always-on connectivity: GPRS provides an "always-on" connection to the internet or

other networks, which means that users do not need to dial in to establish a connection each
time they want to access data.
Compatibility with existing networks: GPRS is compatible with existing GSM

networks, which means that it can be easily integrated into existing mobile networks
High-speed data transfer: GPRS provides data transfer rates of up to 171 kbps, which is
significantly faster than traditional dial-up connections.
Prepared by: Ms. M. S. Karande Wireless and Mobile Networks (Sub Code: 22622)
Support for multimedia services: GPRS supports multimedia services such as video
streaming, picture messaging, and mobile internet browsing.
Security: GPRS includes several security services such as authentication, access control,
user identity confidentiality, and user information.
Overall, GPRS provides a cost-effective and efficient way for mobile users to access data
services and stay connected to the internet while on the go.
GPRS Architecture
• GPRS is usually attempts to reuse the existing GSM network elements as much as
possible.
• There are new entities called GPRS that supports nodes (GSN) which are responsible
for delivery and routing of data packets between mobile stations and external packets
networks. There are two types of GSNs,
• Serving GPRS Support Node (SGSN)
• Gateway GPRS Support Node (GGSN)
A. Mobile Station:
• GPRS Services required New Mobile Station as the existing GSM phones are not
capable of handling the enhanced air interface or the packet data.
• A wide variety of Mobile stations exist which includes a high-speed version of current
phones to support high-speed data access like PC cards for laptop computers.
• Class – A : Terminals operate GPRS and other GSM services simultaneously.
• Class – B : Terminals can monitor all services but operate either GPRS or GSM.
• Class - C : Terminals operate only GPRS service.
B. Base Station Subsystem:
• Each BSC requires the installation of Packet Control Units in addition to software
upgrade.
• They provide physical and logical data interface to BSS to estimate packet data traffic.
• BTS too require a software upgrade but typically does not involve hardware
enhancements.
• When the traffic is originated at the subscriber mobile then it is transported over the air
interface to BTS and then from BTS to BSC, the same way in standard GSM call.
• But at output of BSC the traffic is separated, the voice is sent to the mobile switching
centre per standard GSM and the data is sent to the new device called the SGSN via
the PCU
• PCU
• The PCU or Packet Control Unit is a hardware router that is added to the BSC.
• It differentiates data destined for the standard GSM network (circuit switched data) and
data destined for the GPRS network (Packet Switched Data).
• The PCU itself may be a separate physical entity, or more often these days it is
incorporated into the base station controller, BSC, thereby saving additional hardware
costs.
C. Core Network (CN):
MSC (Mobile Switching Controller) is the central unit of the network. It controls mobility
management, call set up, location updating, routing, basic switching and supplementary
services.
HLR (Home Location Register) is a database that stores subscriber information, such as the
mobile station's identity, the services to which it has access, and its current location.
VLR (Visitor Location Register) temporarily stores the IMSI of each roaming subscriber.
AUC (Authentication Centre) is strongly protected database which handles authentication

and encryption key for every single subscriber in HLR and VLR.
EIR (Equipment Identity Register) to check for stolen phones
D.GRPS Support Nodes:
• SSGN:
• The Serving GPRS Support Node is responsible for authentication of GPRS mobiles,
registration of mobiles in the network, mobility management, and collecting information
for charging for the use of the air interface.
• GGSN:
• The Gateway GPRS Support Node is the interface between the GPRS network and
external networks, such as the internet.
• It performs functions such as packet routing, IP address allocation, and charging.
2.2. GPRS Support Nodes

1. Serving GPRS Support Node: (SGSN):
• Ciphering, Authentication
• Data Compression
• Mobility management
• Session management
• Logical link management towards the MS
• Charging data
• Packet routing & transfer
• Connection - HLR, MSC, BSC and SMS-MSC
2. Gateway GPRS Support Node (GGSN):

• External interfaces (Mobile IP applications, Internet/Intranets)
• Access functionality
• ‘Traditional’ gateway functionality
• Subscriber addresses publish
• Routing
• Charging data
GPRS Services
• Instant messaging and presence
• Multimedia messaging service
• Point-to-Point and Point-to-Multipoint services
• SMS messaging and broadcasting
• Push-to-talk over cellular
• Wireless Access Protocol (WAP)-communication protocol used for mobile browsers
• Quality of service in GPRS

The QoS is a vital feature of GPRS services as there are different QoS support requirements
for assorted GPRS applications like real time multimedia, web browsing, and e-mail transfer.
GPRS QoS 4 Quality of Service Parameters :
1. Service Precedence
• The preference given to a service when compared to another service is known

as Service Precedence. This level of priority is classified into three levels called:
• high
• normal
• low
2. Reliability
• This refers to the ability of the network to maintain a consistent level of performance and
availability over time.
3. Delay
• This refers to the time it takes for data to travel between the source and destination
devices, and it is typically measured in milliseconds (ms).
4. Throughput
• The throughput specifies the maximum/peak bit rate and the mean bit rate.
Mobility Management
• Procedures that handle mobility of user are called GPRS Mobility Management (GMM).
• Mobility management is the means by which GPRS keeps track of a mobile subscriber
location while connected to the Network.
• Keep track of the current location of an MS
• Different scenarios can exist when the MS enters a new cell and possibly a new routing
area
• Cell update
• Routing Area Update
Mobility Management states
• A GPRS MS has one of three mobility management states:
1. IDLE STATE
MS is not using GPRS

service.
2. READY STATE
• MS’s location is known in

accuracy of cell
• Performing a GPRS attach,

MS gets into Ready state.
3. Standby state is entered
• When MS does not send any packets for longer period of time.
• Ready Timer Expires
Routing in GPRS
• Assume 2 intra – PLMN backbone networks of different PLMN.
• Intra – PLMN backbone networks connect GSNs of same PLMN or the same network
operator. These are private packet based networks of the GPRS network provider.
• These intra PLMN networks are connected to inter PLMN backbone
• An Inter PLMN backbone network connects GSNs of different PLMNs & Operators
• To install such a backbone, a roaming agreement is necessary between 2 GPRS

network providers A GPRS mobile station located in PLMN1 sends IP packets to a host
connected to the IP network (Web server connected to IP n/W)
• The SGSN encapsulates the IP packets coming from mobile station, examines the PDP
contexts and routes them through the intra – PLMN GPRS backbone to the GGSN
• The GGSN decapsulates the packets and sends them out on the IP network.
• Using IP routing mechanisms, packets are delivered to the host through Router
• An IP address has been assigned to the mobile by the GGSN of PLMN 2.
• Thus the MS‟s IP address has the same network prefix as the IP address of the GGSN
in PLMN2.
• The GGSN encapsulates the incoming IP packets and tunnels them through the inter-
PLMN GPRS backbone to the appropriate SGSN in PLMN 1.
• The SGSN decapsulates the packets and delivers them to the MS
• The HLR stores the user profile, current SGSN address and PDP(Packet Data
Protocol) addresses for every GPRS user in PLMN.
Logical channels in GPRS
• Packet broadcast control channel (PBCCH).
• The PBCCH broadcasts information relative to the cell in which the mobile camps and
information on the neighbour cells.
• This information is used by the mobile in order to access the network.
• Packet common control channel (PCCCH).

• The PCCCH is present in the cell only if the PBCCH is present in the cell.
• When it is not present in the cell, the common control signalling for GPRS is handled on
the GSM common control channels (CCCH).
• PCCCH is composed of packet random access channel (PRACH), used for random
access, packet paging channel (PPCH), used for paging, and packet access grant
channel (PAGCH), used for access grant.
• The PRACH is used by the MS to initiate uplink access to the network. The PPCH is
used by the network to page the mobile in order to establish a downlink packet transfer.
• The PAGCH is used by the network to assign radio resources to the mobile for a
packet transfer.
• Packet data traffic channel (PDTCH).

• The PDTCH is used to transfer user data during uplink or downlink packet transfer.
• The PDTCH is a unidirectional channel, either uplink (PDTCH/U) for a mobile-originated

packet transfer or downlink (PDTCH/D) for a mobile-terminated packet transfer.
• Packet associated control channel (PACCH). The PACCH is a unidirectional channel

that is used to carry signalling during uplink or downlink packet data transfer.
• Packet timing advance control channel (PTCCH)
• The PTCCH is a bidirectional channel that is used for TA update. The PTCCH is an
optional channel.
How does GPRS architecture differ from GSM?
• The following table depicts the architectural differences between

GPRS and GSM
Components Difference of GPRS System with GSM System
Mobile Station New mobile station is needed for accessing GPRS

services. They are backward compatible with GSM
for voice calls
Base Transceiver Software upgrade is needed in the existing BTS

Station
Base Station Software upgrade and new hardware, Packet
Controller Control Unit are needed for GPRS.
GPRS Support Installation of new core network elements, known
Nodes as serving GPRS support node, and gateway GPRS
support node are needed to deploy GPRS
Databases Requires software upgrade to handle new models

and functions to handle databases involved in the
network
2.3. WLAN-Wireless Local Area Network

• WLAN is a local area data network without wires
• Mobile user can access information and network resources through wireless LAN as
they attend meeting, collaborate with other users or move to other locations in the
premises.
• WLANs use various wireless communication standards, including IEEE 802.11, which
includes different versions like 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, and
802.11ax
Applications of WLAN
• Office/Campus Environment
• Factory Shop Floor
• Homes
• Workgroup Environment
• Public Places
• War/Defense Sites
Wireless LAN 802.11 Advantages

1. Mobility:
WLANs provide users with the ability to move around freely within the coverage area without
being tethered to a wired connection.
2. Low implementation costs.
Easy to setup, relocate, change and manage.
3. Installation speed: Fast and easy
4. Network Expansion: Go where wires cannot. Penetrate through buildings and walls
5. Scalability: WLAN can be configured in many topologies
Disadvantages of WLANs
• Quality of service: WLANs offer lower quality than their wired counterparts.
• Restrictions:
– All wireless products have to obey with national regulations.
– Restricted frequencies to minimize interference.
• Safety and security:
– Senders and receivers are operated by laymen and, radiation has to be low.
All standards must offer (automatic) encryption, privacy mechanisms, support for secrecy etc
• There are two basic system architectures in WLAN:
1. Infrastructure Network Architecture:

Devices communicate with each other via access point which is a wireless router
2. Adhoc Network Architecture:

No infrastructure or access point.
Devices cluster communicate with each other
Infrastructure Network Architecture
• Components of Architecture:
1. Stations
2. Access Points
3. Portal
4. Basic Service Set (BSS)
5. Extended Service Set(ESS)
6. Distributed System
Stations
• All components that can connect into a wireless medium in a network are referred to as
stations.
• Wireless stations can be mobile devices such as laptops, personal Digital Assistants, IP
phones and other smartphones or non portable devices such as desktop computers,
printers and workstations that are equipped with a wireless network interface
Access Points
• Access Points (APs) , normally wireless routers, are base stations for the wireless
network
• APs transmit and receive radio frequencies for wireless enabled devices to
communicate with
• It uses as Central Device in WLAN architecture
Portal:
• It is a typical access point which interconnects wired LAN and wireless LAN.
• It is the logical interconnection between the two networks
Basic Service Set

• Basic Service Set (BSS) is the building block of WLAN
• BSS is a set of all stations that can communicate with each other at physical layer.
• Every BSS has an identification (ID) called the BSSID which is the MAC address of the
access point servicing the BSS.
• In BSS, there wireless stations could be Mobile or Stationary
• BSS can be of two categories depending upon mode of operation:
• Infrastructure BSS: Here, the devices communicate with other devices through access
points.
• Independent BSS: Here, the devices communicate in peer-to-peer basis in an ad hoc

manner.
Extended Service Set

• An extended service set (ESS) is a set of connected BSSs that communicate with each
other.
• Access points in an ESS are connected by a distribution system.
• Each ESS has an ID called the SSID which is a 32-byte (maximum) character string
Distributed System
• A distribution system (DS) connects access points in an extended service set.
• The concept of a distributed system can be used to increase network coverage through
roaming between cells
• It can be wired or wireless
Adhoc Network Architecture
• There is no access point in WLAN architecture, then it will be

Adhoc architecture.
• It have stand alone network
• It cannot send the data to other BSS
• In Adhoc architecture, stations can locate the other stations

in same BSS but can communicate only if they agreement
between them.
It is peer to peer network topology
RFID
•RFID (Radio Frequency Identification) is a technology that uses radio waves to identify and
track objects.
•An RFID system consists of three main components:
1. Reader,
2. Antenna, and
3. Tag.
•The tag contains a unique identifier, which can be read by the reader when the tag is in range
of the antenna.
RFID system components
Ethernet
RFID
Reader
RFID Tag RF Antenna Network Workstation

Block diagram of RFID
The components of the RFID system are explained in more detail below:
1.Reader /Interrogator:
•The reader is a device that transmits a radio signal to the antenna, which in turn sends the
signal to the tag.
•The reader also receives the data from the tag and sends it to a computer for processing.
•The reader can be either fixed or handheld and can be connected to a computer or other
device for data processing
2. Antenna:
•The antenna is a component that sends and receives radio signals to and from the tag.
•The antenna can be a simple wire or a complex array of antennas, depending on the specific
application.
3. Tag:
•The tag is a small electronic device that contains a unique identifier Electronic Product Code
(EPC)and can be attached to an object.
•The tag can be either passive or active.
•A passive tag does not have its own power source and is powered by the radio signal from
the reader, while an active tag has its own power source and can transmit data over longer
distances
Computer:
• The computer is a device that receives data from the reader and processes it.
• The computer can be used to manage the data collected by the RFID system, such as
tracking inventory, monitoring equipment, or managing access to restricted areas.
Overall, an RFID system is a powerful technology that can be used in a variety of applications,
such as inventory management, supply chain management, and asset tracking.
By using radio waves to identify and track objects, RFID systems offer a flexible and efficient
way to manage and monitor assets and resources
RFID tags
• Tags can be attached to almost anything:
– Items, cases or pallets of products, high value goods
– vehicles, assets, livestock or personnel
Passive Tags Active Tags
Do not require power – Draws from Interrogator Battery powered

Field
Lower storage capacities (few bits to 1 KB) Higher storage capacities (512 KB)
Shorter read ranges (4 inches to 15 feet) Longer read range (300 feet)
Usually Write-Once-Read-Many/Read-Only tags Typically, can be re-written by RF

Interrogators
Less Costly Expensive
Operating Frequency:
• RFID tags are classified based on the frequency at which they operate.
The three main types are:
• Operating Frequency
Low-Frequency (LF):
•Operate at 125 kHz and 134 kHz.
•These are used in applications such as animal tracking, access control, and payment
systems.
High-Frequency (HF):
•Operate at 13.56 MHz.
•These are used in applications such as smart cards, public transport ticketing, and inventory
management.
Ultra-High-Frequency (UHF):
•Operate at 860 MHz to 960 MHz.
•These are used in applications such as supply chain management, asset tracking, and retail
inventory management
RFID applications
1. Manufacturing and Processing
1. Inventory and production process monitoring
2. Warehouse order fulfillment
2. Supply Chain Management
1. Inventory tracking systems
2. Logistics management
3. Retail
1. Inventory control and customer insight
2. Auto checkout with reverse logistics
4. Security
1. Access control
2. Counterfeiting and Theft control/prevention
5. Location Tracking
1. Traffic movement control and parking management
2. Wildlife/Livestock monitoring and tracking
2.4. BLUETOOTH( IEEE 802.15 )

▪ BLUETOOTH is a radio communication technology that enables low-power, low-
cost, short range wireless networking between devices
• It was originally developed in the 1990s by Ericsson, but it is now maintained and
developed by the Bluetooth Special Interest Group (SIG), a consortium of companies
that includes many major technology companies.
• Bluetooth uses radio waves to transmit data over short distances, typically up to 10
meters (33 feet). It operates on the 2.4 GHz band, which is a globally available
frequency range that does not require a license to use.
• Bluetooth devices can connect and communicate with each other without the need for
cables or a Wi-Fi network.
• Bluetooth is used in a wide range of devices, including smartphones, headphones,

speakers, smartwatches, fitness trackers, and many other consumer electronics.
It is also used in a variety of industrial and medical applications, such as wireless sensors,
remote monitoring devices, and medical equpment.
Bluetooth features
• Bluetooth technology has several key features that make it a popular choice for wireless
communication. Here are some of the main features of Bluetooth:
1. Wireless Communication: Bluetooth enables wireless communication between devices
without the need for cables or wires.
2. Low Power Consumption:

Bluetooth uses low power consumption technology which means that it can run for a long
time on a small battery. This makes it ideal for use in portable devices such as wireless
headphones, smartwatches, and fitness trackers.
3. Compatibility:
Bluetooth is a widely adopted technology and is compatible with most modern
smartphones, tablets, and computers. This makes it easy to connect and use different
devices with each other.
4. Automatic Pairing: Bluetooth devices can be paired automatically once they are within
range, making it easy to connect and use new devices with each other.
5. Range: Bluetooth has a range of up to 10 meters (33 feet) which makes it ideal for use in
small to medium-sized rooms.
6. Security: Bluetooth uses encryption to secure the communication between devices. This
means that unauthorized users cannot easily access the data being transferred.
7. Multi-Device Support: Bluetooth technology can connect multiple devices at the same
time. This makes it ideal for use in environments where multiple devices need to be connected
and used simultaneously.
8. Audio Streaming: Bluetooth is commonly used for streaming audio from a mobile device to
wireless headphones or speakers. This allows for a more convenient and flexible listening
experience without the need for cables.
• Overall, Bluetooth technology has several key features that make it a popular choice for
wireless communication and device connectivity.
Architecture of Bluetooth
• There are two types of Bluetooth networks −
• Piconets
• Scatternets
• Architecture of Bluetooth
1. Piconets
• Piconets are small Bluetooth networks, formed by at
most 8 stations, one of which is the master node and the
rest slave nodes (maximum of 7 slaves).
• Master node is the primary station that

manages the small network.
• The slave stations are secondary stations that

are synchronized with the primary station.
• Communication can take place between a master

node and a slave node in either one-to-one or one-to-many manner.
• Besides the seven active slaves, there can be up to 255 numbers of parked nodes
(inactive slaves)
2. Scatternet
• A scatternet is an interconnected collection of two or more piconets.
• They are formed when a

node in a piconet, whether a
master or a slave, acts as a slave
in another piconet.
This node is called the bridge

between the two piconets, which
connects the individual piconets
to form the scatternet
WiMAX (IEEE 802.16 )
• Acronym for Worldwide Interoperability for Microwave Access.
• Based on Wireless MAN technology.
• A wireless technology optimized for the delivery of IP centric services over a wide area.
• A scalable wireless platform for constructing alternative and complementary broadband

networks.
• The IEEE 802.16 Working Group develops standards that address two types of usage
models −A fixed usage model (IEEE 802.16-2004).
– A portable usage model (IEEE 802.16e).
WIMAX Architecture
The Architecture of the WIMAX comprises of:
1. Core Network:
• It is the standard Internet network.
• It provides the platform for the broadband connectivity
2. BS(Base Station)
• It is the WIMAX Cell Site.
• They are towers with antennas equipped Over It.
• The communication between subscriber station and base station is two way.
▪ Uplink (from SS to BS)
▪ Downlink (from BS to SS)
3. SS (Subscriber Station)
• It is the subscriber station equipped with an antenna. This antenna is usually mounted
on building.
• It is connected to the base station via Microwave links
4. TE (Terminal Equipment)
• It can be any device like mobile, laptop etc.
• It is connected to the subscriber station via Access point
• The telephone is connected to the subscriber station via Ethernet
• WiMAX provides two forms of wireless service:
• Line-of-sight, a fixed dish antenna points directly at the receiver’s dish. This signal is
much stronger and uses higher frequencies, reaching a possible maximum frequency of
66GHz.
• Non-line-of-sight, much like Wi-Fi, where a small antenna on your computer connects to
the tower. These kinds of transmissions use a low frequency range, between 2 GHz to
11GHz.
WIFI
• WiFi stands for Wireless Fidelity
• Wireless fidelity is wireless technology that uses radio frequency to transmit data
through the air
• Wi-Fi (wireless technology) is an alternative to Technology , which is commonly used

,for connecting devices in wireless using radio waves.
• It is based on the IEEE 802.11 family of standards and is primarily a local area
networking (LAN) technology designed to provide in-building broadband coverage.
• Current WiFi systems support a peak physical-layer data rate of 54 Mbps and typically
provide indoor coverage over a distance of 100 feet.
• WiFi has become the de facto standard for last mile broadband connectivity in homes,
offices, and public hotspot locations.
Wi-Fi Technology
• Wi-Fi networks use Radio Technologies to transmit and receive data at high speed:
▪ IEEE 802.11b
▪ IEEE 802.11a
▪ IEEE 802.11g
IEEE 802.11b
• Appear in late 1999
• Operates at 2.4GHz radio spectrum
• 11 Mbps (theoretical speed) - within 30 m Range
• 4-6 Mbps (actual speed)
• 100 -150 feet range
• Most popular, Least Expensive
Interference from mobile phones and Bluetooth devices which can reduce the transmission
speed
IEEE 802.11a
• Introduced in 2001
• Operates at 5 GHz (less popular)
• 54 Mbps (theoretical speed)
• 15-20 Mbps (Actual speed)
• 50-75 feet range
• More expensive
• Not compatible with 802.11b
IEEE 802.11g
• Introduced in 2003
• Combine the feature of both standards (a, b)
• 100-150 feet range
• 54 Mbps Speed
• GHz radio frequencies
Elements of a WI-FI Network

• Access Point (AP) –
• The AP is a wireless LAN transceiver or “base station” that can connect one or many
wireless devices simultaneously to the Internet.
• Wi-Fi cards - They accept the wireless signal and relay information. They can be
internal and external.
• Safeguards - Firewalls and anti-virus software protect networks from uninvited users
and keep information secure
Wi-Fi Network Topologies

1. Peer-to-peer topology (Ad-hoc Mode)
2. AP-based topology (Infrastructure Mode)
1. Peer-to-peer topology (ADHOC)

• AP is not required.
• Client devices within a cell can communicate

with each other directly.
• It is useful for setting up a wireless network

quickly and easily.
2.Infrastructure network
• The client communicates through Access Point.
• Any communication has to go through AP.
• If a Mobile Station (MS), like a computer, a PDA,

or a phone, wants to communicate with another
MS, it needs to send the information to AP first,
• then AP sends it to the destination MS
Wi-Fi Security
▪ Service Set Identifier (SSID):
▪ The SSID is the name of the Wi-Fi network that devices connect to.
▪ The SSID can be changed by the network administrator to make the network easier to
identify or to improve security.
▪ Wired Equivalent Privacy (WEP)
▪ Wireless Protected Access (WPA)
Advantages of Wi-Fi
• Mobility
• Ease of Installation
• Flexibility
• Cost
• Reliability
• Security
• Use unlicensed part of the radio spectrum
• Roaming
• Speed
Limitations
• Interference
• Degradation in performance
• High power consumption
• Limited range
BASIS FOR BLUETOOTH WIFI
COMPARISON
Bandwidth Low High
Hardware Bluetooth adapter on all Wireless adapter on all the devices of the
requirement the devices connecting network and a wireless router.
with each other.
Ease of Use Fairly simple to use and It is more complex and requires
switching between configuration of hardware and software.
devices is easier.
Range 10 meters 100 meters
Security Less secure Security features are better. Still, there are
comparatively some risks.
Power consumption Low High
Frequency range 2.400 GHz and 2.483 2.4 GHz and 5 GHz
GHz
Flexibility Supports limited It provides support for a large number of

number of user users
Modulation GFSK (Gaussian OFDM (Orthogonal frequency division

techniques frequency shift keying) multiplexing) and QAM (Quadrature
Amplitude Modulation)
MSBTE QUESTIONS
1. Write the IEEE standard for WIFI and WIMAX (2-A)
2. Explain any 4 GPRS Services (2-U)
3. How does GPRS architecture differ from GSM (2-A)
4. Differentiate between Bluetooth and WIFI on the basis of Range, Bandwidth, Modulation
technique and number of devices connected (2-A)
5. Explain operational principle of Mobile IP in detail (2-U)
6. List any two GPRS Services.
7. Write IEEE standard for Bluetooth and WiFi.
8. Draw GPRS architecture and list the logical channels in GPRS.
9. Describe the terms home agent and foreign agent.
10. State the processes involved in the use of RFID in student attendance in a college.
11. Explain the functions performed by GPRS support nodes.
12. Explain the Quality of service parameters of GPRS.
13. Compare GSM networks with GPRS networks.
14. Explain the Logical channels in a GPRS system in short.
15. List any two applications of GPRS
16. Describe Mobility Management in GPRS
17. Enlist the GPRS network nodes
18. Draw the architecture of WLAN and describe it
Wireless Application Protocol and 3G
Mobile Services (20 Marks)
3.1. Mobile Internet Standards

• The challenges in moving from fixed line PCs to Mobile Devices
• To understand the challenges (and pitfalls) of moving to a Mobile Internet, first consider
the fixed line Internet!
• Initially, most usage was email and web
• Access was initially targeted at general public
• Access was charged from day one!
• Early networks unsuited for packet-switched data
• Early approaches to providing content had to contend with new technical challenges:
1. Limited Screen Size and limited input capability
2. Limited memory, processor and power
3. Intermittent connectivity
Wireless Application Protocol

• WAP stands for Wireless Application Protocol.
• A “standard” created by wireless and Internet companies to enable Internet access from
a cellular phone
• It is a protocol designed for micro-browsers and it enables the access of internet in the
mobile devices.
• wapforum.org:
– co-founded by Ericsson, Motorola, Nokia, Phone.com
– 450 members in 2000, comprise of Handset manufacturers, Wireless service

providers, ISPs, Software companies in the wireless industry
– Goals
• deliver Internet services to mobile devices
• enable applications to scale across a variety of transport options and

device types
• independence from wireless network standards
• GSM, CDMA IS-95, TDMA IS-136, 3G systems (UMTS, W-CDMA)
Wireless Application Protocol Model
Application Layer:
▪ This layer contains the Wireless Application Environment (WAE)
▪ General purpose application environment based on a combination of www and Mobile

Telephony Technologies
▪ It defines the user interface on the phone It contains WML and WTA (Wireless
Telephony Application)
▪ Primary objective-Interoperable environment
▪ WAE includes a microbrowser server environment which provides
▪ Wireless Markup Language(WML)
▪ WML script
▪ Wireless Telephony Application (WTA)
▪ Content formats
2. Session Layer:
• This layer contains Wireless Session Protocol (WSP)
• Opens a session of communication between client and server
• Establish protocol and negotiations
• Exchanges encoded data
• Exchanges requests and replies
3. Transaction Layer:
This layer contains Wireless Transaction Protocol (WTP)
• It deals with transaction and retransmission of data, separation and concatenation of

data
• It runs on top of datagram service
• Light weight transaction oriented protocol
• Three classes of transaction services
– Unreliable one way requests
– reliable one way requests
– reliable two way request reply transactions
4. Security Layer:
This layer contains Wireless Transaction Layer Security (WTLS).
• Based on Industry-standard Transport layer security protocol
• Optimized for use over narrow band communication channels
Features
• Data Integrity
• Privacy
• Authentication
• Denial of service protection
5. Transport Layer:
This layer contains Wireless Datagram Protocol (WDP).
• THE WAP datagram protocol is the transport layer that sends and receives messages
via any available bearer n/w including SMS ,USSD,IS-136 packet data and GPRS
• Operates above the data capable bearer services supported by various n/w types
• Provides a common interface to the upper layer protocols and hence they function
independent of the underlying wireless n/w
Bearers:
• Differing levels of quality of services with respect to throughput error rate and delays
• WAP protocols are designed to compensate for tolerate these varying levels of service
• WAP specification lists the bearers that are supported and techniques used to allow
WAP protocols to run over each bearer.
Wireless Markup Language (WML)
• WML stands for Wireless Markup Language
• It is an application of XML which is defined in a document type definition
• WML documents have extension .wml
• It takes care of the small screen and the low bandwidth of transmission
• WML is the mark-up language defined in the WAP specification
• WAP sites are written in WML while websites are written in HTML
• It is similar to HTML, both of them use tags and written in plain text format
• WML supports Client side scripting
• WML decks and cards
• The main difference between HTML and WML is that of basic unit of navigation in
HTML is a page while that in WML is a card
• A WML contains multiple cards and they form a deck
• When a WML page is accessed from a mobile phone all the cards in the page are
downloaded from WML server
• So if the user goes to another card of the same deck the mobile browser does not have
to send any request to the server since the files that contains the deck is already stored
in wireless device
• You can put links text images i/p fields many other elements in the cards
<?xml version="1.0"?>
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML

1.1//EN“"http://www.wapforum.org/DTD/wml_1.1.xml">
<wml>
<card id=“First_card" title=“First Card">
<p>
Welcome to WML!
</p>
</card>
</wml>
Wireless Application Protocol and 3G
Mobile Services (20 Marks)
3.1. Mobile Internet Standards

• The challenges in moving from fixed line PCs to Mobile Devices
• To understand the challenges (and pitfalls) of moving to a Mobile Internet, first consider
the fixed line Internet!
• Initially, most usage was email and web
• Access was initially targeted at general public
• Access was charged from day one!
• Early networks unsuited for packet-switched data
• Early approaches to providing content had to contend with new technical challenges:
1. Limited Screen Size and limited input capability
2. Limited memory, processor and power
3. Intermittent connectivity
Wireless Application Protocol

• WAP stands for Wireless Application Protocol.
• A “standard” created by wireless and Internet companies to enable Internet access from
a cellular phone
• It is a protocol designed for micro-browsers and it enables the access of internet in the
mobile devices.
• wapforum.org:
– co-founded by Ericsson, Motorola, Nokia, Phone.com
– 450 members in 2000, comprise of Handset manufacturers, Wireless service

providers, ISPs, Software companies in the wireless industry
– Goals
• deliver Internet services to mobile devices
• enable applications to scale across a variety of transport options and

device types
• independence from wireless network standards
• GSM, CDMA IS-95, TDMA IS-136, 3G systems (UMTS, W-CDMA)
Wireless Application Protocol Model
Application Layer:
▪ This layer contains the Wireless Application Environment (WAE)
▪ General purpose application environment based on a combination of www and Mobile

Telephony Technologies
▪ It defines the user interface on the phone It contains WML and WTA (Wireless
Telephony Application)
▪ Primary objective-Interoperable environment
▪ WAE includes a microbrowser server environment which provides
▪ Wireless Markup Language(WML)
▪ WML script
▪ Wireless Telephony Application (WTA)
▪ Content formats
2. Session Layer:
• This layer contains Wireless Session Protocol (WSP)
• Opens a session of communication between client and server
• Establish protocol and negotiations
• Exchanges encoded data
• Exchanges requests and replies
3. Transaction Layer:
This layer contains Wireless Transaction Protocol (WTP)
• It deals with transaction and retransmission of data, separation and concatenation of

data
• It runs on top of datagram service
• Light weight transaction oriented protocol
• Three classes of transaction services
– Unreliable one way requests
– reliable one way requests
– reliable two way request reply transactions
4. Security Layer:
This layer contains Wireless Transaction Layer Security (WTLS).
• Based on Industry-standard Transport layer security protocol
• Optimized for use over narrow band communication channels
Features
• Data Integrity
• Privacy
• Authentication
• Denial of service protection
5. Transport Layer:
This layer contains Wireless Datagram Protocol (WDP).
• THE WAP datagram protocol is the transport layer that sends and receives messages
via any available bearer n/w including SMS ,USSD,IS-136 packet data and GPRS
• Operates above the data capable bearer services supported by various n/w types
• Provides a common interface to the upper layer protocols and hence they function
independent of the underlying wireless n/w
Bearers:
• Differing levels of quality of services with respect to throughput error rate and delays
• WAP protocols are designed to compensate for tolerate these varying levels of service
• WAP specification lists the bearers that are supported and techniques used to allow
WAP protocols to run over each bearer.
3.2. Wireless Markup Language (WML)

• WML stands for Wireless Markup Language
• It is an application of XML which is defined in a document type definition
• WML documents have extension .wml
• It takes care of the small screen and the low bandwidth of transmission
• WML is the mark-up language defined in the WAP specification
• WAP sites are written in WML while websites are written in HTML
• It is similar to HTML, both of them use tags and written in plain text format
• WML supports Client side scripting
• WML decks and cards
• The main difference between HTML and WML is that of basic unit of navigation in
HTML is a page while that in WML is a card
• A WML contains multiple cards and they form a deck
• When a WML page is accessed from a mobile phone all the cards in the page are
downloaded from WML server
• So if the user goes to another card of the same deck the mobile browser does not have
to send any request to the server since the files that contains the deck is already stored
in wireless device
• You can put links text images i/p fields many other elements in the cards
<?xml version="1.0"?>
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML

1.1//EN“"http://www.wapforum.org/DTD/wml_1.1.xml">
<wml>
<card id=“First_card" title=“First Card">
<p>
Welcome to WML!
</p>
</card>
</wml>
3.3. International Mobile Telecommunication 2000 (IMT 2000)

• IMT 2000 is that global standard to satisfy market demand for mobile services in the
Twenty first century.
Objectives of IMT 2000 system are as follows:
• Common spectrum worldwide (1.8 – 2.2 GHz band)
• Date rates of :
9.6 Kbps or higher for global (mega cell),144 Kbps or higher for vehicular(macro
cell),384 Kbps or higher for pedestrian (micro cell) and up to 2 Mbps for indoor environments
(pico cell)
• Global seamless roaming.
• Multiple environments, that are not only confined to cellular, but also includes cellular,
cordless, satellite, LANs, wireless Local loop (WLL)
• Enhanced performance and security.
• Wide range of telecommunications services (voice, data, multimedia etc)
• Flexible radio bearers for increased spectrum efficiency
• Full integration of wireless and wireline systems
3.4. Wideband Code Division Multiple Access (W-CDMA)

• Wideband-CDMA or W-CDMA is a term used to denote the UMTS radio-interface for
the paired bands, UMTS FDD.
• Common spectrum for IMT 2000 world-wide is from 1.8 GHz-2.2 GHz band or
• For Uplink: 1885-2025 MHz (Mobile satellite services) Downlink: 2110-2200 MHz
(Mobile satellite services)
• W-CDMA is officially known as IMT-2000 CDMA Direct Spread (CDMA DS).
• In W-CDMA the bandwidth of the radio channel is 5 MHz.
• The term is used in contrast to the competitive CDMA system, CDMA2000 and its
predecessor cdmaOne, which make use of radio channels of 1.25 MHz width
The main characteristics / features / specifications of W-CDMA are:
• Wideband-CDMA or W-CDMA is a term used to denote the UMTS radio-interface for

the paired bands, UMTS FDD.
• Common spectrum for IMT 2000 world-wide is from 1.8 GHz-2.2 GHz band or
• For Uplink: 1885-2025 MHz (Mobile satellite services) Downlink: 2110-2200 MHz
(Mobile satellite services)
• W-CDMA is officially known as IMT-2000 CDMA Direct Spread (CDMA DS).
• In W-CDMA the bandwidth of the radio channel is 5 MHz.
• The term is used in contrast to the competitive CDMA system, CDMA2000 and its
predecessor cdmaOne, which make use of radio channels of 1.25 MHz width.
• Wideband Direct Sequence CDMA;
• Frequency Division Duplex
• Chip rate: 3.84 Mcps can be extended to 8.192 or 16.384 Mcps (Megachips per second)
• No need to synchronize the base stations
• Variable spreading code, Spreading factor from 4 to 256
• Bandwidth between 4.4 and 5 MHz
Code division multiple access ( CDMA 2000 )
• Features of CDMA 2000
• CDMA 2000 is an up gradation of 2 and 2.5G CDMA technology.
• It supports much higher data rates as compared to those of 2G and 2.5G systems.
• Fundamental principle is the high speed data packet network designed for mobility
using internet protocol.
• Channel bandwidth 1.25MHz per radio channel
• Upgradation ensures backward compatibility with existing CDMA.
• It has improved capabilities over W-CDMA at each cell can be introduced without
changing the base station entirely.
• Number of users that can be supported by 3G CDMA 2000 is almost twice the users
supported by 2G CDMA system.
• Longer battery life
Features of Third generation (3G) standard system
• Multi-megabit internet access.
• Voice activated cells.
• Unparalleled network capacity.
• Ubiquitous “ always on” access.
• Communications using voice over internet protocol.
• Various 3G standards are:
• W-CDMA
• IMT 2000
• CDMA 2000
COMPARISON BETWEEN 3G and 4G
Parameters 3G Technology 4G Technology
Full Form The term 3G is an The term 4G is an abbreviation for the

abbreviation for the third fourth generation technology.
generation technology.
Maximum Upload Rate It can go up to 5 It can go much higher, about 500

Megabytes per second. Megabytes per second.
Maximum Rate of The 3G technology The 4G technology can download videos

Download offers a maximum at a much faster rate, that can go as high
download rate of about as 1 Gigabyte per second.
21 Megabytes per
second.
Switching Techniques It utilises the packet It utilises both the message switching as
switching technique. well as the packet switching techniques.
Range of Frequency The frequency of the 3G The frequency range of the 4G

technology ranges technology ranges somewhat between 2
somewhat between 1.8 to 8 Gigahertz.
to 2.5 Gigahertz.
Leniency The 3G technology is The 4G technology is both vertically as

horizontally lenient. well as horizontally lenient.
Network Architecture The network architecture The network architecture of the 4G

of the 3G technology is a technology is cell-based for a wide area
wide area cell-based along with the integration of WLAN.
one.
Error Correction The 3G technology The 4G technology performs error

performs error correction correction using the concatenated codes.
using the turbo codes.
Quality of Service in 3G Communication
• Network Services are considered end-to-end, this means from a Terminal Equipment
(TE) to another TE. An End-to-End Service may have a certain Quality of Service (QoS)
which is provided for the user of a network service.
• It is the user that decides whether he is satisfied with the provided QoS or not. To
realise a certain network QoS a Bearer Service with clearly defined characteristics and
functionality is to be set up from the source to the destination of a service.
• A bearer service includes all aspects to enable the provision of a contracted QoS.
There are four different QoS classes:
1. Conversational class
2. Streaming class
3. Interactive class
4. Background class
Traffic Class Conversational Streaming Class Interactive Class Background

Class Class
Traffic Real Time Real Time Best Effort Best Effort

Pattern
Fundamental Preserve time Preserve time Request Destination is

Characteristics relation between relation between Response Pattern not expecting
information information the data within a
entities of the entities of the Preserve Payload certain time
stream stream content
Preserve
Payload content
Example of Voice Streaming Video Web Browsing Background

the application download of
emails
3.5. UMTS
Features /Specifications of UMTS
• Frequency spectrum: Uplink 1920-1980 MHz
Downlink 2110-2170 MHz
• It is more robust for multipath delays.
• It provides higher immunity towards frequency selective fading.
• It has very high packet data rates of 2.048Mbps.
• It has very high channel bandwidth of 5 MHz.
• It has backward compatibility with the GSM systems.
• It has high frame structure of 16 slots per frame.
• It gives signals of higher voice and data quality and also small bit-error rates.
• It has a common world-wide spectrum band.
• It can operate in multiple radio environments such as cellular, cordless, satellite, LAN
etc.
• It has a wide range of telecommunication services such as voice, data, multimedia,

internet etc.
• It has global seamless connectivity (roaming).
UMTS architecture
• User Equipment (UE):
The User Equipment or UE is the name given to what was previous termed the mobile, or
cellphone.
The new name was chosen because the considerably greater functionality that the UE could
have.
• Radio Network Subsystem (RNS):

The RNS also known as the UMTS Radio Access Network, UTRAN, is the equivalent of the
previous Base Station Subsystem or BSS in GSM.
It provides and manages the air interface for the overall network.
• Core Network:
The core network provides all the central processing and management for the system. It is the
equivalent of the GSM Network Switching Subsystem or NSS.
The core network is then the overall entity that interfaces to external networks including the
public phone network and other cellular telecommunications networks.
UMTS system uses the same core network as the GPRS and uses entirely new radio
interface.
The new radio network in UMTS is called UTRAN (UMTS Terrestrial Radio Access Network)
and is connected to the core network (CN) of GPRS via Iu interface.
The Iu is the UTRAN interface between the Radio network controller RNC and CN.
The mobile terminal in UMTS is called User Equipment (UE).
The UE is connected to Node-B over high speed Uu (up to 2 Mbps) Interface.
The Node-B are the equivalent of BTS in GSM and typically serve a cell site.
Several Node-Bs are controlled by a single RNCs over the Iub interface.
The RNCs are connected to CN through Iu interface.
The packet switched data is transmitted through Iu-PS interface and circuit switched data is
transferred over Iu-CS interface.
One of the new interfaces in UTRAN is Iur interface which connects two RNCs and has no
equivalent in GSM system.
The Iur interface facilitates handling of 100 percent of RRM (Radio Resource Management)
and eliminates the burden from CN.
UMTS also supports GSM mode connections in which case the MS connect to the CN through
Um interface to BSS and BSS connects through A (Gb interface in GPRS) interface to CN.
Applications of UMTS
• Multimedia Messaging Service (MMS)
• Multimedia streaming
• Video telephony
• Computer Games
Compare UMTS with CDMA 2000
Advantages of CDMA 2000

1. Increased voice capacity.
2. Higher data throughput.
3. Multi caste services.
4. Frequency band flexibility.
5. Migration paths.
6. Serves multiple markets.
7. Supports multiple service performances.
8. Full backward compatibility.
9. Increased battery life.
10. Power control
COMPARISON BETWEEN CDMA2000 vs WCDMA
3.6. Features of the 4G systems

1. Support interactive multimedia, voice, video, wireless internet and other broadband services.
2. High speed, high capacity and low cost per bit.
3. Global mobility, service portability, scalable mobile networks.
4. Seamless switching, variety of services based on Quality of Service (QoS) requirements
5. Better scheduling and call admission control techniques.
6. Ad hoc networks and multi-hop networks.
1. Peak data rates:
Downlink – 1Gbps;
Uplink -300Mbps
2. Spectrum efficiency: 3 times greater than LTE.
3. 10 times faster than the 3G network.
4. Peak spectrum efficiency:
Downlink -30bps/Hz;
Uplink – 15bps / Hz
5. 4G LTE is flexible and reliable.
6. Easy to standardize and it offers affordability
State the features of 4.5G and 5G
Features
1) Network based on the user experience.
2) Enhanced system performance.
3) Business models, managements and operations.
4) Beam division multiple access (BMDA) technology.
5) Filter band multicarrier (FBMC) multiple access.
6) For computing and achieving low latency, high mobility, high scalability and real time
executing.
7) Ultra Wide band (UBC) networks.
8) World combination service mode (WSGM)
4G Architecture
• The Constituent parts of 4G LTE network are
• User Equipment (UE): It could be any device capable of establishing communication
functions like mobile phones, tabs, computers, etc.
• Evolved UMTS Terrestrial Radio Access Network (E-UTRAN):
• It controls radio communication between user equipment and EPC.
• LTE mobile can connect with just one cell and one base station at a time. Main
operations performed by EBS(Evolved Base Station)
– Analog and digital processing functions of LTE air interface are used to transmit
and receive radio transmission to all the LTE-enabled devices.
– Handles low-level operation by sending the signalling messages and commands.
• Evolved Packet Core (EPC):
• It communicates with internal and external packet data networks and IP multimedia
subsystem. It consists of following blocks:
– HSS: Home Subscriber Server holds all the information about all the network
operator’s subscribers in a central database.
– MME: Mobility Management Entity
– handles the high-level operation by the signalling messages and HSS.
– S-GW: Signaling Gateway
– performs mobility anchoring and forward data between PDN Gateway and Base
Station.
– P-GW:Packet Data Network Gateway
– communicates with PDN’s employing interfaces.
– It performs operations like IP address allocation and packet filtering.
– PCRF: Policy and Charging Rule Function
– is accountable for controlling the flow-based charging operations in the Policy

Control Enforcement Function (PCEF) and policy control decision-making.
Applications of 4G Technology
• 4G Ultra high speed internet access - E-mail or general web browsing is available
• 4G Data intensive interactive user services - Services such as online satellite mapping
will load instantly
• 4G Multiple User Video conferencing - subscribers can see as well as talk to more than
one person.
• 4G Location-based services - a provider sends wide spread, real time weather or traffic
conditions to the computer or phone, or allows the subscriber to find and view nearby
businesses or friends whilst communicating with them
• 4G HDTV - a provider redirects a high definition TV channel directly to the subscriber

where it can be watched.
• 4G High Definition Video on demand - a provider sends a movie to the subscriber.
• 4G Video games on demand - a provider sends game data directly to the subscriber
where they can play in real time
VoLTE
• VoLTE stands for voice over Long Term Evolution.
• It is a digital packet voice service that is delivered over IP via an LTE access network.
Voice calls over LTE are recognised as the industry-agreed progression of voice services
across mobile networks, deploying LTE radio access technology
Benefits of VoLTE
• The implementation of VoLTE offers many benefits, both in terms of cost and operation.
• VoLTE: Provides more efficient use of spectrum than traditional voice
• Meets the rising demand for richer, more reliable services;
• Eliminates the need to have Voice on one network and data on another;
• Unlocks new revenue potential, utilising IMS(IP Multimedia Subsystem) as the common
service platform;
• Can be deployed in parallel with video calls over LTE and RCS (Rich Communication
Services) multimedia services, including video share, multimedia messaging, chat and
file transfer;
• Ensures that video services are fully interoperable across the operator community, just
as voice services are, as demand for video calls grows;
• Increases handset battery life by 40 per cent (compared with VoIP);
• Delivers an unusually clear calling experience; and Provides rapid call establishment
time
5G Features
• Up to 10Gbps data rate - > 10 to 100x speed improvement over 4G and 4.5G networks
• 1-millisecond latency
• Packet switching
• CDMA multiplexing
• Up to 100x number of connected devices per unit area (compared with 4G LTE)
• 99.999% availability
• 100% coverage
• 90% reduction in network energy usage
• Up to 10-year battery life for low power IoT device
QUESTIONS
1. What is Wireless application protocol? (4M)
2. Describe Wireless Markup Language.
3. Draw the WAP protocol stack and state the functions of any four protocols.
4. State two specifications of IMT 2000.
5. Compare WCDMA and CDMA 2000 on the basis of channel Bandwidth, Chip rate,
Duplex mode, Modulation, Frame length and Power Control rate
6. Draw the architecture of 4G and explain.
7. Draw the architecture of UMTS and explain.
8. Compare the features of 3G and 4G
9. State two features of 5G technology.
10. Enlist the features of 4G
11. Write any two applications of WLL
12. Enlist any four specifications of UMTS
13. Draw WLL architecture and describe it
14. Describe quality of service in 3G network
15. Differentiate between 4G and 5G with respect to (6M)
i) Data rate
ii) Bandwidth
16. iii)Spectral efficiency
17. iv)latency
18. v) Mobility
19. vi) Transmission time interval
20. Draw the architecture of UMTS and explain function of each block (6 M)
21. State the advantages of CDMA 2000 over 3G GSM standards
Unit IV: WLL, Signal encoding techniques
and Spread spectrum modulation(10 Marks)
4.1. WLL Architecture

Wireless local loop (WLL) network
WLL stands for Wireless Local Loop.
Microwave wireless link can be used to create a wireless local loop such as shown in figure.
The components are
PSTN:
It is Public Switched Telephone Network which is a circuit switched network. It is a collection of
world’s interconnected circuit switched telephone networks.
Switch Function:
Switch Function switches the PSTN among various WANUs.
WANU:
It is short for Wireless Access Network Unit.
It is present at the local exchange office. All local WASUs are connected to it.
Its functions includes:
• Authentication,
• Operation & maintenance,
• Routing,
• Transceiving voice and data.
It consists of following sub-components:
i. Transceiver: It transmits/receives data.
ii. WLL Controller: It controls the wireless local loop component with WASU.
iii. AM: It is short for Access Manager. It is responsible for authentication.
iv. HLR: It is short for Home Location Register. It stores the details of all local WASUs
WASU:
• It is short for Wireless Access Subscriber Units. It is present at the house of the
subscriber.
• It connects the subscriber to WANU and the power supply for it is provided locally
WLL ( Wireless Local Loop) Importance

• The importance of WLL is that only once the charges has to be paid for wireless
equipment, after that there is no additional costs involved.
• WLL can greatly improve telecommunication facility and services in an expensive way.
Advantages of WLL: (any two)

• High bandwidth is available
• Faster deployment
• Lower deployment costs
• Lower network maintenance, management and operating cost
Applications of WLL
There are two types of WLL :-
1 LMDS (Local Multipoint Distribution Services)
2 MMDS (Multichannel Multipoint Distribution Services)
Local Multipoint Distribution Service(LMDS)

• Stationary Broadband wireless access technology
• Deliver- Voice, Data, Video Services
• It operates at 28 GHz or 36 GHz frequency.

• It is installed similar to cellular system cell based layout.
• In LMDS a data access can be FDMA, TDMA or CDMA.
• Modulation either Phase Shift Keying (PSK) or Amplitude Modulation (AM)
• Cell size or range of BS is 5 miles.
• It uses P2MP (Point-to-multipoint communication) and P2P (Point-to-point) topologies for
end communication with CPEs (Customer Premises Equipment).
• The figure-1 depicts LMDS architecture. It consists of NOC (Network Operation

Center), BS (Base Station), CPE (Customer Premises Equipment), fiber based
infrastructure.
• Multiple NOCs are interconnected together.
• Fiber backbone infrastructure consists of SONET, OC-12, OC-3, DS3 optical links, CO
equipments etc. Moreover NOC is interfaced with ATM, IP systems, PSTN and Internet.
• BS is interfaced with optical equipments on one side and wireless on the other.
• It houses optical to electrical and electrical to optical interfaces as well as RF up/down

converters.
• RF up converter is used to convert data to be transmitted on modulated RF waveforms.
• The RF down converter does the reverse operation.
• CPEs are installed at customer premises and are linked with BS using wireless
microwave links. They are available from multiple vendors.
• It consists of functionalities viz. modulation, demodulation, RF up conversion and RF

down conversion etc.
• CPEs utilize multiple access schemes viz. TDMA, FDMA and CDMA for communication
with BSs in the LMDS network.
Multichannel Multipoint Distribution Service(MMDS)

Features:
• It operates at 28 GHz or 36 GHz frequency.
• It is installed similar to cellular system cell based layout.
• Deliver- Voice, Data, Video Services
• In LMDS a data access can be FDMA, TDMA or CDMA.
• Modulation either Phase Shift Keying (PSK) or Amplitude Modulation (AM)
• Cell size or range of BS is 5 miles.
• It uses P2MP (Point-to-multipoint communication) and P2P (Point-to-point) topologies

for end communication with CPEs (Customer Premises Equipment).
The figure-2 depicts MMDS architecture.
• It consists of Hub equipment and customer side equipments.
• Hub consists of antenna tower, RF equipments, Modem, Router for connection with
internet and network management system (i.e. NMS).
• Customer side equipments include antenna, wireless modem, ethernet switch, PCs etc.
• Hub antenna tower receives wireless signals from multiple users similar to
P2MP (Point-to-multipoint communication) topology.
• Each user premise antenna and Hub antenna is connected with P2P (Point-to-point)
microwave link
4.2. WLL Types

Fixed Wireless Terminal (FWT)
• FIXED WIRELESS TERMINAL (FWT) Is a fixed radio telephone unit that interfaces
to a standard telephone set acting as the transmitter and receiver between the
telephone and the base station
• Fixed Wireless Terminal (FWT) units differ from conventional mobile terminal units
operating within cellular networks – such as GSM – in that a fixed wireless terminal or
desk phone will be limited to an almost permanent location with almost
no roaming abilities.
• The Fixed Wireless Terminal (FWT) will be wall mounted and provided with an indoor
type or outdoor type antenna depending on the location of the premises keeping in view
the strength of the radio signal to be transmitted and received.
• The antenna is connected to wall set .
• A conventional telephone instrument is connected to the wall set through a short
telephone cable. The wall set is powered by 230 V commercial A.C. supply available in
the subscriber’s premises.
WT with mobility
• WT WLL is a communication system that connects
customers to the Landline network using radio
frequency signals instead of conventional copper
wires, for the full or part connection between the
subscriber and the exchange
• This comes with superior voice quality and high

speed data capabilities.
• CDMA is popular with more than 100 million

subscribers worldwide, and the number keeps on
increasing exponentially.
• Terminal Type: Hand Held Terminal.
• In this case, subscriber can carry a small handset of CDMA technology.
• There is no antenna or any other equipment at subscribers premises.
4.3. Local Exchange Carrier (LEC)

Local Exchange Carrier (LEC) is a local telecom Exchange that provides telecommunication
services within the area and operates within a local area
Key responsibilities of the local exchange

• Number portability:
• In accordance with the rules provided by the telephone commission, they are to assist
with number portability and provide all technical help as and when needed.
• Resale of telecommunication services: A local exchange carrier is not allowed to

prohibit or superimpose discriminatory limitations for resale of their telecommunication
services
• Dialing parity:
• It is the responsibility of the local exchange carrier for providing dialing parity to all
telecommunication service providers without any possible delays and with all possible
assistance.
• Comply to standards and policies:
• They must comply to the standards and policies along with setting the monitoring
requirements as mentioned by the public service commission.
• Reciprocal compensation:
• In order to transport and end telecommunication services, arrangements for reciprocal
compensation must be made as needed.
4.4. Line Coding Techniques
• Data as well as signals that represents data can either be digital or analog.
• Line coding is the process of converting digital data to digital signals.
• By this technique we converts a sequence of bits to a digital signal.
• At the sender side digital data are encoded into a digital signal and at the receiver side
the digital data are recreated by decoding the digital signal.
Line coding
Unipolar Polar Bipolar
Differential
NRZ NRZ RZ Machester NRZ (AMI)
Manchester
RZ NRZ-L RZ
NRZ-I Pseudoternary
Unipolar Signaling
• Unipolar signaling is also called as On-Off Keying or simply OK.
• The presence of pulse represents a 1 and the absence of pulse represents a 0.
• There are two variations in Unipolar signaling −
1. Non Return to Zero (NRZ)
2. Return to Zero (RZ)
Unipolar Non-Return to Zero NRZ
In this type of unipolar signaling, a High in data is represented by a positive pulse called
as Mark, which has a duration T0 equal to the symbol bit duration. A Low in data input has no
pulse
Unipolar Non-Return to Zero (NRZ)
Unipolar Return to Zero (RZ)

• In this type of unipolar signaling,
• a High in data, though represented by a Mark pulse, its duration T0 is less than the
symbol bit duration.
• Half of the bit duration remains high but it immediately returns to zero and shows the
absence of pulse during the remaining half of the bit duration.
Polar Signaling
There are two methods of Polar Signaling. They are −
• Polar NRZ
• Polar RZ
• Polar NRZ
In this type of Polar signaling, a High in data is represented by a positive pulse,
while a Low in data is represented by a negative pulse. The following figure
depicts this well.
Polar RZ
In this type of Polar signaling,
a High in data, though represented by a Mark pulse, its duration T0 is less than the symbol bit
duration.
Half of the bit duration remains high but it immediately returns to zero and shows the absence
of pulse during the remaining half of the bit duration.
However, for a Low input, a negative pulse represents the data, and the zero level remains
same for the other half of the bit duration. The following figure depicts this clearly.
Bipolar Signaling
• This is an encoding technique which has three voltage levels namely +, - and 0. Such a
signal is called as duo-binary signal.
• An example of this type is Alternate Mark Inversion (AMI).
• For a 1, the voltage level gets a transition from + to – or from – to +, having

alternate 1s to be of equal polarity. A 0 will have a zero voltage level.
• Even in this method, we have two types.
1. Bipolar NRZ (AMI)
2. Bipolar RZ
Manchester
In this Manchester encoding
0 is represented as low-to-high and
1 is represented as high-to-low.
Modulation
• Modulation is the process of varying one or more properties of a periodic waveform
called the carrier signals with a modulating signal that digitally contains information to
be transmitted
• The process of varying any of the three characteristics as the Amplitude, Frequency or
the Phase of a carrier signal is called as modulation
• In this modulation, the amplitude of the carrier signal varies in accordance with the
message signal, and other factors like phase and frequency remain constant.
In digital modulation, a message signal is converted from analog to digital message, and then
modulated by using a carrier wave
Digital Modulation
4.5. Amplitude Shift Keying

Amplitude shift keying (ASK) is the digital modulation technique.
In Amplitude shift keying, the amplitude of the carrier signal is varied to create signal elements.
Both frequency and phase remain constant while the amplitude changes.
Amplitude Shift Keying Principle
• ASK Block Diagram
ASK Modulator
ASK Demodulator
• The carrier is a sinewave of frequency .
• The digital signal from the computer acts as the modulating signal
• The ASK modulator is nothing but a multiplier followed by a band pass filter.
• Due to the multiplication, the ASK output will be present only when a binary “1” is to be
transmitted
• The ASK output corresponding to a binary “0” is zero.
• The carrier is transmitted when a binary 1 is to be sent and no carrier is transmitted

when a binary 0 is to be sent.
Binary Phase Shift Keying BPSK

Phase Shift Keying PSK is the digital modulation technique in which the phase of the carrier
signal is changed by varying the sine and cosine inputs at a particular time
This is also called as 2-phase PSK or Phase Reversal Keying.
In this technique, the sine wave carrier takes two phase reversals such as 0° and 180°.
Phase-shift keying (PSK) is a digital to analog modulation scheme based on changing, or

modulating, the initial phase of a carrier signal.
• PSK is used to represent digital information, such as binary digits zero (0) and one (1).
The modulation of PSK is done using a balance modulator, which multiplies the two signals
applied at the input.
• Here, the carrier undergoes two phase reversal such as 0° and 180°
• Amplitude and frequency of the original carrier signal is kept constant.
Frequency Shift Keying
• Frequency shift keying (FSK) is the digital modulation technique.
• In Frequency shift keying, the frequency of the carrier signal is varied to create signal
elements.
• Both amplitude and phase remain constant while the frequency changes
Bit 1 is represented by high frequency (f1) carrier signal
Bit 0 is represented by low frequency (f0) carrier signal
Types of Modulation
Pulse Code Modulation (PCM)
• Pulse code Modulation is used to convert Analog Signals into Digital Data
• Steps:
1. Sampling:
• In PCM first we do sampling to convert analog signal into discrete signal
• Number of samples of the signal are taken at regular intervals at a higher frequency of
signal
• 2. Quantization: After that we do quantization to convert discreet signal into digital signal
• 3. Line coding:
• After that we do encoding of that digital signal.
• Binary digits are then transferred into digital signal using digital to digital encoding
techniques
2. Quantization
• The digitization of analog signals involves the rounding off of the values which are
approximately equal to the analog values.
• The method of sampling chooses a few points on the analog signal and then these
points are joined to round off the value to a near stabilized value.
• Such a process is called as Quantization.
• Quantization is representing the sampled values of the amplitude by a finite set of

levels, which means converting a continuous-amplitude sample into a discrete-time
signal.
Advantages
• Pulse Code Modulation is used in long-distance communication.
• The efficiency of the transmitter in PCM is high.
• Higher noise immunity is seen.
• Efficient method.
• As the PCM signal is digital in nature, storage is possible.
Disadvantages
• The bandwidth requirement is high.
• PCM is a complex process, since it involves encoding, decoding and quantisation of the
circuit
• Applications of Pulse Code Modulation
• It is used in telephony and compact discs.
• Pulse Code Modulation is used in satellite transmission systems and space

communications.
Differential Pulse Code Modulation (DPCM)
• PCM is a straightforward system, but it is not very efficient as it generates
many bits and thus requires so much bandwidth.
• Differential PCM (DPCM) is a technique of analog to digital signal conversion
• This technique samples the analog signal and then quantizes the difference between
the sampled value and its predicted value
• Then encodes the signal to form a digital value
• Since this difference (prediction error) is much smaller than the sample value, fewer bits
are required to quantize it.
• This means that DPCM can achieve performance levels at lower bit rates than PCM
Delta Modulation
• A modulation technique that converts or encodes message signal into a binary bit
stream is known as Delta Modulation
• Delta Modulation is a simplified form of DPCM technique, also viewed as 1-bit DPCM
scheme.
• Here only 1 bit is used to encode 1 voltage level thus, the technique allows transmission
of only 1 bit per sample.
• The type of modulation, where the sampling rate is much higher and in which the step
size (Δ delta) after quantization is of a smaller value, such a modulation is termed
as delta modulation.
Features of Delta Modulation
• An over-sampled input is taken to make full use of the signal correlation.
• The quantization design is simple.
• The quality is moderate.
• The design of the modulator and the demodulator is simple.
• The stair-case approximation of output waveform.
• The step-size is very small, i.e., Δ delta
• The bit rate can be decided by the user.
• This involves simpler implementationAdvantages of Delta Modulation
• Design is easy and simple.
• It is a 1-bit quantizer.
• As only 1 bit is transmitted per sample, the ultimate transmission rate required is very
much less as compared to PCM
Disadvantages of Delta Modulation

• When the value of the delta is small, slope overload distortion is seen, which is a type of
noise.
• When the value of delta is large, granular noise is seen, which is a type of noise.
Parameters PCM DPCM Delta Modulation
Bit Rate 4,8 or 16 bots/sample Less than PCM 1 bit/sample
Levels Depends on number of bits Two Fixed Number of

Levels
Quantization Error & Depends on Level Present but less Slope overload
Distortion than PCM distortion and
Granular Noise
Feedback Not present Exists Exists
Complexity Complex Simple Simple
Bandwidth for Highest Lesser than Lowest
transmission PCM
SNR Good Fair Poor
Area of Application Audio and Video Telephony Speech & Video Speech and Images
Spread Spectrum Modulation

• Spread Spectrum:
– The bandwidth of the transmitted signal is much greater than the bandwidth of
the original message is known as Spread Spectrum
– The bandwidth of the transmitted signal is determined by the message to be

transmitted and by an additional signal known as the Spreading Code.
• The main advantage of spread spectrum communication technique is to prevent

“interference” whether it is intentional or unintentional.
• The signals modulated with these techniques are hard to interfere and cannot be
jammed.
• Hence, these techniques are used for military purpose
• Types of Spread Spectrum
• Frequency Hopping Spread Spectrum (FHSS)
• Direct Sequence Spread Spectrum (DSSS)
Frequency Hopping Spread Spectrum (FHSS)
• This is frequency hopping technique, where the users are made to change the
frequencies of usage, from one to another in a specified time interval, hence called
as frequency hopping.
• Frequency of carrier is periodically modified following a specified sequence of frequency
• This sequence is known as hopping sequence or spreading code
• The amount of time spent on each frequency hop is called as Dwell time.
• For example, a frequency was allotted to sender 1 for a particular period of time.
• Now, after a while, sender 1 hops to the other frequency and sender 2 uses the first
frequency, which was previously used by sender 1.
• This is called as frequency reuse.
• The frequencies of the data are hopped from one to another in order to provide a secure
transmission.
▪ Slow Hopping:
In slow hopping, multiple bits are transmitted on a particular or same frequency
▪ Fast Hopping:
In fast hopping, individual bits are split and are transmitted on different frequencies
Advantages of FHSS:
• Secure
• Simple implementation as compared to DSSS
• High efficiency
Disadvantages:
• Less Robust
Direct Sequence Spread Spectrum DSSS

• Whenever a user wants to send data using this DSSS technique, each and every bit of
the user data is multiplied by a secret code, called as chipping code.
• This chipping code is nothing but the spreading code which is multiplied with the original
message and transmitted.
• The receiver uses the same code to retrieve the original message.
• FHSS
– Bluetooth
– frequency-hopping code division multiple access (FH-CDMA)
• DSSS
– CDMA
– GPS
– LAN Technology
– Satellite communication Technology
Questions
1. Explain the principle of working of ASK and BPSK with suitable waveforms for the bit
sequence 110101100. (S-2022)
2. Draw the block schematic of WLL architecture and explain.
3. Write any two applications of WLL.
4. Differentiate between PCM and DPCM (any four point).
5. Differentiate between PCM and DPCM on the basis of Bitrate, quantization Error &
Distortion, Application and Feedback
6. Define the term LEC (Local Exchange Carrier)
7. Draw the block schematic of WLL architecture and explain.
8. Encode the datastream 1011000101 using the following techniques
i) RZ Bipolar
ii)AMI
iii)Manchester
iv)NRZ-unipolar
9. State any two limitations of Delta Modulation
10. Draw the labeled wireless local loop architecture and list the two functions of each
i) WANU ii) WASU
11. Encode the datastream 01001110 using the following techniques
i) Unipolar – NRZ ii) Polar – RZ
12. Explain the working principle of ASK and FSK with suitable waveforms using the given
bit sequence 10110
13. Write any two applications of WLL
14. Differentiate between DSSS and FHSS (any four points)
15. Draw WLL architecture and describe it
16. Draw the given waveforms for the data 101011001
i) Unipolar RZ
ii) Unipolar NRZ
iii)AMI
iv)Manchester
v) Polar RZ
vi)Polar NRZ
UNIT-V Mobile Ad-hoc Network & Wireless
Sensor Network (16 Marks)
ADHOC NETWORK
A kind of Wireless Network which can be designed for fulfilling particular purposes that is
served by establishment of the whole setup on the fly.
Various Types:
• Mobile Adhoc Network(MANET)
• Wireless Sensor Network (WSN)
5.1. MANET
• A Mobile Adhoc Network (MANET) is a continuously self-configuring, infrastructure-less
network of mobile devices connected without wires.
• Each mobile node is equipped with a wireless transmitter and receiver with an antenna.
• Topology preferably suitable for MANET is dynamic autonomous topology
Characteristics/ Features of MANET

1. Autonomous collection of Devices: Mobile Ad hoc Network (MANET) is an
autonomous collection of mobile devices such as laptops, smart phone etc. that communicate
with each other over wireless link.
2. Dynamic topologies: The network topology may change randomly and unpredictably as
nodes are free to move arbitrarily; thus, links may be bidirectional or unidirectional.
3. Autonomous Behavior: Each node can act as a host and router, which shows its
autonomous behavior.
4. No hardware or physical infrastructure:
In MANET mobile devices can communicate and send data to each other autonomously, no
hardware or physical infrastructure is involved;
Each node behaves as a router and they forward traffic to other specified nodes in the network
5. Self-configured wireless network: An ad hoc network is a self-configured wireless

network that allows each wireless node to forward and receive data dynamically.
6. It is self-repairing: They consist of a set of mobile nodes connected wirelessly in a self-

configured, self-healing network.
7. Limited physical security:

Wireless networks are more prone to security threats. than wire line networks, such as
eavesdropping, spoofing, and denial of services (DoS) attacks.
8. Energy-Constrained Operation:
Mobile nodes are characterized by less memory, less power, and lightweight features.
Therefore, almost all the nodes rely on batteries or other exhaustible means for their energy
9. Bandwidth constrained & less Reliability:

Wireless links usually have less reliability, efficiency, stability, and capacity as compared to a
wired network.
10. Anywhere connectivity:

MANET allows users to access and exchange information regardless of their geographic
position or proximity to infrastructure
MANET Topologies
• MANET may operate as standalone fashion or they can be the part of larger internet.
• They form highly dynamic autonomous topology with the presence of one or multiple
different transceivers between nodes.
• Autonomous Behavior:
• Each node can act as a host and router, which shows its autonomous behavior.
• Typically communicate at radio frequencies (30MHz-5GHz)
• TORA is a routing algorithm and is mainly used in MANETs to enhance scalability
• TORA is an adaptive routing protocol.
• It is therefore used in multi-hop networks
Types of MANET
1. Vehicular Ad hoc Network (VANETs) –
Enable effective communication with another vehicle or with the roadside equipments.
2. Intelligent vehicular ad hoc networks(InVANETs) deals with another vehicle or with the
roadside equipment.
3. Smart Phone Ad hoc Network (SPANC) –

To create peer-to-peer network without relying on cellular carrier networks, wireless
access points or traditional network infrastructure.
4. Here peer can join or leave the network without destroying it.
5. Internet based Mobile Ad hoc Network (iMANETs) –

It supports internet protocols such as TCP/UDP and IP. To link mobile nodes and
establish routes distributed and automatically.
6. Hub-Spoke MANET:
Multiple sub MANET’s may be connected in hub-spoke VPN to create a geographically
distributed MANET.
7. Normal Ad-hoc routing algorithm does not apply directly.
8. Military or Tactical MANETs –

This is used by the military units. Emphasis on data rate, real time demand, fast re-
routing during mobility, security, radio range, etc.
9. Flying Ad hoc Network (FANETs) –

This is composed of unmanned aerial vehicle (commonly known as drone). Provides
links to remote areas and mobility.
Advantages
• Separation from central network administration.
• Each nodes can play both the roles ie. of router and host showing autonomous nature.
• Self configuring and self healing nodes, does not require human intervention.
Disadvantages
• Resources are limited due to various constraints like noise, interference conditions, etc.
• Lack of authorization facilities.
• More prone to attacks due to limited physical security.
Design Challenges in Manet

1. Limited Bandwidth –
• The wireless networks have a limited bandwidth in comparison to the wired networks.
• Wireless link has lower capacity as compare to infrastructure networks.
• The effect of fading, multiple accesses, interference condition is very low in ADHOC
networks in comparison to maximum radio transmission rate.
2. Dynamic topology - Due to dynamic topology the nodes has less trust between
them.
3. High Routing - In ADHOC networks due to dynamic topology some nodes changes
their position which affects the routing table
4. Problem of Hidden terminal –

The Collision of the packets are held due to the transmission of packets by those node which
are not in the direct transmission range of sender side but are in range of receiver side.
5. Transmission error and packet loss –

By increasing in collisions , hidden terminals, interference, uni-directional links and by the
mobility of nodes frequent path breaks a higher packet loss has been faced by ADHOC
networks.
6. Mobility –
Due to the dynamic behaviour and changes in the network topology by the movement of the
nodes ,ADHOC networks faces path breaks and it also changes in the route frequently.
7. Security threats –
New security challenges bring by Adhoc networks due to its wireless nature.
In Adhoc networks or wireless networks the trust management between the nodes leads to the
numerous security attacks
Applications of MANET
1. Personal area networking - cell phone, laptop, ear phone, wristwatch
2. Military environments- soldiers, tanks, planes
3. Civilian environment- Car network meeting rooms
4. Meeting rooms- sports stadiums, boats, small aircraft
5. Emergency operations- search-and-rescue, policing and fire fighting
5.2. Wireless Sensor Network

A Wireless Sensor Network is one kind of wireless network includes a large number of
circulating, self-directed, minute, low powered devices named sensor nodes called motes
• These networks certainly cover a huge number of spatially distributed, little, battery-
operated, embedded devices that are networked to caringly collect, process, and
transfer data to the operators, and it has controlled the capabilities of computing &
processing. Nodes are the tiny computers, which work jointly to form the networks.
• The sensor node is a multi-functional, energy efficient wireless device. The applications
of motes in industrial are widespread.
• A collection of sensor nodes collects the data from the surroundings to achieve specific
application objectives. The communication between motes can be done with each other
using transceivers.
• In a wireless sensor network, the number of motes can be in the order of hundreds/
even thousands. In contrast with sensor n/ws, Ad Hoc networks will have fewer nodes
without any structure.
BLOCK Diagram of Wireless Sensor Node
A Wireless Sensor Network (WSN) is a wireless network consisting of spatially distributed

autonomous devices using sensors to monitor physical or environmental conditions.
• A WSN system incorporates a gateway that provides wireless connectivity back to the wired
world and distributed nodes
Sensors: Sensors are used by wireless sensor nodes to capture data from their environment.
They are hardware devices that produce a measurable response to a change in a physical
condition Like temperature or pressure.
• Sensors are classified into two categories: Passive and Active sensors.
§ Passive sensors sense the data without actually manipulating the environment by active
probing. They are self-powered, that is, energy is needed only to amplify their analog signal.
§ Active sensors actively probe the environment, for example, a sonar or radar sensor, and
they require continuous energy from a power source.
Microcontroller: The controller performs tasks, processes data and controls the functionality of
other components in the sensor node. While the most common controller is a microcontroller,
other alternatives that can be used as a controller are: a general purpose desktop
microprocessor, digital signal processors, FPGAs (Field Programmable Gate Array) and ASICs
(Application Specific Integrated Circuits).
— Digital signal Processors may be chosen for broadband wireless communication
applications, but in Wireless Sensor Networks the wireless communication is often modest:
i.e., simpler, easier to process modulation and the signal processing tasks of actual sensing of
data is less complicated
— Transceivers:
Sensor nodes often make use of ISM band, which gives free radio, spectrum allocation and
global availability.
The possible choices of wireless transmission media are radiofrequency (RF), optical
communication (laser) and infrared.
— Memory:
Flash memories are used due to their cost and storage capacity. Memory requirements are
very much application dependent.
— Power source:
Two power saving policies used are Dynamic Power Management (DPM) and Dynamic
voltage Scaling (DVS).
DPM conserves power by shutting down parts of the sensor node which are not currently used
or active.
DVS scheme varies the power levels within the sensor node depending on the non-
deterministic workload
There are 2 types of architecture used in WSN:
1. Layered Network Architecture
2. Clustered Architecture
Layered WSN Network Architecture
Layered Network Architecture makes use of a few

hundred sensor nodes and a single powerful base
station.
Network nodes are organized into concentric

Layers.
It consists of 5 layers and three cross layers.
• The 5 layers are:
1. Application Layer–
Responsible for traffic management and provide software for different applications that
translate the data in an understandable form or send queries to obtain certain information
2. Transport Layer-
The function of this layer is to provide reliability and congestion avoidance where a lot of
protocols designed to provide this function are either applied on the upstream or downstream.
3. Network Layer-
The major function of this layer is routing, handling the major challenges are in the power
saving, limited memory and buffers, sensor does not have a global ID and have to be self
organized.
The basic idea of the routing protocol is to define a reliable path and redundant paths.
4. Data Link Layer-
Responsible for multiplexing data streams, data frame detection, MAC, and error control,
ensure reliability of Point–point or point– multipoint. Errors or unreliability comes from.
5. Physical Layer –
Responsible for frequency selection, carrier frequency generation, signal detection, Modulation
and data encryption
The cross layers :
These layers are used to manage the network and make the sensors work together in order to
increase the overall efficiency of the network
• Three functions are-
1.Power Management Plane
2.Mobility Management Plane-
• Detect sensor nodes movement.
• Node can keep track of neighbors and power levels (for power balancing )
3.Task Management Plane-
• Schedule the sensing tasks to a given area.
• Determine which nodes are off and which ones are on
2. Clustered Network Architecture
• In Clustered Network Architecture, Sensor Nodes autonomously clubs into groups
called clusters.
It is based on the Leach Protocol which makes use of clusters. Leach Protocol stands for Low
Energy Adaptive Clustering Hierarchy.
• Properties of Leach Protocol:
• It is a 2-tier hierarchy clustering architecture.
• It is a distributed algorithm for organizing the sensor nodes into groups called clusters.
• The cluster head nodes in each of the autonomously formed clusters create the Time-
division multiple access (TDMA) schedules.
• It makes use of the concept called Data Fusion which makes it energy efficient
Characteristics of Wireless Sensor Network

• Simple to use
• Cross-layer design
• Scalability to large scale of distribution
• Capability to ensure strict environmental conditions
• The consumption of Power limits for nodes with batteries
• Capacity to handle with node failures
• Some mobility of nodes and Heterogeneity of nodes
Advantages of Wireless Sensor Networks

• Network arrangements can be carried out without immovable infrastructure.
• Apt for the non-reachable places like mountains, over the sea, rural areas and deep
forests.
• Flexible if there is a casual situation when an additional workstation is required.
• Execution pricing is inexpensive.
• It avoids plenty of wiring.
• It might provide accommodations for the new devices at any time.
• It can be opened by using a centralized monitoring.
• Wireless sensor networks may comprise of numerous different types of sensors like low
sampling rate, seismic, magnetic, thermal, visual, infrared, radar, and acoustic, which
are clever to monitor a wide range of ambient situations.
• Military Applications
• Health Applications
• Environmental Applications
• Home Applications
• Commercial Applications
• Area monitoring
• Health care monitoring
• Environmental/Earth sensings
• Air pollution monitoring
• Forest fire detection
• Landslide detection
• Water quality monitoring
• Industrial monitoring
Q. Explain the energy constraints in sensor nodes in WSN and name the
protocols to design energy efficiency in WSN
• Wireless sensor node is microelectronic device means it is equipped with a limited number
of power source.
• Nodes are dependent On battery for their power.
• Hence power conservation and power management is an important issue in wireless

sensor network.
• Due to this reason researchers are focusing on the design of power aware protocols and
algorithm for sensors network.
• Protocol used:
• Hierarchal routing protocols are considered more energy efficient when compared with flat
and location based routing protocols.
• A number of hierarchal based energy efficient routing protocols have been referred to in the
literature review such as LEACH , TEEN and APTEEN , PEGASIS , MECN and SMECN ,
SOP , HPAR , VGA , Sensor Aggregate, TTDD , Energy Efficient Self-Healing , Energy
Efficient Position Based , and CELRP.
Network Topologies in WSN

• Star Topology –
In star topology, there is a single central node known as hub or
switch and every node in the network is connected to this hub.
Star topology is very easy to implement, design and expand.
As all the data flows through the hub, it plays an important role in the
network and a failure in the hub can result in failure of entire network
• Tree Topology -
A tree topology is a hierarchical network where
there is a single root node at the top and this
node is connected to many nodes in the next
level and this continues.
The processing power and energy consumption

is highest at the root node and keeps on
decreasing as we go down the hierarchical
order
• Mesh Topology –
In mesh topology, apart from
transmitting its own data, each
node also acts as a relay for
transmitting data of other
connected nodes.
Mesh topologies are further

divided into Fully Connected
Mesh and Partially Connected
Mesh.
In fully connected mesh

topology, each node is connected to every other node while in partially connected mesh
topology, a node is connected one or more neighboring nodes.
5.3. Classification of Clustering Algorithms
Depending on characteristics and functionalities of sensor nodes there are various clustering
algorithms.
Hence it can be classified based on cluster formation criteria,
algorithm complexity and cluster head selection
Based on Cluster head selection

It is further categorized in four different algorithm types as shown:
i)Heuristic Algorithms: It refers to finding algorithm with reasonable runtime and the
optimal solution eg Linked Cluster Algorithm (LCA)
ii) Weighted algorithms: These algorithms use a combination of metrics such as the
remaining energy, transmission Power etc to satisfy more generalized goals than single
criterion protocols
eg. Weighted Clustering Algorithm (WCA)
iii) Hierarchical Algorithms: In this there is a competition in the CH selection for a given
round
Eg LEACH, HEED
iv) Grid Algorithms: In the grid algorithm one of the sinks(primary sink) dynamically and
randomly builds the cluster Grid. The CHs are arranged in a grid like manner
Eg. Power efficient Gathering in Sensor Information Systems (PEGASIS) and GROUP are grid
algorithm
2. Based on the complexity of algorithm

i)Constant convergence Time Algorithms: The algorithms which converge completely
in a fixed number of iterations, whatever the size of the nodes population is called as constant
convergence time clustering algorithms
eg. HEED(Hybrid Energy Efficient Distributed Clustering) and LEACH (Low Energy Adaptive
Clustering Hierarchy protocol)
ii) Variance Convergence Time Algorithms: These algorithms enable more control of
the cluster properties than the constant time it has suitability for networks which have a large
number of nodes
Eg LCA (Land Covered Area) and WCA (Water Covered Area)
3. Based on Cluster Formation Criteria

i) Distributed Clustering Algorithms:
In this type of algorithms there is no fixed CH and the CH keeps changing from node to node
based on some preassigned parameters.
Depending on the parameters which will be used for the cluster heads selection and the
clusters formation the distributed algorithms are classified into 4 subtypes namely
Probabilistic, Iterative Identify based and Neighborhood-based.
Probabilistic approach: Clustering relies upon pre-assigned probability values for sensor nodes
eg LEACH, EEHC (Energy Efficient Hierarchical Clustering) and HEED
ii) Centralized Clustering Algorithms:
With the help of vector quantization, in this method the base station node manages the
clustering.
The criteria for CH selection and cluster formation based on the nodes proximity and on the
information received from other closely located nodes
Eg.
LEACH-C
BCDCP (Base-Station Controlled Dynamic Clustering Protocol )
WCA (Water Covered Area)
QUESTIONS
1. Draw the MANET Topology and explain. State two applications of MANET. (S-2022)
2. Draw the block diagram of a sensor node in WSN and state the function of various
components (S-2022)
3. Draw the architecture of WSN and explain. (S-2022)
4. State two applications of MANET.
5. Classify Clustering algorithm.
6. Draw the block diagram of a sensor node in WSN and state the function of various
components
7. Draw the architecture of WSN and explain.

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Unit I BASICS OF PCS AND GSM (12 Marks)

Evolution of Mobile Communications

• Voice Calls eg AMPS(Advanced Mobile Phone System)

• Voice calls +SMS

• GSM (Global System for Mobile Communication)

• CDMA (Code-Division Multiple Access)

• GPRS (General Packet Radio Service)

EDGE(Enhanced Data rates for GSM Evolution)

• UMTS(Universal Mobile Telecommunications System)

LTE (Long Term Evolution) VoLTE (Voice Over LTE)

LTE-A (LTE Advanced)

Cellular Telephony Network

❖ LARGER AREA DIVIDED

❖ EACH WITH ITS OWN

• Base Station (BTS –Base Transceiver Station)

1.1. Personal Communication Service(PCS)

• The PCS Network Architecture is a communication network structure in which

• The PCS Network Architecture is divided into two sections:

• Wireline Transport Network

• Protocols are a collection of rules that must be followed to establish a connection.

• A cell is a radio coverage region that each BS in a radio network has.

• To provide wireline customers with communication services, MSC connects to the

1.2. Global System for Mobile Communications

GSM network layout

GSM network areas

In a GSM network, the following areas are defined −

1. Base Station System (BSS):

2. Network and Switching Subsystem (NSS)

3. Operation Support Subsystem(OSS)

1. Base Station System (BSS):

This system consists of

i. Mobile Station (MS)

1. Mobile Equipment (ME)

2. Subscriber Identity Module (SIM)

2. Portable Mobile Unit

3. Hand portable Unit

Subscriber Identity Module(SIM)

1. International Mobile Subscribers Identity(IMSI) –

2. Temporary Mobile Subscriber Identity ( TMSI ) –

– It is an temporary identity that is allocated to an MS by the VLR when it is in roaming

– It is an alias of the IMSI and is used in its place for privacy

3. Location Area Identity ( LAI ) -

– Each LA in a PLMN has its own identifier.

– Identifies the current location of the subscriber.

4. Subscribers Authentication Key ( Ki ) –

– This is used to authenticate the SIM card.

5. Mobile Station International Standard Data Number ( MSISDN ) –

This is the telephone number of the mobile

Base Transreceiver Station (BTS):

• Decoding, decrypting, and equalizing received signals

• Communicates with Mobile station and BSC

Base Station Controller (BSC)

– Channel allocation for the duration of call

– Maintains the call

– Control the power transmitted by BTS or MS

– Control of frequency hopping

2. Network and Switching Subsystem (NSS):

Mobile Switching Center (MSC)

• Manages communication between