UNIT 3

Network and Communication aspects in IoT

Network and communication aspects are crucial components of IoT (Internet
of Things) systems. IoT relies on a network of interconnected devices to
collect, transmit, and exchange data, enabling the seamless flow of
information for various applications. Here are key network and communication
aspects in IoT:

1. Connectivity Technologies:

IoT devices use various connectivity technologies to communicate with each

other, the cloud, and end-users. Common IoT connectivity technologies
include:

 Wi-Fi: IoT devices can connect to existing Wi-Fi networks, making it suitable
for home automation and indoor applications.
 Bluetooth: Bluetooth and Bluetooth Low Energy (BLE) are used for short-
range communication between IoT devices and smartphones or gateways.
 Cellular Networks: IoT devices can connect to cellular networks (2G, 3G, 4G,
and 5G) for wide-area coverage, often used in applications like asset tracking
and smart cities.
 LoRaWAN: Low Range Wide Area Network (LoRaWAN) is a long-range, low-
power wireless communication technology used for IoT applications with low
data rates.
 Zigbee: Zigbee is a wireless communication protocol that is used in home
automation and industrial IoT applications, especially for creating mesh
networks.
 NB-IoT and LTE-M: These are low-power cellular technologies designed
specifically for IoT devices.
 Satellite Communication: In remote and outdoor applications, satellite
communication is used to connect IoT devices.
 Wired Connections: Ethernet or other wired connections can be used for
reliable and high-bandwidth communication in certain applications.
 2. IoT Protocols:

IoT devices communicate using specific protocols that dictate how data is
structured, transmitted, and received. Common IoT protocols include:

 MQTT (Message Queuing Telemetry Transport): A lightweight publish-

subscribe protocol for efficient data transmission.
 CoAP (Constrained Application Protocol): Designed for resource-
constrained devices, often used in IoT and IIoT applications.
 HTTP/HTTPS: Traditional web protocols can be used for IoT communication
when necessary.
 WebSockets: Enables bidirectional communication for real-time applications.
 AMQP (Advanced Message Queuing Protocol): A messaging protocol used
for reliable, asynchronous communication.
 DDS (Data Distribution Service): Used for real-time data sharing in complex
and mission-critical systems.
 Modbus: A protocol for industrial applications, commonly used in supervisory
control and data acquisition (SCADA) systems.

3. Edge Computing:

Edge computing brings data processing closer to the IoT devices, reducing
latency and network traffic. It involves the use of edge devices or gateways
that can filter, aggregate, and analyze data before transmitting it to the cloud
or central servers.

4. Security and Privacy:

Security is paramount in IoT networks. Devices should be protected from

unauthorized access, and data transmission should be encrypted. Security
mechanisms like secure boot, device authentication, and over-the-air (OTA)
updates are essential.

5. Scalability:
IoT networks need to be scalable to accommodate an ever-growing number
of devices. Scalability ensures that networks can handle large volumes of data
and device connections.

6. Quality of Service (QoS):

QoS mechanisms ensure that IoT applications receive the necessary level of
service. Depending on the application, latency, reliability, and bandwidth
requirements can vary.

7. Standards and Interoperability:

Standardization is crucial for ensuring interoperability between different IoT

devices and systems. Standards like MQTT, CoAP, and others play a vital role
in achieving compatibility.

8. 5G and Beyond:

The rollout of 5G networks offers increased bandwidth and low latency,

making it a significant enabler for IoT applications that require high data rates
and real-time responsiveness.

IoT networks and communication are at the core of the IoT ecosystem,
allowing devices to exchange information and enabling the data-driven
decision-making that characterizes the Internet of Things. Planning for the
right network and communication infrastructure is essential to the success of
IoT projects across various industries.

Wireless Medium Access Issues

Wireless medium access issues in IoT (Internet of Things) are unique challenges that arise from the
large number of IoT devices sharing wireless channels and the diverse range of applications they
serve. These issues can have a significant impact on the efficiency and reliability of IoT networks.
Some of the wireless medium access issues in IoT include:

1. Scalability:
 Issue: IoT networks often consist of a massive number of devices, leading to increased contention for
wireless channel access. As the number of devices grows, the chances of collisions and delays in data
transmission also increase.
 Solution: Implementing efficient medium access control (MAC) protocols designed for scalability,
such as various forms of contention-based access with adaptive mechanisms.

2. Heterogeneity:

 Issue: IoT devices can vary significantly in terms of data rate, power requirements, and
communication technology (e.g., Wi-Fi, LPWAN, Bluetooth). Coordinating access to the wireless
medium for such a diverse range of devices can be challenging.
 Solution: Utilize protocols and access schemes that can accommodate heterogeneous device types,
such as dynamically adjusting contention window sizes to adapt to varying device capabilities.

3. Energy Efficiency:

 Issue: Many IoT devices are battery-powered and have strict power constraints. Constantly
contending for wireless access can lead to increased energy consumption.
 Solution: Implement low-power wireless protocols and mechanisms that allow devices to enter sleep
modes when not actively transmitting data. This can help conserve energy.

4. Real-time Requirements:

 Issue: Some IoT applications, like industrial automation and remote monitoring, have strict real-time
requirements. Contention and delays can affect the timely delivery of critical data.
 Solution: Employ quality of service (QoS) mechanisms and prioritize real-time traffic to ensure low-
latency communication.

5. Collision Avoidance:

 Issue: In crowded IoT environments, devices may compete for channel access and inadvertently
cause collisions, leading to data loss and retransmissions.
 Solution: Implement collision avoidance techniques, such as Carrier Sense Multiple Access with
Collision Avoidance (CSMA/CA) or time-slot-based access schemes to minimize collisions.

6. Network Congestion:

 Issue: As the number of IoT devices grows, network congestion may occur, especially in dense
deployments. This can lead to performance degradation.
 Solution: Use congestion control mechanisms to monitor and manage network congestion, adapt to
varying traffic loads, and optimize channel access.

7. Interference and Coexistence:

 Issue: IoT devices often share the same wireless spectrum with other networks, creating interference
and coexistence challenges.
 Solution: Employ techniques like Dynamic Frequency Selection (DFS), Automatic Channel Selection
(ACS), or adaptive transmission power control to mitigate interference issues.

8. Synchronization:

 Issue: Lack of synchronization among IoT devices can lead to contention problems, especially in
applications that require precise coordination.
 Solution: Use synchronization protocols to ensure that devices are coordinated in their access to the
medium.

Addressing wireless medium access issues in IoT networks requires careful network design, selection
of appropriate wireless technologies and protocols, and optimization based on the specific
requirements of the IoT application. It's essential to consider factors such as the number of devices,
data rate, latency requirements, power constraints, and interference in the design of IoT networks.

MAC Protocol survey in IoT

In IoT (Internet of Things) networks, the Medium Access Control (MAC)

protocol plays a critical role in governing how devices share the wireless
medium and coordinate access to transmit and receive data. Various MAC
protocols are used in IoT applications, each with its own characteristics and
suitability for specific scenarios. Here's a survey of some commonly used MAC
protocols in IoT:

1. CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance):

 Characteristics: CSMA/CA is a contention-based protocol. Devices listen
to the channel and only transmit when they detect it is idle, avoiding
collisions.
 Suitability: It is suitable for low-power IoT devices and applications
where devices need to share the medium efficiently and avoid collisions.
2. TDMA (Time Division Multiple Access):
 Characteristics: TDMA allocates specific time slots to devices for
transmission. Each device transmits during its assigned time slot.
 Suitability: TDMA is ideal for applications that require strict timing
control and low latency, making it well-suited for industrial IoT (IIoT) and
sensor networks.
3. Random Access MAC Protocols:
 Characteristics: These protocols, such as ALOHA and slotted ALOHA,
allow devices to transmit data at random times.
 Suitability: They are suitable for applications where devices have
sporadic and low-duty-cycle traffic, such as environmental monitoring.
4. IEEE 802.11 (Wi-Fi) MAC:
 Characteristics: Wi-Fi uses contention-based CSMA/CA with additional
features for contention window adjustment and acknowledgment
mechanisms.
 Suitability: Wi-Fi is suitable for IoT applications with high data rates,
such as smart home devices, but may not be power-efficient for battery-
powered devices.
5. IEEE 802.15.4 MAC (used in Zigbee):
 Characteristics: IEEE 802.15.4 defines a low-power, low-data-rate MAC
protocol that allows devices to synchronize and transmit data using
superframes.
 Suitability: Zigbee and similar protocols based on IEEE 802.15.4 are
suitable for low-power, low-data-rate IoT applications like home
automation and industrial control systems.
6. LoRaWAN MAC:
 Characteristics: LoRaWAN uses an adaptive data rate scheme and
ALOHA-based MAC protocol to enable long-range, low-power
communication in IoT networks.
 Suitability: LoRaWAN is ideal for wide-area IoT networks, including
smart cities and agriculture, where long-range communication is
required.
7. NB-IoT MAC:
 Characteristics: Narrowband IoT (NB-IoT) is a cellular-based IoT
technology with a unique MAC layer optimized for low-power, wide-
area coverage.
 Suitability: NB-IoT is designed for applications that require reliable,
long-range, and low-power connectivity, such as smart meters and asset
tracking.
8. Sigfox MAC:
 Characteristics: Sigfox is a proprietary LPWAN technology with a simple

MAC protocol. Devices transmit data directly to base stations in a
scheduled manner.
 Suitability: Sigfox is suitable for IoT applications with low data rates and
where minimal device configuration is needed.
9. Weightless MAC:
 Characteristics: Weightless is an LPWAN technology with a flexible
MAC protocol that supports various data rates, modes, and modulation
schemes.
 Suitability: Weightless is used in a variety of IoT applications,
particularly in agriculture, environmental monitoring, and smart cities.

The choice of MAC protocol for an IoT application depends on factors such as
the type of devices, the network architecture, traffic patterns, energy
constraints, and communication range. IoT developers must select the most
suitable MAC protocol based on their specific requirements to ensure efficient
and reliable wireless communication in IoT networks.

Survey Routing Protocols

Routing protocols play a crucial role in IoT (Internet of Things) networks by determining how data is
forwarded from source devices to destination devices through the network. The choice of a routing
protocol depends on various factors, including the network architecture, device constraints, and
application requirements. Here is a survey of some common routing protocols used in IoT:

1. RPL (Routing Protocol for Low-Power and Lossy Networks):

 Characteristics: RPL is a standardized routing protocol for low-power and lossy networks
(LLNs). It is designed to operate in resource-constrained environments, making it well-suited
for IoT applications.
 Suitability: RPL is ideal for applications where devices have limited resources and operate in
mesh network topologies. It supports various routing metrics and modes to adapt to specific
use cases.
2. 6LoWPAN Routing:
 Characteristics: 6LoWPAN (IPv6 over Low-Power Wireless Personal Area Networks) routing
adapts IPv6 routing protocols to the constraints of low-power, low-data-rate networks,
typically used in IoT.
 Suitability: It is suitable for IoT applications that require IPv6 compatibility and seamless
integration with the internet.
3. Constrained Application Protocol (CoAP) Routing:
  Characteristics: CoAP is a lightweight application-layer protocol that can be combined with
various underlying routing protocols.
 Suitability: CoAP is used in IoT applications that require simple and efficient communication,
particularly in constrained environments.
4. MQTT (Message Queuing Telemetry Transport) Routing:
 Characteristics: MQTT is a lightweight publish-subscribe messaging protocol often used in
IoT. While it is not a routing protocol per se, it relies on underlying transport and routing
mechanisms.
 Suitability: MQTT is suitable for IoT applications with a focus on low overhead and efficient
message distribution.
5. OSPF (Open Shortest Path First) and BGP (Border Gateway Protocol):
 Characteristics: These are traditional routing protocols used in larger, more complex IoT
deployments, where the network architecture resembles a traditional IP network.
 Suitability: OSPF and BGP are suitable for industrial IoT (IIoT) and smart city applications
where traditional networking infrastructure is in use.
6. Zigbee Routing:
 Characteristics: Zigbee uses various routing mechanisms, such as tree routing and mesh
routing, to enable low-power, low-data-rate wireless communication.
 Suitability: Zigbee is ideal for home automation and industrial control systems where device
communication is based on the IEEE 802.15.4 standard.
7. LoRaWAN Routing:
 Characteristics: LoRaWAN uses a star-of-stars network topology with centralized network
servers for routing and data aggregation.
 Suitability: LoRaWAN is well-suited for long-range, low-power IoT applications, including
smart agriculture and asset tracking.
8. Bluetooth Mesh Routing:
 Characteristics: Bluetooth mesh utilizes a mesh network topology with a relay-based
approach to extend coverage.
 Suitability: It is suitable for IoT applications like home automation, where devices form a
local mesh network for communication.
9. 5G NR (New Radio) Routing:
 Characteristics: 5G NR includes routing and network slicing features that can support
diverse IoT use cases.
 Suitability: 5G NR is ideal for applications requiring high data rates and ultra-reliable low-
latency communication, such as autonomous vehicles and smart cities.

The choice of a routing protocol in IoT depends on the specific requirements of the application,
including data rates, device capabilities, power constraints, and network topology. IoT developers
and network architects should carefully consider these factors when selecting a routing protocol for
their IoT deployment.
 Sensor Deployment and Node Discovery
Sensor deployment and node discovery are crucial steps in setting up and
maintaining an efficient and reliable IoT (Internet of Things) network. These
processes involve strategically placing sensors and discovering nodes within
the network. Here's a more detailed overview of these activities:

Sensor Deployment:
1. Identify Deployment Goals: Before deploying sensors, clearly define the
objectives of your IoT project. Understand the specific data you need to
collect, the coverage area, and the desired outcomes.
2. Site Survey: Conduct a site survey to identify the most suitable locations for
sensor placement. Consider factors such as environmental conditions, signal
range, power sources, and accessibility.
3. Power Source: Determine the appropriate power source for the sensors.
Depending on the application, this may involve selecting between battery
power, solar panels, wired power, or energy harvesting solutions.
4. Sensor Selection: Choose sensors that are well-suited to your application and
the deployment environment. Ensure that the selected sensors can provide the
required data accuracy and precision.
5. Communication Technology: Select the appropriate communication
technology for your IoT network, such as Wi-Fi, Bluetooth, Zigbee, LoRaWAN,
or cellular. Ensure that the sensors are compatible with the chosen
communication technology.
6. Enclosures and Mounting: Select suitable enclosures and mounting methods
to protect sensors from environmental conditions, vandalism, or tampering.
Use weatherproof enclosures for outdoor deployments.
7. Data Collection Strategy: Determine how data will be collected from the
sensors. Decide whether data will be transmitted in real-time, at regular
intervals, or in response to specific events. Consider the impact of the data
collection strategy on power consumption and data storage.
8. Test Deployment: Before a full-scale deployment, conduct a small-scale test
deployment to identify any issues with sensor placement, connectivity, and
data collection. Adjust the deployment strategy based on the test results.
9. Scale Up: Once the test deployment is successful, scale up the deployment to
the desired size, adding sensors as needed. Continuously monitor the network
to ensure its continued functionality and reliability.

Node Discovery:
Node discovery is the process of identifying and registering devices (nodes)
within an IoT network. This is especially important when deploying new
devices or expanding an existing network:

1. Device Registration: When adding new devices to the network, register each
device with the network coordinator or gateway. This typically involves
providing a unique identifier for the device, such as a MAC address or device
ID.
2. Initialization: Configure and initialize new devices according to the network's
specifications. Set communication parameters, security credentials, and any
required network configurations.
3. Network Discovery: Devices need to discover the presence of the network
coordinator or gateway. This may involve scanning for available network
identifiers or broadcasting messages to identify and connect to the network.
4. Handshaking and Authentication: Devices typically engage in handshaking
and authentication processes to establish secure connections with the
network. This can include exchanging encryption keys or security credentials.
5. Onboarding Process: Implement a simplified onboarding process for new
devices, using technologies like Wi-Fi Protected Setup (WPS), QR codes, or
Near-Field Communication (NFC) to facilitate the initial connection and
registration of devices.
6. Management and Monitoring: Continuously manage and monitor devices
once they are registered and part of the network. This includes tracking device
status, data output, and any necessary firmware updates or maintenance.
7. Scalability: Ensure that the node discovery process is scalable to
accommodate a growing number of devices as your IoT network expands.

Proper sensor deployment and node discovery are critical for the success of
your IoT project. Strategic placement of sensors and efficient onboarding of
 devices ensure that your network can operate effectively and deliver the
desired results.

Data Aggregation and dissemination in IoT

Data aggregation and dissemination are essential processes in IoT (Internet of Things) systems, as
they involve collecting data from various sensors and devices, processing and organizing that data,
and distributing it to the appropriate destinations for analysis, visualization, and decision-making.
Here's an overview of these processes:

Data Aggregation in IoT:

1. Data Collection: IoT devices and sensors continuously collect data from the physical environment or
specific processes. This data can include sensor readings, environmental parameters, device status
information, and more.
2. Local Processing: In some cases, data is initially processed locally on the IoT device to reduce the
amount of raw data that needs to be transmitted. Local processing can involve data filtering,
aggregation, or basic analysis.
3. Data Integration: Data from multiple sensors or devices may need to be integrated and correlated
to provide a comprehensive view of the system or environment being monitored. Integration is often
performed at the edge or within IoT gateways.
4. Data Transformation: Data may need to be transformed into a common format or standardized
before aggregation. This step ensures that data from various sources is compatible for further
processing.
5. Data Aggregation Methods:
 Temporal Aggregation: Aggregating data over time intervals (e.g., hourly averages).
 Spatial Aggregation: Combining data from multiple sensor locations.
 Statistical Aggregation: Calculating summary statistics (e.g., mean, median) for data sets.
 Event-Based Aggregation: Aggregating data around specific events or triggers.
6. Data Reduction: Aggregated data is often smaller in volume compared to raw data, which helps in
conserving bandwidth and storage resources. Data reduction techniques like downsampling or
summarization can be applied.

Data Dissemination in IoT:

1. Data Storage: Aggregated data can be stored in databases, data lakes, or other storage solutions,
depending on the retention and retrieval requirements of the IoT application.
2. Data Analysis: Data can be analyzed in real-time or in a batch mode to extract insights, detect
anomalies, and trigger automated actions. Analytical tools and algorithms are applied to the
aggregated data.
3. Visualization: Aggregated data is often visualized through dashboards or reports to make it more
understandable and actionable for end-users or operators. Data visualization tools can help convey
insights effectively.
4. Alerts and Notifications: If specific conditions or events are detected in the aggregated data, alerts
and notifications can be generated to inform stakeholders or trigger responses. For example, in a
smart home, an alert may be sent when a smoke detector detects smoke.
5. Data Sharing and Distribution:
 Cloud Services: Aggregated data can be sent to cloud platforms for central storage, analysis,
and access by authorized users.
 Edge Devices: In edge computing scenarios, some data processing and aggregation can
occur at the edge to reduce latency and improve real-time decision-making.
 Peer-to-Peer: Data may be disseminated directly between IoT devices within a network.
 APIs: Data can be made available through APIs (Application Programming Interfaces) to
enable integration with other applications and services.
6. Security and Privacy: It's crucial to ensure the security and privacy of the aggregated data during
dissemination. Data encryption, access control, and authentication mechanisms are essential to
protect sensitive information.
7. Scalability and Redundancy: Consider the scalability and redundancy of the data dissemination
infrastructure to handle increased data volumes and ensure high availability.

Data aggregation and dissemination in IoT systems are vital for turning raw sensor data into
actionable insights. By efficiently collecting, processing, and distributing data, IoT applications can
deliver real-time monitoring, analysis, and decision support across a wide range of industries and use
cases.