KR20010003645A - Apparatus for processing atm signalling in mobile communication system - Google Patents

Abstract

PURPOSE: A device for performing asynchronous transfer mode(ATM) signaling in a mobile communication system is provided to define parameters for the setup and release of ATM connection for the call request and call release of a service user, and to use specific messages corresponding to signal to set up and release the ATM connection. CONSTITUTION: A signaling message processor(212) extracts information in each field inside received messages, to deliver the information to a switched virtual circuit manager(SVCM). The SVCM(211) performs operations for setting up and releasing SVC virtual connection from the information delivered from the signaling message, and delivers operated results to a signaling message generator(213). The signaling message generator(213) inserts information of the setup and release of the connection delivered from the SVCM(211) in each field for transmitting. A database stores information for setting up and releasing the connection and information on asynchronous transfer mode(ATM) resources.

Description

AP signaling device in mobile communication system {APPARATUS FOR PROCESSING ATM SIGNALLING IN MOBILE COMMUNICATION SYSTEM}

The present invention relates to an ATM signaling method of a mobile communication system, and more particularly to a signaling method for fast call setup.

The mobile communication system does not use a fixed terminal, but a system that provides a communication service to a service user who carries and moves the terminal. Many technologies related to wireless communication, mobility management, and existing communication networks are applied to mobile communication systems. Various techniques have been developed for the method of using radio frequency, and now, CDMA (Code Division Multiple Access) method is in the spotlight. The mobile communication system should always check and update the status whether the user is in a serviceable area or moving to another service area with respect to the movement. In addition, it is also necessary to control the state of the terminal,

On the other hand, when the ATM technology is applied to the mobile communication system, it is necessary to define a variety of parameters for the establishment and release of the ATM connection for the call request or call release of the service user, the present invention is a mobile communication system applied ATM This paper defines various concepts of establishing and releasing ATM connection by using specific message called signaling and describes its application.

1 is a diagram showing the structure of a general mobile communication system.

Referring to FIG. 1, a mobile communication system includes a mobile switching center (MSC), a control station (BSC, base station controller), a base station (BTS, base station transceiver system), and a mobile station (MS) mobile. It consists of a unit system that performs a unique function called Station. These unit systems perform their own functions, send and receive messages to each other through the network that binds them, and perform the functions of the entire system.

Conventional ATM signaling protocols include UNI 3.0, UNI 3.1, UNI 4.0, PNNI, and Q.2831, Q.2971, which were enacted by the ATM Forum. Provides the ability to establish or release an ATM connection for a. A brief look at the messages of the standard protocol is shown in Table 1 below.

Kinds Usage direction Essential Information Information length ALERTING Signaling that signaling has started BOTH PD, CR, MSG type, MSG length 9 bytes CALLPROCESSING Notification that processing of call setup request is started BOTH PD, CR, MSG type, MSG length 9 bytes CONNECT Inform the receiving party that the call has been received BOTH PD, CR, MSG type, MSG length 9 bytes CONNECTACKNOWLEDGE Confirm that the call has been received from the exchange to the receiver N-> U _D PD, CR, MSG type, MSG length 9 bytes SETUP We ask for setting of specific issue BOTH PD, CR, MSG type, MSG lengthTR_Dsec, B_Capa, QoS_param 31-35 bytes RELEEASE Request to release a particular call (U _S- > N) Notify that a particular call has been released (N-> U _D ) BOTH PD, CR, MSG type, MSG lengthCause 15-43 bytes RELEASECOMPLETE Confirm that release of specific issue is completed BOTH PD, CR, MSG type, MSG length 9 bytes NOTITY Convey any additional information BOTH PD, CR, MSG type, MSG lengthNotification indicator 14 STATUS Report on response error to STATUS ENQUIRY BOTH PD, CR, MSG type, MSG lengthCall Status, Cause 19-48 bytes STATUSENQUUIRY Require status BOTH PD, CR, MSG type, MSG length 9 bytes

And look at the format of each message is shown in Table 2 below.

Protocol Discriminator all 0 length of Call Reference Flag Call Refernce value Call Refernce value Call Refernce value Message Type Message Type Message Length Message Length Variable Length Information elements as required

Existing protocol signaling messages as shown in Table 1 define only information for setting and releasing ATM SVC connection in a wired network, and thus there is no definition for a wireless environment and mobility for characteristics of mobile communication. Many problems are expected when applying protocol signaling to a mobile communication system employing ATM.

The expected problems are as follows.

First, it is a problem to pass data of wireless environment with high probability of error to the ATM environment between each unit system without filtering.

Second, the same signal is introduced into the system several times due to fading.

Third, in order to solve the problems 1 and 2, a load of a base station unit system is increased in order to remove an error by applying a medium access control (MAC) function and transfer the error into the system.

Fourth, a system load is expected due to the ability to always check whether there is an error for a specific ATM connection for signaling.

Fifth, when a mobile station changes its service area and moves, it is necessary to set up a new call in the changed service area as soon as possible, and to quickly transmit data from the base station connected at the beginning of call setup or from the base station connected at the beginning of call setup. Retransmissions are required, and when the movement is complete, the existing call must be released, but the time taken to establish or release a new call in the prior art is relatively long.

In order to solve the first to third problems, protocols such as Q.2971 + have been proposed, which adds definitions of wireless environment and mobility to the prior art. This resulted in increased results compared to the standard protocol.

Therefore, when the conventional techniques proposed to date are applied to a mobile communication system to which ATM is applied, there is a problem that call setup requests or call cancellation requests of service users may be dropped.

Conventional protocols, on the other hand, define only signaling between the ATM terminal and the ATM switcher (User to Network), between the ATM switcher and the ATM switcher (Network-to-Network), and only the specific connection whose VPI / VCI is 0/5. I use it. This structure is well applied in the case of wired ATM switch, but in the mobile communication system with ATM, SVC connection must be set up within a specific unit system. Therefore, ATM signaling must be performed only on a specific processor board. Have.

Accordingly, an object of the present invention is to provide a new signaling method in a mobile communication system employing ATM.

Another object of the present invention is to provide new signaling message formats in a mobile communication system employing ATM.

Another object of the present invention is to provide new functional blocks implemented according to a new signaling scheme in a mobile communication system employing ATM.

In order to achieve the above objects, the ATM signaling performing apparatus of the mobile communication system extracts information from each field in a received message and delivers the information to the SVCM, and an SVC virtual connection from the information delivered from the signaling message. A signaling message for performing a series of operations for setting and releasing a message, and inserting the SVCM for transmitting the result to a signaling message generator and inserting and releasing information of a connection received from the SVCM into each field of the message. And a database for storing information on ATM resources and information for performing the establishment and release of the connection.

1 is a diagram showing the structure of a mobile communication system.

2 is a diagram illustrating an apparatus for performing ATM signaling in a mobile communication system according to the present invention.

3 illustrates an ATM address system in accordance with the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is implemented as a software functional block on the processor board of each unit system in an ATM-applied mobile communication system, and is matched with a call processing block operating with the functional block of the present invention. Meanwhile, the MAC function block for transmitting a message to the terminal is operated in the base station so that an error in the wireless environment does not flow into the system.

In the present invention, the connection for ATM signaling is set up by allocating enough bandwidth at the time of initialization of the system as in the conventional standard protocol. However, unlike the conventional standard protocol, which uses only a specific connection of VPI / VCI = 0/5, the present invention uses an ATM connection for IPC (Inter Processor Communication) between each unit system. Therefore, a processor board that performs ATM signaling has a distributed structure that can be any processor board of each unit system.

The configuration of the present invention consists of a signaling message processor, a signaling message generator, a switched virtual circuit manager (SVCM), and an SVC connection data base.

The signaling message processor receives messages, extracts information from each field in the message, and delivers the information to the SVCM. The SVCM performs a series of operations for establishing or releasing an SVC connection from the conveyed information and conveys the result to the signaling message generator. The signaling message generator inserts the connection establishment and release information received from the SVCM into each field of the message and transmits the information. On the other hand, in the SVC connection database, information for performing an operation of adding a new connection or releasing an existing connection from SVCM received information, and information about allocated ATM resources or assignable ATM resources are stored.

Hereinafter, the operation according to the present invention will be described.

The operation according to the present invention is largely 1) simplified message definition, 2) method of using IPC ATM connection established at system initialization, 3) operation of signaling message processor, 4) operation of signaling message generator, 5) Describes the operation of SVCM, 6) divided into information of the SVVC database.

First, the signaling message according to the present invention is shown in Table 3 below.

Kinds Usage direction Required Information Required Information Length SVC INIT require signaling Call Processing-> SVCM CR, MSGtype, MSGlengthREQtype (2BIT), TR_Desc (6Bit) QOS_param (8Bytes) 12 BYTES SVC INITACKNOWLEDGE Response to SVC INIT SVCM-> call processing CR, MSGtype, MSGlength 3 SETUP DONE The requested SVC setup is complete SVCM-> call processing CR, MSGtype, MSGlengthVPI / VCI (3Bytes), Cause (1Bytes) 7 RELESE DONE Requested release of SVC completed SVCM-> call processing CR, MSGtype, MSGlengthCause (1Bytes) 4 CONNECT SETUP Notify message completion Between SVCs CR, MSGtype, MSGlengthVPI / VCI (3Bytes), Cause (1Bytes) 7 CONNECT ACKNOWLEDGE CONNECT response between main processor boards in charge of signaling between unit systems Between SVCs CR, MSGtype, MSGlength 3 SETUP We ask for setting of specific issue Between SVCs CR, MSGtype, MSGlengthTR_Desc (1Bytes), QOS_param (8Bytes) 12 RELEASE Require specific issue Between SVCs CR, MSGtype, MSGlengthCause (1Bytes) 4 RELEASE COMPLETE Signals that processing of a RELEASE message is complete Between SVCs CR, MSGtype, MSGlengthCause (1Bytes) 4

Each signaling message format is shown in Table 4 below.

Flag Call reference value Message Type Message Length Variable Length information elements as required

First of all, only messages essential to the standard protocol are accepted, and the format of each message is newly defined as shown in Table 4 above. Essential information commonly used in each newly defined message is Call Reference (CR), MSG Type, MSG length, etc. as shown in Table 4 above.

First of all, the CR (Call Reference) value is assigned when setting up a call and the total number of SVCs that can be set at the same time is limited to 128. The flag value is set to 0 when the call processing function block of the own processor board is requested, and set to 1 when the setting is requested from another processor board, and is set to the call processing function block or the SVCM function block. Make it easier to manage each set call. On the other hand, the CR value is assigned during the establishment of a particular call and is not deleted until the call is released, and the same CR value is not assigned to the new call immediately after being deleted, thereby preventing malfunction of call management. The MSG type (Message Type) is a value for distinguishing each message defined in Table 3, and there are 9 currently defined messages but can be extended up to 256. MSG length (Message length) is a value that records the length of the information to be additionally transmitted in the unit of the present invention in bike units, and defines that up to 256 bytes of additional information can be transmitted. If the total number of SVCs to be supported at the same time is not sufficient as 128, the CR value of 1 byte may be added to the front of the MSG type, which is the second element of Table 4, to define 256 SVCs simultaneously.

Hereinafter, each message defined in Table 3 will be described in detail.

The SVC INIT message is a SVCM function block when an ATM SVC connection needs to be established, for example, when a call establishment or reception request from a service user is received from a call processing function block or a handover should be initiated. Message requesting to turn on or off. REQ type of the essential information of the message is a value indicating the setting or release of the SVC. Here, in case of release, connection can be released only by CR value, but in case of setting, additional information such as TR_Desc and QoS_Param to be serviced should be given. These additional information is transmitted in addition to the Variable Length Information elements field of Table 4 above.

The SVC INIT ACKNOWLEDGE message is a response message indicating that the signaling for establishing an ATM SVC connection has been initiated on receipt of the SVC INIT message from the SVCM function block to the call processing function block.

When the SVC INIT message requires call setup, the SETUP DONE message indicates that the ATM SVC connection is established to the destination through signaling if the VPI / VCI value of the additional information is present and delivers the Cause value of the additional information if it does not exist. This message indicates that an ATM connection is available or unavailable for the CR value.

The RELEASE DONE message indicates that the SVC INIT message releases the ATM SVC connection through signaling, and deletes the corresponding CR value so that it can be used again for another call. Communicate the cause of the release as additional information.

The CONNECT message indicates that the ATM SVC connection is set up to the destination through signaling if there is a VPI / VCI value of every additional information exchanged between the SVCM function block of the specific board and the SVCM function block of the destination. This message indicates that an ATM connection is available or unavailable for a specific CR value by passing the Cause value.

In the CONNECT ACKNOWLEDGE message, if a CONNECT is transmitted for a setting request of an ATM SVC in one unit system, the CONNECT ACKNOWLEDGE message needs to pass through another SVCM function block in the middle of signaling when setting an ATM SVC between unit systems. This message indicates that the SVCM function block that has been transmitted has sent a CONNECT message to the destination, and has sent a CONNECT message for a CR value to the destination with the SVCM function block that has sent the CONNECT message.

The SETUP message is a request for setting the ATM from the SVCM function block to the destination SVCM function block as a request for a call processing function block. Requires the allocation of ATM resources for use by the ATM SVC.

The RELEASE message is a request for the release of ATM from the SVCM function block to the destination SCVM function block as a request for the call processing function block. The RELEASE message requests the release of the ATM resource set for a specific CR value in the SVC INIT message. Communicate the cause of the release as additional information.

The RELEASE COMPLETE is a message indicating that there is a release of ATM SVC for a specific CR value in the SVCM function block of the destination and is a message to be delivered to the SVCM function block of the processor requesting the release of the call.

On the other hand, these signaling messages do not use the specific ATM connection of VPI / VCI = 0/5 used in the standard protocol, but use the IPC ATM connection set by PVCM at system initialization. Instead of using the existing address format such as E.164 of bytes, the system address format of 4 bytes as shown in FIG. 3 is defined and used. That is, a method of transmitting and receiving a signaling message in a header format used in an IPC message is used. In addition, in the mobile communication system consisting of up to 32 BSCs and up to 256 BTSs as defined in FIG. 3, all processor boards including redundancy and BSMs can be maintained.

A method of using an IPC ATM connection established at system initialization will now be described.

The functional blocks of the present invention use the ATM PVC connection for the system IPC generated by the Permanent Virtual Circuit Manager (PVCM) during system initialization with the ATM connection for signaling. As a result of the ATM PVC connection set at the time of initializing the system as shown in FIG. 2, the PVCM stores the PVC connection data base in a specific memory as a PVC connection data base and refers to the IPC function block or the SSCOP function block. Find the ATM connection identifier. The found ATM connection identifier is used in the ATM device driver under the IPC function block. After converting a given PDU (Packet Data Unit) into an ATM Cell, the original PDU is reassembled from the received ATM Cell to identify which ATM connection identifier is used and then the IPC function block or Transfer to SSCOP function block.

Looking at the operation of each functional block shown in Figure 2 as follows.

First, the signaling message processor 212 receives a signaling message from an external processor board from an IPC function block, separates MSG Type, MSG lengt, CR value, etc. from each message field, and extracts additional information when there is additional information. And transmits the necessary information to the SVCM function block 211.

Next, the signaling message generator 213 sets values in fields such as CR value, MSG Type, and MSG length from the information received from the SVCM function block 211, and adds this information to the message when there is information to be added. Creates a message to send to the processor board. The generated message can be sent to the internal function block or external processor board using the functions provided by the lower IPC function block.

Next, the operation of the SVCM function block 211 will be described in connection with each of the above messages. The SVCM function block 211 basically matches the call processing function block 215 and an external SVCM function block.

First, the SVCM function block 211 receives the SVC INIT message from the call processing function block 215 to determine the ATM SVC set by the processor board and the ATM SVC set from the outside for each flag value in the Call Reference field of Table 4. Manage separately. Reads REQ type for received CR value and distinguishes whether it is setup request or release request. In case of SETUP, the destination address transmitted from call processing function block, TR_Desc value and QOS_Param value of additional information are acquired and signaled. The message generator 213 requests the creation and transmission of a SETUP message, records the corresponding CR value in the SVC connection database 214, and stores the current state of the generation and transmission of the SETUP message. In case of release, request to send the release message to the destination address generated and sent to signaling message generator 213 without additional information, record the CR value in SVC Connection Data Base214, and store the current state of generation and transmission of release message. do. On the other hand, in addition to the above process, the SVC INIT ACKNOWLEDGE message is generated by the signaling message generator 213 and requested to be transmitted to the call processing function block 215 through IPC216.

Upon receiving the SETUP message from the external SVCM function block, check the information in the SVC Connection Data Base214 to determine whether the resource for the ATM SVC connection is set in the corresponding CR value. If the connection is not established, TR_Desc is requested. , Check whether it can be assigned to QOS_Param. If it is assignable, it sets up corresponding ATM SVC connection to its own processor, and if it is already established for the corresponding CR value or if it cannot be set up in the available ATM resource, it transmits to the signaling message generator 213 by reflecting the contents of Cause. Requires the creation and transmission of a CONNECT message to the processor board that sent the setup message. Meanwhile, the CR value is recorded in the SVC Connection Database 214 as a result of processing of the setup message, and the current state is generated and transmitted.

Then, it checks whether the corresponding ATM SVC connection is established for the release message received from the external SVCM function block, and if there is, releases the corresponding ATM connection and adds the resource of the connection to the available ATM resource. Also, delete all information about the CR value in the SVC connection database 214. On the other hand, the ATM SVC connection does not exist for the corresponding CR value or the release result of the ATM connection is reflected in the cause information and transmitted to the signaling message generator to send the RELEASE message to the processor board that sent the RELEASE message to the processor board. The processor block that sent it requests creation and transmission in a RELEASE COMPLETE message.

In addition, it is checked whether information on a corresponding CR value exists in the SVC Connection Data Base214 for a CONNECT message received from an external SVCM function block. If it exists, check whether the setup message is generated and transmitted. If the status is checked and the VPI / VCI value of the additional information is present, it means that the ATM SVC connection has been successfully set up. Therefore, the setup message is generated by the signaling message generator to reflect the VPI / VCI value of the additional information. Request is sent to processing function block 215. On the other hand, if the status is inconsistent or the VPI / VCI value of the additional information does not exist, it is corrected to the transmission state of the setup down message reflecting the Cause value of the additional information. If the information about the CR value does not exist, it must be retransmitted to another processor board. Therefore, the received information is sent back to the signaling message generator 213 to request retransmission to the destination board. Create and send. In this case, if there is no information about the CR for the SVC connection database 214, the information does not need to be managed, and thus no additional information is stored or modified.

And, if the state of the CR value for the connection confirmation SVC connection database received from the external SVCM function block is the generation and transmission state of the connection message, and if the state is confirmed, the ATM SVC state for the corresponding CR value is completed. Reflect, store, and enable the corresponding channel of the lower ATM device driver.

Then, check whether the status of the corresponding CR value in the release completion message connection database received from the external SVCM function block is the generation and transmission state of the release message.When the state is confirmed, the release message is generated by the signaling message generator213. To transmit to the call processing function block 213. On the other hand, the SVC connection database 214 is modified to send a release down message for the corresponding CR.

Next, the SVC connection database 214 is a set of data used to specify the result of the state of processing each message according to the operation of the SVCM, and to compare the state for processing of each message.

As described above, when the ATM technology is applied to a mobile communication system, various parameters for establishing and releasing ATM connection for call request or call release of a service user are defined, and specific messages corresponding to signaling are used. To simplify and define the various concepts of establishing or releasing ATM connections.

Claims (3)

In the AT signaling device of the mobile communication system, A signaling message processor for extracting information from each field in the received message and delivering the information to the SVCM; The SVCM performing a series of operations for establishing and releasing an SVC virtual connection from the information delivered from the signaling message, and delivering the result to a signaling message generator; A signaling message generator for inserting and transmitting information on connection establishment and release received from the SVCM into each field of the message and transmitting the information; AMT signaling apparatus comprising a database for storing information for performing the establishment and release of the connection and information on ATM resources. The method of claim 1, The messages accepted by the ATM signaling execution device, An SVC INIT message requesting signaling An SVC INIT ACKNOWLEDGE message in response to the SVC INIT, A SETUP DONE message indicating that the requested SVC setup is complete, A RELEASE DONE message indicating that the release of the requested SVC is complete, A CONNECT SETUP message indicating that the message has been processed; A CONNECT ACKNOWLEDGE message corresponding to a connection response between main processor boards in charge of signaling between unit systems; A SETUP message requesting the setting of a specific issue, A REELEASE message requesting the release of a particular call, The AT signaling device comprising a RELEASE COMPLETE message indicating that the processing of the REELEASE message is completed. The method of claim 2, The essential information commonly used by the messages includes a call refernce (CR), a message type (MSG Type), a message length (MSG Length), and the like.