CN100403815C - A method and system for realizing circuit type data service call - Google Patents

Abstract

The invention discloses a method for implementing a circuit-type data service call, which is applied to an IP-based core network and an IP-based code division multiple access system. The method includes: an originating terminal sends a circuit-type data service call to a mobile switching center request; the mobile switching center activates network interworking function resources and codec resources through the media gateway according to the circuit data service call request; the mobile switching center establishes a connection with the receiving terminal so that the originating terminal and the receiving terminal can perform circuit data services. According to the present invention, TC resources are uniformly managed by the media gateway, and the base station controller does not need to configure TCs, thereby saving system resources.

Description

A method and system for realizing circuit type data service call

technical field

The present invention relates to a communication technology, in particular to a method and system for realizing circuit-type data service calls in an IP-based core network and an IP-based code division multiple access system.

Background technique

In the CDMA (Code Division Multiple Access) system, a circuit-type data service, also called IWF (Internetworking Function) service, is specified. This service allows G3 (three types) fax service and asynchronous data service to be initiated by the mobile station. Due to the particularity of the air interface, circuit-type data services are likely to cause delays, bit errors, and other problems. In order to avoid such problems, the air interface transmits unmodulated fax or asynchronous data, and then transmits them in the BSC (base station controller) or MSC. (Mobile Switching Center) is connected to an IWF device, which is used to complete the modulation process of fax or asynchronous data.

In the prior art, when the MSC of the CDMA system in the circuit domain is connected to the IWF, it is necessary to rely on the TC (code converter) on the BSC side to complete the conversion of the IWF service into a 64K circuit according to the ISLP protocol (Intersystem Link Protocol) Data, and then the IWF inversely converts these data before performing the modulation process. The flow of the IWF service call in the prior art is introduced below.

The call service flow in the prior art is described below with reference to FIG. 1 . In this flow, take the use of ISUP between MSC (Mobile Switching Center) and PSTN (Public Switched Telephone Network) as an example.

Step 101, MS (mobile station) sends initial call request (CM Service Request), in this process, MS sends initial call request to BSC at first, after BSC selects A port circuit, then this initial call request is sent to MSC, so The above-mentioned call origination request message has a parameter SO, which indicates that this call is an IWF service.

Step 102, the MSC selects the circuit selected by the BSC or another A-port circuit according to the configuration, and sends an Add (Add) command message to the MGW, which contains BC (bearer capacity) and SO parameters, and the BC, SO The parameter is used to indicate that the call is an IWF service call, so that the MGW (media gateway) inserts IWF resources for the corresponding T endpoint.

Step 103, MGW allocates C (context) for the call, allocates T endpoint for the circuit, inserts IWF resources, and then returns an Add Response (Add Rsp) message to the MSC.

In step 104, the MSC initiates an assignment request (ASSIGN) to the BSC to allocate ground circuits and air links for this IWF service.

Step 105: After the BSC has allocated the ground circuit and the air link, it sends an ASSIGN CMP message to the MSC.

Step 106, after the MSC selects the outgoing circuit, it issues an Add command to the MGW, requesting the MGW to add the outgoing circuit to the corresponding C.

In step 107, the MGW assigns a corresponding T (T2) to the outgoing circuit, adds T2 to C, and then sends an Add Response (Add Rsp) message to the MSC.

In step 108, the MSC sends a modification (Mod) command message to the IWF of the MGW, so as to activate the IWF.

Step 109: The MGW executes the Mod command to activate the IWF. At this time, the IWF can start the process of establishing a fax channel such as PPP negotiation with the MS, and then return a change response (Mod Rsp) to the MSC.

In step 110, the MSC sends an initial address message (IAM) to the PSTN, so as to establish a circuit to the PSTN.

Step 111, the PSTN switch finds the corresponding fax machine according to the called number in the IAM message and rings (RING).

Step 112, the PSTN exchange sends an Address Complete Message (ACM) to the MSC, indicating that the called party has ringing.

Step 113, the facsimile machine answers (ANSWER) the call to the PSTN switch.

Step 114: After receiving the answer signal from the fax machine, the PSTN switch sends an answer message (ANM) to the MSCe, indicating that the fax machine has answered, and the MSC connects the IWF resource between the PSTN circuit and the A port circuit.

Step 115, the fax process starts between the calling MS and the called fax machine.

Therefore, in the above prior art, when the MSC is connected to the IWF, the BSC needs the TC to perform data codec conversion. After the A interface of the CDMA system and the core network are IP-based, if it is still required to support this function, not only the BSC is required Support TDM (time division multiplexing) and IP at the same time, and BSC also needs to retain the codec that converts IWF data into ISLP data, so that the BSC system cannot be simplified after IP, and affects TrFO/RTO (codec-free) after IP operation/remote code conversion operation) and other services.

Therefore, there is a need for a new method, which can support the process of implementing the IWF service without using the TC after the MSCe is connected to the IWF under the softswitch architecture.

Contents of the invention

The object of the present invention is to provide a method and system for implementing IWF service calls, in the IP-based core network and IP-based code division multiple access system, the IWF service can be realized without configuring TC resources in the BSC.

The invention provides a method for realizing a circuit-type data service call, including:

A. The mobile switching center receives the circuit data service call request sent by the originating terminal;

B. The mobile switching center applies for a codec through the media gateway according to the call request of the circuit-type data service to convert the inter-network interworking function data to the inter-system link protocol data, and activates the inter-network interworking function resource and the codec resource;

C. The mobile switching center establishes a connection with the receiving terminal, so that the originating terminal and the receiving terminal can perform circuit-type data services.

The originating terminal and the receiving terminal respectively include: a mobile station and a fixed station.

When the originating terminal is a mobile station, the step A further includes:

A1. The originating terminal sends a circuit data service call request to the mobile switching center through the base station controller.

When the originating terminal is a fixed station, the step A further includes:

A2. The originating terminal sends the circuit type data service call request to the mobile switching center through the public switched telephone network.

Before carrying out described step B, described method also comprises the step: mobile switching center obtains the sign that does not pass through inter-network interworking function business to intersystem link agreement data conversion, and obtaining method is as follows:

When the originating terminal is a mobile station, the mobile switching center obtains from the circuit type data service call request a sign that has not been converted from the inter-networking function service to the inter-system link protocol data;

When the receiving terminal is a mobile station, the mobile switching center obtains from the paging response returned by the base station controller the sign that the Internet interworking function service has not been converted to the intersystem link protocol data.

When the originating terminal is a mobile station, the step B further includes:

B1, the mobile switching center sends an add command to the media gateway, so that the media gateway allocates the user datagram protocol port number and address, and allocates an endpoint corresponding to the user datagram protocol port number and address;

B2. The mobile switching center sends an assignment request to the base station controller, so that the base station controller assigns the user datagram protocol port, address and air link of the network interworking function service;

B3. The mobile switching center sends a change command to the media gateway to activate the inter-network interworking function service.

When the receiving terminal is a mobile station, the step B further includes:

B1. The mobile switching center initiates paging to the mobile station;

B2. The mobile switching center sends an add command to the media gateway, so that the media gateway allocates the user datagram protocol port number and address, and allocates an endpoint corresponding to the user datagram protocol port number and address;

B3. The mobile switching center sends an assignment request to the base station controller, so that the base station controller assigns the user datagram protocol port, address and air link of the network interworking function service;

B4. The mobile switching center sends a change command to the media gateway to activate the service of the interworking function between networks.

Described step B1 further comprises:

B11, the mobile switching center sends an add command to the media gateway, so that the media gateway distributes the calling side endpoint and the context of the call;

B12. The mobile switching center initiates paging to the mobile station.

The present invention also provides a system for implementing circuit-type data service calls, including:

The originating terminal is used to send a circuit-type data service request to the mobile switching center;

The mobile switching center is used to control the codec used by the media gateway to apply for the conversion of the inter-network function data to the inter-system link protocol data according to the circuit-type data service request, activate the inter-network function resource, and control the assignment of the base station controller UDP port number and address, air link;

A base station controller for assigning user datagram protocol port numbers and addresses, air links under the control of the mobile switching center;

The media gateway is used to apply for the codec for converting the inter-networking function data to the inter-system link protocol data, and manage the transcoder resources and the inter-networking function resources;

The receiving terminal is used to receive service data of the inter-network interworking function.

Therefore, according to the present invention, by extending the bearer update request message so that there is no TC in the BSC and it is not necessary to support the detection of circuit-type data services on all inter-office TDM time slots, the IWF service can be realized, thereby System resources are saved. Therefore, it is suitable for realizing transmission of circuit data services in IP-based core network and IP-based code division multiple access system.

Description of drawings

Fig. 1 shows the flow chart of realizing IWF service in the prior art;

Fig. 2 has shown the flow chart of sending IWF business from MS to facsimile machine of the present invention;

Fig. 3 shows the flow chart of sending IWF service from facsimile machine to MS in the present invention.

Detailed ways

In order to make it easier for those skilled in the art to understand and realize the present invention, the embodiments of the present invention are described in conjunction with the accompanying drawings.

The basic idea of the present invention is that when the IWF service initiates/ends a call, the BSC specifies in the A2p parameter in the initial call request/paging response message that the RTP bearer data is an IWF service, indicating that the BSC does not perform codec conversion of the IWF data Work. In this way, when the MSCe sends an Add command to the MGW, the parameter indicates that the MGW needs to perform IWF data conversion, and the MGW then performs IWF service data conversion according to the service type parameter SO.

In order to realize the present invention, firstly, the relevant signaling used in the present invention is extended.

1. In order to realize the present invention, it is necessary to expand the Bearer Format ID bit representing the IWF service type. In the present invention, the extended Bearer Format ID bit only indicates that the BSC has not converted IWF data to ISLP data, but in order to be compatible with another patent In the document "A Method and System for Switching Voice Services to Circuit-Type Data Services", the A2p parameter expansion in the Bearer Update Request (bearer update request) message is still used here. If the ID takes these 8 extended values, it means that the BSC has not converted IWF data to ISLP data. The service type of the IWF has been specified in the SO in the originating call request message CM Service Request/or paging response message Paging Rsp. The bearer update request message includes: A2p bearer special parameters and A2p session parameters. In the present invention, the A2p bearer special parameter is extended to indicate that the BSC does not convert IWF data to ISLP data, so that ISLP data conversion can be performed on IWF data in the MGW. The format of A2P bearer special parameters is as follows:

A2p Bearer Format-Specific Parameters

As can be seen from the above table, A2p Bearer Format-Specific Parameters include bearer format ID (Bearer Format ID) and RTP bearer type (RTP Paylod Type Value), bearer format ID is 4 bits, currently only defined The enumerated value of 0-7, according to the present invention, defines the enumerated value 8-F of the bearer format ID and the corresponding RTP bearer type to indicate that the BSC does not convert IWF data to ISLP data, and its definition is as follows, wherein, Table 1 It shows the service types corresponding to the currently defined 0-7 enumeration values, and Table 2 shows the 8-F enumeration values and corresponding RTP bearer types of the present invention.

Table 1

Bearer Format IDs & RTP Payload Types

Table 2

BearerFormat ID Encoding Name RTP PayloadType Value Meaning 8 ASYNDATA_SET1 11H Asynchronous Data rate set 1 9 GRPFAX_SET1 12H Group 3 Fax rateset 1 A ASYNDATA_SET2 13H AsynchronousDatarate set 2 B GRPFAX_SET1 14H Group 3 Fax rateset 2 C AFAX_SO_4100 15H Asynchronous Data Revision1, 9.6kbs or 14.4kbs D AFAX_SO_4101 16H Group 3 FaxRevision 1, 9.6kbs or 14.4kbs E AFAX_SO_20 17H Analog Fax rateset 1 F AFAX_SO_21 18H Analog Fax rateset2

The flow of the IWF service call from the MS to the facsimile machine in the present invention will be described below with reference to FIG. 2 .

Step 201, MS sends initial call request, after BSC receives initial call request, BSC distributes the UDP (User Datagram Protocol) port number and address that A interface uses, then sends initial call request (CM_SERV_Req) message to MSCe, and this message carries There are A2p bearer parameters, A2p bearer parameters include: A2p bearer session parameters (A2p Bearer Session-Level Parameters), A2p bearer special parameters (A2p Bearer Format-Specific Parameters), bearer format ID (Bearer Format ID ) indicates whether the IWF service needs to be converted from IWF data to ISLP data, wherein 8-F indicates that there is no conversion from IWF data to ISLP data; the service type of IWF is specified by another parameter SO in the origination request message.

Step 202, MSCe sends an add (Add) command message to the MGW, the command message contains BC and SO parameters to indicate that the call is an IWF service and its corresponding bearer capacity; the command message also has an ISLP flag, where If it is FALSE, it means that the BSC has not converted the IWF data to the ISLP data; the adding command also has a RmtSDP parameter, and the RmtSDP parameter is the BSC side SDP (Session Description Protocol) information.

Step 203: After receiving the add command, the MGW allocates the UDP port number and address for the A interface, and allocates C (context) for the call, and allocates the T endpoint corresponding to the call, and the MGW inserts the IWF resource at the T endpoint , and apply for a codec for converting IWF data to ISLP data, and return an Add Rep (Add Rep) message to MSCe, and the response message includes the local SDP information LocSDP.

Step 204, MSCe sends assignment request (Assignment Reqest) message to BSC, assigns the UPD port and address of this IWF service, air link, has A2p bearer parameter in the assignment request message, wherein A2p bears the weight in the special parameter Bearer Format ID (Bearer Format ID) indicates whether this IWF service has been converted to ISLP data.

Step 205, when the assignment of the UPD port, address, and air link is completed, the BSC returns an assignment completion message to the MSCe.

In step 206, the MSCe sends a modification (Mod) command message to the MGW, so as to activate the IWF service.

Step 207, the MGW executes the change command, thereby activating the IWF.

Step 208, at this time, the IWF can start the process of establishing a fax channel such as performing PPP negotiation with the MS.

Step 209, after the MSCe selects the outgoing circuit, it issues an Add command to the MGW, requesting the MGW to add the outgoing circuit to the corresponding C.

In step 210, the MGW allocates corresponding T(T2) to the outgoing circuit, and adds T2 to C.

In step 211, the MSCe sends an initial address message (IAM) to the PSTN, so as to establish a circuit to the PSTN.

Step 212, the PSTN switch finds the corresponding fax machine according to the called number in the IAM message and rings (RING).

In step 213, the PSTN exchange sends an Address Complete Message (ACM) to the MSC, indicating that the called party has ringing.

Step 214, FAX (facsimile machine) answers (ANSWER) the call to the PSTN switch.

Step 215: After receiving the answer signal from the fax machine, the PSTN switch sends an answer message (ANM) to the MSCe, indicating that the fax machine has answered, and the MSCe connects the IWF resource between the PSTN circuit and the A5 port circuit.

In step 216, the MSCe sends a modification (Mod) command message to the MGW, so as to activate the IWF service.

Step 217, the MGW executes the change command, thereby activating the IWF.

Step 218, the fax process starts between the calling MS and the called fax machine.

Step 219, disconnect the call.

The process of receiving IWF services by the MS is described below by taking the fax machine sending a fax to the MS as an example.

In step 301, the FAX initiates an IWF call by dialing to the PSTN.

Step 302, PSTN sends an initial address message (IAM) to MSCe, and establishes a circuit to MSCe.

Step 303, the MSCe sends an add (Add) command to the MGW.

Step 304, after receiving the add command, the MGW allocates the call context C (C1) and the calling side endpoint T (T1).

Step 305, after the MSC determines that the called user is in the local office, it initiates paging (Paging) to the BSC.

Step 306, BSC returns a paging response (Paging Res), with A2p bearer parameters in the paging response, wherein the bearer format ID (Bearer Format ID) in the A2p bearer special parameters is IWF, and the SO parameter indicates the service type of the IWF service.

Step 307, MSCe sends an add (Add) command to MGW, with BC and SO parameters in the command, used to indicate that the call is an IWF service call; at the same time, it also has an ISLP flag, here is FALSE, indicating that the BSC does not carry out IWF data Conversion to ISLP data; the RmtSDp parameter in the command is the SDP information on the BSC side.

Step 308: After receiving the add command, the MGW allocates the UDP port number and address for the A interface, and allocates the T endpoint T2 corresponding to the UDP port number and address, adds T2 to C1, and inserts the IWF resource at the T2 endpoint , apply for a codec that converts IWF data to ISLP data, and then return an Add Response (Add Rsp) message to MSCe, and the response message includes the local SDP information LocSDP.

Step 309, MSCe sends an assignment request (Assignment Request) message to BSC, so that BSC assigns the UPD port and address and air link of this IWF service, and the assignment request message has A2p bearer parameters, wherein A2p bears special parameters The bearer format ID (Bearer Format ID) in is IWF.

Step 310: After the .BSC assigns the UPD port, address and air link of this IWF service, it returns an Assignment Complete message to the MSCe.

In step 311, the MSCe sends a modification (Mod) command message to the MGW in order to activate the IWF service.

Step 312, the MGW executes the Mod command, thereby activating the IWF.

Step 313, at this time, the IWF can start the process of establishing a fax channel such as performing PPP negotiation with the MS.

In step 314, the MSCe sends an initial address message (IAM) to the PSTN, so as to establish a circuit to the PSTN.

Step 314a, the PSTN switch finds the corresponding fax machine according to the called number in the IAM message and rings (RING).

In step 315, the BSC sends a connect message to the MSCe to answer the call.

Step 316, MSCe sends a response message to PSTN.

Step 316a, PSTN sends a connection message to the fax machine.

In step 317, the MSCe sends a modification (Mod) command message to the MGW, so as to activate the IWF service.

Step 318, the MGW executes the change command, thereby activating the IWF.

Step 319, transfer the IWF data between the FAX and the MS.

Step 320, tear down after the call is completed.

The present invention also provides a system for implementing circuit-type data services, including: an originating terminal, configured to send a circuit-type data service request to the mobile switching center, and the circuit-type data service request includes The sign of ISLP data conversion; the mobile switching center is used to control the media gateway to insert and activate the interworking function resources according to the circuit type data service request, and control the base station controller to assign UDP port number and address, and air link; the base station controller , used to assign UDP port numbers and addresses, and air links under the control of the mobile switching center; media gateways, used to manage code converter resources and inter-networking function resources; receiving terminals, used to receive inter-network interworking function services data. The originating terminal and the receiving terminal include a mobile station and a fixed station, and the fixed station is a facsimile machine connected to the PSTN and other data service receiving terminals.

Therefore, according to the present invention, by extending the bearer update request message so that there is no TC in the BSC and it is not necessary to support the detection of circuit-type data services on all inter-office TDM time slots, the IWF service can be realized, thereby System resources are saved. Therefore, it is suitable for realizing transmission of circuit data services in IP-based core network and IP-based code division multiple access system.

Although the present invention has been described by the embodiments, those of ordinary skill in the art know that, without departing from the spirit and essence of the present invention, the present invention can have many modifications and variations, and the scope of the present invention is defined by the appended rights Requirements to limit.

Claims (9)

1. A method for realizing a circuit-type data service call, comprising: A. The mobile switching center receives the circuit data service call request sent by the originating terminal; B. The mobile switching center applies for a codec for converting the inter-network interworking function data to the inter-system link protocol data through the media gateway according to the call request of the circuit-type data service, and activates the inter-network interworking function resource; C. The mobile switching center establishes a connection with the receiving terminal so that the originating terminal and the receiving terminal can perform circuit-type data services. 2. The method for implementing a circuit-type data service call according to claim 1, wherein the originating terminal and the receiving terminal respectively include: a mobile station and a fixed station. 3. The method for realizing a circuit-type data service call according to claim 2, wherein when the originating terminal is a mobile station, said step A further comprises: A1. The originating terminal sends a circuit data service call request to the mobile switching center through the base station controller. 4. The method for realizing a circuit-type data service call according to claim 2, wherein, when the originating terminal is a fixed station, said step A further comprises: A2. The originating terminal sends the circuit type data service call request to the mobile switching center through the public switched telephone network. 5. The method for realizing a circuit-type data service call according to any one of claims 1 to 4, characterized in that, before performing the step B, the method further comprises the step: the mobile switching center obtains The sign of data conversion from inter-system interworking function business to inter-system link protocol can be obtained as follows: When the originating terminal is a mobile station, the mobile switching center obtains from the circuit type data service call request a sign that has not been converted from the inter-networking function service to the inter-system link protocol data; When the receiving terminal is a mobile station, the mobile switching center obtains from the paging response returned by the base station controller the sign that the Internet interworking function service has not been converted to the intersystem link protocol data. 6. The method for realizing a circuit-type data service call according to claim 2, wherein when the originating terminal is a mobile station, said step B further comprises: B1, the mobile switching center sends an add command to the media gateway, so that the media gateway allocates the user datagram protocol port number and address, and allocates an endpoint corresponding to the user datagram protocol port number and address; B2. The mobile switching center sends an assignment request to the base station controller, so that the base station controller assigns the user datagram protocol port, address and air link of the network interworking function service; B3. The mobile switching center sends a change command to the media gateway to activate the inter-network interworking function service. 7. The method for realizing a circuit-type data service call according to claim 1, wherein when the receiving terminal is a mobile station, said step B further comprises: B1. The mobile switching center initiates paging to the mobile station; B2. The mobile switching center sends an add command to the media gateway, so that the media gateway allocates the user datagram protocol port number and address, and allocates an endpoint corresponding to the user datagram protocol port number and address; B3. The mobile switching center sends an assignment request to the base station controller, so that the base station controller assigns the user datagram protocol port, address and air link of the network interworking function service; B4. The mobile switching center sends a change command to the media gateway to activate the service of the interworking function between networks. 8. The method for realizing a circuit-type data service call according to claim 7, wherein said step B1 further comprises: B11, the mobile switching center sends an add command to the media gateway, so that the media gateway distributes the calling side endpoint and the context of the call; B12. The mobile switching center initiates paging to the mobile station. 9. A system for implementing a circuit-type data service call, characterized in that it comprises: The originating terminal is used to send a circuit-type data service request to the mobile switching center; The mobile switching center is used to control the codec used by the media gateway to apply for the conversion of the inter-network function data to the inter-system link protocol data according to the circuit-type data service request, activate the inter-network function resource, and control the assignment of the base station controller UDP port number and address, air link; A base station controller for assigning user datagram protocol port numbers and addresses, air links under the control of the mobile switching center; The media gateway is used to apply for the codec for converting the inter-networking function data to the inter-system link protocol data, and manage the transcoder resources and the inter-networking function resources; The receiving terminal is used to receive service data of the inter-network interworking function.

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