CN101959320B - Method and device for realizing compatibility of codec types among calling stations - Google Patents

Abstract

The invention discloses a method for realizing codec type compatibility between calling offices, which includes: the originating office transmits the selected codec list SCL to the office backward; deletes the incompatible SCL from the forward office from the SCL The codec of the deleted SCL will be transmitted backward to the office; the incompatible codec in the SCL transmitted from the forward office will be deleted from the SCL of the landing office, and it will be used as the available codec list ACL of the landing office; The transmitted SCL deletes the incompatible codec in the ACL of the landing office, and uses it as the ACL of the forward office, and transmits it to the forward office; after the intermediate office receives the ACL of the intermediate office from the backward office, it transmits it from the forward office Delete the incompatible codec in the ACL of the intermediate office from the SCL, and transmit it to the forward office as the ACL of the forward office. The method of the invention provides guarantee for the smooth docking of network equipment of various manufacturers. The invention also correspondingly discloses a device for realizing codec type compatibility between calling offices.

Description

A method and device for implementing inter-office codec type compatibility

technical field

The invention relates to the technical field of mobile communication, in particular to a method and device for realizing codec type compatibility between calling offices.

Background technique

In GSM (Global System for Mobile CommuNicatioNs, Global System for Mobile Communications) network and WCDMA (WidebaNd Code DivisionN Multiple Access, Wideband Code Division Multiple Access) network, due to the coexistence of GSM network and WCDMA network, especially after the GSM network realizes IP, The establishment of a call requires the cooperation of multiple network elements, and the types of codecs supported by each network element are also different. Therefore, the cooperation of multiple codec types is required to establish a call. For narrowband multi-rate codecs, there is compatibility among various codec types UMTS_AMR_2, FR_AMR, UMTS_AMR, OHR_AMR, HR_AMR. For example, UMTS_AMR_2 has multi-rate compatibility with FR_AMR, OHR_AMR, and HR_AMR; UMTS_AMR_2 has single-rate compatibility with UMTS_AMR; and FR_AMR, OHR_AMR, and HR_AMR has multi-rate compatibility. The agreement does not clearly provide an algorithm that all manufacturers follow, which makes it impossible for the equipment of each manufacturer to connect smoothly. For example, as shown in Figure 1, because the protocol requirements are not clear, Vendor 2 considers codec compatibility when processing, and takes it for granted that the equipment of Vendor 1 in the forward office should be able to handle this compatibility, so the returned codec The decoding (ACL=FR_AMR, HR_AMR, SC=FR_AMR) is not in the codec list (SCL=UMTS_AMR_2, UMTS_AMR) supported by vendor 1, but in fact vendor 1 does not support this kind of compatibility. Vendor 1 thinks that this situation should be handled by vendor 1. 2 Handle it by yourself, so there is a situation where the equipment of the two manufacturers fails to connect due to unclear protocol requirements.

This article aims to provide a clear codec compatibility algorithm, so that the compatibility between codecs can be used to form TRFO (TraNscoder Free OperationN, codec-free operation), and the communication equipment of various manufacturers can be smoothly connected.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method and device for realizing codec type compatibility between calling offices, so as to effectively solve the problem of codec type compatibility between calling offices and ensure smooth connection of communication equipment of various manufacturers.

The method for implementing codec type compatibility between calling offices of the present invention is applied to a communication system including an originating office, an intermediate office, and a landing office, wherein the number of intermediate offices is N, and N is an integer greater than or equal to 0. The calling office of the present invention The implementation method of codec type compatibility includes the following steps:

The calling office transmits the selection codec list SCL of the calling office to the office backward;

After the intermediate office receives the SCL transmitted from the forward office, it deletes the incompatible codec in the SCL transmitted from the forward office from the SCL supported by the intermediate office, and transmits the deleted SCL backward to the office;

After the landing office receives the SCL transmitted from the forward office, it deletes the incompatible codec in the SCL transmitted from the forward office from the SCL supported by the landing office, and uses it as the available codec list ACL of the landing office;

The landing office deletes the incompatible codec in the ACL of the landing office from the SCL transmitted by the forward office, uses it as the ACL of the forward office, and transmits it to the forward office;

After the intermediate office receives the ACL of the intermediate office transmitted from the backward office of the intermediate office, it deletes the incompatible codec in the ACL of the intermediate office from the SCL transmitted by the forward office of the intermediate office , as the ACL of the forward office of the intermediate office, and transmit to the forward office of the intermediate office;

The backward office refers to the next office of the originating office or the intermediate office;

The forward game refers to the middle game or the previous game of the landing game.

Further, the implementation method of inter-office codec type compatibility of the present invention also includes:

The landing office determines the selected codec SC of the landing office from the ACL of the landing office;

After the landing office deletes the code incompatible with the SC of the landing office in the ACL of the forwarding office, determine the SC of the forwarding office and transmit it to the forwarding office;

After deleting the code incompatible with the SC of the intermediate office in the ACL of the forward office, the intermediate office determines the SC of the forward office and transmits it to the forward office.

Furthermore, the landing office determines the selected codec SC of the landing office from the ACL of the landing office, and the solution adopted includes: obtaining the SC of the landing office according to the characteristics of the base station system.

Further, the landing office determines the SC of the forwarding office, and the adopted scheme includes: after the landing office deletes the code incompatible with the SC of the landing office in the ACL of the forwarding office, take priority The codec with the highest level is used as the SC of its forward office;

The intermediate office determines the SC of the forward office, and the scheme adopted includes: after the intermediate office deletes the codes incompatible with the SC of the intermediate office in the ACL of the forward office, the code with the highest priority is selected. Decode the SC as its forward office.

Further, the intermediate office includes a tandem office or a gateway office.

Further, the intermediate office transmits the deleted SCL backward to the office through an initial address IAM message.

Further, the intermediate office or the landing office transmits the ACL or SC of the forward office to the forward office through an application transmission APM message.

The device for implementing codec type compatibility between calling offices of the present invention includes an originating office, an intermediate office, and a landing office, wherein the number of the intermediate offices is N, and N is an integer greater than or equal to 0;

The calling office is used to transmit the selection codec list SCL of the calling office to the office;

The intermediate office is used to, after receiving the SCL transmitted from the forward office, delete the incompatible codec in the SCL transmitted from the forward office from the SCL supported by the intermediate office, and send the deleted SCL backward transmission to the office;

The landing office is used to, after receiving the SCL transmitted by the forward office, delete the incompatible codec in the SCL transmitted by the forward office from the SCL supported by the landing office, and use it as the available codec of the landing office. codec list ACL;

The landing office is also used to delete the incompatible codec in the ACL of the landing office from the SCL transmitted by the forward office, as the ACL of the forward office, and transmit to the forward office;

The intermediate office is also used to delete the ACL of the intermediate office from the SCL transmitted by the forward office of the intermediate office after receiving the ACL of the intermediate office transmitted from the backward office of the intermediate office The incompatible codec is used as the ACL of the forward office of the intermediate office, and is transmitted to the forward office of the intermediate office;

The backward office refers to the next office of the originating office or the intermediate office;

The forward game refers to the middle game or the previous game of the landing game.

Further, the landing office is also used to determine the selected codec SC of the landing office from the ACL of the landing office;

The landing office is also used to determine the SC of the forward office after deleting the code incompatible with the SC of the landing office in the ACL of the forward office, and transmit it to the forward office;

The intermediate office is also used to determine the SC of the forward office after deleting the code incompatible with the SC of the intermediate office in the ACL of the forward office, and transmit it to the forward office.

Further, the intermediate office includes a tandem office or a gateway office.

The beneficial effects of the present invention are:

The present invention provides a codec compatibility algorithm commonly followed by all manufacturers, so that network elements using different codec types can form TRFO as much as possible when establishing a call, greatly improve voice quality, and save resource overhead for network element codec conversion , and at the same time provide a guarantee for the smooth docking of network equipment from various manufacturers.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used to explain the present invention together with the implementation of the present invention, and do not constitute a limitation to the present invention. In the attached picture:

Figure 1 shows a special case of failure during the interconnection process of the live network;

Fig. 2 is a schematic flow diagram of a method for implementing inter-office coding and decoding type compatibility according to the present invention;

Fig. 3 is the schematic diagram of the first embodiment of the method of the present invention;

Fig. 4 is the schematic diagram of the second embodiment of the method of the present invention;

FIG. 5 is a schematic structural diagram of a device for implementing inter-office codec type compatibility according to the present invention.

In the above figures, MSC-O represents the originating exchange, that is, the originating office; MSC-T represents the terminating exchange, that is, the landing office; T represents the tandem office; GMSC represents the gateway office.

Detailed ways

The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

The method for realizing codec type compatibility between calling offices of the present invention is applied to a communication system including an originating office, an intermediate office, and a landing office, wherein the number of intermediate offices is N, and N is an integer greater than or equal to 0.

Fig. 2 is a schematic flowchart of a method for implementing codec type compatibility between calling offices in the present invention. As shown in the figure, the method for implementing codec type compatibility between calling offices in the present invention specifically includes the following steps:

1. The originating office transmits the selected codec list SCL of the originating office to the office;

2. After the intermediate office receives the SCL transmitted by the forward office, it deletes the incompatible codec in the SCL transmitted by the forward office from the SCL supported by the intermediate office, and sends the deleted SCL backward through the initial address IAM message transmission to the office;

3. After receiving the SCL transmitted by the forward office, the landing office deletes the incompatible codecs in the SCL transmitted by the forward office from the SCL supported by the landing office, and uses them as the available codec list ACL of the landing office; and, According to the characteristics of the base station system, the landing station determines the selected codec SC of the landing station from the ACL of the landing station;

4. The landing office deletes the incompatible codec in the ACL of the landing office from the SCL transmitted by the forward office, and uses it as the ACL of the forward office, and transmits the APM message to the forward office through the application transmission; and, the landing office After the office deletes the codec incompatible with the SC of the landing office in the ACL of its forward office, it takes the codec with the highest priority as the SC of its forward office, and transmits the APM message to its forward office through the application transmission;

5. After the intermediate office receives the ACL of the intermediate office transmitted from the backward office of the intermediate office, it deletes the incompatible codec in the ACL of the intermediate office from the SCL transmitted by the forward office of the intermediate office, and uses it as the forward codec of the intermediate office. The ACL of the forward office, and transmits the APM message to the forward office of the intermediate office through the application transmission; and, after deleting the code incompatible with the SC of the intermediate office in the ACL of the forward office, the intermediate office takes the one with the highest priority The codec acts as the SC of its forward office, and transmits the APM message to its forward office through the application transmission.

The backward office refers to the next office of the calling office or the intermediate office;

The forward game refers to the previous game of the middle game or the landing game.

Intermediate offices include tandem offices or gateway offices.

Fig. 3 is a schematic diagram of the first embodiment of the method of the present invention, as shown in the figure, when the codec type of the originating office or the forwarding office received by the landing office is inconsistent with the codec type of the intermediate office, the compatibility algorithm of the present invention can be used to To implement TRFO, it specifically includes the following steps:

Step 101. The landing office receives the codec information SCL1 of the calling office or the forwarding office. SCL1 carries the codec information supported by the calling office or the forwarding office, and the landing office stores the codec information.

Step 102, the landing office uses SCL1 to negotiate with the codec SCL-local supported by the landing office, and the negotiation supports codec compatibility.

In this step, the codecs not supported in SCL1 need to be deleted in SCL-local, and the algorithm supports compatibility. As shown in the figure, SCL1=UMTS_AMR_2, UMTS_AMR, and SCL-local=FR_AMR, HR_AMR, because UMTS_AMR_2 is multi-rate compatible with FR_AMR, HR_AMR, but UMTS_AMR is incompatible with FR_AMR, HR_AMR, so in the case of the same rate , the codec obtained through this compatibility algorithm must be the codec supported in SCL-local, that is, the codec list ACL1 available in the final landing site is FR_AMR, HR_AMR, assuming that it is obtained according to the characteristics of the base station system BSS (Base Station System) Select codec SC1 (Selected Codec) as FR_AMR.

Step 103: Determine that the available codec for call establishment at the landing office is ACL1, and after the selected codec is SC1, it is necessary to obtain the codec information ACL2 and SC2 sent to the originating office or forwarding office through a compatibility algorithm.

In this step, it is necessary to delete the unsupported codecs in ACL1 in SCL1, and use the negotiated result as the available codec list ACL2 of the originating office or forwarding office, and delete the codecs unsupported in SC1 in ACL2, and Obtain the codec with the highest priority from the negotiation result as the selected codec SC2 of the calling office or the forwarding office. As shown in the figure, ACL1=FR_AMR, HR_AMR, SC1=FR_AMR, and SCL1=UMTS_AMR_2, UMTS_AMR, because UMTS_AMR_2 is multi-rate compatible with FR_AMR, HR_AMR, but UMTS_AMR is incompatible with FR_AMR, HR_AMR, so the same rate In this case, delete the codec not supported in ACL1 from SCL1 to obtain the codec used by the calling office or the forwarding office, and this algorithm makes the codec negotiated must be the codec supported by the calling office or the forwarding office. For decoding, because this process supports compatibility, ACL2=UMTS_AMR_2 is obtained; similarly, because SC1=FR_AMR, the process of deleting codecs not supported by SC1 from ACL2 is compatible, so it is obtained that SC2=UMTS_AMR_2.

It can be seen from the above process that the codec information used by the landing office is within the codec range supported by the landing office, and the codec information sent to the forward office is also within the codec range of the forward office. The compatibility algorithm of the office ensures the smooth connection of equipment from different manufacturers, and can ensure that the call is a TRFO call to the maximum extent, ensuring the voice quality and reducing the TC resource overhead.

Fig. 4 is a schematic diagram of the second embodiment of the method of the present invention, as shown in the figure, when the tandem office or the gateway office receives the codec type of the originating office or the forward office inconsistent with the codec type of the intermediate office, it can also use a compatible The algorithm implements TRFO, and the specific steps are as follows:

Step 201, the tandem office or the gateway office receives the codec information SCL1 of the originating office or the forwarding office, and SCL1 carries the codec information supported by the originating office or the forwarding office, and the tandem office or the gateway office saves the codec information information.

Step 202, the tandem office or the gateway office uses SCL1 to negotiate with the codec SCL-local supported by the intermediate office (that is, the tandem office or the gateway office). The negotiation supports codec compatibility, and the negotiation result is before (including the intermediate office) Office) the codec information supported by all nodes, the negotiation result is the SCL2 of the user's subsequent codec negotiation;

In this step, you need to delete codecs that are not supported in SCL1 in SCL-local, and of course the algorithm supports compatibility. As shown in the figure, SCL1=FR_AMR, HR_AMR, and SCL-local=UMTS_AMR_2, HR_AMR, because FR_AMR, HR_AMR and UMTS_AMR_2, HR_AMR are multi-rate compatible, so in the case of the same rate, the user's follow-up The codecs negotiated are UMTS_AMR_2 and HR_AMR.

Step 203, the negotiation result SCL2 of the tandem office or the gateway office is used for subsequent codec negotiation, and sent to the backward office through an IAM message.

Step 204, if the backward office is not a landing office, then the backward office adopts a method similar to step 202, using SCL2 to negotiate with the codec supported by the backward office, the negotiation supports codec compatibility, and the negotiation result is The user subsequently encodes and decodes the negotiated SCL3, and sends SCL3 to the backward office to continue processing;

If the backward office is a landing office, the landing office uses SCL1 to negotiate with the codec list supported by the landing office. The negotiation supports codec compatibility, that is, delete the codecs that are not supported by SCL1 in the codec list supported by the landing office , to obtain the codec list available for the landing station, and then obtain the selected codec of the landing station according to the characteristics of the base station system; then delete the codec incompatible with the available codec list of the landing station in SCL2, and obtain the forward direction The available codec list ACL1 of the office (that is, the tandem office or the gateway office), and then delete the codec incompatible with the selected codec of the landing office in ACL1 to obtain a new codec list, and then take the priority The codec with the highest level is the selected codec SC1 for the forward office of the landing office.

Step 205. The tandem office or gateway office receives the APM message from the backward office, which carries the negotiation results ACL1 and SC1. At this time, the tandem office or gateway office needs to determine the ACL2 and SC2 sent to the forward office through a compatibility algorithm information.

In this step, it is necessary to delete the codec not supported in ACL1 in SCL1 through the compatibility algorithm, and use the codec as ACL2 sent forward to the office; and delete the codec not supported in SC1 in ACL2 through the compatibility algorithm , and send the one with the highest priority as SC2 to the forward office. As shown in the figure, SCL1=FR_AMR, HR_AMR, and ACL1=UMTS_AMR_2, HR_AMR, because FR_AMR, HR_AMR and UMTS_AMR_2, HR_AMR are multi-rate compatible, so in the case of the same rate, ACL2=FR_AMR, ACL2=FR_AMR, HR_AMR. Because SC1=UMTS_AMR_2, and FR_AMR, HR_AMR and UMTS_AMR_2 are multi-rate compatible, in the case of the same rate, FR_AMR and HR_AMR are obtained through the compatibility algorithm, and because FR_AMR has a higher priority than HR_AMR, it is obtained that SC2=FR_AMR.

Fig. 5 is a schematic structural diagram of a device for implementing inter-office codec compatibility in the present invention as a specific embodiment. As shown in the figure, the device for implementing inter-office codec compatibility in the present invention includes an originating office, an intermediate office, and In the landing game, the number of intermediate games is N, and N is an integer greater than or equal to 0.

The calling office is used to transmit the selection codec list SCL of the calling office to the office.

The intermediate office is used to delete the incompatible codec in the SCL transmitted by the forward office from the SCL supported by the intermediate office after receiving the SCL transmitted by the forward office, and send the deleted SCL to the Backward transmission.

The landing office is used to delete the incompatible codecs in the SCL transmitted from the forward office from the SCL supported by the landing office after receiving the SCL transmitted by the forward office, and use it as the available codec list ACL of the landing office; and , according to the characteristics of the base station system, determine the selected codec SC of the landing office from the ACL of the landing office.

The landing office is also used to delete the incompatible codec in the ACL of the landing office from the SCL transmitted by the forward office, as the ACL of the forward office, and transmit the APM message to the forward office through the application transmission; and After deleting the codec incompatible with the SC of the landing office in the ACL of the forwarding office, take the codec with the highest priority as the SC of the forwarding office, and transmit the APM message to the forwarding office through the application transmission.

The intermediate office is also used to delete the incompatible codec in the ACL of the intermediate office from the SCL transmitted by the forward office of the intermediate office after receiving the ACL of the intermediate office transmitted from the backward office of the intermediate office , as the ACL of the forward office of the intermediate office, and transmit to the forward office of the intermediate office through the application transmission APM message; and after deleting the code incompatible with the SC of the intermediate office in the ACL of the forward office , take the codec with the highest priority as the SC of its forward office, and transmit it to its forward office through the application transmission APM message.

The backward game refers to the next game of the calling game or the middle game, and the forward game refers to the middle game or the previous game of the landing game. Intermediate offices include tandem offices or gateway offices.

The above descriptions are only preferred examples of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. A method for implementing codec type compatibility between calling offices, which is applied to a communication system including an originating office, an intermediate office, and a landing office, wherein the number of intermediate offices is N, and N is an integer greater than or equal to 0, and its characteristics Including the following steps: The calling office transmits the selection codec list SCL of the calling office to the office backward; After the intermediate office receives the SCL transmitted from the forward office, it deletes the incompatible codec in the SCL transmitted from the forward office from the SCL supported by the intermediate office, and transmits the deleted SCL backward to the office; After the landing office receives the SCL transmitted from the forward office, it deletes the incompatible codec in the SCL transmitted from the forward office from the SCL supported by the landing office, and uses it as the available codec list ACL of the landing office; The landing office deletes the incompatible codec in the ACL of the landing office from the SCL transmitted by the forward office, uses it as the ACL of the forward office, and transmits it to the forward office; After the intermediate office receives the ACL of the intermediate office transmitted from the backward office of the intermediate office, it deletes the incompatible codec in the ACL of the intermediate office from the SCL transmitted by the forward office of the intermediate office , as the ACL of the forward office of the intermediate office, and transmit to the forward office of the intermediate office; The backward office refers to the next office of the originating office or the intermediate office; The forward game refers to the previous game of the middle game or the landing game; The landing office determines the selected codec SC of the landing office from the ACL of the landing office; After the landing office deletes the code incompatible with the SC of the landing office in the ACL of the forwarding office, determine the SC of the forwarding office and transmit it to the forwarding office; After deleting the code incompatible with the SC of the intermediate office in the ACL of the forward office, the intermediate office determines the SC of the forward office and transmits it to the forward office. 2. The method according to claim 1, wherein the determining the selected codec SC of the landing office from the ACL of the landing office comprises: obtaining the SC of the landing office according to the characteristics of the base station system. 3. The method according to claim 1, wherein the determination of the SC of the forwarding office by the landing office comprises: deleting the SC in the forwarding office by the landing office that is different from the SC of the landing office. After compatible codecs, take the codec with the highest priority as the SC of the forward office; The intermediate office determines the SC of its forward office, including: after the intermediate office deletes the codec incompatible with the SC of the intermediate office in the ACL of its forward office, and takes the codec with the highest priority as its SC of the forward bureau. 4. The method according to claim 1, wherein the intermediate office comprises a tandem office or a gateway office. 5. The method according to claim 1 or 4, wherein the intermediate office transmits the deleted SCL backward to the office through an initial address IAM message. 6. The method according to claim 1 or 4, wherein the intermediate office or the landing office transmits the ACL or SC of the forwarding office to the forwarding office through an application transmission APM message. 7. A device for implementing codec type compatibility between calling offices, characterized in that it includes an originating office, an intermediate office, and a landing office, wherein the number of the intermediate offices is N, and N is an integer greater than or equal to 0; The calling office is used to transmit the selection codec list SCL of the calling office to the office; The intermediate office is used to, after receiving the SCL transmitted by the forward office, delete the incompatible codec in the SCL transmitted by the forward office from the SCL supported by the intermediate office, and send the deleted SCL backward transmission to the office; The landing office is used to, after receiving the SCL transmitted by the forward office, delete the incompatible codec in the SCL transmitted by the forward office from the SCL supported by the landing office, and use it as the available codec of the landing office. codec list ACL; The landing office is also used to delete the incompatible codec in the ACL of the landing office from the SCL transmitted by the forward office, as the ACL of the forward office, and transmit to the forward office; The intermediate office is also used to delete the ACL of the intermediate office from the SCL transmitted by the forward office of the intermediate office after receiving the ACL of the intermediate office transmitted from the backward office of the intermediate office The incompatible codec is used as the ACL of the forward office of the intermediate office, and is transmitted to the forward office of the intermediate office; The backward office refers to the next office of the originating office or the intermediate office; The forward game refers to the previous game of the middle game or the landing game; The landing office is also used to determine the selected codec SC of the landing office from the ACL of the landing office; The landing office is also used to determine the SC of the forward office after deleting the code incompatible with the SC of the landing office in the ACL of the forward office, and transmit it to the forward office; The intermediate office is also used to determine the SC of the forward office after deleting the code incompatible with the SC of the intermediate office in the ACL of the forward office, and transmit it to the forward office. 8. The device for implementing codec type compatibility between calling offices according to claim 7, characterized in that: The intermediate office includes a tandem office or a gateway office.