WO2010083773A1

WO2010083773A1 - Coding-decoding negotiation method, communication system, and device for encrypted voice call

Info

Publication number: WO2010083773A1
Application number: PCT/CN2010/070328
Authority: WO
Inventors: 朱浩鹏; 李毅; 李�杰; 罗少华; 谢宁
Original assignee: 华为技术有限公司
Priority date: 2009-01-24
Filing date: 2010-01-22
Publication date: 2010-07-29
Also published as: CN101478621A; CN101478621B

Abstract

The present invention discloses a coding-decoding negotiation method, communication system, and device for encrypted voice call, which are used in the field of communication. In the method of the present invention, after the mobile switch server (MSC SERVER) receives a signaling message related to the voice call, it sends encrypted voice call detection event to the media gateway (MGW) when establishing a time division multiplexing (TDM) endpoint. After the MSC SERVER receives a notification message reported by the MGW, it modifies the coding-decoding type of the IP endpoint, which is at the MGW, to G.711 format, and sends a message to the MSC SERVER on the opposite office side to notify the MSC SERVER to modify the coding-decoding type of the IP endpoint, which is at the opposite MGW, to G.711 format. The method of the present invention enables reliable transmission for the encrypted voice call, without the necessity of inserting any interworking function (IWF) resource.

Description

Method, communication system and device for encoding and decoding of encrypted voice call The present application claims to be submitted to the Chinese Patent Office on January 24, 2009, the application number is 200910105294.3, and the invention name is "codec negotiation method for encrypted voice call, communication system" The priority of the Chinese Patent Application, the entire disclosure of which is incorporated herein by reference.

Technical field

The present invention relates to the field of communications technologies, and in particular, to a method, a communication system, and a device for encoding and decoding an encrypted voice call.

Background technique

In 2G mobile communication, the mobile terminal uses RPE-LTP (Regular Pulse Excitation-Long Term Prediction) to transmit the voice signal at 13 kbps. After receiving the voice signal of the mobile terminal, the BSC converts the voice content into G. The .711 format code is transmitted over E1 in a time division multiplexed TDM mode with a fixed rate of 64 kbps. In this way, the voice content of the sender and receiver of the voice are consistent and will not be changed.

However, the transmission in the above manner has a problem of high occupied bandwidth, low transmission efficiency, and high communication cost. With the development of communication technology, the communication network introduces IP technology. When voice is transmitted in the IP bearer network, it is generally encoded and decoded in AMR format, which can effectively improve the bandwidth utilization. However, AMR is a lossy compression codec algorithm. Some information in speech is lost after AMR encoding, which causes damage to the speech quality. When the speech passes through multiple AMR encoding and decoding, it will be seriously distorted.

Currently, an implementation manner of an existing encrypted telephone is to implement interworking through a data service manner. The technology is that the terminal initiates an encrypted call in a data service manner, and the MSC SERVER instructs to insert a network interworking function unit IWF resource on the media gateway MGW, and implements in-band protocol conversion by the IWF, and finally realizes that the encrypted phone transmits by using the G.711 encoding format. . Since this method requires the insertion of IWF resources on the MGW, the communication cost is high. Summary of the invention

The embodiment of the present invention provides a method, a communication system, and a device for encoding and decoding an encrypted voice call. The encrypted voice call can be implemented in the IP bearer network by using the G.711 format without inserting the IWF resource on the MGW. transmission.

An embodiment of the present invention provides a method for encoding and decoding an encrypted voice call, where the method includes:

After receiving the signaling message related to the voice call, the mobile switching server MSC SERVER determines that the bearer types of the voice call on both sides of the local office media gateway MGW are IP bearer and TDM bearer respectively, and the codec types selected on both sides are inconsistent. When the TDM endpoint is established, the encrypted voice call detection event is sent to the media gateway MGW;

The MSC SERVER receives the notification message reported by the local office MGW, and the notification message is that the local office MGW detects the inband signal sent by the encrypted terminal, and recognizes that the current voice call is an encrypted voice call, and then sends the local voice call to the local end office. Point MSC SERVER sent;

The MSC SERVER modifies the codec type of the IP endpoint on the local office MGW to the G.711 format, and sends a message to the peer office MSC SERVER to notify the peer office MSC SERVER of the IP endpoint on the opposite MGW. The codec type is modified to the G.711 format, and the local office MGW and the opposite office MGW transmit the voice call through the IP bearer.

The encrypted voice call codec negotiation method provided by the embodiment of the present invention sends an encrypted voice call detection event to the MGW through the MSC SERVER, so that during the voice call, the MGW can detect the encrypted voice and report it to the MSC SERVER, and the MSC SERVER completes. Modification of the codec type of the IP endpoint on the MGW and notifying the peer MSC SERVER to complete the modification of the codec type of the IP endpoint on the MGW, realizing the reliable transmission of the encrypted voice call, and by this method, the IWF resource does not need to be inserted on the MGW. P is competing for lower communication costs.

The embodiment of the invention further provides a method for encoding and decoding a voice call, the method comprising:

The mobile switching server MSC SERVER in the voice call communication path receives the voice call related After the signaling message is determined, the bearer types of the voice call on the two sides of the media gateway MGW are respectively the IP bearer and the TDM bearer, and the codec types selected on the two sides are inconsistent, and the TDM endpoint is automatically sent to the media gateway MGW when the TDM endpoint is established. Switching an indication event or an encrypted voice call detection event;

The MGW detects the in-band tone reported by the encrypted terminal, and recognizes that the current call is an encrypted voice call;

If the MGW receives an automatic handover indication event, the codec type of the IP endpoint on the MGW is automatically changed to the G.711 format.

If the MGW receives the encrypted voice call detection event, the MGW sends a notification message to the MGW. After receiving the notification message, the MSC SERVER changes the codec type of the IP endpoint on the MGW to the G.711 format.

The encrypted voice call codec negotiation method provided by the embodiment of the present invention sends an encrypted voice call detection event or an automatic handover indication event to the MGW through the MSC SERVER in the voice call communication path, so that the MGW detects the encrypted voice and completes the local office. The modification of the IP endpoint codec type on the MGW realizes reliable transmission of the encrypted voice call, and in this way, the IWF resource does not need to be inserted on the MGW, and the communication cost is low.

The embodiment of the present invention further provides a communication system for implementing an encrypted voice call, including a local office mobile switching server MSC SERVER, a local office media gateway MGW, a peer office mobile switching server MSC SERVER, and a peer office. The media gateway MGW, the local office MGW and the peer office MGW transmit voice calls through the IP bearer, where

The local office mobile switching server MSC SERVER is configured to receive the signaling message related to the voice call, and determine that the bearer types of the voice call on both sides of the local office media gateway MGW are respectively IP bearer and TDM bearer, and are selected on both sides. The codec type is inconsistent, and when the TDM endpoint is established, the encrypted voice call detection event is sent to the media gateway MGW;

The local office MGW is configured to receive an encrypted voice call detection event sent by the local office mobile switching server MSC SERVER, detect an inband signal sent by the encrypted terminal, and identify the current language. After the voice-to-call is an encrypted voice call, a notification message is sent to the local office MSC SERVER, and the local office MSC SERVER is also used to receive the notification message reported by the MSC SERVER, and the IP endpoint on the local office MGW. The codec type is modified to the G.711 format, and a message is sent to the peer office MSC SERVER to notify the opposite office MSC SERVER to modify the codec type of the IP endpoint on the opposite MGW to the G.711 format;

The peer MSC SERVER is configured to receive the message sent by the local office MSC SERVER, and modify the codec type of the IP endpoint on the peer MGW to the G.711 format.

The embodiment of the present invention further provides a mobile switching server MSC SERVER, comprising: a determining unit, configured to determine, after receiving a signaling message related to a voice call, whether the type of the codec in the selected voice call is consistent;

And the sending unit is configured to: when the determining unit determines that the bearer type of the voice call on both sides of the local office media gateway MGW is an IP bearer and a TDM bearer, and the codec types selected on the two sides are inconsistent, when the TDM endpoint is established And sending an encrypted voice call detection event to the media gateway MGW; the modifying unit is configured to receive the notification message reported by the MGW, and modify the codec type of the IP endpoint on the local office MGW to the G.711 format, where the notification message is The local station MGW detects the in-band tone transmitted by the encrypted terminal, and recognizes that the current voice call is an encrypted voice call, and then sends the voice call to the MSC SERVER.

The embodiment of the invention further provides a media gateway MGW, including:

The receiving unit is configured to receive an encrypted voice call detection event sent by the local office mobile switching server MSC SERVER, where the encrypted voice call detection event is that the MSC SERVER determines that the voice call is after receiving the signaling message related to the voice call. The bearer types of the two ends of the local media gateway MGW are respectively the IP bearer and the TDM bearer, and the codec types selected by the two sides are inconsistent. When the TDM endpoint is established, the bearer is sent to the media gateway MGW.

a detection and identification unit, configured to detect, after the receiving unit receives the encrypted voice call detection event The inband signal sent by the secret terminal, after identifying that the current voice call is an encrypted voice call, sending a notification message to the MSC SERVER;

The codec type modification unit is configured to modify the codec type of the local IP end of the voice call to the G.711 format under the control of the MSC SERVER.

The communication system, the mobile switching server MSC SERVER and the media gateway MGW provided by the embodiment of the present invention deliver an encrypted voice call detection event to the MGW through the MSC SERVER, so that the MGW can detect the encrypted voice during the voice call, and艮 MSC SERVER, MSC SERVER completes the modification of the codec type of the IP endpoint on the MGW, realizing the reliable transmission of the encrypted voice call, and by this way, it is not necessary to insert the IWF resource on the MGW, and P strives to reduce the communication cost.

DRAWINGS

FIG. 1 is a flowchart of a method for negotiating an encrypted voice call codec according to an embodiment of the present invention. FIG. 2A is a network architecture diagram of an application of an encrypted voice call codec negotiation method according to an embodiment of the present invention.

FIG. 2B is a flowchart of a method for negotiating an encrypted voice call codec in the networking architecture of FIG. 2A. FIG. 3 is a flow chart of a method for encoding and decoding a coded voice call in the system architecture of FIG. 2A. FIG. 4 is a networking architecture of a cross-T office interconnection according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of a networking architecture in the case of starting a CMN according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of a communication system for implementing an encrypted voice call according to an embodiment of the present invention. FIG. 7 is a structural diagram of a mobile switching server according to an embodiment of the present invention.

FIG. 8 is a structural diagram of another mobile switching server according to an embodiment of the present invention.

FIG. 9 is a structural diagram of a media gateway according to an embodiment of the present invention.

detailed description FIG. 1 is a flowchart of a method for negotiating an encrypted voice call codec according to an embodiment of the present invention.

After receiving the signaling message related to the voice call, the mobile switching server MSC SERVER determines that the bearer type of the voice call on both sides of the local office media gateway MGW is IP bearer and TDM bearer, and the codec types selected on both sides are inconsistent. And sending an encrypted voice call detection event to the media gateway MGW when establishing the TDM endpoint;

The TDM bearer is encoded in the G.711 format. When determining whether the codec types selected on both sides are consistent, the MSC SERVER determines whether the codec type selected in the IP bearer is in the G.711 format. If yes, the MGW is determined. The codec types selected on both sides are the same. If not, it is determined that the codec types selected on both sides of the MGW are inconsistent.

The encrypted voice call detection event sent by the MSC SERVER to the MGW is a new H.248 event, which is used to instruct the MGW to report the notification message to the MSC SERVER after detecting the encrypted voice call.

12. The local office MGW detects the inband signal sent by the encrypted terminal, and recognizes that the current voice call is an encrypted voice call, and sends a notification message to the MSC SERVER;

The in-band signal tone is sent by the encrypted terminal through the in-band signal. For example, the calling encrypted terminal can transmit a special in-band signal tone through the in-band signal CNG, and the called encrypted terminal can transmit the special signal through the in-band signal ANS/ANSAM. In-band tones, the in-band tones can be in-band tones similar to Modem/Fax.

After receiving the notification message sent by the MGW, the MSC SERVER changes the codec type of the IP endpoint on the local office MGW to the G.711 format, and sends a message to the opposite office MSC SERVER to notify the opposite end office. The point MSC SERVER modifies the codec type of the IP endpoint on the peer MGW to the G.711 format.

The voice call is transmitted between the local office MGW and the peer office MGW through an IP bearer.

The local office can be the calling side office, the tandem office, or the called side office. The encrypted voice call codec negotiation method provided by the embodiment of the present invention sends an encrypted voice call detection event to the MGW through the MSC SERVER, so that during the voice call, the MGW can detect the encrypted voice and report it to the MSC SERVER, and the MSC SERVER completes. Modification of the codec type of the IP endpoint on the MGW and notifying the peer office to modify the codec type of the IP endpoint, so that the encrypted voice call can be encoded and transmitted in the IP network through the G.711 format, thereby ensuring the implementation of the encrypted voice service. In this way, there is no need to insert IWF resources on the MGW, and P strives to reduce communication costs. The embodiment of the present invention further provides an encryption voice call codec negotiation method, the method includes: after the mobile switching server MSC SERVER in the voice call communication path receives the voice call related signaling message, determining that the voice call is at the media gateway MGW The bearer types of the two sides are the IP bearer and the TDM bearer, and the codec types selected on the two sides are inconsistent. When the TDM endpoint is established, the automatic switching indication event or the encrypted voice call detection event is sent to the media gateway MGW.

The encrypted voice detection event or the automatic handover indication event is a new H.248 event.

Different from the encrypted voice call codec negotiation method provided by the previous embodiment, in this embodiment, the MSC SERVER in the voice call communication path sends an encrypted voice call detection event or an automatic handover indication event to the MGW, thereby implementing the MGW. The encrypted voice is detected, and the modification of the IP endpoint codec type on the MGW of the local office is completed, thereby realizing the reliable transmission of the encrypted voice call. In this way, the IWF resource does not need to be inserted on the MGW, and the communication cost is low. 2A is a networking diagram of an application of an encrypted voice call codec negotiation method according to an embodiment of the present invention. As shown in the figure, BSC-0 is an access device on the calling side, and MSC SERVER-S1 is a calling side mobile. The switching server, the MGW1 is the calling side media gateway, the MSC SERVER-S2 is the called side mobile switching server, the MGW2 is the calling side media gateway, and the BSC-T is the accessing device on the called side, where between the MGW1 and the MGW2 For the IP bearer, there is a TDM bearer between the MGW and the BSC, and T1, T2, Τ3, and Τ4 are respectively endpoint resources established by the MGW for the voice bearer.

As shown in FIG. 2B, FIG. 2 is a flowchart of a method for negotiating a ciphering voice call codec in the network architecture of FIG. 2A. In this embodiment, an encrypted voice is sent to the called side MGW through the MSC SERVER of the called end office. The call detection event implements the detection of the encrypted voice call and the modification of the codec type, and the method includes:

21. In the process of establishing a voice call, when the called end office MSC SERVER-S2 determines that the incoming call bearer type is IP, the outgoing call bearer is TDM, and the codec type selected by the IP bearer is not in the G.711 format, then the request is made. When the MGW2 creates the TDM endpoint T4, the encrypted call detection event is carried in the PREPARE_BEARER_REQ message sent to the MGW2. The encrypted telephone detection event is a new H.248 event, which is used to indicate that the MGW is detecting the call. After encrypting the voice call, send a notification message to the MSC SERVER;

22. After completing the resource allocation, the MGW2 reports the PREPARE-BEARER-RSP message to the MSC SERVER-S2;

After allocating the resources, the MSC SERVER-S2 calls the called terminal, performs the authentication and the like, and connects the call to the called terminal. The intermediate process between the two steps is the prior art, and is not described here.

23. The called encrypted terminal receives the DTAP_CONNECT message after the response of the MSb, and enters the call state;

24. The called encrypted terminal sends a special in-band signal tone through the in-band signal ANS/ANSAM, such as an in-band tone similar to Modem/Fax; 25, MGW2 detects the in-band signal tone, recognizes that this is an encrypted voice call, and reports a NOTIFY message to the MSC SERVER-S2;

26, MSC SERVER-S2 sends a MODIFY-CHAR-REQ message to the media gateway MGW2, and changes the codec type Codec of the IP endpoint T3 to the G.711 format;

27. After the modification of the MGW2 is completed, the MODIFY_CHAR_RSP message is reported to the MSC SERVER-S2;

28. The MSC SERVER-S2 sends an APM message to the MSC SERVER-S1, requesting the peer office to modify the Codec of the IP endpoint to G.711;

After receiving the APM message sent by the MSC SERVER-S2, the MSC SERVER-SI sends a MODIFY-CHAR-REQ message to the MGW1, and changes the Codec of the IP endpoint T2 to the G.711 format.

210. After the modification of the MGW1 is completed, the MODIFY_CHAR_RSP message is reported to the MSC SERVER-S1;

211. The MSC SERVER-SI sends an APM message to the MSC SERVER-S2, indicating that the Codec modification is successful.

The foregoing embodiment provides a specific method for cryptographic voice call codec negotiation, which implements the detection and notification of the encrypted voice call by the called side end office, and the embodiment of the present invention further provides the encrypted voice through the calling side end office. The method of detecting and notifying the call.

FIG. 3 is a flowchart of a method for negotiating a ciphering voice call codec in the system architecture of FIG. 2A. In this embodiment, an encrypted voice call detection event is sent to the calling side MGW through the MSC SERVER of the calling side end office. Implementing detection of encrypted voice calls and modification of codec type, the method includes:

31. In the process of establishing a voice call, when the calling end office MSC SERVER-S1 determines that the incoming call bearer type is TDM, the outgoing call bearer type is IP, and the codec type selected by the IP bearer is not G.711, then the MGW1 is requested. When the TDM endpoint T1 is created, the encrypted call detection event is carried in the PREPARE_BEARER_REQ message sent to the MGW1. The encrypted telephone detection event is a new H.248 event, which is used to indicate that the MGW is detecting the call. Encrypted voice call Afterwards, the notification message is sent to the MSC SERVER;

32. After completing the resource allocation, the MGW1 reports the PREPARE-BEARER-RSP message to the MSC SERVER-S1;

Subsequent steps are continued, and the intermediate process between 32 and 33 is a prior art and will not be described here.

33. The calling and encrypting terminal MSa receives the call response message DTAP_CONNECT sent by the MSC SERVER-S1, and reports the DTAP_CONNECT_ACK message to enter the call state;

34. The calling encrypted terminal sends a special in-band signal tone through the in-band signal CNG, such as a band tone similar to Modem/Fax;

35, MGW1 detects the in-band signal tone, recognizes that this is an encrypted voice call, and reports a NOTIFY message to the MSC SERVER-S 1;

36. The MSC SERVER-S1 sends a MODIFY_CHAR_REQ message to the media gateway MGW1, and changes the codec type Codec of the IP endpoint T2 to the G.711 format.

37. After the modification of the MGW1 is completed, the MODIFY_CHAR_RSP message is reported to the MSC SERVER-S1;

38. The MSC SERVER-SI sends an APM message to the MSC SERVER-S2, requesting the peer office to modify the codec of the IP endpoint to G.711;

After receiving the APM message sent by the MSC SERVER-S1, the MSC SERVER-S2 sends a MODIFY-CHAR-REQ message to the MGW2, and changes the Codec of the IP endpoint T3 to the G.711 format.

310. After the modification of the MGW2 is completed, the MODIFY_CHAR_RSP message is reported to the MSC SERVER-S2;

311. The MSC SERVER-S2 sends an APM message to the MSC SERVER-S 1, indicating that the Codec modification is successful.

The encrypted voice call codec negotiation method provided by the above two embodiments respectively implements detection and notification of an encrypted voice call at the calling side office and the called side office point, and is notified by the MSC SERVER. The MGW sends an encrypted voice call detection event, so that the MGW can detect the encrypted voice and report it to the MSC SERVER during the voice call. The MSC SERVER completes the modification of the codec type of the IP endpoint on the MGW and notifies the peer office to complete the MGW. Modification of the codec type of the IP endpoint, so that the voice call call can be encoded in the G.711 format on the IP bearer, and the reliable transmission of the encrypted voice call is realized, and the IWF resource does not need to be inserted in the MGW. P is competing for lower communication costs.

Figure 4 provides another networking architecture when interconnecting across T-offices, where TMSC SERVER acts as the mobile switching server of the tandem office, and MGW2 acts as the media gateway of the tandem office, with the calling side device and the called side on both sides. The device, wherein the MGW2 and the calling media gateway MGW1 are IP bearers, and the MGW2 and the called media gateway MGW3 are TDM bearers. In the network architecture, referring to the foregoing embodiment, the voice call can be established. When establishing the TDM endpoint T4, the TMSC SERVER sends an encrypted telephone detection event to the MGW2, so that when the called encrypted terminal transmits the inband signal through the inband signal, the MGW2 receives the inband signal transmitted from the MGW3. Therefore, the current call is identified as an encrypted voice call, and reported to the TMSC SERVER. The TMSC SERVER completes the modification of the Codec type of the IP endpoint T3 on the MGW2, and the T3 codec type is modified to the G.711 format, and the calling side MSC SERVER- S1 sends an APM message, and requests the peer office to modify the Codec of the IP endpoint. The MSC SERVER-SI modifies the codec type in the IP endpoint T2 on the MGW1 to the G.711 format. The specific implementation in this case is similar to the embodiment corresponding to FIG. 2A and will not be described in detail.

Under the network structure corresponding to FIG. 4, the detection and notification of the encrypted voice can also be completed through the calling side. Similar to the embodiment corresponding to FIG. 3, the MSC SERVER-S1 can issue an encrypted telephone detection event to the MGW1 when the TDM endpoint T1 is established, so that when the calling encrypted terminal transmits the inband signal through the in-band signal, the MGW1 Receiving the in-band signal tone sent by the calling side encryption terminal, thereby identifying that the current call is an encrypted voice call, and reporting it to the MSC SERVER-SI, and the MSC SERVER-SI completes the modification of the Codec type of the IP endpoint T2 on the MGW1, and the T2 is edited. The decoding type is modified to G.711 format, and an APM message is sent to the sinking and ending TMSC SERVER, requesting the peer office to modify the IP endpoint. Codec, TMSC SERVER changes the codec type in IP endpoint T3 on MGW2 to G.711 format. Since the specific implementation in this case is similar to the embodiment corresponding to FIG. 3, it will not be described in detail.

FIG. 5 is a schematic diagram of a network architecture in the case of initiating a CMN (Call Coordination Node). In this case, the signaling plane of the calling and called parties interacts through the tandem office mobile switching server. The TMSC SERVER, and the bearer plane implements the point-to-point interworking between the MGW on the calling and the calling side, wherein the MGW is used between the MGW on the calling and the calling side, and the TDM bearer is used between the MGW and the access side device BSC. The codec negotiation method for implementing the encrypted voice call in the embodiment of the present invention is consistent with the networking architecture of FIG. 2A, and the method for detecting and notifying the encrypted voice call can be implemented on the called side in the manner corresponding to the embodiment of FIG. 2B. The detection and notification of the encrypted voice call can also be implemented on the calling side in the manner corresponding to the embodiment of FIG. 3, which is different from the network processing of FIG. 2A, the APM sent between the MSC SERVER-S1 and the MSC SERVER-S2. Messages need to be forwarded through the TMSC SERVER. Other processing is the same as the foregoing embodiment, and the description thereof will not be repeated here.

As can be seen from the above embodiments, in the foregoing embodiment, the MSC SERVER sends a voice encryption detection indication to the MGW under the following conditions:

1. The MSC SERVER sends a voice encryption detection indication to the voice call service;

2. When the MSC SERVER is in the IP bearer and the TDM bearer on both sides of the MGW, and the Codec selected on both sides is inconsistent, the voice encryption detection indication is sent to the endpoint on the TDM side.

Since the TDM bearer is encoded in the G.711 format, it is determined whether the codec selected on both sides is consistent or not. The main judgment is whether the codec type selected by the IP bearer is G.711. If not, it is determined that the codecs on both sides are inconsistent.

Therefore, in other networking modes, as long as the MSC SERVER determines that the above two conditions are met, the voice encryption detection indication can be sent to the MGW when the TDM bearer is established, so that the G.711 format transmission is performed on the IP bearer. Need to insert IWF resources.

In the embodiment of the present invention, the voice encryption detection indication is sent by each MSC SERVER in the voice call communication path, and the voice encryption detection indication is sent, the encrypted voice is detected, and the IP is detected. The modification of the endpoint codec type, wherein the conditions for the voice cipher detection indication issued by each MSC SERVER are the same as those of the foregoing embodiment. Taking the networking mode of FIG. 2A as an example, and in combination with the description of the embodiment of FIG. 2B and FIG. 3, since both MSC SERVER-S1 and MSC SERVER-S2 satisfy the condition for issuing a voice encryption detection indication, the MSC in the voice call communication path When establishing the TDM endpoint T1, the SERVER-S1 sends a voice encryption detection indication to the MGW1, and the MSC SERVER-S2 sends a voice encryption detection indication to the MGW2 when the TDM endpoint T4 is established, and the MGW1 and the MGW2 respectively perform the detection of the encrypted voice call, and After identifying that the current call is an encrypted voice call, sending a notification message to the corresponding MSC SERVER, and the MSC SERVER-S1 and the MSC SERVER-S2 respectively modify the codec type of the IP endpoint on the MGW1 and the MGW2. In fact, this implementation is to combine the implementations corresponding to FIG. 2B and FIG. 3, and delete the related message between the MSC SERVER-S1 and the MSC SERVER-S2 to notify the other party to modify the IP endpoint codec type. The conditions for the MSC SERVER to send the voice encryption detection indication are the same as those of the foregoing embodiment, and are described in detail in the foregoing embodiments, and are not repeatedly described herein.

The voice transmission detection indication, the detection of the encrypted voice, and the modification of the IP endpoint codec type in the voice call communication path are also applicable to the manners in the network architecture of FIG. 4 and FIG. 5, and the specific implementation thereof Figure 2A is similar to the networking mode. In the network architecture corresponding to Figure 4, the MSC SERVER-S1 sends a voice encryption detection indication to the MGW1, and the MSC SERVER-S2 sends a voice encryption detection indication to the MGW2. The detection of the encrypted voice call and the modification of the IP endpoint codec type are completed.

The embodiment of the present invention provides another solution in the manner of performing the detection of the encrypted voice and the modification of the IP endpoint codec type in the voice call communication path. The difference from the above embodiment is that the communication path is different. After the MSC SERVER meets the conditions of the foregoing delivery indication, the automatic handover indication event may be sent to the MGW when the TDM endpoint is established, and the automatic handover indication event is also a new H.248 event, which is used to indicate that the MGW is detecting After the current call is a voice encrypted call, the codec type of the IP endpoint corresponding to the call is automatically modified to the G.711 format. among them, The manner in which the MGW detects and recognizes a call as an encrypted voice call is the same as that of the foregoing embodiment, and will not be described here.

The encrypted voice call codec negotiation method provided by the foregoing embodiment sends an encrypted voice call detection event or an automatic handover indication event to the MGW through each MSC SERVER in the voice call communication path, so that the MGW detects the encrypted voice and completes the local MGW. The modification of the IP endpoint codec type realizes reliable transmission of the encrypted voice call, and in this way, the IWF resource does not need to be inserted on the MGW, and the communication cost is low.

As shown in FIG. 6, the embodiment of the present invention further provides a communication system for implementing an encrypted voice call, the system comprising:

The local office mobile switching server MSC SERVER 61, the local office media gateway MGW 62, the peer office mobile switching server MSC SERVER 63, the peer office media gateway MGW 64, the local office MGW 62 and the opposite office The MGW 64 transmits a voice call through the IP bearer, wherein the local office mobile switching server MSC SERVER 61 is configured to receive a signaling message related to the voice call, and determine that the voice call is on both sides of the local office media gateway MGW. The bearer types of the IP bearer and the TDM bearer are inconsistent, and the encrypted voice call detection event is sent to the media gateway MGW when the TDM endpoint is established.

The local office MGW 62 is configured to receive an encrypted voice call detection event sent by the local office mobile switching server MSC SERVER, detect an inband signal sent by the encrypted terminal, and identify that the current voice call is an encrypted voice call. And sending a notification message to the local office MSC SERVER, the local office MSC SERVER 61 is further configured to receive the notification message reported by the MSC SERVER, and modify the codec type of the IP endpoint on the local office MGW to G. 711 format, and send a message to the peer office MSC SERVER to notify the opposite office MSC SERVER to modify the codec type of the IP endpoint on the opposite MGW to the G.711 format;

The peer office MSC SERVER 63 is configured to receive the message sent by the local office MSC SERVER 61, and modify the codec type of the IP endpoint on the peer office MGW 64 to the G.711 format. The local office is the calling side office, the called side office or the tandem office. The system embodiment provided by the present invention is applicable to the various network architectures provided in the foregoing FIG. 2A, FIG. 4, and FIG. 5, and the specific implementation is the same as the foregoing method embodiment, and the description is not repeated herein.

As shown in FIG. 7, a mobile switching server MSC SERVER according to an embodiment of the present invention includes:

The determining unit 71 is configured to determine, after receiving the signaling message related to the voice call, whether the codec type selected by the voice call is consistent on the side;

The instructing the sending unit 72 is configured to establish a TDM endpoint when the determining unit determines that the bearer type of the voice call on both sides of the local office media gateway MGW is an IP bearer and a TDM bearer respectively, and the codec types selected on both sides are inconsistent The cryptographic voice call detection event is sent to the media gateway MGW. The modifying unit 73 is configured to receive the notification message reported by the MGW, and modify the codec type of the IP endpoint on the local office MGW to the G.711 format. The notification message is sent to the MSC SERVER by the local station MGW after detecting the inband signal sent by the encrypted terminal and identifying that the current voice call is an encrypted voice call.

If the mobile switching server of each office in the voice call communication path is required to be implemented according to the embodiment of the present invention, the voice call can be transmitted on the IP bearer by using the G.711 format, thereby ensuring the implementation of the encrypted voice call, and Need to insert IWF resources.

In another embodiment of the present invention, the mobile switching server MSC SERVER may further include only the determining unit 71 and the instructing sending unit 72, wherein the sending unit 72 is different from the indicating sending unit 72, and it is to the media gateway. The MGW delivers an automatic handover indication event, which is used to instruct the MGW to automatically modify the codec type of the IP endpoint corresponding to the call to the G.711 format after detecting that the current call is a voice encrypted call.

As shown in FIG. 8, another mobile switching server MSC SERVER according to an embodiment of the present invention includes The determining unit 81 is configured to determine, after receiving the signaling message related to the voice call, whether the codec type selected by the voice call is consistent on the side;

The sending unit 82 is configured to establish a TDM endpoint when the determining unit determines that the bearer type of the voice call on both sides of the local office media gateway MGW is an IP bearer and a TDM bearer, and the codec types selected on the two sides are inconsistent. And sending an encrypted voice call detection event to the media gateway MGW; the modifying unit 83 is configured to receive the notification message reported by the MGW, and modify the codec type of the IP endpoint on the local office MGW to the G.711 format, where The notification message is sent to the MSC SERVER by the local station MGW after detecting the inband signal sent by the encrypted terminal and identifying that the current voice call is an encrypted voice call;

The notification unit 84 is configured to: after the modifying unit receives the notification message reported by the MGW, send a message to the opposite office MSC SERVER to notify the opposite office MSC SERVER to modify the codec type of the IP endpoint on the opposite MGW to G.711 format;

Corresponding to the foregoing method embodiment, the MSC SERVER may be in the calling side office, the called side office, or the tanner office. The specific application scenarios and implementations may also refer to the description in the method embodiment.

Further, when the peer MSC SERVER has the above function, it can notify the local office to change the codec type of the IP endpoint on the MGW to G.711 by sending a message to the MSC SERVER of the local office. The format, the modification unit 83 is further configured to receive the message sent by the peer MSC SERVER, and modify the codec type of the IP endpoint on the local office MGW to the G.711 format, where the peer MSC SERVER sends The message is used to instruct the local office to modify the codec type of the IP endpoint to the G.711 format.

The MSC SERVER provided by the embodiment of the present invention delivers an encrypted voice call to the MGW. After detecting the event, the IP endpoint codec type on the local MGW is modified to G.711 after receiving the notification message reported by the MGW, and the IP endpoint codec type on the peer MGW is modified to G by notifying the peer MSC SERVER. .711, the transmission of the encrypted voice call through the G.711 format on the IP bearer is realized, and the method does not need to insert the IWF resource, and the P strives to reduce the communication cost.

As shown in FIG. 9, the embodiment of the present invention further provides a media gateway MGW, including: a receiving unit 91, configured to receive an encrypted voice call detection event delivered by the local office mobile switching server MSC SERVER, the encrypted voice The call detection event is that after the MSC SERVER receives the signaling message related to the voice call, it determines that the bearer types of the voice call on both sides of the local office media gateway MGW are respectively IP bearer and TDM bearer, and the codec types selected on both sides are inconsistent. When the TDM endpoint is established, it is sent to the media gateway MGW;

The detecting and identifying unit 92 is configured to: after receiving the encrypted voice call detecting event, the receiving unit detects the inband signal sent by the encrypted terminal, and after identifying that the current voice call is an encrypted voice call, sending a notification message to the MSC SERVER;

The codec type modification unit 93 is configured to modify the codec type of the local IP endpoint of the voice call to the G.711 format under the control of the MSC SERVER.

The encrypted voice call detection event is a new H.248 event, and is used to instruct the MGW to send a notification message to the MSC SERVER after detecting that the current voice call is an encrypted voice call.

The media gateway provided by another embodiment of the present invention further includes a receiving unit 91, a detecting and identifying unit 92, and a codec type modifying unit 93, which is different from the media gateway in that the receiving unit 91 receives the received It is an automatic handover indication event delivered by the local office mobile switching server MSC SERVER. The automatic handover indication event is also determined by the MSC SERVER after receiving the signaling message related to the voice call, and determines that the voice call is at the local office media gateway MGW. The bearer types on both sides are the IP bearer and the TDM bearer, and the codec types selected on the two sides are inconsistent. When the TDM endpoint is established, the MDM is sent to the media gateway MGW. The automatic handover indication event is used to indicate that the MGW detects the current call. After the voice encrypted call, the codec type of the IP endpoint corresponding to the call is automatically changed to G.711. format;

The detecting and identifying unit 92 is configured to: after receiving the automatic switching indication event, the receiving unit detects the inband signal sent by the encrypted terminal, and after identifying that the current voice call is an encrypted voice call, notifying the codec type modifying unit 93;

The codec type modification unit 93 is configured to automatically modify the codec type of the IP endpoint corresponding to the call on the MGW to G.711 after receiving the notification sent by the detection and identification unit 92.

The system and device embodiments disclosed above can be referred to the description of the foregoing method embodiments, and all have the beneficial effects described in the foregoing method embodiments.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus a necessary general hardware platform, and of course, can also be through hardware, but in many cases, the former is a better implementation. the way. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, may be embodied in the form of a software product stored in a readable storage medium, such as a floppy disk of a computer. A hard disk or optical disk or the like includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods described in various embodiments of the present invention.

In summary, the above description is only a preferred embodiment of the technical solution of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

A method for encoding and decoding an encrypted voice call, the method comprising: the mobile switching server MSC SERVER receiving the signaling message related to the voice call, determining that the voice call is in the local office media gateway MGW The bearer type of the bearer is the IP bearer and the TDM bearer, and the codec types selected by the two sides are inconsistent. When the TDM endpoint is established, the encrypted voice call detection event is sent to the media gateway MGW.

The MSC SERVER receives the notification message reported by the local office MGW, and the notification message is that the local office MGW detects the inband signal sent by the encrypted terminal, and recognizes that the current voice call is an encrypted voice call, and then sends the MSC SERVER to the MSC. SERVER sent;

The method for encoding and decoding a voice-encrypted call according to claim 1, wherein the determining whether the voice call is selected on the two sides of the local office media gateway MGW is inconsistent:

It is determined whether the codec type selected in the IP bearer is in the G.711 format. If yes, it is determined that the codec types selected on both sides of the MGW are the same. If not, it is determined that the codec types selected on both sides of the MGW are inconsistent.

The method for encoding and decoding a voice-encrypted call according to claim 1, wherein the encrypted voice detection event is a newly added H.248 event, and is used to indicate that the MGW detects the encrypted voice call. Send a notification message to the MSC SERVER.

The method for encoding and decoding a voice-encrypted call according to claim 1, wherein the MSC SERVER sends a message to the opposite office MSC SERVER to notify the opposite office that the MSC SERVER will be on the opposite MGW. Modification of the codec type of the IP endpoint to the G.711 format includes: The MSC SERVER sends an APM message to the peer office MSC SERVER to notify the peer office MSC SERVER to change the codec type of the IP endpoint on the peer MGW to the G.711 format.

The method for encoding and decoding negotiation of a voice-encrypted call according to claim 1, wherein the MSC SERVER is a calling-side office MSC SERVER, a called-side office MSC SERVER, or a tandem office MSC. SERVER^

A method for encoding and decoding an encrypted voice call, the method comprising: the mobile switching server MSC SERVER in the voice call communication path receiving the signaling message related to the voice call, determining that the voice call is at the media gateway The bearer types on both sides of the MGW are the IP bearer and the TDM bearer, and the codec types selected on the two sides are inconsistent. When the TDM endpoint is established, the automatic switching indication event or the encrypted voice call detection event is sent to the media gateway MGW.

The method for encoding and decoding a voice-encrypted call according to claim 6, wherein the determining the codec type selected by the voice call on both sides of the media gateway MGW includes: determining the selected one of the IP bearers Whether the decoding type is G.711 format. If yes, it determines that the codec types selected on both sides of the MGW are the same. If not, it determines that the codec types selected on both sides of the MGW are inconsistent.

The method for encoding and decoding a voice-encrypted call according to claim 6, wherein the encrypted voice detection event or the automatic handover indication event is a new H.248 event.

9. A communication system for implementing an encrypted voice call, the system comprising: The local office mobile switching server MSC SERVER, the local office media gateway MGW, the peer office mobile switching server MSC SERVER, the peer office media gateway MGW, the local office MGW and the peer office MGW pass The IP bearer transmits a voice call, wherein

The local office MGW is configured to receive an encrypted voice call detection event sent by the local office mobile switching server MSC SERVER, detect an inband signal sent by the encrypted terminal, and identify the current voice—the call is an encrypted voice call. After that, send a notification message to the local office MSC SERVER.

The local office MSC SERVER is further configured to receive the notification message reported by the MGW, modify the codec type of the IP endpoint on the local office MGW to the G.711 format, and send a message to the opposite office MSC SERVER. The MSC SERVER is notified to notify the peer office to change the codec type of the IP endpoint on the peer MGW to the G.711 format.

The communication system for implementing an encrypted voice call according to claim 9, wherein the local office is a calling side office point, a called side office point, or a tandem office office point.

11. A mobile switching server MSC SERVER, comprising:

a determining unit, configured to determine, after receiving a signaling message related to the voice call, whether the voice call is consistent in the selected codec type;

And the sending unit is configured to: when the determining unit determines that the bearer type of the voice call on both sides of the local office media gateway MGW is an IP bearer and a TDM bearer, and the codec types selected on the two sides are inconsistent, when the TDM endpoint is established Sending an encrypted voice call detection event to the media gateway MGW; a modifying unit, configured to receive the notification message reported by the MGW, and modify the codec type of the IP endpoint on the local office MGW to the G.711 format, where the notification message is sent by the local office MGW when detecting the encrypted terminal In-band tones, which are sent to the MSC SERVER after the current voice call is an encrypted voice call.

The MSC SERVER according to claim 11, wherein the MSC SERVER further includes:

a notification unit, configured to send a message to the opposite office MSC SERVER after receiving the notification message reported by the MGW or after modifying the codec type of the IP endpoint on the local office MGW to the G.711 format The peer MSC SERVER is notified to change the codec type of the IP endpoint on the peer MGW to the G.711 format, and the local office MGW and the opposite office MGW transmit the voice call through IP 7.

The MSC SERVER according to claim 11, wherein the modifying unit is further configured to receive a message sent by the peer MSC SERVER, and modify the codec type of the IP endpoint on the local office MGW to G. In the 711 format, the message sent by the peer MSC SERVER is used to indicate that the local office changes the codec type of the IP endpoint to the G.711 format.

14. A media gateway MGW, characterized in that:

The detecting and identifying unit is configured to: after receiving the encrypted voice call detecting event, the receiving unit detects the inband signal sent by the encrypted terminal, and after identifying that the current voice call is an encrypted voice call, sending a notification message to the MSC SERVER;

Codec type modification unit, used to control the voice call under the control of the MSC SERVER The codec type of the local IP endpoint is modified to the G.711 format.