WO2008028316A1

WO2008028316A1 - Voice message format in trunked communication and transmission method therefor

Info

Publication number: WO2008028316A1
Application number: PCT/CN2006/002164
Authority: WO
Inventors: Zhigang Wen
Original assignee: Zte Corporation
Priority date: 2006-08-24
Filing date: 2006-08-24
Publication date: 2008-03-13
Also published as: CN101502142B; CN101502142A

Abstract

A voice message format in trunked communication and transmission method therefor are disclosed. With the method, the network bandwidth between the base station system and the trunked dispatch server could be saved. The method includes: (a) after establishing a trunked call, the speak user begins speaking, sends voice frames to the base station system; (b) the base station system encapsulates every N voice frames into a voice message and sends the message to a trunked dispatch server; (c) the trunked dispatch server transmits the receiving voice message to the base station system to which all the users in the speak user group belong; (d) the base station system to which all the users in the group belong disassembles the received voice message into N voice frames and transmits the frames to listening users in the group on original order. The voice message includes transmission header, data packet header and the voice data part. The transmission header contains transmission format information. The data packet header contains the user and the voice data information. The voice data part contains multiple voice frames arranged on precedence order.

Description

Voice 4 艮 text format in cluster communication and transmission method thereof

Technical field

The present invention relates to a trunking communication system, and more particularly to a voice message format and a transmission method thereof in a trunking communication system.

Background technique

The trunking communication system based on mobile communication combines cellular communication technology with a dedicated dispatch communication system, and adopts a half-duplex communication communication system, which can realize fast connection and support group call (ie, one-to-many call mode). . Such a trunking communication system can be widely applied to enterprises, public security, police, and military departments that have high requirements for command and scheduling functions.

Group call is an important service feature in a cluster system. By sharing a pre-reverse traffic channel under a sector, a large-capacity group can be provided to a small range (a group can contain hundreds or thousands of user terminals, and These user terminals are all supported by group calls under a small range of sectors. Allowing a single user to talk to all users in the group at the same time, the users in the group, in addition to being talking, others must be listening.

In the trunking communication, the general length of the voice frame sent by the mobile station from the air interface is relatively small, and in the transmission process from the base station system to the cluster scheduling server, the transmission header is added before the payload, by IP or In other ways, the network bandwidth is wasted. In order to save the network resources between the base station and the cluster scheduling server, the packets between the base station system and the cluster scheduling server must be re-encapsulated. Summary of the invention

The technical problem to be solved by the present invention is to provide a method for transmitting voice messages in a trunking communication to save network bandwidth between the base station system and the cluster scheduling server.

In order to solve the above problem, the present invention provides a method for transmitting voice messages in trunk communication, including the following steps:

After the cluster call is established, the user is said to start speaking, and the user's terminal is to the associated base station. The system sends a voice frame;

(b) after receiving the N voice frames, the base station system encapsulates the voice packets into a voice message and sends the message to the cluster scheduling server.

(c) after receiving the voice packet, the cluster scheduling server forwards the voice packet to the base station system to which all users in the user group belong;

(d) After receiving the voice message, the base station system to which all the users belong to the group splits the voice message into N voice frames and sends them to the listening users in the group in the original order.

Further, the foregoing method may further have the following features: In steps (b) and (d), in the base station system, the base station controller or the cluster scheduling client encapsulates the N voice frames into one voice message. And splitting a voice message into N voice frames.

Further, the foregoing method may further have the following features: In step (b), when the base station controller encapsulates the voice message, the data packet header is added before the N voice frames, and then the transmission header is added.

Further, the foregoing method may further have the following features: the data packet header includes: a user identifier, a frame sequence number, and a frame number; and the transmission header includes: a universal route encapsulation header and an IP header.

Further, the foregoing method may further have the following features: in the step (d), after the base station controller in the base station system to which the user belongs receives the voice message, if there is a user terminal in the service scope, The voice message is split into N voice frames, and the base transceiver station transmits the voice frames to the listening user terminals in the respective service ranges in the original order.

Further, the above method may also have the following features: The value of N ranges between 2 and 20.

Further, the above method may also have the following features: The method is applied to a trunking communication system of the CDMA system.

Another technical problem to be solved by the present invention is to provide a voice message format in a cluster communication. Using such a message format to transmit voice can save network bandwidth between the base station system and the cluster scheduling server, and improve network utilization. In order to solve the above problem, the present invention provides a voice message format in a cluster communication, which is transmitted between a base station system and a cluster scheduling server, including a transmission header, a packet header, and a voice data portion. The transmission header includes transmission mode information, and the data packet header includes user and voice data information, and the voice data portion includes a plurality of voice frames arranged in order.

Further, the foregoing voice message format may also have the following features: The transmission header includes an IP header and a GRE header.

Further, the voice message format may further have the following features: the data packet header includes a user identifier, a voice frame sequence number, and a voice frame number.

Further, the voice message format may further have the following features: The voice data portion includes 2 to 20 voice frames.

It can be seen from the above that the present invention effectively saves network bandwidth while encapsulating the voice frame of the user by encapsulating the voice frame of the user. If each voice frame is transmitted, the network utilization rate is 39.6%, and the network bandwidth is seriously wasted in the process of transmission. The transmission mode of encapsulating the four voice frames together, the network utilization rate is 71.7%, which is good. It saves network bandwidth between the base station system and the cluster scheduling server, and has great commercial value. BRIEF abstract

1 is a schematic structural diagram of a network of a trunking communication system according to an embodiment of the present invention;

2 is a schematic diagram of a method for transmitting a voice packet in a trunking communication according to an embodiment of the present invention; and FIG. 3 is a format of a voice packet in a trunking communication according to an embodiment of the present invention.

Preferred embodiment of the invention

The technical solution of the present invention is as follows: After receiving the voice message of the speaking user, the base station system does not immediately transmit between the base station system and the cluster scheduling server, but receives the N messages of the speaking user, and then encapsulates Together, and then transmit, to save the network bandwidth between the base station system and the cluster scheduling server. 1 is a network structure diagram of a cluster system based on a code division multiple access (CDMA) code division multiple access (CDMA) system, which relates to a PDS (PTT Dispatch Server, cluster scheduling server) according to an embodiment of the present invention; , PDC (PTT Dispatch Client, Cluster Scheduling Client), BS (Base Station Base Station System, including BSC (Base Station Controller) and BTS (Base-station Transceiver System)), MS (Mobile) A cluster system network consisting of a station, a mobile station, also called a terminal.

In the specific implementation of Figure 2, the PDC can be externally placed in the BSC or built into the BSC. In this example, the PDC is built in the BSC. In the example of the present invention, MS1, MS2 and MS3 belong to the same group, MS1 and MS2 are within the coverage of BTS1, MS3 is within the coverage of BTS2, and BSC1/PDC1 and BSC2/PDC2 are connected to the PDS through the router and the Internet. For a CDMA-based digital trunking system, the voice frame transmission time of the air interface is 20 ms. In this example, four voice frames (N=4) are encapsulated into one voice message for transmission on the base station system side, and N can also be set to other. Value.

Figure 2 shows the flow of the voice transmission method of the embodiment, including the following steps: Step 201, the cluster call setup is completed, MS1 is the user, other users in the group are listening users, MS1 starts speaking, voice Frames 1, 2, 3, 4 are sent to the BTS 1 to which the MS 1 belongs at intervals of 20 ms;

Step 202: The BTS1 forwards the voice frame to the BSC1/PDC1.

Step 203: The BSC1/PDC1 receives the BTS1 voice frame, does not immediately send the message to the PDS, but receives the 4th voice frame, and then encapsulates the 4 voice frames into a voice message, plus the GRE header and the IP header. , sent to the PDS;

Since the user's speech is paused, some of the N speech frames contain voice information, and some may be empty frames (frames that the mobile station sends to the base station when the user does not speak), regardless of whether or not voice information is included. When the cumulative total is 4, the base station system should be sent by the cluster scheduling server to ensure the delay of the voice.

The PDS receives the voice message and simultaneously distributes the voice message to the PDC1 and the PDC2. The following steps 204-206 and steps 207-209 are concurrent. Step 204: The PDS forwards the voice message to the BSC1/PDC1, and the PDS does not perform any change on the voice payload.

After step 205, BSC1 / PDC1 received voice packets Gen ¹ ^, ^^ Gen voice message is split into four speech frames is transmitted to the BTS1;

Step 206: The BTS1 sends the voice frame to the MS2 in sequence at an interval of 20 ms on the air interface.

3, 4, because MS1 is the user, BTS1 does not send a voice frame to MS1;

If only the user is in BSC1, the PDS will still send a voice message to BSC1/PDC1, and BSC1 will determine who is the user and will not send it to the user.

Step 207: The PDS forwards the voice message to the BSC2/PDC2, and the PDS does not perform any change on the voice payload.

Step 208: After receiving the voice packet, the BSC2/PDC2 splits the voice packet into four voice frames and sends the voice packet to the BTS2.

Step 209: The BTS2 sends the voice frames 1, 2, 3, and 4 to the MS3 in sequence at an interval of 20 ms on the air interface.

Subsequent speech frames, such as voice frames 5~8, 9-12, ..., etc., are sent to the terminal in the same manner as voice frames 1~4.

FIG. 3 shows the format of a voice message used in the trunking communication of this embodiment. The format of the voice message refers to a format transmitted in the base station system and the cluster scheduling server.

As shown, the voice message includes a transmission header, a packet header, and N voice data. among them:

The transmission header is determined by the transmission mode, and may be an IP transmission mode or another transmission mode. For example, the example uses IP and GRE (Generic Routing Encapsulation) to transmit, the transmission header includes an IP header and a GRE header, and the IP is the bottom layer. , GRE is the upper level. However, other transmission methods and corresponding transmission heads can also be used.

Packet header including information about the speech data, this example comprises: said user's IMSI (International Mobile Subscriber Identification Number, international mobile subscriber identity another ¹ J code), the frame number and frame number; content header portion may themselves by the manufacturer Setting, if adopted It says user identification, such as ESN instead of IMSI.

The voice data is a voice of the user, including a plurality of voice frames arranged in order, and is specifically referred to the embodiment of the present invention.

The invention encapsulates the voice frame of the user, and effectively saves the network bandwidth while ensuring the delay of the voice. To save the network bandwidth and ensure the voice delay, the value of N should be determined according to the actual application. The larger the value of N is, the higher the bandwidth is saved, but the voice delay is larger. The value of N is higher. Less, less bandwidth savings, but the smaller the speech delay, the value of N is generally recommended 2 to 20.

As can be seen from the above example, in a CDMA-based cluster system, the length of a voice frame per 20 ms is 21 bytes, and the IP header is 20 bytes, and the GRE header is 12 bytes. If each voice frame is transmitted, the network utilization rate is 39.6%. In the process of transmission, the network bandwidth is seriously wasted, and the transmission mode of encapsulating four voice frames together has a network utilization ratio of 71.7%, which can well save the network bandwidth between the base station system and the cluster scheduling server. Great commercial value.

The invention may, of course, be embodied in a variety of other embodiments without departing from the spirit and scope of the invention. The above process can also be applied to the system cluster system. These respective changes and modifications are intended to fall within the scope of the appended claims.

For example, for the base station system BSC/PDC in the embodiment, the BSC may be responsible for encapsulating the N voice frames into voice messages or splitting the voice messages into N voice frames. But it can also be done by the PDC, which is two specific ways of implementation.

Industrial applicability

The invention encapsulates the voice frame of the user, and effectively saves the network bandwidth while ensuring the delay of the voice. If each voice frame is transmitted, the network utilization rate is 39.6%, and the network bandwidth is seriously wasted in the process of transmission. The transmission mode of encapsulating the four voice frames together, the network utilization rate is 71.7%, which is good. It saves network bandwidth between the base station system and the cluster scheduling server, and has great commercial value.

Claims

Claim

A method for transmitting voice packets in a trunking communication, comprising the following steps:

(a) after the cluster call is established, the user is said to start speaking, and the terminal of the user sends a voice frame to the affiliated base station system;

2. The method according to claim 1, wherein in steps (b) and (d), in the base station system, a base station controller or a cluster scheduling client encapsulates N voice frames into one Voice ^ ¹艮 text, and a voice 艮 text into N voice frames.

3. The method according to claim 1, wherein in step (b), the base station controller adds a packet header before the N speech frames when the voice message is encapsulated, and then adds a transmission header. .

4. The method according to claim 3, wherein the data packet header comprises: a user identifier, a frame sequence number, and a frame number; and the transmission header comprises: a universal route encapsulation header and an IP header.

The method according to claim 1, wherein in the step (d), the group controller in the base station system to which the user belongs receives the voice message, if there is a user in the service scope, The terminal then splits the voice message into N voice frames, and the base transceiver station transmits the voice frames to the listening user terminals in the respective service ranges in the original order.

6. The method of claim 1, wherein the value of N is between 2 and 20.

7. The method of claim 1 wherein the method is applied to a CDMA system of trunked communication systems.

8. A voice message format in a cluster communication, the voice message being in a base station system and a cluster The transmission between the scheduling servers includes a transmission header, a packet header, and a voice data portion, the transmission header includes transmission mode information, the packet header includes user and voice data information, and the voice data portion includes Multiple speech frames arranged in sequence.

9. The voice message of claim 8, wherein the transmission header comprises an IP header and a GRE header.

10. The voice message of claim 8, wherein the data packet header comprises a user identification, a voice frame number, and a number of voice frames.

The voice message of claim 8, wherein the voice data portion comprises 2 to 20 voice frames.