CN1567792A

CN1567792A - Transmission method for encrypting voice data in CDMA system

Info

Publication number: CN1567792A
Application number: CN03139783.2A
Authority: CN
Inventors: 朱龙明; 谭继奎; 刘英男
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2003-07-08
Filing date: 2003-07-08
Publication date: 2005-01-19
Anticipated expiration: 2023-07-08
Also published as: CN1264296C

Abstract

The invention is an encrypted voice data transmitting method in CDMA system, including: 1. as initiating encrypted call, building a direct connection between MAC multiplex sublayer and ISLP adaptation layer circuit data; 2. after building the encrypted call initiation, directly transmitting encrypted voice circuit data generated by the ISLP adaptation layer to the MAC multiplex sublayer and storing the circuit data in buffer memory of the MAC multiplex sublayer; 3. according to CDMA aerial interface standard in forward MAC multiplex sublayer, and corresponding to multiplex types, reading the circuit data in the buffer memory to form data blocks, multiplexing and then sending them to the physical layer; in backward MAC multiplex sublayer, demultiplexing the received service data frames corresponding to the multiplex types into circuit data blocks and directly send them to ISLP adaptation layer. It increases the transmission rate of circuit data byte stream in the air and then reduces the delay time of encrypted voice.

Description

The transmission method of encrypted voice data in the cdma system

Technical field

The present invention relates to the transmission method of encrypted voice in a kind of cdma network, relate in particular in the cdma system transmission method encrypted voice data.

Background technology

Enciphoring voice telecommunication in the cdma system is different from general ordinary voice communications, need certain confidentiality, the both sides' of general speech scrambling speech is after encrypting through special-purpose encrypting module, form with circuit data service communicates in cdma system, therefore belong to the communication of a kind of CDMA circuit data service, in cdma system, be responsible for the transmission of circuit data between (ISLP) adaptation layer of link protocol between system and CDMA are aerial by radio link protocol (RLP).But, because RLP adopts the mode of transparent transmission to circuit data, only break by aerial transformat at the byte stream of forward direction to circuit data, oppositely circuit data is being directly passed to outside the circuit data adaptation layer, is not taking to confirm that the mechanism that retransmits guarantees that circuit data carries out reliable transmission aloft.And RLP not only needs to send some control frames to communicate control in order to keep mobile phone and base station the communicating by letter of same level, and also need increase packet header and the bag tail of RLP in each that issue multiplex sublayer is adapted at business data packet of aerial transmission.Therefore, the length of the length-RLP head and tail of the length-multiplex sublayer head of the maximum frame length-physical layer head or tail of transmission of the real circuit data maximum length of transmission aloft=aloft.

Transmission bottleneck in cdma system is aloft, and whether the encrypted voice data transmission is unobstructed, depends on the transmission rate that cdma system is aerial.This is because be different from general unencryped word communication, encrypted voice data is that general unencryped word data are encrypted the data that the back produces in process, the information data redundancy has increased much compared with unencryped word, and the skyborne transmission rate of cdma system that is used for the transmission circuit data is only applicable to transmit the data with unencryped word data message amount as much.By RLP layer transmission circuit data, it is required in each traffic frame occupation space to keep peer layer communicaton, and then can influence the speed of data aerial transmission in the base station.If the speed of data aerial transmission in the base station is fast inadequately, encrypted voice data then can accumulate gradually in base station side.Ji Lei result needs the base station to provide a very big buffer memory to store these encrypted voice data in advance like this, but the impossible unconfined increasing of this buffer memory, therefore, in extended telephone conversation, probably can lose a large amount of circuit data byte streams because buffer memory overflows, the lot of data buffer memory has also increased the transmission delay of encrypted voice simultaneously.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of method of transmitting encrypted voice data in cdma system fast, it is required in each traffic frame occupation space for keeping peer layer communicaton to have overcome RLP, has overcome the transmission delay of circuit data in cdma base station system.

For realizing the technical problem to be solved in the present invention, the invention provides the transmission method of encrypted voice data in a kind of cdma system, described cdma system comprises adaptation layer and the physical layer of link protocol ISLP between media access control layer MAC, system, described method comprises: step 1: encrypted voice rises when exhaling, and sets up the MAC multiplex sublayer and is connected with the direct of adaptation layer circuit data of ISLP; Step 2: after encrypted word rose and exhales foundation, the encrypted voice circuit data that the adaptation layer of ISLP produces was directly passed to the MAC multiplex sublayer, and circuit data is left in the buffer memory of MAC multiplex sublayer; Step 3: according to the CDMA air-interface standard, corresponding multiplexing type reads the circuit data in the buffer memory in the MAC multiplex sublayer, forms data block, carry out multiplexing after, mail to physical layer; In the business data frame that the MAC multiplex sublayer is sent here physical layer, corresponding multiplexing type, demultiplexing goes out circuit data, directly mails to the adaptation layer of worker SLP.

Adopt the method for the invention, compared with prior art, improved the skyborne transmission speed of encrypted voice circuit data byte stream, solved the problem of encrypted voice time-delay.

Description of drawings

Fig. 1 is the flow chart that encrypted voice is set up and conversed.

Fig. 2 is the transfer function schematic diagram of MAC multiplex sublayer to the encrypted voice circuit data.

Embodiment

In the encrypted voice transport service of existing mobile communication system, the MAC multiplex sublayer has three kinds of professional sources: top signaling is handled the back as the professional source of encrypted voice data as the source of signaling traffic, common speech business source and encrypted voice circuit data by RLP after inserting sub-layer processes by signaling link.Realize in the mobile communication system of the present invention in the transmission method of encrypted voice data, do not handle directly as the professional source of the encrypted voice data of MAC multiplex sublayer by RLP by the encrypted voice circuit data that the adaptation layer of ISLP produces.Fig. 1 is the flow chart that encrypted voice of the present invention is set up and conversed.When the encrypted voice call setup of encrypted word terminal, the MAC multiplex sublayer is directly set up circuit data with the ISLP adaptation layer and is connected; After the encrypted voice call setup gets up, directly pass to the MAC multiplex sublayer by the forward direction encrypted voice circuit data that the adaptation layer of ISLP produces, and circuit data is stored in the buffer memory of MAC multiplex sublayer; Signaling traffic, normal speech business and encrypted voice data business are after the MAC multiplex sublayer is multiplexing according to air-interface standard, and the Service Data Unit that forms physical layer is transferred to physical layer, forms forward direction air traffic Frame by physical layer again and issues the encrypted word terminal.Vice versa, after multiplex sublayer receives that physical layer transmits the reverse traffic Frame, behind the air-interface standard demultiplexing, isolate the adaptation layer that signaling traffic, normal speech business and encrypted voice data business are transferred to ISLP, wherein, the encrypted voice data business directly is not transferred to the adaptation layer of ISLP by the processing of RLP.Handle as follows to the encrypted speech circuit data: the MAC multiplex sublayer is according to the CDMA air-interface standard, and corresponding different multiplexing type is carried out multiplexing and demultiplexing to circuit data, makes it be suitable for transmitting aloft; According to the CDMA air-interface standard, corresponding different multiplexing type reads the circuit data in the current buffer memory that needs length, forms data block in forward direction MAC multiplex sublayer, carry out multiplexing after, mail to physical layer; At the reverse traffic Frame that reverse MAC multiplex sublayer is sent here physical layer, corresponding different multiplexing types, demultiplexing goes out the circuit data piece, mails to the adaptation layer of ISLP.

Fig. 2 is the transfer function schematic diagram of MAC multiplex sublayer to the encrypted voice circuit data.The MAC multiplex sublayer is as follows to the processing of forward direction encrypted voice circuit data: the buffer memory of the byte stream of encrypted voice circuit data is deposited in the multiplex sublayer increase, and the size of buffer memory is according to the speed of encrypting module output and consider that aerial traffic signaling determines.According to air-interface standard, multiplex sublayer will be carried out the multiplexing process of forward direction at set intervals so that provide a Service Data Unit with full-length to physical layer.Need to judge whether multiplexing encrypted voice circuit data before multiplexing process, the circuit data that needs then to take out the respective length byte from buffer memory carries out the multiplexing of the aerial Frame of forward direction, and the data that just read in the deletion buffer memory.This buffer memory is kept two variable V (r) and V (s), and the new encrypted voice data of first variable V (r) sensing leaves the initial address in the buffer memory in, and after having deposited new encrypted voice circuit data, the value that changes first variable V (r) is to new position at every turn; Second variable V (s) is pointed to multiplex sublayer and is read data cached initial address, and after multiplex sublayer read and deletes circuit data, the value that changes second variable V (s) was to new position.

As follows in the reverse process of cdma system to the encrypted voice circuit data: multiplex sublayer is carried out demultiplexing to the Service Data Unit that physical layer transmits, directly send the encrypted voice circuit data byte stream that obtains the adaptation layer of ISLP to, the length of the reverse encryption voice data byte stream of Huo Deing can not be above the treatable maximum length of adaptation layer of ISLP here.

Claims

1, the transmission method of encrypted voice data in a kind of cdma system, described cdma system comprises adaptation layer and the physical layer of link protocol ISLP between media access control layer MAC, system, it is characterized in that: described transmission method comprises:

Step 1: encrypted voice rises when exhaling, and sets up the MAC multiplex sublayer and is connected with the direct of adaptation layer circuit data of ISLP;

Step 2: after encrypted voice rose and exhales foundation, the encrypted voice circuit data that the adaptation layer of ISLP produces was directly passed to the MAC multiplex sublayer, and circuit data is left in the buffer memory of MAC multiplex sublayer;

Step 3: according to the CDMA air-interface standard, corresponding multiplexing type reads the circuit data in the buffer memory of MAC multiplex sublayer, forms data block in the MAC multiplex sublayer, carry out multiplexing after, mail to physical layer; In the business data frame that the MAC multiplex sublayer is sent here physical layer, corresponding multiplexing type, demultiplexing goes out circuit data, directly mails to the adaptation layer of ISLP.

2, method according to claim 1, it is characterized in that: in the described step 2 forward direction circuit data is left in the buffer memory of MAC multiplex sublayer and further comprise: first variable points to the encrypted voice circuit data and leaves initial address in the buffer memory in, after depositing the encrypted voice circuit data, the value that changes first variable is to new position.

3, method according to claim 1, it is characterized in that: the circuit data that reads in the buffer memory in the described step 3 further comprises: second variable points to the initial address that multiplex sublayer reads the buffer circuit data, after multiplex sublayer read and deletes circuit data, the value that changes second variable was to new position.