WO2009146631A1 - Method, device and system for data transmission - Google Patents

Abstract

A method for data transmission, involves: data information is received, data information is transmitted via the Time Division Multiplexing (TDM) transmission interface if it is voice service information, or else data information is transmitted via the packet transmission interface if it is packet service information. A device and a system for data transmission are also provided. The method, device and system of the embodiments of the present invention can solves the problem of high cost and low bandwidth usage when the packet service is transmitted via the TDM transmission tunnel in prior art.

Description

 METHOD, APPARATUS AND SYSTEM FOR DATA TRANSMISSION This application claims priority from Chinese Patent Application No. 200810067617. X, entitled "Method, Apparatus and System for Data Transmission", filed on June 2, 2008. The entire contents of which are incorporated herein by reference. Technical field

 The present invention relates to data transmission services, and more particularly to data transmission between a base transceiver station and a base station controller. Background technique

 GSM (Global System for Mobi Le Communications) consists of three subsystems, such as: Network Subsystem (NSS), Base Station Subsystem (BSS), and Operation Support Subsystem (OSS). The Operations Support System).

 NSS is the core of the whole system. It plays the role of exchange, connection and management between GSM mobile users and between mobile users and other communication network users.

 0SS mainly performs functions such as mobile user management, mobile device management, and network operation and maintenance. BSS is the most direct basic component of GSM and wireless cellular. It is directly connected to the mobile station through the wireless interface, and is responsible for wireless information transmission and reception, radio resource management and power control. At the same time, it is connected to the NSS to implement mobile. Communication between users or mobile users and fixed network users, transmitting system information and user information. The base station subsystem can be divided into two parts: one is a base transceiver station (BTS, Base Transceiver Station), and the other is a base station controller (BSC). The BTS is responsible for wireless transmission and the BSC is responsible for control and management.

The main standard interfaces involved in BSS include A interface, Um interface and Abis interface. The A interface is a communication interface between the NSS and the base station subsystem BSS, and the physical link is usually implemented by using a standard 2.48 Mbit/s digital transmission link. Through this interface, mobile station (MS, Mobi le Station) management information, base station management information, mobility management information, connection management information, and the like can be transmitted. The Um interface is a communication interface between the MS and the BTS, and is used for communication between the mobile station and the GSM, and the physical link is a wireless link. The information transmitted by this interface mainly includes radio resource management information, mobility management information, and connection management information.

 The Ab i s interface is the communication interface between the BSC and the BTS in the BSS. Communication between the BSC and the BTS is typically accomplished using a standard 2. 048 Mbit/s PCM digital link. This interface supports all user-facing services and supports control of BTS wireless devices and allocation of radio frequencies.

 In carrying out the process of the present invention, the inventors have found that at least the following problems exist in the prior art:

 The early services of GSM products are mainly voice. The transmission of information between each network element is based on TDM (Time Division Multiplexing). Each base station only provides a single type of transmission channel. With the introduction of GSM products such as GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rate for Global Evolution), the Abis transmission interface is increasingly carrying packet services. Different from voice services, packet services occupy high transmission bandwidth, are bursty, and are not sensitive to delays.

 In the prior art, in order to solve the bearer problem of the packet service, the existing TDM transmission channel is simply expanded to meet the growing demand for packet services, and there are many disadvantages such as: TDM (Time Diviser Multiplexer) The cost of the equipment is too high; the TDM transmission monopolizes the transmission channel, and cannot realize different carrier frequencies, transmission resource sharing between different base stations, and low bandwidth utilization. Summary of the invention

 The main purpose of the embodiments of the present invention is to provide a method, an apparatus, and a system for data transmission, which solve the problem of high cost and low bandwidth utilization when transmitting packet services through a TDM transmission channel in the prior art.

 A data transmission method provided by an embodiment of the present invention includes:

 Receiving data information;

 If the data information is voice service information, the data information is sent through a TDM transmission interface;

If the data information is packet service information, pass the data information through a packet transmission interface Send.

 An apparatus for data transmission provided by an embodiment of the present invention includes:

 a data information receiving unit, configured to receive data information, and send the data information to a data information sending unit;

 The data information sending unit receives the data information, and when the data information is voice service information, sends the data information to a TDM transmission interface; when the data information is packet service information, the data information is sent to Packet transmission interface;

 The TDM transmission interface receives the voice service information and transmits the voice service information; the packet transmission interface receives the packet service information, and transmits the packet service information. A data transmission system provided by an embodiment of the present invention includes a base station and a base station controller, and further includes a data transmission device as described above;

 The base station is configured to send data information to the data transmission device, or receive data information from the data transmission device;

 The base station controller is configured to receive data information from the data transmission device or to transmit data information to the data transmission device.

 As can be seen from the foregoing technical solutions, the embodiments of the present invention provide two transmission interfaces: TDM transmission and packet transmission. For voice services, a TDM interface can be used to ensure that the delay and jitter meet the requirements of the protocol, and the QoS (Quality of Service) is guaranteed. , service quality); For packet services, the encapsulated component group data frames are transmitted through the packet transmission interface, which is simple and easy to implement, and has less improvement to the existing transmission network; and at the same time, solves the problem of high cost and bandwidth utilization when transmitting packet services using the TDM transmission channel. The problem of low rates. DRAWINGS

 The drawings described herein are provided to provide a further understanding of the invention, and are not intended to limit the invention. In the drawing:

 1 is a schematic diagram of data transmission of an Abis interface according to an embodiment of the method of the present invention;

 2 is a schematic diagram of an HDLC switching function according to an embodiment of the present invention;

Figure 3 is a schematic view of an embodiment of the apparatus of the present invention; 4 is a schematic view of another embodiment of the present invention;

 FIG. 5 is a schematic diagram of a statistical multiplexing transmission interface according to an embodiment of the present invention; FIG.

 Figure 6 is a schematic diagram of an embodiment of the system of the present invention. detailed description

 The embodiment of the present invention provides a TDM transmission interface and a packet transmission interface, and sends the received voice service information through the TDM transmission interface to ensure that the delay and the jitter meet the requirements of the protocol, and ensure the transmission QoS; The packet transmission interface is sent to solve the problem of high cost and low bandwidth utilization when transmitting packet services using the TDM transmission channel.

 The embodiments of the present invention are further described in detail below with reference to the accompanying drawings. As shown in FIG. 1 , the embodiment of the present invention uses a high-level data link control (HDLC) transmission interface as a packet transmission interface to transmit packet service information. For description, it should be noted that the packet transmission interface may also be other transmission interfaces, such as an ATM transmission interface, an IP transmission interface, and the like. Specific packet transmission interface The steps of using the HDLC transmission interface for packet service transmission are as follows:

 Step 201: The BSC receives the data information.

 Step 202: The BSC acquires QoS information of the received data information.

 Step 203: The BSC determines, according to the QoS information, whether the data information is voice service information or packet service information.

 Step 204-a: If it is determined that the data information is voice service information, the BSC encapsulates the data information into a TDM data frame, and proceeds to step 205-a;

 Step 204-b: If it is determined that the data information is packet service information, the BSC encapsulates the data information into HDLC data frames, and proceeds to step 205-b;

The complete HDLC frame of the BSC package is composed of a flag field (F), an address field (A), a control field (C), an information field (Info), a frame check sequence field (PCS), and the like, as shown in Table 1. 0 1 1 1 1 1 1 0

 Address A

 Control C

 Information Info

Frame check sequence FCS

 Frame check sequence FCS

0 1 1 1 1 1 1 0

 In order to improve efficiency, a small amount of change can be made to the HDLC frame format for the transmission of GSM service data, as follows:

 (1) Retain and add the address field: from 8 bits to 12 bits, which can represent 4096 addresses, combined with other flags, can be used to identify different users or service flows;

 (2) Reserved control field: Custom control information;

 (3) Adding the frame number SN field: SN indicates the sequence number of the frame sequence, which is used to indicate the sequence of data transmission, and the frame loss detection and other scenarios;

 (4) Add priority identifier Pri field: The Pri field is used to identify the priority relationship of the user service flow, which is convenient for guaranteeing different QoS according to the priority in the transmission process;

 (5) Leave the FCS field and the Flag field.

 The above field definitions can be adjusted according to actual needs.

 Therefore, in the GSM application, the standard "HDLC frame" format or the defined HDLC frame format can be used to complete the GSM user data encapsulation. Gp, HDLC transport interface can use non-standard HDLC technology, user can define the frame format to distinguish different user data streams.

Table 2 shows an example of the format of a defined HDLC frame: 0 1 1 1 1 1 1 0

 Address A

 Address A Control c

 Frame number SN priority Pri

 Information Info

Frame check sequence FCS

 Frame check sequence FCS

 0 1 1 1 1 1 1 0 Table 2

 The ATM technology is similar to the HDLC technology. In the case of using the HDLC, the ATM can also be used. Therefore, the embodiment of the present invention can also use the ATM technology. Similarly, the embodiment of the present invention can also use the IP technology.

 Step 205-a: The BSC transmits the encapsulated TDM frame to the receiving end BTS through the TDM transmission interface.

206;

 Step 205-b: The BSC transmits the encapsulated HDLC data frame to the receiving end BTS through the HDLC transmission interface, and proceeds to step 206;

 In the above step 205-b, the transmitting end BSC sends the HDLC data frame to the receiving end B TS through the HDLC transmission interface, and the BSC sets different user data according to the priority identifier Pri field in the HDLC data frame, S-positive DLC. Data frames are mapped to different priority queues, and high-priority data is prioritized to ensure higher bandwidth and lower latency. Low-priority data can reduce bandwidth, allow for larger delays, and even discard some packets if necessary. At the same time, when HDLC data frames are transmitted, HDLC data frames of multiple HDLC channels can be switched to one HDLC channel. Different data streams can be distinguished according to HDLC address field A or other user IDs. HDLC switching function The address field A is mainly used.

The HDLC switching function is implemented as shown in Figure 2. After HDLC1 and HDLC2 pass through the switch module, they are merged into HDLC3. For the convenience of description, the frame format is drawn into two segments: an address field (ADDR) and a data field (DATA, Everything except the address).

 After the packet switching module receives a message from HDLC1, it can obtain a replacement information by looking up the packet switching table:

 HDLCl (A: 0x05 ) <— > HDLC3 (A: 0x35)

 The meaning is that the packet with the address 0x05 from HDLC1 is switched to the HDLC3 interface and the address is changed to 0x35.

 According to the exchange table information, the packet switching module modifies the address field of the data packet header, changes from 0x05 to 0x35, and sends the data packet from the HDLC3 transmission interface. For example, when the packet switching module receives the message with the address 0x05 from the BSC via the HDLC1 transmission interface, it can be exchanged and sent to the receiving end BTS through the HDLC3 transmission interface.

 Similarly, when receiving a message from HDLC2 with address 0x28, the packet switching module is based on the exchange table information:

 HDLC2 (A: 0x28) <— > HDLC3 (A: 0x52)

 The address field is modified to 0x52 and sent from the HDLC3 to the receiver.

 Conversely, packets received from HDLC3 can also be sent through HDLC1/HDLC2 through the same operation.

 The above is an example of switching the data frames of the two HDLC transmission interfaces to an HDLC transmission interface. The HDLC data frames of the multiple HDLC transmission interfaces are switched to an HDLC transmission interface, and are not described here.

It can be seen from the above functional description that the packet switching module can transmit data independent of different HDLC channels (such as HDLC 1/HDLC2) to HDLC3. Under the appropriate business model, this feature allows the combined data channel bandwidth to be less than the sum of all data channel bandwidths before the merger. Thereby achieving the purpose of saving transmission bandwidth. For example, for bursty services: web browsing function, the user clicks on the link, and requests the page data to be sent to the client as soon as possible. In order to avoid the user waiting for a long time, the bandwidth is required to be 1M, and the transmission time is 1 second. After that, the user reads the content of the webpage and does not need to transmit new data within 20 seconds. Referring to FIG. 2, if HDLC1 and HDLC2 are associated with users 1, 2, and HDLC3 is connected to the server, the bandwidths of HDLC1, HDLC2, and HDLC3 are both 1M. Then, User 1 does not affect any online operation of User 2 at all within 20 seconds after reading the page. Even if User 1 and User 2 click on the link at the same time, the effect on the opening speed of the web page is small. In this case, HDLC3 selects 1M bandwidth instead of HDLC1+HDLC2 = 2M bandwidth, which can save HDLC3 construction or rental costs.

 In the GSM product, the base station is connected to HDLC1/HDLC2, and there are burst services in the base station, such as the above network. Associated with HDLC3 is a base station controller. Usually, HDLC3 is a convergence layer network, and the rental cost is high. The above functions can save the construction or rental cost of the convergence layer network between the base station and the base station.

 The HDLC switching function can be used in the base station BTS and the base station controller to aggregate user data between carriers. It can also be used as an independent device to aggregate data between BTS and BSC of different base stations.

 Step 206: The BTS receives the TDM data frame or the HDLC data frame sent by the BSC. For the received HDLC data frame, according to the obtained FCS field of the frame check sequence, it is confirmed whether the data reception is correct. If the reception is correct, according to the HDLC data. The address field establishes a receive context and buffers the received user data; further processing is performed according to the service.

 Further, when the transmitted HDLC data frame uses a non-standard HDLC technology, for example, using the frame format of Table 2 above, it is detected whether the frame is lost or sorted according to the frame number SN, and then further processed according to the service.

 In the above embodiment, the transmitting end is a BSC, and the data frame is sent to the receiving end BTS through the Abi s interface as an example to describe the data transmission method. When the sending end is a BTS, the data transmission method is similar when the data frame is sent to the receiving end BSC through the Abi s interface, and is not described here.

 The second embodiment of the present invention further provides a device for data transmission, as shown in FIG. 3, including a data information receiving unit 401, a data information transmitting unit 402, a packet transmission interface 403, and a TDM transmission interface 404. The data information receiving unit 401 is used. Receiving data information, for example, receiving data information from a base station or a base station controller;

 The data information sending unit 402 is configured to: when the data information is voice service information, send the data information to a TDM transmission interface, where the data information is packet service information, and send the data information to a packet transmission interface;

 The packet transmission interface 403 is configured to receive and transmit the packet service information.

The packet transmission interface may be an HDLC transmission interface, and the HDLC transmission interface is used to encapsulate the data information The HDLC data frame is loaded and transmitted; for example, when the data information receiving unit 401 receives the packet service information from the base station (BTS), the HDLC transmission interface may encapsulate the packet service information into an HDLC data frame to the base station controller. The BSC transmits; or when the data information receiving unit 401 receives the packet service information from the base station controller BSC, the HDLC transmission interface may encapsulate the packet service information into an HDLC data frame and send it to the base station (BTS).

 The packet transmission interface may also be an ATM transmission interface or an IP interface, and used to encapsulate the data information into an ATM data frame or an IP data frame, and send the data.

 The TDM transmission interface is configured to receive and transmit the voice service information.

 In another embodiment of the present invention, the data information sending unit further includes a QoS information acquiring module, configured to acquire QoS information of the data information, and determine, according to the QoS information, whether the data information is voice service information or packet service information, if it is a grouping The service information is sent to the HDLC transmission interface for transmission, and if it is voice service information, the data information is sent to the TDM transmission interface for transmission.

 When the packet transmission interface is an HDLC transmission interface, the apparatus embodiment of the present invention further includes a packet switching module 405 and a time slot switching module 406, as shown in FIG. 4:

 The packet switching module 405 is configured to receive packet service information sent by the HDLC transmission interface, and exchange HDLC data frames of multiple HDLC packet transmission interfaces to an HDLC transmission interface for transmission; Receiving voice service information sent by the TDM transmission interface, and exchanging TDM data frames of multiple TDM transmission interfaces to a TDM transmission interface for transmission.

 As shown in Figure 5, 1 is a packet switching module, which can exchange data of multiple HDLC channels to one HDLC channel. Different data streams can be distinguished according to the HDLC address field or other user identifiers. With the packet switching module 1, the data transmission between the different base stations can be realized by using the transmission channel between the 1 and the BSC. For example: When there is no data in BTS1, the transmission channel between 1 and BSC can be fully provided to BTS2; conversely, when there is no data to be transmitted in BTS2, the HDLC channel between 1 and BSC is fully provided to BTS1.

 2 is a TDM time slot switching module, which can exchange time slots in different E1/T1 to the same E1. This is a prior art, and those skilled in the art should understand that it will not be repeated here.

ATM technology is similar to HDLC technology, and ATM can also be used in the case of HDLC. Therefore, the present invention The embodiment can also use the ATM transmission interface. Similarly, the packet transmission interface can also use IP technology. When the packet transmission interface is an ATM interface, 1 is an ATM switch, and when the packet transmission interface is an IP interface, 1 is a router or a switch.

 The third embodiment of the present invention further provides a system for data transmission, including a base station 701, a base station controller 703, and a data transmission device 702, as shown in FIG. 6;

 The base station is configured to send data information to the data transmission device, or receive data information from the data transmission device;

 The base station controller is configured to receive data information from the data transmission device, or send data information to the data transmission device;

 The data transmission device includes a data information receiving unit, a data information transmitting unit, a packet transmission interface, and a TDM transmission interface;

 The data information receiving unit is configured to receive data information, for example, receive data information from a base station or a base station controller;

 The data information sending unit is configured to: when the data information is voice service information, send the data information to a TDM transmission interface; where the data information is packet service information, and send the data information to a packet transmission interface ;

 The packet transmission interface is configured to receive and transmit the packet service information;

 The packet transmission interface may be an HDLC transmission interface, and the HDLC transmission interface is configured to encapsulate the data information into an HDLC data frame and transmit the information; for example, receiving, by the data information receiving unit, a packet service from a base station (BTS) The HDLC transmission interface may encapsulate the packet service information into an HDLC data frame and send it to the base station controller BSC; or when the data information receiving unit 401 receives the packet service information from the base station controller BSC, the HDLC transmission interface may The packet service information is encapsulated into HDLC data frames and sent to a base station (BTS).

 The packet transmission interface may also be an ATM transmission interface or an IP interface, and is configured to encapsulate the data information into an ATM data frame or an IP data frame and transmit the data.

The TDM transmission interface is configured to receive and transmit the voice service information. The data information sending unit further includes a QoS information acquiring module, configured to acquire QoS information of the data information, and determine, according to the QoS information, whether the data information is voice service information or packet service information.

 When the packet transmission interface is an HDLC transmission interface, the data transmission device further includes a packet switching module and a time slot switching module;

 The packet switching module is configured to receive packet service information sent by the HDLC transmission interface, and exchange HDLC data frames of multiple HDLC packet transmission interfaces to an HDLC transmission interface for transmission;

 The time slot switching module is configured to receive voice service information sent by the TDM transmission interface, and exchange TDM data frames of multiple TDM transmission interfaces to a TDM transmission interface for transmission. The data transmission device may exist independently or may be located in the base station or in the base station controller.

 It can be seen from the foregoing embodiment that by providing two transmission interfaces, TDM transmission and packet transmission, different services can be used according to different QoS requirements. For voice services, a TDM interface can still be used to ensure delay. The jitter meets the requirements of the protocol and guarantees the transmission QoS. For the packet service, the packet switching module is used to implement the packet service statistical multiplexing function, and the HD is used or the HDLC-like technology to implement the Abis interface split transmission function; Under the premise of service quality, statistical multiplexing of packet services is realized to meet the bandwidth demand of expanding data transmission.

 The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention; although the embodiments of the present invention have been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art will understand that The technical solutions are modified, or some of the technical features are replaced by equivalents; and the modifications and substitutions do not deviate from the spirit and scope of the technical solutions of the embodiments of the embodiments of the present invention.

Claims

 A method for data transmission, comprising:  Receiving data information;  If the data information is voice service information, the data information is sent through a TDM transmission interface;  If the data information is packet right service information, the data information is sent through a packet transmission interface.  2. The method according to claim 1, wherein after receiving the data information, the method further comprises:  Obtaining QoS information according to the data information, and determining the data information according to the QoS information Whether it is voice service information or group service information.  The method of claim 1, wherein the packet transmission interface is an advanced data link control protocol HDLC transmission interface, and the sending the data information through the packet transmission interface is specifically:  Encapsulating the data information into an HDLC data frame;  And transmitting the HDLC data frame through the HDLC transmission interface.  The method of claim 3, wherein the HDLC data frame includes at least a user identification field and an address field, and the HDLC data frame is sent through the HDLC transmission interface, and further includes:  The HDLC data frames of the plurality of HDLC transmission interfaces are switched to an HDLC transmission interface for transmission, and the plurality of HDLC data frames are distinguished by the user identification field. The method of claim 4, wherein the HDLC data frame further includes a priority identifier field, where the transmitting the HDLC data frame through the HDLC transmission interface, further comprising: according to the priority The Level Identification field maps HDLC data frames to different priority queues for transmission. The method of claim 1, wherein the sending the data information through the TDM transmission interface further includes:  The data information is encapsulated into TDM data frames, and TDM data frames of multiple TDM interfaces are exchanged to a TDM transmission interface for transmission.  The method according to claim 1 or 2, wherein the packet transmission interface is an ATM transmission interface or an IP transmission interface.  A data transmission apparatus, comprising: a data information receiving unit, a data information transmitting unit, a time division multiplexing TDM transmission interface, and a packet transmission interface:  The data information receiving unit is configured to receive data information, and send the data information to the data information sending unit;  The data information sending unit is configured to receive the data information, and when the data information is voice service information, send the data information to the TDM transmission interface, when the data information is packet service information, Transmitting the data information to the packet transmission interface;  The TDM transmission interface is configured to receive and transmit the voice service information;  The packet transmission interface is configured to receive and transmit the packet service information.  The device according to claim 8, wherein the data information transmitting unit further comprises:  The QoS information obtaining module is configured to obtain QoS information of the data information, and determine, according to the QoS information, whether the data information is voice service information or packet service information.  The device according to claim 8, wherein the packet transmission interface is an advanced data link control protocol (HDLC) transmission interface, configured to encapsulate the packet service information into an HDLC data frame and transmit the packet.  The device of claim 10, further comprising:  a packet switching module, configured to receive packet service information sent by the HDLC transmission interface, and exchange HDLC data frames of multiple HDLC transmission interfaces to an HDLC transmission interface for transmission; a time slot switching module, configured to receive voice service information sent by the TDM transmission interface, and multiple The TDM data frame of the TDM transmission interface is switched to a TDM transmission interface for transmission.  A data transmission system, comprising: a base station, a base station controller, further comprising the data transmission device according to any one of claims 8 to 11,  The base station is configured to send data information to the data transmission device, or receive data information from the data transmission device;  The base station controller is configured to receive data information from the data transmission device or to transmit data information to the data transmission device.  13. The system of claim 12 wherein said data transmission device is located within a base station or base station controller.