无线接入网络中的数据传输方法 技术领域 Data transmission method in wireless access network
本发明涉及一种无线网络通信技术,尤其涉及一种无线接入网络 中的数据传输方法。 The present invention relates to a wireless network communication technology, and in particular, to a data transmission method in a wireless access network.
背景技术 Background technique
实现用户终端与核心网络间的数据传输是无线接入网络中实现 不同用户终端间通信的必要条件。 目前, 无线接入网络中的数据传输 的业务均集中于 MC (无线网络控制器) 中, 这种集中了所有无线业 务和控制功能的 RNC对数据业务的传输处理速度大大降低,影响了无 线接入网络的通信质量。 因此, 随着无线网络技术和业务的发展, 无 线接入网络中控制与业务功能的分离已经成为发展趋势。 Data transmission between the user terminal and the core network is a necessary condition for implementing communication between different user terminals in the wireless access network. At present, the data transmission services in the wireless access network are concentrated in the MC (radio network controller). This RNC, which integrates all wireless services and control functions, greatly reduces the transmission and processing speed of data services, which affects the wireless access network. The quality of the incoming communication. Therefore, with the development of wireless network technology and services, the separation of control and service functions in wireless access networks has become a development trend.
在控制与业务功能分离无线接入网络中,与无线接口物理层密切 相关的信令将大部分终止于基站,与业务相关的功能也将逐步移至基 站中。基于这种情况,若仍采用现有无线接入网络中的数据传输方法, 则无法适应这种控制与业务分离的无线接入网络。 In a wireless access network where control and service functions are separated, most of the signaling closely related to the physical layer of the wireless interface will terminate at the base station, and service-related functions will gradually be moved to the base station. Based on this situation, if the existing data transmission method in the wireless access network is still adopted, it cannot adapt to such a wireless access network where control is separated from services.
而且,在现有的无线接入网络与用户终端之间的数据传输都是通 过一个基站提供资源, 数据传输速率受限于该无线传输技术, 很难有 较大幅度的提高,这种状况将无法满足数据传输业务对无线网络传输 速率不断提高的要求。 另外, 无线技术具有的交叉覆盖特性和并行收 发特性使用户设备具有同时与多个基站通信的能力,利用这种能力可 以在单个基站传输能力有限的情况下通过多基站的合作实现更高的 传输性能。 但是, 目前的无线网络标准并没有提供这种由多个基站传
送单个数据业务的方法。 In addition, data transmission between the existing wireless access network and the user terminal provides resources through a base station. The data transmission rate is limited by the wireless transmission technology, and it is difficult to improve it to a large extent. This situation will The data transmission service cannot meet the requirements of increasing wireless network transmission rates. In addition, the cross-coverage and parallel transmission and reception characteristics of wireless technology enable user equipment to communicate with multiple base stations at the same time. With this capability, higher transmission can be achieved through the cooperation of multiple base stations when the transmission capacity of a single base station is limited. performance. However, current wireless network standards do not provide such transmission by multiple base stations. Method for sending single data service.
发明内容 Summary of the Invention
本发明的目是的提供一种无线接入网络中的数据传输方法,使得 无线接入网络中数据传输速率的大幅度提高成为可能。 The purpose of the present invention is to provide a data transmission method in a wireless access network, which makes it possible to greatly increase the data transmission rate in a wireless access network.
本发明的目的是这样实现的: 无线接入网络中的数据传输方法, 包括: The object of the present invention is achieved as follows: A data transmission method in a wireless access network includes:
在下行阶段, 用户数据从核心网传送给用户终端: In the downlink phase, user data is transmitted from the core network to the user terminal:
( 1 )无线接入网网关从核心网接收用户数据, 并将其转换成相 应的帧格式; (1) The radio access network gateway receives user data from the core network and converts it into a corresponding frame format;
( 2 ) 无线接入网网关将用户数据帧通过无线承载传送给基站; (2) the radio access network gateway transmits the user data frame to the base station through a radio bearer;
( 3 )基站将数据帧编码调制转换成无线接口的传输块, 通过物 理信道发送给用户终端; (3) The base station encodes and modulates the data frame into a transmission block of the wireless interface, and sends it to the user terminal through a physical channel;
在上行阶段, 用户数据从用户终端传送到核心网: In the uplink phase, user data is transmitted from the user terminal to the core network:
( 4 )基站从用户终端接收传输块, 将其解调解码转换成相应的 数据帧; (4) The base station receives the transmission block from the user terminal, and demodulates and converts the transmission block into a corresponding data frame;
( 5 )基站将数据帧通过无线承载传送给无线接入网网关; ( 6 ) 无线接入网网关将基站传来的数据帧进行格式转换后发送 给核心网。 (5) The base station transmits the data frame to the radio access network gateway through the radio bearer; (6) The radio access network gateway converts the data frame transmitted from the base station to the core network after format conversion.
所述的步骤(2 ) 包括: The step (2) includes:
( 21 )无线接入网网关将各个用户的数据帧复用在 IP数据报中; (21) The radio access network gateway multiplexes the data frames of each user in the IP datagram;
( 22 )将 IP数据报分别发送给服务基站和漂移基站。 (22) Send the IP datagram to the serving base station and the drift base station respectively.
所述的服务基站为一个;所述的漂移基站的数目为才艮据用户的数
据流量、 数据传输质量和数据传输速率确定。 The serving base station is one; the number of the drifting base stations is the number of users according to the number of users. Determined based on traffic, data transmission quality, and data transmission rate.
所述的步驟(22 ) 包括: The step (22) includes:
( 31 )如果无线接入网网关与漂移基站间存在直接传输链路, 则 无线接入网网关直接向漂移基站传输数据; (31) If there is a direct transmission link between the radio access network gateway and the drift base station, the radio access network gateway directly transmits data to the drift base station;
( 32 )如果无线接入网网关与漂移基站间不存在直接传输链路, 则无线接入网网关通过服务基站向漂移基站传输数据。 (32) If there is no direct transmission link between the radio access network gateway and the drift base station, the radio access network gateway transmits data to the drift base station through the serving base station.
所述的步骤(3 ) 包括: The step (3) includes:
( 41 )基站对接收的 IP数据报进行解复用 , 得到各个用户的数 据帧; (41) The base station demultiplexes the received IP datagram to obtain a data frame of each user;
( 42 )服务基站与漂移基站间交换用户数据和与数据传输相关的 控制信令; (42) The user base station and the drift base station exchange user data and control signaling related to data transmission;
( 43 )基站对数据帧进行编码调制生成无线传输块; (43) The base station performs code modulation on the data frame to generate a wireless transmission block;
( 44 )基站将无线传输块通过无线信道传送给用户终端; ( 45 )用户终端对无线传输块进行解调和解码,得到用户数据帧; ( 46 )用户终端对来自各个基站的同一业务数据帧进行组合, 得 到完整的数据帧。 (44) The base station transmits the wireless transmission block to the user terminal through the wireless channel; (45) The user terminal demodulates and decodes the wireless transmission block to obtain a user data frame; (46) The user terminal performs the same service data frame from each base station Combine them to get the complete data frame.
所述的步骤( 45 )为: 用户终端根据服务基站和漂移基站发来的 传输块承载的互不相同的扰码分别对其进行接收和解码。 The step (45) is as follows: the user terminal receives and decodes the transmission block bearers transmitted by the serving base station and the drifting base station with different scrambling codes, respectively.
所述的核心网与无线接入网网关间、 无线接入网网关与基站间、 基站与基站之间的数据传输采用基于 IP协议的传输协议栈。 The data transmission between the core network and the radio access network gateway, between the radio access network gateway and the base station, and between the base station and the base station uses a transmission protocol stack based on the IP protocol.
所述的步骤(21 ) 中复用后的 IP数据报结构包括: The multiplexed IP datagram structure in the step (21) includes:
连接标识字段: 连接标识用于标识被复用数据的来源;
数据序列号字段:数据序列号用于标识被复用数据在相应来源中 的位置。 Connection ID field: The connection ID is used to identify the source of the multiplexed data; Data sequence number field: The data sequence number is used to identify the position of the multiplexed data in the corresponding source.
所述的复用后的 IP数据报结构还包括: The multiplexed IP datagram structure further includes:
复用头字段: 复用头用于标识数据的复用状态。 Multiplexing header field: Multiplexing header is used to identify the multiplexing status of the data.
传输层协议采用 UDP (用户数据报协议) 时, 所述的连接标识 为 UDP端口号。 When the transport layer protocol uses UDP (User Datagram Protocol), the connection identifier is a UDP port number.
传输层协议采用 RTP (实时传输协议) 时, 所述的连接标识为实 时业务的同步源标识。 When the transport layer protocol uses RTP (Real-time Transport Protocol), the connection identifier is a synchronization source identifier of a real-time service.
由上述技术方案可以看出,本发明是通过在无线接入网络中建立 的无线接入网网关和基站直接在用户终端与核心网之间传送用户数 据。这种基于无线接入网络中数据业务功能与控制功能分离的数据传 输方法, 有利于加快数据在无线接入网络中的传输速度, 提高日益增 长的高速数据业务的传输性能, 适应无线通信技术发展的需要。 本发 明还提供了由多个基站传送单个数据业务的数据传输方法,进一步为 大幅度提高无线接入网络中数据传输速度提供了可能性。 It can be seen from the above technical solution that the present invention directly transmits user data between a user terminal and a core network through a radio access network gateway and a base station established in a radio access network. This data transmission method based on the separation of data service functions and control functions in a wireless access network is beneficial to speeding up the transmission speed of data in the wireless access network, improving the transmission performance of increasingly high-speed data services, and adapting to the development of wireless communication technologies Need. The present invention also provides a data transmission method for transmitting a single data service by multiple base stations, further providing the possibility for greatly improving the data transmission speed in a wireless access network.
附图说明 BRIEF DESCRIPTION OF THE DRAWINGS
图 1为本发明应用的无线接入网络结构示意图; FIG. 1 is a schematic structural diagram of a wireless access network applied by the present invention;
图 2 为本发明中无线接入网网关与多个基站的数据传输示意图 FIG. 2 is a schematic diagram of data transmission between a radio access network gateway and multiple base stations in the present invention
A; A;
图 3 为本发明中无线接入网网关与多个基站的数据传输示意图 FIG. 3 is a schematic diagram of data transmission between a radio access network gateway and multiple base stations in the present invention
B; B;
图 4为本发明的具体实施流程图;
图 5为带有复用标识的 IP数据报结构示意图。 4 is a flowchart of a specific implementation of the present invention; FIG. 5 is a schematic diagram of an IP datagram structure with a multiplexing identifier.
具体实施方式 所示的控制与业务功能分离的无线接入网络,该网络将现有的 RNC分 为控制与业务两种实体, 一种实体为无线接入网网关: 负责核心网业 务节点与基站之间的数据传输, 另一种实体为无线接入服务器: 负责 无线资源管理和移动性管理等功能。 The radio access network with separated control and service functions is shown in the detailed description. The network divides the existing RNC into two types of control and service entities. One entity is a radio access network gateway: responsible for core network service nodes and base stations. Data transmission between the other entities is a wireless access server: responsible for functions such as wireless resource management and mobility management.
基于上述无线接入网网关,本发明所述的无线接入网络中的数据 传输方法包括:用户数据从核心网传送给用户终端的下行阶段和将用 户数据从用户终端传送到核心网的上行阶段,现结合图 4对下行阶段 的数据传输过程进行说明, 具体过程如下: Based on the above radio access network gateway, the data transmission method in the radio access network according to the present invention includes: a downlink phase in which user data is transmitted from the core network to the user terminal and an uplink phase in which the user data is transmitted from the user terminal to the core network. Now, the data transmission process in the downlink phase will be described with reference to FIG. 4. The specific process is as follows:
步骤 1: 无线接入网网关通过 Iu- U接口从核心网接收用户数据, 并将其转换成 lug接口的帧格式; Step 1: The radio access network gateway receives user data from the core network through the Iu-U interface and converts it into the frame format of the lug interface;
lug接口包括无线接入网网关与服务基站之间的接口 Iugl ,及无 线接入网网关与漂移基站之间的接口 Iug2 , 如图 2所示; The lug interface includes the interface Iugl between the radio access network gateway and the serving base station, and the interface Iug2 between the wireless access network gateway and the drift base station, as shown in Figure 2;
Iugl 接口上的帧格式主要是由无线接入网网关和服务基站在建 立 Iugl接口上的传输链路时通过协商而确定; Iug2接口上的帧格式 通常与 Iugl接口上的帧格式相同, 以使漂移基站便于在传输数据的 过程中与服务基站通过 IuNB接口的帧同步实现用户数据的传输同 步; The frame format on the Iugl interface is mainly determined through negotiation between the radio access network gateway and the serving base station when establishing a transmission link on the Iugl interface; the frame format on the Iug2 interface is usually the same as the frame format on the Iugl interface, so that The drift base station is convenient to realize the synchronization of user data transmission through the frame synchronization of the IuNB interface with the serving base station during the data transmission process;
然后, 无线接入网网关需要通过 lug接口 (包括 Iugl和 Iug2 ) 将用户数据帧发送至基站, 基站包括服务基站和漂移基站, 具体过程
包括: Then, the radio access network gateway needs to send user data frames to the base station through the lug interface (including Iugl and Iug2), and the base station includes the serving base station and the drift base station. The specific process Including:
步骤 2: 在无线接入网网关中将用户数据帧封装至 IP数据报中; 不同用户的数据帧可以通过复用的方式封装在同一个 IP数据报 里,封装后的数据报结构如图 5所示,以便提高 lug接口的传输效率, 在 IP 数据报中的复用数据可以通过连接标识符和数据序列号来标 识,其中连接标识符主要用来识别被复用数据来自哪一个用户的哪一 个连接;数据序列号用来标识被复用数据是某一个用户的第几个数据 分組, IP 数据^ :艮中还可以用一个复用头用来标识用户数据的复用状 态, 以便提高解复用时的速度; Step 2: Encapsulate user data frames into IP datagrams in the radio access network gateway; data frames of different users can be encapsulated in the same IP datagram by multiplexing. The structure of the encapsulated datagram is shown in Figure 5 As shown, in order to improve the transmission efficiency of the lug interface, the multiplexed data in the IP datagram can be identified by the connection identifier and the data sequence number, where the connection identifier is mainly used to identify which user the multiplexed data comes from. One connection; the data sequence number is used to identify the multiplexed data is the number of data packets of a certain user, IP data ^ : A multiplexing header can also be used to identify the multiplexing status of user data in order to improve the resolution Speed during multiplexing;
连接标识符对于不同的传输控制层协议一般是不同的, 例如: 基 于 UDP协议的连接采用 UDP端口号作为连接标识符;而基于 RTP协议 的连接则采用实时流的同步源标识作为连接标识符; Connection identifiers are generally different for different transmission control layer protocols. For example: UDP-based connections use UDP port numbers as connection identifiers; RTP-based connections use real-time stream synchronization source identifiers as connection identifiers;
步驟 3:通过 lug接口上的传输网络层将上述经过复用封装的 IP 数据报从无线接入网网关传送到基站端,基站包括服务基站和漂移基 站; Step 3: The multiplexed and encapsulated IP datagram is transmitted from the radio access network gateway to the base station through the transmission network layer on the lug interface. The base station includes the serving base station and the drift base station;
对于某一个数据业务,必然需要有一个服务基站提供与用户终端 的数据链路, 以通过该链路进行数据传输; 同时, 对于同一个数据业 务, 还可能有一个或多个漂移基站提供与用户终端的数据链路, 并利 用这些数据链路向用户终端传输服务基站无法承担的用户数据,或者 向用户终端传输能够提高服务基站数据传输质量或传输速度的信息, 所采用的漂移基站的数目根据用户的数据流量、数据传输质量和数据 传输速率确定;
当无线接入网网关与漂移基站之间有直接的链路连接时,无线接 入网网关与漂移基站之间通过 Iug2接口传输用户数据,如图 2所示; 当无线接入网网关与漂移基站之间没有直接的链路连接时,无线 接入网网关通过服务基站向漂移基站传输用户数据,服务基站与漂移 基站之间为通过 IuNB接口传输用户数据, 如图 3所示; For a certain data service, it is necessary to have a serving base station to provide a data link with the user terminal for data transmission through the link. At the same time, for the same data service, there may be one or more drifting base stations to provide the user with the user. The data link of the terminal, and use these data links to transmit user data that the serving base station cannot bear to the user terminal, or to transmit to the user terminal information that can improve the data transmission quality or transmission speed of the serving base station. The number of drifting base stations used is based on The user's data traffic, data transmission quality and data transmission rate are determined; When there is a direct link connection between the radio access network gateway and the drift base station, user data is transmitted between the radio access network gateway and the drift base station through the Iug2 interface, as shown in Figure 2; When there is no direct link connection between the base stations, the radio access network gateway transmits user data to the drift base station through the serving base station, and the user base station and the drift base station transmit user data through the IuNB interface, as shown in FIG. 3;
步骤 4: 在基站中将 IP数据报解封装, 恢复用户数据帧, 即得 到不同用户的数据帧; Step 4: Decapsulate the IP datagram in the base station and recover the user data frame, that is, the data frames of different users are obtained;
不同用户的数据帧被与上述复用过程完成相逆的解复用过程从 IP数据报中取出, 放入等待空中接口传输的队列里; The data frames of different users are taken out of the IP datagram by a demultiplexing process that is inverse to the above-mentioned multiplexing process, and are put into a queue waiting for transmission on the air interface;
步骤 5: 服务基站与一个或多个漂移基站通过 IuNB接***换与 数据传输相关的信令; 当无线接入网网关与漂移基站之间没有直接 的链路连接时, 服务基站与漂移基站之间还通过 IuNB接口传输用户 数据; Step 5: The serving base station and one or more drifting base stations exchange signaling related to data transmission through the IuNB interface; when there is no direct link connection between the radio access network gateway and the drifting base station, the serving base station and the drifting base station User data is also transmitted through the IuNB interface;
之后便是用户数据在空中无线接口的传输过程, 包括: 步骤 6: 由基站(包括服务基站和漂移基站)将等候在上述无线 接口传输队列中的数据帧编码调制生成无线传输块; The following is the transmission process of user data over the air wireless interface, including: Step 6: The base station (including the serving base station and the drift base station) encodes and modulates the data frames waiting in the wireless interface transmission queue to generate a wireless transmission block;
步棟 7: 基站将上述无线传输块通过无线接口 (包括图 2、 图 3 所示的无线接口 1和无线接口 2 )上的无线信道传送到 UE (用户)端; 服务基站与漂移基站通过空中接口 1和空中接口 2向 UE的传输 在一般情况下是并行的, UE通过服务基站和漂移基站中不同小区所 采用的扰码来区别来自不同小区的传输块,并用与小区——对应的接 收器对这些传输块分别接收和解码;
步骤 8: UE端对接收到抚线传输块进行解调和解码, 取出其中的 用户数据帧; Step 7: The base station transmits the above wireless transmission block to the UE (user) through a wireless channel on the wireless interface (including wireless interface 1 and wireless interface 2 shown in FIG. 2 and FIG. 3); the serving base station and the drifting base station pass through the air The transmission from the interface 1 and the air interface 2 to the UE is generally parallel. The UE distinguishes the transmission blocks from different cells by using the scrambling codes used by different cells in the serving base station and the drift base station, and uses the reception corresponding to the cell- The receiver receives and decodes these transmission blocks separately; Step 8: The UE demodulates and decodes the received transmission block, and takes out a user data frame therefrom.
步骤 9: UE中的应用协议层将分别来自服务基站和漂移基站的数 据帧组合成为与 Iu-u接口上的数据帧相同的用户数据帧, 即组合成 为无线接入网网关从核心网接收的原始数据帧。 Step 9: The application protocol layer in the UE combines the data frames from the serving base station and the drift base station into the same user data frame as the data frame on the Iu-u interface, that is, the radio access network gateway receives the data frame from the core network Raw data frame.
至此,完成了控制和业务功能分离的无线接入网络中的下行数据 传输过程。 So far, the downlink data transmission process in the radio access network with separated control and service functions has been completed.
因为上行阶段与下行阶段的数据传输过程类似,所以对上行阶段 的数据传输过程不再做详细说明, 仅说明其中的主要数据传输过程, 过程如下: Because the data transmission process in the upstream phase is similar to the data transmission phase in the downstream phase, the data transmission process in the upstream phase will not be described in detail, and only the main data transmission process will be described. The process is as follows:
第一步: 基站通过无线接口从用户终端接收传输块, 将其解调解 码转换成 lug接口的数据帧; Step 1: The base station receives the transmission block from the user terminal through the wireless interface, and demodulates it into a data frame of the lug interface.
第二步:基站将数据帧通过 lug接口的无线承载传送给无线接入 网关; Step 2: The base station transmits the data frame to the wireless access gateway through the radio bearer of the lug interface;
第三步: 无线接入网关将基站传来的数据帧转换成为 Iu接口的 数据帧格式, 发送给核心网中适当的媒体网关节点; Step 3: The wireless access gateway converts the data frame transmitted from the base station into the data frame format of the Iu interface and sends it to the appropriate media gateway node in the core network.
当多个基站间存在宏分集的情况时,无线接入网关先将多个基站 传输的数据帧合成正确的数据帧, 然后进行帧格式转换。
When there is macro diversity between multiple base stations, the wireless access gateway first synthesizes the data frames transmitted by the multiple base stations into correct data frames, and then performs frame format conversion.