WCDMA MBMS解决方案

多媒体广播/组播业务（MBMS）是一种共享网络资源从一个数据源向多个目标传送数据的技术.MBMS不仅能实现纯文本低速率的消息类组播和广播,还能实现高速多媒体业务的组播和广播.介绍了基于WCDMA PS域网的MBMS网络结构,MBMS提供广播和组播两种业务模式的业务流程,以及3GPP在制定MBMS规范的时候,对无线接口进行的必要修改.最后认为手机电视是MBMS很重要的应用方向.     

IMT—Advanced增强多媒体多播技术

多媒体多播（MBMS）通过点到多点方式实现由一个数据源向多个用户发送数据,能有效节省网络资源,是下一代宽带移动通信系统关注的重点技术。文章基于MBMS技术的发展历程、最新标准进展、前沿研究热点、演进过程,剖析了第3代移动通信系统（UMTS）R6MBMS和第3．9代移动通信系统（LTE）R10增强多媒体多播（E—MBMS）的逻辑架构;阐述了LTER10中E-MBMS的协议设计,包括关键术语、区域配置、逻辑信道映射和复用、控制消息流程及计数过程;给出了IMT—Advanced中E-MBMS技术发展,包括多基站协作、分层编码、喷泉码传输和终端协作传输的新趋势。     

Convolutional fountain distribution over fading wireless channels

Mobile broadband has opened the possibility of a rich variety of services to end users. Broadcast/multicast of multimedia data is one such service which can be used to deliver multimedia to multiple users economically. However, the radio channel poses serious challenges due to its time‐varying properties, resulting in each user experiencing different channel characteristics, independent of other users. Conventional methods of achieving reliability in communication, such as automatic repeat request and forward error correction do not scale well in a broadcast/multicast scenario over radio channels. Fountain codes, being rateless and information additive, overcome these problems. Although the design of fountain codes makes it possible to generate an infinite sequence of encoded symbols, the erroneous nature of radio channels mandates the need for protecting the fountain‐encoded symbols, so that the transmission is feasible. In this article, the performance of fountain codes in combination with convolutional codes, when used over radio channels, is presented. An investigation of various parameters, such as goodput, delay and buffer size requirements, pertaining to the performance of fountain codes in a multimedia broadcast/multicast environment is presented. Finally, a strategy for the use of ‘convolutional fountain’ over radio channels is also presented.     

TD-MBMS的演进及其增强型技术探讨

文章首先介绍了TD-MBMS的演进过程,包括在系统架构、承载类型、传输方式和信道结构上的变化。通过对照现有系统的不足之处,给出了改进的方法,并从中对TD-MBMS的增强型技术进行了探讨。随后文章着重介绍的3GPP R9版本中MBMS的一些新特性,包括BCCH信道参数的变化和DSI的引入,并提出了一些尚待解决的问题。     

Multimedia Broadcast Multicast Service Performance and its Enhancements in WCDMA Networks

Multimedia Broadcast Multicast Service (MBMS) in Wideband Code Division Multiple Access (WCDMA) networks is used to transmit information from one source to vast amount of recipients. The MBMS technique eases the load of the network and therefore allows network to serve more subscribers. The very aim of this study is to evaluate the performance of Release 6 MBMS and its performance enhancements in WCDMA networks. Special attention will be focused on macro and receive diversity which are considered in addition to time diversity provided by long interleaving as enhancements on MBMS performance. 3GPP Release 6 specifications for MBMS introduce two macro diversity schemes: soft and selective combining. The effect of those combining scheme concepts together with and without receive diversity provided by multiple receive antennas are examined. Also, a concept closely related to the receive diversity called Rx-switching i.e., turning the another receive antenna off in good channel situations for power saving purposes is studied. The system level performance of MBMS point-to-multipoint (p-t-m) mode is evaluated with dynamic system level tool in which e.g., mobility of users and interactions of the radio resource management functionalities are explicitly taken into account. Our studies indicate that macro diversity brings significant gains to the MBMS performance. Receive diversity together with macro diversity schemes improves the performance even more and therefore enhances the cell throughput that MBMS can offer. Furthermore, based on the findings of this study it seems that 2Rx Rake receiver can operate with a single antenna significant amount of time without sacrificing desired coverage and thus provide clear power saving opportunities.

基于MBMS的手机电视技术

文章介绍了基于多媒体广播和组播技术(MBMS)的手机电视技术,分析了3GPP中的MBMS技术和基于TD-MBMS的网络架构,并从逻辑结构、业务模式和信道结构等方面简单分析了从MBMS到E-MBMS的演进。     

TD-SCDMA MBMS无线网络规划解决方案

针对TD-SCDMA无线网络引入MBMS业务后的无线信道资源配置以及覆盖问题,文章简要介绍了大唐移动的规划解决方案,对MBMS的信道配置以及MBMS的覆盖规划进行了阐述。     

3GPP LTE标准化进展

为了保持在移动通信领域的技术及标准优势,3GPP启动其长期演进（LTE）的标准化工作。在物理层（层1）、空中接口协议结构层（层2）和网络结构方面,3GPPLTE采纳一系列先进技术和创新理念,IP语音（VoIP）业务和多媒体广播及多播业务（MBMS）的解决方案的优化正在进行中,目前已经实现高数据率、低时延和基于全分组的设计目标。     

TD-SCDMA系统中MBMS业务的终端实现分析

简要介绍了手机电视业务的标准和TD-MBMS组网技术,并重点分析了TD-MBSM终端实现时需要考虑的问题,以及重邮信科MBMS技术方案的主要特点.     

TD-MBMS关键技术及UTN组网试验分析

本文介绍了TD-SCDMA系统的中MBMS技术,深刻描述了MBMS的总体架构和关键技术,对MBMS的组网技术进行了分析;通过在外场的组网测试对UTN宏分集进行了测试和验证,并对测试数据给出对比分析以及得出初步测试结论,最后对MBMS业务应进行了展望。