卫星集群IP多播组呼业务协议研究

现有集群通信覆盖范围有限,为实现全方位集群通信,提出将卫星通信与集群通信相结合。以TETRA为例,分析了现有国内外集群通信系统集群业务的实现方式。针对电路域集群,提出实现分组域多媒体集群。为更利于工程实现,提出了基于MBMS技术的卫星集群IP多播组呼业务协议流程,并分析了实现中需要解决的关键问题及解决方案。该方案将为卫星移动通信集群业务的发展提供新的方向。     

Error resilient video over multimedia broadcast multicast services (MBMS)

With available data rates for mobile devices constantly increasing, services such as video broadcast and multicast are becoming feasible. A new standard called Multimedia Broadcast Multicast Services (MBMS) is being developed by 3GPP to enable new class of spectrum-efficient multimedia services. Multicast services are expected to serve a diverse user base with varying connectivity and capabilities. We analyze the problem of video error resilience in MBMS services that is critical to maintain consistent quality for end users. The existing error resilience techniques for IP multicasting are not applicable in the MBMS environment. In this paper, we present error resilience techniques that are applicable within the context of the MBMS standard. We propose an Intra Block Refresh method for MBMS services and the results show improved performance. We develop a methodology that can be applied to adapting traditional error resilience tools for the MBMS environment.     

实现手机电视的技术方式

DVB-H手机电视技术从传统的数字电视技术演进而来并广泛应用于3G移动通信中。回顾数字电视技术的发展历史,比较基于手机的流媒体业务、MBMS、DVB-H、MediaFLO和DVB-S不同调制方式的数字电视技术的优缺点,并分析5种传输系统在不同网络环境中的运行性能。     

TD-MBMS物理层方案研究

第三代移动通信技术TD-SCDMA发展至今,R4,R5已经商用普及,手机电视业务的需求更加强烈,对MBMS提出了更高的要求,基于MBMS的技术要求,通过借用cost231_hata模型的市区环境,分别对SFN检测技术和联合检测两种宏分集技术进行测试仿真,得到了两种宏分集的的优缺点,并提出改进方案。     

3G杀手业务“BCMCS”

本文对CDMA2000网络中的BCMCS业务进行了介绍，主要涉及BCMCS的网络结构、业务流程、承栽链路的建立、网络协议栈等方面。     

一种有效的MBMS业务调度方法

由于无线链路的容量受限,广播组播信道需要更加科学的调度机制,以便充分地利用无线资源。文章在综合考虑CN业务调度、RAN业务调度策略以及反馈机制的基础上,提出了一种有效用于MBMS业务的端到端调度方法,并给出了业务调度的仿真分析。该方法包括从所有实体中分离调度子功能的分配方法、反馈策略以及架构的演进。     

MBMS业务中的解密算法的研究

MBMS移动多媒体广播/组播业务,基于广播业务的一对多的特性,为了保证数据传输过程的保密性,流媒体传输过程的安全问题已受到普遍关注.一个具有安全保护功能的RTP协议即SRTP协议系统的实现不仅有利于对抗网络安全攻击,而且能够为用户提供隐私、加密和认证保护.因此,MBMS中的解密算法的研究就显得非常重要.     

MBMS中模型的关系表达和自动复合研究

由于决策环境的变化及决策范围的扩展,DSS中模型不断被分批开发和增加,同时决策问题的复杂性往往导致模型的多样性,由此模型关系的表达和管理往往比较复杂,模型间的冗余及整体关系难于掌握。使用扩展的Petri网表达MBMS中各模型的相互关系,论述了PN自动成图算法,增强决策者对整个MBMS的整体掌握程度,有利于发现模型间的求解冲突与冗余;同时,通过从决策目标出发,通过基于PN的逆向推导,发现决策问题求解路径,降低了DSS应用门槛。     

The multimedia broadcast/multicast service

This article provides an overview of the multimedia broadcast/multicast service (MBMS) for universal mobile telecommunications system (UMTS) networks. We first outline the features of UMTS networks as defined by the 3rd generation partnership project (3GPP) in order to provide a background for the discussion to follow. We then present the overall MBMS architecture, the services that it provides to the users and the differences between the broadcast and multicast options. The implementation details of MBMS are explained in terms of the modifications needed to the network, the new signaling procedures required and the impact of MBMS on the radio part of the network. We then describe how the security architecture of UMTS is used to support content protection and key distribution for MBMS groups. We evaluate the prospects of MBMS by comparing it first with IP multicast and then with DVB‐H, considered by many to be the closest competitor of MBMS. Finally, we conclude with a discussion of the technical and business challenges still faced by MBMS. Copyright © 2006 John Wiley & Sons, Ltd.     

LTE架构下的多媒体资源分发方案研究

为了提高3G以及未来的移动通信系统中多媒体数据的传输率,文章提出了结合点对点(P2P)和增强型多媒体组播和广播业务(E-MBMS)技术的LTE环境下的多媒体资源分发(CPEMRD)方案。该方案结合了P2P的扩展能力和E-MBMS的可靠性、可管理性,构建了可管理的、能够承载电信级内容应用的多媒体资源分发平台。该方案缓解了终端接入数量受限以及带宽窄、通信不稳定的问题,实现了用户间点对点互动功能。