Cost analysis and efficient radio bearer selection for multicasting over UMTS

Along with the widespread deployment of the Third Generation (3G) cellular networks, the fast‐improving capabilities of the mobile devices, content, and service providers are increasingly interested in supporting multicast communications over wireless networks and in particular over Universal Mobile Telecommunications System (UMTS). To this direction, the Third Generation Partnership Project (3GPP) is currently standardizing the Multimedia Broadcast/Multicast Service (MBMS) framework of UMTS. In this paper, we present an overview of the MBMS multicast mode of UMTS. We analytically present the multicast mode of the MBMS and analyze its performance in terms of packet delivery cost under various network topologies, cell types, and multicast users' distributions. Furthermore, for the evaluation of the scheme, we consider different transport channels for the transmission of the multicast data over the UMTS Terrestrial Radio‐Access Network (UTRAN) interfaces. Finally, we propose a scheme for the efficient radio bearer selection that minimizes total packet delivery cost. Copyright © 2008 John Wiley & Sons, Ltd.     

Exploiting MIMO Technology for Optimal MBMS Power Allocation

In mobile networks, the provision of rich multimedia services, such as Mobile TV, is considered of key importance. To this end, Multimedia Broadcast/Multicast Service (MBMS)—that was introduced in the Release 6 of Universal Mobile Telecommunication System (UMTS)—is envisaged to play an instrumental role in the proliferation of mobile market. The reason behind the design of MBMS was the need to provide multiple users with the same data at the same time in 3GPP (3rd Generation Partnership Project) cellular networks. Still, MBMS performance is limited by the base stations’ transmission power. As an aftermath, efficient power allocation techniques should be implemented so as to ensure the mass provision of multimedia applications to mobile users. This paper proposes a novel mechanism for efficient radio bearer selection during MBMS transmissions. The proposed mechanism is based on the concept of transport channels combination in any cell of the network. Furthermore, the mechanism exploits the performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas and manages to efficiently deliver multiple MBMS sessions. The proposed mechanism is thoroughly evaluated and compared with the radio bearer selection mechanisms proposed by 3GPP.     

Cost optimization of MBSFN and PTM transmissions for reliable multicasting in LTE networks

Long Term Evolution (LTE) systems have been specified and designed to accommodate small, high performance, power-efficient, end-user devices. The evolved Multimedia Broadcast/Multicast Service (e-MBMS) feature is introduced by the 3rd Generation Partnership Project (3GPP) as a complement to the existing MBMS service in order to accommodate multicast groups that are interested in receiving the same data. MBMS service is provided by MBMS over a Single Frequency Network (MBSFN) and/or Point-To-Multipoint (PTM) transmission methods. One of the challenges of MBMS is the complete error recovery of the transmitted files, a matter of great importance since the distribution of binary data must result in 100% error-free download. To fulfill this tight requirement, Forward Error Correction (FEC) mechanism has been proposed by 3GPP. In this work, we investigate the reliable multicasting by introducing a transmission method that combines the advantages of MBSFN and PTM transmission methods. We compare several FEC-based file recovery methods and evaluate them against various network parameters in a realistic simulation environment. The comparison is based on a cost-oriented analysis of MBMS service that takes into account the transmission cost over all the interfaces and nodes of the LTE architecture. The simulation results are performed with the aid of a new simulation tool and show that the performance of the file repair schemes depend on the network configuration.     

国际手机电视技术现状研究综述

介绍了手机电视技术特点,并比较了3种实现方法.重点阐述了多媒体广播组播业务,DVB-H,T-DMB,S-DMB等技术方案.最后,分析了手机电视技术所面临的一些问题.     

基于GBA的MBMS终端安全体系研究

给出了3GPP中基于GBA的多媒体广播组播业务（MBMS）安全体系结构,分析了MBMS基于GBA的终端密钥管理体系及实现流程。     

An Efficient Mechanism for UMTS Multicast Routing

In this paper, we present a novel scheme for the multicast transmission of data over Universal Mobile Telecommunications System (UMTS) networks. Apart from the normal multicast transmission over UMTS, we consider the handling of exceptional cases caused by user mobility scenarios. The proposed scheme is in accordance with the current specifications of the Multimedia Multicast/Broadcast Service (MBMS) defined by the 3rd Generation Partnership Project (3GPP) and introduces minor modifications in the UMTS architecture and the mobility management mechanisms. The proposed scheme is implemented as an ns-2 network simulator module. The performance of the proposed scheme is validated and analyzed through ns-2 simulation experiments. This new module can be employed to investigate various aspects of UMTS multicast. Furthermore, in order to further highlight the contribution of our mechanism, we have implemented two multicast congestion control mechanisms for UMTS and we have measured their performance for MBMS transmissions.     

An improved mechanism for multiple MBMS sessions assignment in B3G cellular networks

In Universal Mobile Telecommunication System (UMTS), the downlink capacity is limited by the base station transmission power. Therefore, power control plays an important role to minimize the transmitted power shared among unicast and multicast users within a cell. In Multimedia Broadcast/Multicast Service (MBMS), power control targets to the efficient utilization of radio and network resources. However, the expected high demand for such services stresses the need for an efficient scheme, capable of dynamically allocating radio resources to parallel MBMS sessions. This paper proposes a power control mechanism for efficient MBMS session assignment in next generation UMTS networks. The mechanism shares efficiently the available power resources of UMTS base stations to MBMS sessions running in the network. Furthermore, the mechanism is evaluated through several realistic scenarios and the results indicate the ability of the mechanism to utilize efficiently the radio resources and to ensure the service continuity when parallel MBMS services run in the network. Our approach is compared with current 3rd Generation Partnership Project (3GPP) approaches, such as these presented in TS 25.346 and in TR 25.922, in order to highlight the enhancements that it provides.     

MBMS密钥分发过程研究

移动多媒体业务是3G的关键业务,3GPP R6版本中引入多媒体广播组播业务MBMS(Multimedia Broadcast Multicast Service).业务安全在多媒体广播组播业务中至关重要,文中给出了3GPP中MBMS的密钥管理体系和基于GBA的MBMS业务安全体系架构,并分析了MBMS密钥分发的具体实现流程.     

动态控制MBMS速率提高移动网络利用率

文中提出了两种通过动态控制MBMS(多媒体广播及组播)业务速率以提高网络利用率的方法.现有的MBMS业务都只能通过分配固定空口资源给用户提供固定不变的数据速率.文中通过分析移动网络中不同MBMS业务之间和非MBMS业务之间的资源抢占情况,发现动态调整MBMS业务数据速率可以极大提高网络利用率.根据此结论,设计可分层信息编码和设计不同数据流都可以实现动态控制.这两种解决方案都具有极高的使用价值.     

MBMS及其演进

首先介绍了3GPP的多媒体广播和多播业务(MBMS)标准。借助于MBMS,在蜂窝网络中引入了广播和多播能力。而后,论述了MBMS在3GPP后续版本中的演进,重点关注演进的体系结构和MBSFN的概念,最后给出了结论。     

MIMO Based Radio Resource Management for UMTS Multicast Broadcast Multimedia Services

MIMO systems promise high performance gains over conventional single antenna systems. To accomplish high data rates over wireless links the use of multiple transmit and receive antennas is an alternative that does not require any extra bandwidth. It has the potential to address the unprecedented demand for wireless services, particularly for the Multimedia Broadcast Multicast Service (MBMS). This service supports downlink streaming and download-and-play type services to large groups of users. From the radio perspective, MBMS includes point-to-point (PtP) and point-to-multipoint (PtM) modes. New proposed MBMS related enhancements in the physical layer specifications and their effects on resource requirements are presented in this paper, such as the use of High Speed Downlink Packet Access (HSDPA) to broadcast/multicast video streaming using the Deficit Round Robin (DRR) scheduler algorithm as a way to maintain an acceptable QoS for all the users. Other improvements, based on the use of MIMO including macro-diversity, are independent of the mode used and are dependent on deployment scenarios, but can yield substantial reduction in resource demand.     

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.

A forward fast media independent handover control scheme for Proxy Mobile IPv6 (FFMIH-PMIPv6) over heterogeneous wireless mobile network

Proxy Mobile IPv6 (PMIPv6) is a networked-based handover protocol for the IP layer, i.e., the layer 3 mobility management protocol. In this work, we integrate fast handover and IEEE 802.21 Media Independent Handover (MIH) Services with PMIPv6 to improve the handover performance over the heterogeneous wireless network environment. Since it may have multiple candidate destination networks to which a Mobile Node can select for handover, it needs to consider not only the signal strength but also the corresponding networking situation for the proper selection of the next network. To reduce the packet loss situation, the multicast mechanism is adopted to forward packets to these candidate destination networks during the handover processing period. In this work, a Forward Fast Media Independent Handover Control Scheme for Proxy Mobile IPv6 (FFMIH-PMIPv6) is proposed based on the aforementioned concerns. Through the simulations for performance analysis, it shows that the proposed FFMIH-PMIPv6 can have better handover performance in terms of handover latency, packet loss rate and throughput.     

Efficient Resource Allocation Based on Layered Coding in Single Frequency Network with Limited Feedback Scheme

Single frequency network (SFN) can provide Multimedia Broadcast Multicast Service (MBMS) over a large coverage area, so it receives more and more attention from both academia and industry. However, the application of SFN is still restricted by a large number of feedbacks. Therefore, we propose a novel multicast resource allocation algorithm based on limited feedback scheme. In the algorithm, we first design a user limited feedback scheme based on channel gain threshold to effectively reduce feedback load. The scheme determines to which base stations users should report channel state information. Next, to overcome the MBMS capacity limitation drawback, we encode the MBMS data into a base layer and multiple enhancement layers and develop a joint subcarrier and power allocation strategy to maximize the throughput of enhancement layers while guaranteeing the rate requirement of base layer. Simulation results show that the proposed algorithm significantly reduces 83 % of the feedback overhead while achieving a comparable multicast throughput performance to the case of full feedback.     

一种IMS与MBMS融合的方案设计

介绍了多媒体广播组播服务(MBMS)和IP多媒体系统(IMS)的融合方案,分析了该方案的系统架构设计和关键步骤的信令流程.最后,在该方案基础上提出了应用实例,并对该方案的应用前景进行了展望.     

On the Multi-Resolution Techniques for LTE-Advanced

A coordinated multi-resolution and multi-point MIMO transmission method for the LTE-Advanced is presented considering the Evolved-Multimedia Broadcast/Multicast Service (E-MBMS). Fixed relays with MIMO and different adaptive frequency reuse schemes are considered in the proposed scheme to improve the E-MBMS spectral efficiency at the cell borders and/or to save transmission power from the base stations and relays. In order to provide additional diversity over Rayleigh multi-path fading channels, a signal space diversity based on Complex Rotation Matrices (CRM) is used, associated to MIMO, as a multi-resolution technique. The decoding of these signals are facilitated with the use of Maximum Likelihood Soft Output (MLSO) criterion, included in the proposed receiver. The link performance of the MIMO system turbo-coded with hierarchical constellations and CRM is analyzed in terms of bit and block error rate (BER/BLER). The corresponding system level coverage and throughput gains are also evaluated associated to the presence or not of fixed relays and measuring the maximum spectral efficiencies at cell borders of single cell point-to-multipoint or single frequency network. The influence of the cell radius in the performance of the previous cellular topologies with coordinated MIMO transmissions is also evaluated.     

基于LTE MBMS的手机电视业务的研究

文章介绍了目前世界手机业务的发展状况,分析了普遍使用的3G网络中的手机电视业务的应用瓶颈、弊端,并对手机电视业务的载体多媒体广播/组播业务（MBMS）网络结构、业务流程进行了分析,对基于长期演进（LTE）网络MBMS技术从逻辑架构、业务模式、传输模式、信道结构等方面进行了分析研究,最后给出了LTE中MBMS的实现方法及LTE网络中基于MBMS技术的手机电视业务的流程。     

Embracing RaptorQ FEC in 3GPP multicast services

Multimedia Broadcast/Multicast Services (MBMS) have been introduced by Third Generation Partnership Project (3GPP) aiming to efficiently deliver data to mobile users in a one-to-many way. In order to provide reliable multicast transmission, 3GPP recommends exclusively for MBMS the use of a Forward Error Correction (FEC) mechanism on the application layer. Raptor codes are standardized as the Application Layer FEC (AL-FEC) scheme over 3GPP MBMS. However, the 3GPP standardized systematic fountain Raptor code is nowadays considered obsolete, since a new variation of the Raptor codes has emerged. This enhanced AL-FEC scheme, named RaptorQ, promises higher protection efficiency and superior flexibility on the provision of demanding mobile multicast services. In this work, we provide an extensive performance evaluation presenting at first a theoretical performance comparison of the newly introduced RaptorQ FEC scheme with its predecessor Raptor code, examining the enhancements that RaptorQ introduces on the AL-FEC protection robustness. Thereafter, to verify the enhanced performance of RaptorQ, we present several simulation results considering the modeling of the AL-FEC protection over multicast services for next generation mobile networks, utilizing the ns-3 simulation environment. Investigating several mobile system parameters in conjunction with FEC encoding parameters, we provide valuable results regarding the impacts of the examined AL-FEC schemes application on the multicast services performance.     

An improved MBMS power counting mechanism towards long term evolution

One of the key objectives of beyond 3rd generation mobile networks is the realization of enhanced end-user experience through the provision of rich multimedia services. Multimedia Broadcast/Multicast Services (MBMS) framework epitomizes the increasing popularity of such applications and is envisaged to play an instrumental role for the Long Term Evolution (LTE) proliferation in mobile market. For exploiting resource efficiency, MBMS specifications consider the Counting Mechanism which decides whether it is more efficient to deliver MBMS multicast traffic over Point-to-Point (PTP) or Point-to-Multipoint (PTM) bearers. However, the necessity to further improve MBMS resource efficiency and integrate new technologies in the frame of LTE stresses the need for an advanced Counting Mechanism. In this work we propose a novel Power Counting Mechanism for efficient selection of MBMS bearers. The proposed mechanism optimally utilizes power resources and exploits broadband characteristics and performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas used in LTE networks.