阿尔卡特朗讯助力Airtel构建非洲骨干网络基于IP的高性能网络将为企业和个人用户提供全新业务

日前,阿尔卡特朗讯(巴黎证交所和纽约证交所:ALU)宣布,将凭借其先进的IP网络技术支持Bharti Airtel推出全新移动宽带数据和视频业务,助力该运营商满足其非洲网络用户对于移动宽带业务快速增长的需求:目前,非洲地区智能手机的日益普及推动了对视频通话、在线游戏等带宽密集型移动数据业务需求的增长。为了满足并应对这一持续增长的需求,阿尔卡特朗讯将依托其领先的IP/MPLS(互     

DiffServ在内部路由节点上的实现及性能分析

由于 Internet的迅速发展 ,要求它能支持各种不同 Qo S要求的业务 ,包括低时延的实时业务 ,有一定带宽保证的业务 ,和非实时的数据业务。但传统的 Internet只支持非实时的数据业务。本文根据 IETF的建议提出了一种区分业务的体系结构 ,和内部路由结点的实现方案 ,并进行了性能分析。实验结果表明 ,该方案可以支持不同 Qo S要求的业务。     

UBAS助力移动数据业务精细化运营

随着3G网络的部署,移动数据业务的带宽瓶颈被打破,同时智能手机的大量涌现,移动数据业务得到了迅猛发展,给运营商带来了丰厚的收益,但同时带来了诸多挑战。数据业务运营面临的挑战增量不增收数据业务的爆发式增长给网络带来了巨大的流量,且部分低价值业务如P2P占据了大量的带宽,运营商需要不断进行网络扩容以满足需求,但并没有     

一种用于GPON中的动态带宽分配算法

在对GPON系统架构及其带宽分配机制进行深入分析的基础上,提出一种新的用于GPON的动态带宽分配(DBA)算 法。该算法通过区分对待不同类型的T_CONT业务采用不同的分配方法,以实现全业务的服务质量保证;并通过仿 真实验证明了此算法的性能。     

一种用于GPON中的动态带宽分配算法

在对GPON系统架构及其带宽分配机制进行深入分析的基础上，提出一种新的用于GPON的动态带宽分配（DBA）算法。该算法通过区分对待不同类型的T_CONT业务采用不同的分配方法，以实现全业务的服务质量保证；并通过仿真实验证明了此算法的性能。     

基于博弈论的移动WiMAX接纳控制

移动WiMAX是一种重要的宽带无线接入技术,它具有数据传输率高、覆盖范围广、支持多种数据业务等优点。为了保证不同业务的QoS,该文提出一种基于博弈论的接纳控制算法。该算法首先给不同的业务赋予不同的优先级,然后建立一个非合作二人博弈模型,通过求解纳什均衡决定是否接纳连接请求,以及带宽的预留方案。仿真结果表明,该算法能够提高带宽的利用率,降低新发起连接的阻塞概率和切换连接的丢弃概率,并且能给不同业务提供区分服务。     

动态DNS的原理和实现及其在移动分组域网络中的应用

随着数据业务突飞猛进地发展,如何提高＂保持业务连续性＂和＂业务快速有效迁移＂的能力是运营商维护工作的重点内容之一。本文探讨了动态DNS的原理和模拟实现,根据DNS在移动分组域网络中的重要作用,引入DNS动态负载均衡技术,从而自动地实现业务均衡和迁移,并进一步讨论了GGSN状态的监测方法。     

面向业务的带宽预测及分配方法的研究

针对目前的带宽预测主要围绕聚合流量的问题,本文将IP网络承载业务分类,分析了数据、语音、视频等业务的特性及QoS需求,通过建立时延与缓存长度的映射关系,提出一种既满足业务流量的统计特性,又考虑不同业务的可容忍时延及丢失率的带宽预测及分配方法.这种预测及分配方法区分对待网络承载的业务,适用于细粒度的网络资源管理和流量控制.     

一种基于承载效率的小区数据分组信道分配方法研究

近年来,数据业务增长迅猛,对移动网络的数据业务承载能力提出了更高要求。文章研究了基于承载效率的小区数据分组信道分配算法,深入挖掘网络能力,通过现网多场景下的测试表明,该算法能够在保证用户不同业务需求的同时,有效提升网络利用率。     

基于数据业务的手机用户分析与研究

移动互联网的发展,数据业务高速增长,飞速增长的数据业务严重挤占语音信道资源,大量消耗网络资源,对系统的容量带来了较大压力;从数据流量及收益上看,网络面临"通道化"压力,低价值业务占用大量的数据流量带宽;同时,网络中存在少量用户占用大量带宽,实际收益低的现象。数据业务超越语音业务的趋势不可逆转,因此数据业务终将成为中国移动可持续发展的新动力。促进数据业务的发展,需要加强业务的识别、分析和管理,做到"业务可识别,质量可控制,网络可管理",加强网络的精细化运营,需要对用户加以区分,做到"用户差异服务,营销精细化、个性化"。本文的研究就在在数据业务的基础上,对用户进行分析和研究,解决网络流量瓶颈问题。     

IP connectivity for gateway GPRS support node

In the Universal Mobile Telecommunications System, the gateway GPRS support node (GGSN) provides IP connection between the mobile telecommunications network and external packet data networks (e.g., the Internet). Specifically, the GGSN exercises session management to transfer user packets between mobile stations and external data networks. In this article we focus on the GGSN functions for IP connection including access point name processing, IP address allocation, tunneling technologies, and QoS management. Based on our experience as a mobile operator, we give several examples to show how these functions can actually be implemented in a commercial mobile network.     

Call admission control for voice/data integration, in.broadband, wireless networks

This paper addresses bandwidth allocation for an integrated voice/data broadband mobile wireless network. Specifically, we propose a new admission control scheme called EFGC, which is an extension of the well-known fractional guard channel scheme proposed for cellular networks supporting voice traffic. The main idea is to use two acceptance ratios, one for voice calls and the other for data calls in order to maintain the proportional service quality for voice and data traffic while guaranteeing a target handoff failure probability for voice calls. We describe two variations of the proposed scheme: EFGC-REST, a conservative approach which aims at preserving the proportional service quality by sacrificing the bandwidth utilization, and EFGC-UTIL, a greedy approach which achieves higher bandwidth utilization at the expense of increasing the handoff failure probability for voice calls. Extensive simulation results show that our schemes satisfy the hard constraints on handoff failure probability and service differentiation while maintaining a high bandwidth utilization.     

Load-Balancing Based Cross-Layer Elastic Resource Allocation in Mobile Cloud

The paper proposes a hybrid mobile cloud computing system, in which mobile applications can use different resources or services in local cloud and remote public cloud such as computation, storage and bandwidth. The cross-layer load-balancing based mobile cloud resource allocation optimization is proposed. The proposed approach augments local cloud service pools with public cloud to increase the probability of meeting the service level agreements. Our problem is divided by public cloud service allocation and local cloud service allocation, which is achieved by public cloud supplier, local cloud agent and the mobile user. The system status information is used in the hybrid mobile cloud computing system such as the preferences of mobile applications, energy, server load in cloud datacenter to improve resource utilization and quality of experience of mobile user. Therefore, the system status of hybrid mobile cloud is monitored continuously. The mathematical model of the system and optimization problem is given. The system design of load-balancing based cross-layer mobile cloud resource allocation is also proposed. Through extensive experiments, this paper evaluates our algorithm and other approaches from the literature under different conditions. The results of the experiments show a performance improvement when compared to the approaches from the literature.

     

4G蜂窝网中移动互联网IP电视服务的优化研究

4G蜂窝网的频谱分配效率难以负担日益增长的移动IPTV服务与大视频流数据,为此提出了蜂窝网支持移动IPTV服务的优化方案,在保持传统语音电话质量的前提下,提高了移动IPTV服务的性能.首先,为语音电话分配较高的频率分配优先级以维护语音电话的QoS(Quality of Service);然后,采用软频谱复用技术来增强频谱的效率,并降低相邻蜂窝之间的频谱干扰;最终,设计了动态频谱分配算法,对相邻蜂窝间边缘频带的频谱分配进行协调与优化,进一步地提高了频谱利用率.仿真结果显示,本频谱分配算法在不降低语音电话服务质量的前提下,明显地提高了移动IPTV服务的性能.     

Analysis of adaptive bandwidth allocation in wireless networks with multilevel degradable quality of service

A wireless/mobile network supporting multilevel quality of service (QoS) is considered. In such a network, users or applications can tolerate a certain degree of QoS degradation. Bandwidth allocation to users can, therefore, be adjusted dynamically according to the underlying network condition so as to increase bandwidth utilization and service provider's revenue. However, arbitrary QoS degradation may be unsatisfactory or unacceptable to the users, hence resulting in their subsequent defection. Instead of only focusing on bandwidth utilization or blocking/dropping probability, two new user-perceived QoS metrics, degradation ratio and upgrade/degrade frequency, are proposed. A Markov model is then provided to derive these QoS metrics. Using this model, we evaluate the effects of adaptive bandwidth allocation on user-perceived QoS and show the existence of trade offs between system performance and user-perceived QoS. We also show how to exploit adaptive bandwidth allocation to increase system utilization (for the system administrator) with controlled QoS degradation (for the users). By considering various mobility patterns, the simulation results are shown to match our analytical results, demonstrating the applicability of our analytical model to more general cases.     

面向服务移动社交网络中基于信任的分布式服务组合方法

针对服务不透明性、信任需求主观性及移动参与者连接机会性对面向服务移动社交网络中可信服务组合带来的问题,提出基于信任的分布式服务组合方法.该方法基于格模型建立分布式服务信任评估框架,分别在组件和组合级评估服务信任度以避免不可信的数据传输;通过分析服务依赖关系,实现满足全局和局部信任约束可信服务选择;基于蒙特卡洛方法建立可信路径选择、优化和容错算法传输服务评估调用信息.实验结果表明所提方法在服务评估开销低,在路径选择成功率和信任度高,是适应面向服务移动社交网络的服务组合方法.     

Source time scale and optimal buffer/bandwidth tradeoff forheterogeneous regulated traffic in a network node

We study the problem of resource allocation and control for a network node with regulated traffic. Both guaranteed lossless service and statistical service with small loss probability are considered. We investigate the relationship between source characteristics and the buffer/bandwidth tradeoff under both services. Our contributions are the following. For guaranteed lossless service, we find that the optimal resource allocation scheme suggests that sources sharing a network node with finite bandwidth and buffer space divide into groups according to time scales defined by their leaky-bucket parameters. This time-scale separation determines the manner by which the buffer and bandwidth resources at the network node are shared among the sources. For statistical service with a small loss probability, we present a new approach for estimating the loss probability in a shared buffer multiplexer using the “extremal” on-off, periodic sources. Under this approach, the optimal resource allocation for statistical service is achieved by maximizing both the benefits of buffering sharing and bandwidth sharing. The optimal buffer/bandwidth tradeoff is again determined by a time-scale separation     

A Service-Oriented Medical Framework for Fast and Adaptive Information Delivery in Mobile Environment

The need for fast treatment of patients in critical conditions motivates the use of mobile devices to provide prompt and consistent communication between hospitals and physicians. We propose a framework that supports ubiquitous access to medical systems using personalized mobile services and integrated medical systems. The proposed service-oriented medical framework provides dynamically composed services that are adapted to contextual variables such as the user’s role, the network bandwidth, and resources available at mobile devices while supporting task allocation in distributed servers for massive resource-consuming services. It also manages accurate patient data by integrating local medical systems using medical information standards such as Digital Imaging and Communications in Medicine and Health Level 7. We have demonstrated the effectiveness of our framework by building a prototype of context-based adaptation of computerized tomography image retrieval for acute stroke treatments, which allows images to be viewed on mobile devices with WiMax wireless network. The proposed medical framework reduces hospital delays of patients and facilitates treatments in the absence of medical specialists.      

Real-Time Data Delivery Using Prediction Mechanism in Mobile Environments

Mobile data delivery is a critical issue in the mobile computing area. One of the most important problems is the efficient access to data. A proposed solution to this problem is the prefetching technique which consists in putting in reserving the information before the users need it. Low bandwidth, unreliable wireless links, and frequent disconnections of mobile environments make it difficult to satisfy the timing requirements of traditional strategies. This paper investigates broadcast scheduling strategies for push-based broadcast with timing constraints in the form of deadlines ,and proposes a prediction algorithm based on Kalman filter theory for this study. The proposed dissemination policy and adaptive bandwidth allocation scheme obtain sufficient conditions such that all the time-bounded traffic sources satisfy their timing constraints to provide various quality of service guarantees in the broadcast period. Our goal is to identify scheduling algorithms for broadcast systems that ensure requests meeting their deadlines. Our approach examines the performance of traditional real-time strategies and mobile broadcasting strategies, and demonstrates that traditional real-time algorithms do not always perform the best in mobile environments. The proposed design indeed achieves good performance in mobile environments.     

Analysis and engineering of a voice/data packet multiplexer

This paper investigates performance and engineering issues concerning a multiplexer scheme that has been implemented in AT&T's Integrated Access Terminal (IAT) to transport packetized voice and data traffic on shared facilities. The multiplexer serves voice and data traffic according to a dynamic bandwidth allocation scheme in order to simultaneously meet their performance requirements. A bit-dropping procedure is employed for voice packets to provide a graceful degradation of voice quality under overload conditions. An analytical model is developed for the multiplexer service scheme that estimates performance parameters given the voice and data offered loads. The model is used to demonstrate the capacity advantages of dynamic bandwidth allocation, and to generate load-service curves that illustrate the tradeoffs of carrying different combinations of voice and data traffic on the multiplexer. Sensitivity of voice and data performance to the multiplexer time-slice parameters is also investigated. The model is readily embedded in a design approach that determines the bandwidth required to carry the voice and data traffic demands while satisfying all desired performance objectives