Outage Performance with Handover Triggering in Cellular Mobile Networks

An approach to performance evaluation of cellular mobile networksis proposed, which includes the behavior of handover algorithmsin the computation of outage probability.In a general system scenario, with a central cluster and interferingbase stations, the average outage probability is computed along a trip of themobile terminal that involves crossing the boundary between adjacent cells.The effects of correlated co-channel interferersare accounted for in the computationof outage probability, as well as in the dynamics of a relative signalstrengthhandover algorithm.Numerical results are provided and discussed as obtained over a wide rangeof values of system parameters, namely cluster size and channel parameters.Trade-off curves are shown in terms of outage probability and cross-overpoint versus the average number of handovers, and possible design criteriaare outlined.It is also seen that the local outage analysis (without handover triggering)can be referred to as a lower performance bound in cases of practicalinterest.     

一种新的分层移动IPv6快速切换方案研究

分层移动IPv6快速切换在一定程度上减少了切换延时，但切换过程中由网络层移动检测和使用重复地址检测（DAD）配置一个新转交地址引起的延时对实时业务仍然有很大的影响。为了减轻这些影响，文中提出了一种更加有效的快速邻居发现和DAD机制，减小了切换延时，提高了网络的性能。     

Research on the Handover of a Novel Cellular Architecture in Wireless Personal Communication Systems

1　IntroductionHandoverbetweencellsisplayinganimportantroleincellularcommunicationsystems[1～ 1 2 ] .Thehandoverprocedureanditseffectivenessareseriouslylimitedbythecellulararchitectureasaresultofmar ketplanning .Basedonthehexagonalcellulararchi tecture,manyhandoverprocedureshavebeendis cussedandevaluated ,andmostoftheimprovementproposedonthemleadstotheintroductionofsector ingcellularorlayeredcellularmodel.Otherwise ,abetterhandoverprocedureisessentialinmaintainingacallinprogressbutitreflectshi…     

移动卫星网络中基于最小费用的切换算法

对于移动卫星网络,合理的星地链路切换方案需要在保证最小切换时延的同时,能够最优地使用网络资源。该文通过引入业务的中断概率和费用模型,给出了切换过程中重路由的最优触发条件,提出一种基于最小费用的切换(SMCH)算法。该算法可在保证切换业务通信的连续性和时延等指标不被破坏的基础上,通过适当的触发重路由来降低切换费用。仿真表明该算法在保证切换业务的QoS,降低切换费用以及适应性、灵活性等方面都优于同类切换算法。     

WCDMA与GSM系统间切换浅析

本文介绍了WCDMA系统和GSM系统间切换和小区重选的操作过程,分析了压缩模式对网络质量的影响,并对提高切换成功率提出了几点建议.另外,本文对切换相关的GSM网络升级和测量控制参数的设置也进行了讨论.     

TD-LTE系统切换技术的研究

文章介绍时分同步码分多址长期演进(TD-LTE)中的无线资源管理(RRM)的关键技术,及TD-LTE系统的切换流程和协议设计。针对TD-LTE系统现存的一些迫切需求,提出了一种基于切换滞后差值(HOM)和触发时间(TTT)的切换算法,研究了在切换中HOM和TTT对系统性能的影响。动态仿真结果表明随着HOM和TTT的增长,在系统吞吐量没有明显下降的基础上,总切换次数有了大幅度的减少,降低了系统信令的交互频率,节省了系统资源并提高了切换效率。     

基于重叠网络的移动IPv6快速切换

基本的移动IPv6切换延迟太大，不能满足实时业务的要求。本文提出了一种基于重叠网络的移动IPv6快速切换算法，这种算法通过在两个不同的IPv6子网间设置重叠网络来实现IP层的无缝(零延迟)切换。文中给出了算法实现的网络结构及其切换过程，并且对其性能进行了分析。算法实现了移动IPv6快速切换，在大部分情况下都可以达到最佳性能。     

移动IPv6切换时延优化新方法

移动IPv6中,移动节点(MN)在不同子网间移动时,既不中断与通信对端(CN)的通信,也不用改变其本身的IP地址.但是当MN与其家乡代理(HA)之间相距较远时,移动IPv6切换时延较大,对于实时性要求较高的业务无法适用.本文分析比较了目前移动IPv6常用的切换时延优化方法,提出了一种自适应快速层次移动IPv6切换时延优化方法,减小了移动IPv6切换时延,提高了网络的性能.     

TD-SCDMA/GSM双模终端切换问题的研究

TD-SCDMA系统是第三代蜂窝移动通信网络系统,在由2G向3G的过渡阶段,为了保证其过渡的连续性和平滑性,TD-SCDMA与GSM系统间的切换问题显得尤为重要.本丈详细讨论了TD-SCDMA/GSM双模终端在两种制式间切换的问题并提出解决方法,设计双模终端协议栈结构,并研究它们相互切换的具体过程,过程符合协议要求.     

A Novel Modelling Technique for Tracing Mobile Users in a Cellular Mobile Communication System

Mobility of users in a cellular mobile communication system has been formulated mathematically under generalized conditions. Based on this model a computer simulation has been developed. This mobility model is used to examine cell residence time distribution in cellular environments defined by different cell sizes and mobility parameters. It is shown that cell residence time can be described by the generalized gamma distribution.     

基于特征投影的移动IPv6快速切换方法

研究了移动IPv6协议中的越区切换问题,提出了一种基于特征投影的移动IPv6快速切换方法。该方法通过构造先验切换经验与小区覆盖范围的映射关系来协助移动接入网关对切换目的地进行预测。仿真结果表明,文中方法能够获得比FPMIPv6更小的切换延迟,并具有较好的鲁棒性。     

面向移动目标跟踪的动态联盟平滑切换方法

针对传统动态联盟离散生成方式所导致的能耗较大且历史信息易失等不足,提出一种动态联盟的平滑切换方法。首先,预估目标移动的下一位置;然后,检测联盟切换的触发条件;最后,通过新盟主选择、新旧盟主交接以及盟员变动等一系列过程实现联盟的平滑切换。并在目标丢失后,进行联盟修复。联盟的平滑切换将避免联盟因目标移动而反复生成和解散,并保持和利用联盟收集的历史信息。仿真结果显示,该方法能有效维持动态联盟,实现联盟的平滑切换,与传统动态联盟方法相比,降低了系统的能耗和通信成本,提高了目标跟踪的精度,验证了该方法的有效性。     

Fast Handover Mechanism for Seamless Multicasting Services in Mobile IPv6 Wireless Networks

This paper proposes a fast handover mechanism to provide a seamless multicast service for Mobile IPv6 hosts. With the proposed Fast handover based on a Mobile IP-Multi casting (FMIP-M) protocol, the selection of a new multicast service method, service preparation, and initialization procedures are all performed during the fast handover period, thereby enabling a reliable and efficient multicast service. When mobile hosts move to other networks, they can encounter data loss, out-of-synch problems for multicast data, and multicast service exchange latency. Therefore, the proposed FMIP-M allows the new access router to select a suitable multicast service method according to the multicast service-related network conditions and supports a reliable multicast transmission by compensating for data losses from the previous access router. An analysis is conducted of the overheads associated with a fast multicast handover, including the signaling cost and multicast packet-forwarding cost, where the costs are formulated based on timing diagrams, and compared with a fast handover using Mobile IPv6. The performance analysis and numerical results confirm that the proposed FMIP-M provides a fast multicast handover and reliable service with a relatively small signaling cost and packet-delivery cost.     

Scalable Schemes for Call Admission and Handover in Cellular Networks with Multiple Services

The introduction of new service categories withdifferent bandwidth requirements, e.g., data and multimedia, to cellularmobile radio networks makes many of the traditional mechanisms for controlingtraffic unusable orless efficient. The call admission and the handover handling are of the mostsensitive issues in this extension to new services. The performance of allservices includingthe traditional voice and the new services can be dramatically affected ifappropriate schemes are not used. In this paper, we propose call admission andhandover handling schemes for a cellular mobile network that offers twoservice types: voice and data. The data connections are assumed to transmitatdifferent transmission rates that are integer multiples to that of one radiochannel. In the case of congestion, the base station asks the active dataconnections to reduce their transmission rate in order to provide freechannels for the newly arrived request of both service types. This isbasically intended for incoming handover requests. The request will berejected if the transmission rate of the active connections reaches a givenminimum rate. Similar mechanism can also be used for new call arrivals, butsome priority can be given to handovers by setting a higher transmission ratethreshold for the new call rejection. As an extension to the proposedscalability, aqueuing of new calls is also proposed and analyzed. Analytical models werebuilt for the two proposed schemes together with the traditional channelreservation scheme. The effect of different traffic and configurationparameters on the performance measures like the grade of service, blockingprobabilities, and utilization, are studied using the proposed technique.Results show that the proposed schemes provide very good performance and morefairness among the different service types.     

Analysis of Fast Handover Mechanisms for Hierarchical Mobile IPv6 Network Mobility

When a mobile network dynamically changes its point of attachment to the Internet, the various types of movements by a mobile router require handovers, and network mobility (NEMO) is concerned with the management of this movement of mobile networks. Accordingly, this paper investigates the mobile router movement patterns in NEMO network environments, and defines fast hierarchical NEMO handover scenarios based on classified movement patterns. Due to unexpected link breakdowns during the handover procedure, the NEMO handover requires additional latency and packet delivery costs depending on when the breaks occur. For the various handover failure cases, it is also essential to analyze these overhead costs to evaluate and compare the performance of a fast handover. In this paper, the overheads associated with a NEMO fast handover include the latency, buffering cost, and packet loss cost, all of which are formulated based on a timing diagram.

高效频谱调制方式在蜂窝移动通信系统中的性能分析

本文研究高效频谱调制方式ＭＰＳＫ及ＭＱＡＭ在蜂窝移动通信中的应用及其性能。在综合考虑共道干扰，Ｒａｙｌｅｉｇｈ衰落以及高斯噪声等影响因素的基础上，结合分集接收技术，我们给出了ＭＰＳＫ及ＭＱＡＭ应用于蜂窝移动通信时误码率计算的通用近似公式。蒙特－卡洛仿真表明文中给出的误码率近似公式能很好地吻合实际系统的仿真结果。     

A Scheme for Supporting Fast Handover in Hierarchical Mobile IPv6 Networks

This Letter proposes a scheme that supports a fast handover effectively in hierarchical mobile IPv6 networks (F‐HMIPv6) by optimizing the associated data and control flows during the handover. By NS‐2 simulation, we show that the proposed scheme can give better handover performance than a simple combination of existing schemes.     

Performance of Reuse Partitioning in Cellular Systems with Mobile Users

Reuse partitioning (RP) is a simple technique that can be used to increase the traffic capacity in a cellular system. With RP, a cell is divided into several concentric regions, each associated with a different cluster size. In this article, a traffic model is developed to analyze the impact of mobile users on a two-region RP system using fixed channel assignment. The influence of user speed and cell size on the new call blocking probability, P_b, and the call dropping probability, P_d, is investigated. A simpler model that can be used to estimate P_b and P_d in some cases is described. The effect on system capacity of reserving some channels for handoff calls is also studied. It is found that even though prioritized handoff can reduce P_d, it may also degrade the capacity. The accuracy of the analysis is verified using simulation for three mobility models.     

对基于传输负载的动态软切换算法的讨论

介绍了两种基于传输负载的软切换算法 ,并通过系统仿真对它们进行评价和比较。结果表明 ,这两种软切换算法相对于传统的算法提高了资源的利用率以及系统的总体服务质量。     

地空数据通信越区组网切换算法的设计与仿真

提出地空数据通信越区组网目标站点选择算法和越区时间判断算法,设置仿真场景对切换算法进行验证,得出变化飞机航迹更新周期,采用覆盖区域重叠部分和航迹、站点连线夹角综合标准选择目标站点的越区切换方法成功率高,证明了该切换算法在越区组网方案中的优势。