一种基于协作分集技术的切换机制

现有切换管理机制主要采用基于提前切换准备的方法来降低切换过程中的服务中断时间,但是这类切换机制对移动预测算法具有很高的依赖性,因而实际部署的效果不佳。为解决该问题,该文提出了基于协作分集技术的切换机制,通过在切换过程中引入异构协作分集,延长了切换过程中源基站能够为移动终端提供服务的时间,降低对移动预测算法的依赖,从而很好地解决了现有移动管理机制的不足。     

媒体无关切换方案的安全性

针对移动节点移动到外地网络时媒体无关切换(MIH)的服务安全问题,提出一种基于diameter的密钥分发方案,为移动节点和外地MIH服务器建立信任关系,使用消息鉴别码为MIH信令提供完整性保护。使用BAN逻辑对密钥分发方案的安全性进行证明,分析表明该方案性能优于同类方案。     

低轨星座卫星通信系统中多业务条件下的非充分保证切换策略

该文提出了一种适用于低轨星座卫星通信系统多业务条件下的非充分保证切换策略。该策略在小于一个小区最大驻留时间的时间间隔内为到达小区的呼叫安排和预定信道,在呼叫结束环节作为补充策略对存在切换失败风险的信道进行调整。提出了策略在多业务条件下具体的实施方法,根据实时的切换呼叫性能调整策略的非充分程度。通过仿真,分析比较了不同程度非充分保证切换策略的QoS性能,验证了动态自适应调整非充分程度值的IGH策略的有效性。仿真结果表明,相对于保证切换策略,新策略以存在微小切换失败概率为代价,换取了新呼叫阻塞概率的显著降低,是一种适用于多业务低轨卫星通信系统的信道分配策略。     

基于代理的移动组播协议分析

具有针对性地对基于组播代理的移动组播协议进行讨论,对已经提出的属于这一类的移动组播算法从体系结构、组管理和组播分组传输方法,以及组播服务切换三方面进行分析,深入剖析了这些算法的优点和缺陷,并对这些协议综合对比.最后,对基于代理的移动组播进行深层次的总结分析,并提出今后的研究重点.     

移动IPv6概述

文章分析了IPV6支持移动性的优势，概述了移动IPv6协议，并对一些热点问题，如快速切换、平滑切换、移动管理、AAA和服务质量等进行了探讨。     

Integrated power and handoff control for next generation wireless networks

In this paper, joint downlink power control and handoff design is formulated as optimization problems that are amenable to dynamic programming (DP). Based on the DP solutions which are impractical, two new algorithms suitable for next generation wireless networks are proposed. The first one is an integrated hard handoff/power control scheme that endeavors a tradeoff between three performance criteria: transmitted power, number of handoffs, and call quality. The second is a soft handoff/power control algorithm that also takes into account the additional cost of utilizing soft handoff. The proposed algorithms present a paradigm shift in integrated handoff/power control by capturing the tradeoff between user satisfaction and network overhead, therefore enjoy the advantages of joint resource allocation, and provide significant improvement over existing methods. The achievable gains and the tradeoffs in both algorithms are verified through simulations.

A Guard Code Scheme for Handover Traffic Management in WCDMA Systems

A key performance indicator of mobile wireless networks is failure probability of handover calls. In this paper, we propose a Call Admission Control policy which prioritizes handover calls over new calls in WCDMA systems. The OVSF code occupancy of the system is modeled by a Markov chain and the differentiation between handover and new calls is performed at the code level by introducing a “guard code” scheme. The scheme belongs to the well-known family of guard channel schemes and reserves some code capacity to favor the continuation of handover calls over the new calls. As the management of the general case is intractable, we solve certain numerical instances of the problem and manage to calculate several performance metrics like new call blocking and handover failure probabilities and code utilization. We complete our study with simulation results in the case of higher OVSF code tree capacity.

一种ANDSF获取接入网动态信息的方法

下一代异构无线网络环境是宽带移动无线接入和异构分布的网络,如何减少切换时延实现无缝切换是当前需要解决的问题。文章针对在切换之前如何获取有效的接入网信息提出了一种新的方法,即一种ANDSF(接入网发现和选择功能)获取接入网动态信息的方法,该方法可以保证ANDSF中接入网信息及时准确。然后介绍ANDSF功能实体,分析其工作原理,指出其不足,并提出改进方法。     

GSM900／GSM1800双频网技术解决方案初步探讨

介绍了GSM1800的特点,并从网络设计方面对双频网的组网方式、覆盖方式、话务控制、切换算法等技术解决方案进行了初步探讨。     

一种对MBG的路由改进策略

切换时延是终端移动的关键之一。业界已提出多种策略，但需要修改移动IP协议栈。基于MBG的移动IP路由优化策略在预知网络结构的前提下，能有效缩短切换时的通信中断时延。文章最后给出了仿真结果。