双频网的话务分布优化

从参数调整、切换分析、指标对比分析和路测效果统计等方面讨论了双频网的话务分布优化,最后用实例演示了双频网天线互补覆盖、切换门限调整等优化措施。     

Requirements and Algorithms for Cooperation of Heterogeneous Radio Access Networks

This paper defines the requirements for cooperation of heterogeneous radio access networks (RANs) and proposes a novel radio resource management (RRM) framework for support of mobility and quality of service (QoS) in a heterogeneous communication environment comprising IMT-Advanced and legacy systems. The reference IMT-Advanced system is the one developed within the IST project WINNER (IST-2003-507581 Project Wireless Initiative New Radio, ). The RRM mechanisms are evolved from traditional ones to comply with the requirements imposed by a simplified new (RAN) architecture as proposed for IMT-Advanced systems. The RRM mechanisms are evaluated for the scenario of intra-RAN and inter-RAN user mobility. The RRM framework incorporates as novelty improved triggering mechanisms, a network-controlled mobility management scheme with policy enforcement on different levels in the RAN architecture, and a distributed handover and admission control mechanism for fast decision polling at different levels of the RAN. The RRM framework is further enhanced with computational intelligence based on fuzzy logic algorithms to enhance the process of handover. The RRM framework has been evaluated in terms of reduced user blocking probabilities.

WLAN中基于MIPv6的移动VoIP切换性能仿真分析

移动IP是一个在Internet上基于网络层提供移动性支持功能的要求较高的VoIP业务,切换延迟将直接影响到话音质量,严重时甚至会中断正在进行的会话.文章借助ns2网络模拟器仿真分析了WLAN中基于MIPv6的移动VoIP切换性能.结果表明,MIPv6及其扩展协议的切换性能优劣顺序依次为:F-HMIPv6、FMIPv6、HMIPv6、MIPv6.尤其是F-HMIPv6协议,无论端到端延迟还是切换延迟,都得到了最大的改善.所得结论能为网络切换性能的进一步优化提供重要依据.     

移动IPv6技术的研究及其在Linux环境下的实现

文章简介了当前移动IPv4和IPv6的研究情况,着重讨论在一个纯IPv6的环境下移动IPv6协议软件设计中的几个问题。     

利用切换模糊预测改进平滑切换中缓冲区管理的研究

移动IPv6下的平滑切换及缓冲区管理机制主要是为了解决无线网络切换中的丢包问题,然而由于MN缺乏对自身移动状况的感知,存在着比较严重的缓冲区浪费问题。该文利用一个简单的切换模糊预测模型对缓冲区管理机制进行了改进,并引入了一种自适应算法,增强了整个方案的适用性。仿真和分析表明,改进方案能够在尽量不影响上层协议性能的前提下,切实起到提高缓冲区利用率的作用,同时具有简单、适用性强的特点。     

MG—HMIP协议模型的实现及应用

由于无线局域网（WLAN）IEEE802．11协议不能解决移动节点的三层漫游问题，介绍了WLAN与移动IP结合的解决方案。由于上述方案存在切换延时长、不支持微移动性等缺陷，研究了分层移动IP技术，并对分层移动IP进行了改进，提出了一个多GFA分层移动IP（MG—HMIP）模型，并详细介绍了MG—HMIP模型的注册机制和MN选择GFA的机制。最后，给出了MG—HMIP与WLAN结合的模型。这个改进的方案不仅解决了WLAN与传统的Mobile IP结合所存在的切换延时长、频繁切换等问题，而且增强了分层移动IP的网络健壮性。     

An improved handover algorithm based on signal strength plus distance for interoperability in mobile cellular networks

In future generation mobile cellular systems, position location of mobile terminal is expected to be available. In this paper, we propose an initiation algorithm for intersystem handover based on the combination of position location of mobile terminal and the absolute signal strength thresholds. Global System for Mobile communication (GSM) and Universal Mobile Telecommunication Systems (UMTS) networks are considered for interworking. The proposed algorithm reduces the handover rate by around 50% and thus improves the network resource efficiency as compared to that based on signal strength thresholds only.     

宽带卫星网络QoS保证体系

根据宽带卫星网络特点和应用需求特性,对MPLS DiffScrv QoS保证体系进行适当改进,建立了适合宽带卫星网络的Qos保证体系。该体系支持两个基本业务类别,分别采用第2层交换和第3层转发的模式实现分组传递。在这两个基本业务类别内,可以继续划分优先级别。在该体系的设计过程中考虑了切换问题对于QoS的影响。     

NSA场景下切换成功率提升研究

5G作为支撑经济社会数字化、网络化、智能化转型的关键新型基础设施,其快速部署意义和作用极其重大.5G网络的快速建设,网络性能、质量、感知优化未能及时跟进,因此网络优化工作更需快速开展.从NR站间切换入手,讨论切换失败处理思路及方法,并结合现网处理案例,详细阐述了切换失败的处理过程以及提升措施.     

个人通信业务网的越区切换管理

介绍在无线个人通信系统中,当移动台在通话期间从一个无线区移动到另一个无线区时,如何实现越区切换管理、越区切换检测、信道分配和无线链路转接等问题。