3G无线网络规划中的关键问题

本文结合3G无线网络的特点，对3G无线网络规划中的一些关键问题进行了论述。重点讨论了无线系统规划中的小区呼吸、业务量建模、宏小区/微小区分层覆盖等问题。另外对无线网络规划中的静态仿真器作了简要说明。     

3G无线网络规划中的关键问题

对3G无线网络规划中的一些关键问题进行了论述。重点讨论了无线系统规划中的小区呼吸、业务量建模、宏小区／微小区分层覆盖等问题;另外,对无线网络规划中的静态仿真器作了简要说明。     

3G无线网络规划

众所周知 ,无线资源是３Ｇ网络中最为宝贵的资源 ,而无线系统投资在整个３Ｇ网络投资中也占据了相当大的比例 ,因此如何尽量提高频谱效率、充分利用无线网络设施向尽量多的用户提供高性能的接入服务就成了运营商最为关心的一个问题。除了设备和技术水平的因素外 ,无线网络规划也是其中非常重要的一环 ,它将直接影响到网络性能和建设成本。由于设计方法和经验的问题也经常导致网络实际部署后达不到原定的设计要求。１３Ｇ无线规划特点由于ＣＤＭＡ技术具有较高的频谱利用效率 ,目前几种主要３Ｇ技术均基于ＣＤＭＡ接入方式。与传统的时分多址…     

3G无线网络规划

介绍了3G无线网络规划的内容、原则和主要技术指标,分析了规划的流程,论述了规划中需要注意的主要问题.     

3G无线网络规划流程

本文概述了第三代移动通信网络一期建网无线规划的一般流程.并对规划流程中几个关键步骤进行了深入的探讨.     

3G WCDMA无线网络规划

无线网络规划是指根据无线网络建设的整体要求，确定包括覆盖，容量和成本在内的网络目标，以及为实现这些目标所进行的无线接入设备位置和配置的设计。     

谈3G无线网络规划

1、3G无线网络的规划原则 1．13G无线网络规划内容 3G无线网络规划包括在各种情况下计算链路预算、容量和小区基站数目，同时要对基站覆盖进行预测，对其参数进行规划。除此之外，还需要对整个网络进行策划，计算基站中信道单元的数目、传输线路容量、基站控制器、交换机等其他单元的数目。在规划中需引入性能测量，如掉话率和闭塞等指标，用它们来衡量网络性能。     

3G无线网络规划方法

无线资源是3G网络中最宝贵的资源,而无线系统投资在整个3G网络的投资中也占据了相当大的比例.因此如何尽量提高频谱效率、充分利用无线网络设施为尽量多的用户提供高性能的接入服务就成了运营商最为关心的一个问题.除了设备、技术水平的因素外,无线网络规划的优劣将直接影响到网络性能和建设成本;设计方法不当和经验不足等问题也经常导致网络实际部署后达不到设计要求.     

3G无线网络规划方法

一、引言 众所周知,无线资源是3G网络中最为宝贵的资源,而无线系统投资在整个3G网络投资中也占据了相当大的比例,因此如何尽量提高频谱效率,充分利用无线网络设施向尽量多的用户提供高性能的接入服务就成了运营商最为关心的一个问题。除了设备和技术水平的因素外,无线网络规划也是其中非常重要的一环,它将直接影响到网络性能和建设成本。由于设计方法和经验的问题也经常导致网络实际部署后达不到原定的设计要求。     

3G无线网络规划方法

众所周知,无线资源是3G网络中最为宝贵的资源,而无线系统投资在整个3G网络投资中也占据了相当大的比例,因此如何尽量提高频谱效率、充分利用无线网络设施向尽量多的用户提供高性能的接入服务就成了运营商最为关心的一个问题.除了设备和技术水平的因素外,无线网络规划也是其中非常重要的一环,它将直接影响到网络性能和建设成本.由于设计方法和经验的问题也经常导致网络实际部署后达不到原定的设计要求.     

QoS issues in the converged 3G wireless and wired networks

The Internet evolution delineated through the last years has urged the wireless network community to support the deployment of IP multimedia services with guaranteed quality of service (QoS) in 3G wireless networks. This article copes with the interoperability between 3G wireless networks and wired next-generation IP networks, for the provision of services with an a priori known quality level over both environments. More specifically, the UMTS architecture as well as a prototypical implementation of the next-generation Internet based on DiffServ are considered. The article focuses on the mapping among the traffic classes of the two networks at the point where the networks converge, and discusses the requirements and possible solutions for their proper interworking at the signaling and user levels. Simulations prove that proper mapping among the traffic classes of each world is necessary in order to achieve the desired end-to-end traffic characteristics.     

Key management issues in wireless sensor networks: current proposals and future developments

Key management has remained a challenging issue in wireless sensor networks (WSNs) due to the constraints of sensor node resources. Various key management schemes that trade off security and operational requirements have been proposed in recent years. In this article, we first examine the security and operational requirements of WSNs and then review five key management protocols: Eschenauer, Du, LEAP, SHELL, and Panja. Eschenauer's scheme is a classical random key distribution scheme for WSNs. Du's scheme improves on Eschenauer's scheme by using key matrices. LEAP provides a highly flexible key management scheme using four types of keys. SHELL focuses on achieving high robustness, and Panja is optimized for hierarchical WSNs. LEAP, SHELL, and Panja support cluster-based operations and are more aligned with current trends as shown by the new standards, IEEE 802.15.4b and the ZigBee "enhanced" standard. Future developments likely will incorporate the features of LEAP and adjustable robustness enhancements from Eschenauer or Du; extremely security-critical applications may benefit from restructuring SHELL to ease implementation and maintenance. Developments for extremely large WSNs should consider improving Panja's scheme due to its hierarchical scalability feature.     

QoS issues in ad hoc wireless networks

Ad hoc wireless networks consist of mobile nodes interconnected by multihop communication paths. Unlike conventional wireless networks, ad hoc networks have no fixed network infrastructure or administrative support. The topology of the network changes dynamically as mobile nodes join or depart the network or radio links between nodes become unusable. This article addresses some of the quality of service issues for ad hoc networks which have started to receive increasing attention in the literature. The focus is on QoS routing. This is a complex and difficult issue because of the dynamic nature of the network topology and generally imprecise network state information. We present the basic concepts and discuss some of the results. The article concludes with some observations on the open areas for further investigation     

Efficient resource allocation for China's 3G/4G wireless networks

The all-IP DiffServ model is expected to be the most promising architecture for QoS provisioning in China's next-generation wireless networks, due to its scalability, convenience for mobility support, and capability of interworking heterogeneous radio access networks. This article focuses on efficient resource allocation in a wireless DiffServ architecture. Resource utilization efficiency is particularly important for China's wireless networks as the mobile user density in China is and will continue to be much higher than that in other countries. More specifically, we propose a novel buffer sharing scheme to provide assured service for real-time layer-coded multimedia traffic, which can guarantee the specific packet loss requirement of each layer with UDP as the transport layer protocol. An adaptive optimal buffer configuration can be applied to achieve maximum resource utilization over the time-varying channel. Assured service is also provided to TCP data traffic for guaranteed throughput, where the cross-layer coupling between the TCP layer and link layer is exploited to efficiently utilize the wireless resources.     

3G无线接入网的两种传输技术

根据3G技术无线接入网的技术要求,对无线接入网的两种传输技术--多业务传输平台(MSTP)和异步传输模式(ATM)进行了比较,同时考虑到实际组网需适应3G网络的业务特点和传输网的未来发展,结合国内外ATM和MSTP实际应用状况,可以认为MSTP作为3G无线接入网的过渡技术,其成本较低,是目前传送网的最佳解决方案.     

Modelling and planning fixed wireless networks

Abstract  

This paper describes a mathematical model for the automated design of fixed wireless access networks (FWA) through the automatic selection and configuration of base station sites. An optimisation algorithm is presented which generates the fixed wireless access network infrastructure design, and results are presented to illustrate the use of the model and its implementation. Economic measures based on the net present value (NPV) are defined to assess the financial viability of potential network designs. The NPV is used within the mathematical optimization framework to produce cost-effective deployments that maximize economic performance while maintaining technical constraints on the network. The model takes into account time-varying input parameters on CapEx, OpEx, revenues and subscriber requirements to model the dynamic nature of the market. Technical radio constraints taken into account include downlink area coverage, interference, capacity and availability. The model and optimisation framework are illustrated by considering the deployment and configuration of infrastructure for three scenarios representing urban, suburban and rural regions. Experiments illustrating the staged deployment of infrastructure over a number of time periods are also presented.     

无线网络教室设计的几个关键问题

当前越来越多的高校实施了校园网无线覆盖工程.分析了无线教室建设的意义,介绍了无线教室建设的主要技术,并以某学院软件楼为例介绍了无线教室设计的关键问题及其解决方法.     

Call admission control for QoS provisioning in 4G wireless networks: issues and approaches

This article presents a survey on the issues and the approaches related to designing call admission control schemes for fourth-generation wireless systems. We review the state of the art of CAC algorithms used in the traditional wireless networks. The major challenges in designing the CAC schemes for 4G wireless networks are identified. These challenges are mainly due to heterogeneous wireless access environments, provisioning of quality of service to multiple types of applications with different requirements, provisioning for adaptive bandwidth allocation, consideration of both call-level and packet-level performance measures, and consideration of QoS at both the air interface and the wired Internet. To this end, architecture of a two-tier CAC scheme for a differentiated services cellular wireless network is presented. The proposed CAC architecture is based on the call-level and packet-level QoS considerations at both the wireless and wired parts of the network. A performance analysis model for an example CAC scheme based on this architecture is outlined, and typical numerical results are presented.