Multi-Tier Cellular Network Dimensioning

Wireless communications systems enable the end users to be mobile. The majority of the wireless communications networks are cellular networks. Several methods are developed to increase the performance of the cellular networks, which depends on the correct determination of the design parameters as well as the architecture of the system and the traffic requirements. In this study, we introduce a Simulated Annealing (SA) based method to determine the design parameters of a multi-tier cellular network, for which the implementation cost is minimized. The cellular system employs guard channels and allows calls to overflow to upper tiers. We conducted experiments with the SA-based technique on different example problems in two-tier cellular networks and obtained promising results.     

Software-Defined Cellular Mobile Network Solutions

The emergency relating to software-defined networking(SDN),especially in terms of the prototype associated with OpenFlow,pro-vides new possibilities for innovating on network design.Researchers have started to extend SDN to cellular networks.Such newprogrammable architecture is beneficial to the evolution of mobile networks and allows operators to provide better services.Thetypical cellular network comprises radio access network(RAN)and core network(CN);hence,the technique roadmap diverges intwo ways.In this paper,we investigate SoftRAN,the latest SDN solution for RAN,and SoftCell and MobileFlow,the latest solu-tions for CN.We also define a series of control functions for CROWD.Unlike in the other literature,we emphasize only software-defined cellular network solutions and specifications in order to provide possible research directions.     

移动蜂窝物联网无线网络规划的探讨

时代在进步,物联网已深入应用到社会产业体系,强化了我国各个社会产业体系的联系,且向服务行业渗透.我国的经济建设目标聚焦在物联网上,移动通信网络在物联网建设发挥了关键的作用.基于此,本文介绍了移动蜂窝物联网技术,详细研究了蜂窝物联网规划,希望为有关企业提供合理建议.     

GSM数字蜂窝网及其在中国的进展

本文介绍了 GSM 的技术规范,包括系统结构及主要参数,论述了中国选择 GSM 的关键因素,如频段划分、标准公开、设备商品化等。并介绍了GSM 在中国大发展的第一年,16个省市建网计划概况,展望了 GSM 在中国的前景。     

The Impact of Mobility on Cellular Network Configuration

This paper proposes a model for configuring cellular networks to study the dynamics of mobility between a single cell and its adjacent cells. It differs from most models considered in the literature by explicitly incorporating the dependency between the handoff rate and the system state. Besides, the handoff rate is also a function of cell size and subscriber mobility. Extensive computational experiments were done to study the impact of various input parameters on specific performance measures. Several observations are made regarding the system performance and as to how they are affected by the complex interaction between subscriber mobility, cell size, number of channels and the mean call initiation rate. The results of these experiments show that the proposed model, where handoff rates are state-dependent, captures additional traffic due to mobility when compared to the traditional method of modeling handoffs using information about the average behavior. Finally, the economic impact of mobility on system configuration decisions is analyzed. Though an approximation, the above work provides interesting insights about the impact of mobility in configuring cellular networks.     

Mobile Station Positioning Using GSM Cellular Phone and Artificial Neural Networks

In this paper, we describe a novelapproach to mobile station positioning using a GSMmobile phone. The approach is based on the use of aninherent feature of the GSM cellular system (themobile phone continuously measures radio signalstrengths from a number of the nearest base stations(antennas)) and on the use of this information to estimatethe phone's location. The current values of the signalstrengths are processed by a trained artificial neuralnetwork executed at the computer attached to themobile phone to estimate the position of the mobilestation in real time. The neural network configurationis obtained by using a genetic algorithm that searchesthe space of specific neural network types anddetermines which one provides the best locationestimation results. Two general methods are explored:the first is based on using a neural network forclassification and the second uses functionapproximation. The experimental results are reportedand discussed.     

Mobile Agents in the Mobile Telephone Network Management

The paper discusses the application of mobile agents in the management of mobile telephone (cellular) networks. We propose the use of mobile agents for collecting subscriber information, such as location area identifier and cell identifier. By using a subscriber profile containing these data the signaling messages caused by location update could be reduced. We also propose a method to improve the quality of network coverage by collecting measurements data by a mobile agent in the mobile station (mobile phone) or at the mobile switching center. By analyzing these data the network provider would be able to discover areas without proper radio signal coverage (black holes), thereby avoiding expensive and time-consuming measurements done by specially equipped vehicles. In addition, we discuss the basic infrastructure requirements for deployment of the mobile agent technology in cellular networks.     

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.     

蜂窝移动通信系统核心网络的演进与全IP核心网络

分析了现有移动通信网络存在的问题，阐述了第2代移动通信核心网向第3代移动通信核心网演进的必然性：讨论了第2代移动通信核心网向第3代移动通信核心网演进所采用的演进策略，介绍了两种可供选择的全IP核心网络的参考结构。     

使用移动Agent技术的网络管理

当今大型的通信网络往往集成了来自多家厂商的网络和通讯设备，而基于集中式方式的传统网络管理已难以满足用户的需求。移动ａｇｅｎｔ是能够自动在网络各节点间移动并代表其它实体工作的软件实体，引起了人们广泛关注。文章介绍了有关移动ａｇｅｎｔ的基本概念及其系统实现，并讨论了网络管理中移动ａｇｅｎｔ技术的几个应用实例以表明移动ａｇｅｎｔ是解决异构环境的复杂网管的有效途径。     

蜂房分组交换移动通信网的网络结构

本文给出以光纤城域网为基础的蜂房分组交换移动通信网的原理和网络结构，并给出该网络的容量和能支持的移动用户数。     

采用移动代理的分布式网络管理

文章给出了一种采用移动代理的网络管理方案。该方案通过移动代理将管理智能分布到网元,降低了网管平台的开销和网络负荷,可改善网管系统的可扩展性。文章最后还描述了该方案的系统结构和应用。     

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.     

中继蜂窝网络下行协作网络编码中继方法

In this paper, we first overview some traditional relaying technologies, and then pre-sent a Network Coding-Aware Cooperative Relaying (NC2R) scheme to improve the performance of downlink transmission for relay- aided cellular networks. Moreover, sys-tematic performance analysis and extensive simulations are performed for the proposed NC2R and traditional relaying and non-relaying schemes. The results show that NC2R outperforms conventional relaying and non-relaying schemes in terms of blocking probability and spectral efficiency, especially for cell-edge users. Additionally, the location selections for relays with NC2R are also dis-cussed. These results will provide some insights for incorporating network coding into next-generation broadband cellular relay mo-bile systems.     

构建安全的基于移动代理的网络管理系统

在网络管理领域,移动代理技术由于其分布、智能等特性获得了广泛的研究和应用.但网络管理中引入移动代理的同时也带来了许多不安全的因素.通过基于移动代理的网络管理系统运作流程的分析,指出了主机(管理站和管理代理)和移动代理可能面临的各种安全威胁,继而探讨了解决这些威胁的安全策略,最后提出了一个综合的具有灵活性、实现方式多样化的安全模型.     

移动自组网基于动态蜂窝的QoS路由协议

本文为移动自组网提出了一个基于动态蜂窝的QoS路由协议，它利用移动跟踪技术实现了一个分布式动态蜂窝生成协议；采用一个多Qos路由探测算法选择一条能够最大满足QoS要求的路由，并在这条路由上建立端．端主动资源预留；使用移动预测和被动资源预留技术预测源结点和目的结点可能进入的蜂窝集合，并在这些蜂窝集合与目的结点和源结点之间提前进行端．端被动资源预留；融合蜂窝动态检测技术与QoS路由修补技术自动发现和修补断裂的QoS路由．由于该路由协议模仿了固定蜂窝网络中的操作，所以，大大改善了QoS路由的性能．仿真结果表明：在满足QoS条件下，它明显提高了包传输率，减轻了路由负载．     

基于点对点WiFi通信实现移动数据流量卸载的架构：预定-发送

Currently cellular networks do not have sufficient capacity to accommodate the exp-onential growth of mobile data requirements. Data can be delivered between mobile terminals through peer-to-peer WiFi com-munications (e.g. WiFi direct), but contacts between mobile terminals are frequently disrupted because of the user mobility. In this paper, we propose a Subscribe-and-Send architecture and an opportunistic forwarding protocol for it called HPRO. Under Sub-scribe-and-Send, a user subscribes contents on the Content Service Provider (CSP) but does not download the subscribed contents. Some users who have these contents deliver them to the subscribers through WiFi opportunistic peer-to-peer communications. Numerical simulations provide a robust evaluation of the forwarding performance and the traffic of-floading performance of Subscribe-and-Send and HPRO.     

Integrating Heterogeneous Wireless Technologies: A Cellular Aided Mobile Ad Hoc Network (CAMA)

A mobile ad hoc network is a collection of wireless terminals that can be deployed rapidly. Its deficiencies include limited wireless bandwidth efficiency, low throughput, large delays, and weak security. Integrating it with a well-established cellular network can improve communication and security in ad hoc networks, as well as enrich the cellular services. This research proposes a cellular-aided mobile ad hoc network (CAMA) architecture, in which a CAMA agent in the cellular network manages the control information, while the data is delivered through the mobile terminals (MTs). The routing and security information is exchanged between MTs and the agent through cellular radio channels. A position-based routing protocol, the multi-selection greedy positioning routing (MSGPR) protocol, is proposed. At times due to the complicated radio environment, the position information is not precise. Even in these cases, the MT can still find its reachable neighbors (the association) by exchanging hello messages. This association is used in complement with the position information to make more accurate routing decisions. Simulation results show that the delivery ratio in the ad hoc network is greatly improved with very low cellular overhead. The security issues in the proposed architecture and the corresponding solutions are addressed. The experimental study shows that CAMA is much less vulnerable than a pure ad hoc network.     

基于QualNet的移动自组网建模与仿真

为了区别移动自组织网络拓扑变化和外界的攻击或干扰对网络性能的影响,利用无线网络仿真工具QualNet对多种战场应用场景进行建模仿真,比较分析不同场景下的网络性能,给下一步的攻击效果评估提供指标参考.     

移动分组无线网网络层技术的研究与实现

描述了在无线移动环境下实现动态网络管理的一种路由协议,并针对若干技术问题提出了具体解决方案。