共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
Formulas are derived for the congestion in single-cell mobile radio systems in which there are both land-to-mobile and mobile-to-mobile calls and in which mobile-to-mobile calls go via the base station. Two approaches are used. The first yields modified forms of the familiar Erlang and Engset formulas. The second gives more complicated but more accurate formulas. The results of computer simulations to establish the accuracy of the formulas are described. 相似文献
3.
New teletraffic formulas are derived for the congestion in multicell mobile radio telephone systems. Fixed, dynamic, and hybrid channel asignment are considered and "tromboning," where mobileto-mobile calls go via a base station, is taken into account. The formulas agree with previously published sumulation results. 相似文献
4.
5.
6.
The probability of cochannel interference is evaluated for a mobile radio system operating in Rayleigh fading and log-normal shadowing environment. All cochannel cells surrounding the base station are taken into consideration in this evaluation. The results obtained are used to calculate the reuse distance and the cluster size (number of cells in a group). The blocking probability, the number of channels in each cell, the protection ratio, and the standard deviation are taken as parameters in this evaluation. The results show that shadowing has a severe effect on the interference level and on the channel reuse distance ratio. 相似文献
7.
华东三省一市无线寻呼联网化周国伟NetworkingofRadioPagingSystemsinJiangsu,Zhejiang,ShandongandShanghai¥ZhouGuowei无线寻呼是单方向的移动通信,由于其投资少,见效快、传递信息迅... 相似文献
8.
本文研究了国内现用几种典型无线寻呼系统及系统间的联网方案,分析其成功与欠缺的方面,就有关无线寻呼联网的可行性研究、联网方式的选择、联网协议及传输线路的选择等几个关键问题加以阐述和分析,并提出几个较佳的联网方案。 相似文献
9.
10.
阐述了软件无线电的发展动态、基本结构,分析了其关键技术,并对第三代移动通信系统中软件无线电技术的应用和发展作了初步的探讨。 相似文献
11.
寻呼成功率是评价一个移动网络优劣的重要指标之一,也是目前中国三大运营商KPI考评指标体系的重要组成部分。寻呼成功率的高低直接影响着手机做被叫的接通率,同时也影响着用户的感知。笔者通过在交换侧对寻呼的流程进行分析,寻找改善寻呼成功率的各方面因素,从而解决移动通信寻呼成功率低的问题,以便提高移动通信质量、进而提高用户满意度。 相似文献
12.
主要介绍无线寻呼技术的一些新进展,特别是高速寻呼、双向寻呼和语音寻呼,对三种高速寻呼协议FLEX,ERMES和APOC进行了简单评述。 相似文献
13.
An important problem in land mobile radio communications is how to provide reliable data communications to the largest number of users. To explore this problem, several existing ARQ protocols are examined which have application to the land mobile radio channel, as well as some new protocol combinations. All protocols are analyzed for several key system performance measures which are verified by experimental means for static as well as fading channels. Finally, a conclusion is reached regarding a new Protocol combination which is found to offer significant advantages over all other protocols explored. 相似文献
14.
15.
介绍了一种简单易行的移动IP的扩展方案,它通过对基本的移动IP协议进行简单的扩展,使其支持寻呼功能,减少大量的信令开销,使MIP能够支持大量移动用户。 相似文献
16.
Turbo码在无线移动通信系统中的应用 总被引:2,自引:0,他引:2
文章首先分析了Turbo码这一新型信道编码方案的基本编译码原理,然后探讨了它在INMARSAT移动卫星通信系统、CDMA多用户检测及第三代移动通信系统IMT-2000中的具体应用问题。 相似文献
17.
A variety of land mobile radio systems are compared by their spectral and economic efficiencies in providing various user services, system types covered are private one-channel, shared repeater one channel, controlled-access one-channel, trunked multichannel, and cellular. Spectral efficiency is defined to be the number of mobile users that can be served per MHz of spectrum in a core urban area, while economic efficiency is the average system cost per mobile. Both efficiencies vary with the type of usage, hence they are calculated for three major usages-mobile telephone service, dispatch service emergency, and dispatch service nonemergency. Services are described via seven "service parameters," namely call holding time (average), tolerable average wait for channel access, peak busy hour utilization per mobile, audio quality (S/N), noise levels tolerable, and service range. Sensitivity of the basic results to variations in the service parameters are also computed and discussed. 相似文献
18.
数字专用无线通信系统的新进展 总被引:1,自引:0,他引:1
围绕ETSI近几年提出的数字无线电标准TS 102 361(Digital Mobile Radio),TS 102 490和TS 102 658(Digital Private Mobile Radio),阐述了数字专用无线通信系统的近期进展。主要分析了DMR标准和dPMR标准的起源、技术特点、应用情况和发展趋势;将这两种标准与我国现存的其他数字无线电标准进行了比较;在此基础上,结合我国专用无线通信系统现状,分析了两种标准在我国的应用前景。 相似文献
19.
本文通过分析近几年来我国无线寻呼业务的发展状况及趋势,从技术、业务、经营模式等多方面了我国无线寻呼市场具有巨大的发展潜力,并对未来我国无线寻呼业务及市场作了展望 。 相似文献
20.
Telecom Service Market Management Division 《世界电信》1997,10(2):42-44
我国无线寻呼业经过十几年的发展,已经走上了依法管理、健康有序发展的轨道。随着技术的进步和用户需求的变化,业务市场仍在扩大,尽管竞争日趋激烈,但前景依然看好。文中针对目前经营中存在的问题提出了几点新的要求,以引导和规范市场行为。 相似文献