Recent years , with the rapid development of communication , the research of digital trunked radio communication system becomes more and more important 近年来,随着通信的飞速发展,作为专用移动通信系统的数字集群通信系统的研究也变得越来越重要了。
At present , chinasat digital trunking communication network has realized the coverage to many cities such as shanghai , tianjin , jinan , nanjing , qingdao and weifang 目前，中国卫通数字集群通信网已实现上海、天津、济南、南京、青岛和潍坊等城市的覆盖。
Trunking system is one kind of the advanced mobile dispatcher communication system . it represents the technical roadmap of dedicated mobile communication network 集群通信系统，是一种高级移动调度系统，代表着通信体制之一的专用移动通信网发展方向。
So the study of encryption mechanism in digital trunking communication system is most significant to the construction and development of digital trunking communication system in our country 所以数字集群通信系统加密机制的研究,对于我国数字集群通信系统的构建和完善具有极其重要的意义。
In this thesis , the wireline telephone gateway interface will be researched for the interconnection between digital trunking communication system and wireline telephone systems ( such as pabx , pstn etc . ) 本文研究的电话网关接口就是要实现数字集群通信系统和有线电话系统(如pabx 、 pstn等)互联的接口。
Mainly , this paper stresses a new generation of cdma2000 - based trunking network and expounds its architectures , fundamentals , service functions and key technologies , and discusses its operation patterns as well 重点阐述了基于cdma2000技术的新一代集群通信系统的网络结构原理、业务功能、实现的关键技术，以及组网、运作模式。
The development of the dedicated trunking wireless networks and the public cellular mobile telecommunication networks , to some extent , reflects the history of the development and application of the radio telecommunication technology 摘要无线专用集群通信网和移动公众蜂窝通信网的发展，很大程度上反映着无线技术发展和应用的历史。
Digital trunking communication system is mainly used in police , government , national security section and so on . these applications need transmission large amount of secret information , and have high security demand 数字集群通信系统主要用于公安,政府机关,军队和国家安全部门等,它们要在系统中传输大量的机密信息,对通信的保密性要求很高。
Tetra - the new digital trunked communication system , specifies algebraic codebook excited linear prediction ( acelp ) , which is improved codebook excited linear prediction ( celp ) , as its speech codec . the bit rate of it is 4 . 567kbit / s 本文首先详细介绍了新一代数字集群通信系统tetra的语音编解码采用的编码速率4 . 567kbit s的代数码本激励线性预测( acelp )算法。
Trunking communication system is a command and dispatching system which has exchange and control functions . along with the development of the digital communication technique , the digital trunking communication system becomes a hot research aspect gradually 集群通信系统是一种具有交换和控制双重功能的指挥调度系统,随着数字通信技术的发展,数字集群通信系统逐渐成为研究热点。
