【作者】 李博；

【导师】 谢晓明；

【作者基本信息】 北京化工大学 ， 计算机应用技术， 2009， 硕士

【摘要】 无中心移动通信系统是我国专业移动通信系统的重要组成部分。它使用单工对讲方式工作,工作频率在915.0125-916.9875MHz之间。该系统具有无中心组网、数字选呼、自动接续、多址用户多信道共用、链路分散控制等诸多技术特点,拥有广阔的实际应用前景和深入开发潜力。目前我国的900M无中心移动通信系统尚处在以模拟话音加数字信令为主导技术的模拟阶段。欧洲电信标准化协会已实施了ETSI TS 102 490-DPMR、ETSI TS 102361-DMR等对讲机数字协议,而我国针对无中心呼叫控制协议的数字化研究尚处于空白。随着我国通信技术的不断发展,尤其是“数字化”时代的到来,传统无中心移动通信系统的数字化改造势在必行。本文以数字无中心移动通信系统的呼叫控制功能为研究对象,提出并设计了一套基于无中心体制的呼叫控制数字化解决方案。本文介绍了数字无中心移动通信系统自身的技术特点,详细叙述了呼叫控制功能的具体实现方法和设计思路。针对实际应用在以ARM7LPC2128处理器为MCU运算核心的硬件环境中对呼叫控制协议进行了完整的分析测试,进一步验证了呼叫控制协议的可行性和可靠性,同时对呼叫建立时间等QoS指标进行了分析。此数字呼叫控制协议与传统模拟体制相比有了较大的提高,全数字的信令设计使得无中心数字对讲机的技术特点更加突出,扩展能力以及实用性也大大加强。该呼叫控制方案已应用于数字无中心对讲机的嵌入式系统开发中。更多还原

【Abstract】 Land mobile communication system without a centre controller plays an important part in the field of private network communication in China. The working is simplex system, and the working frequency is from 915.0125MHz to 916.9875MHz. The system has many technical characteristic, for example network without a centre controller, digital selective-calling, automatic call connection, multi-channel share for multiple access users, disperse Link control. There is great room for practicality and development. At present in China, the Land mobile communication system without a centre controller is in the Analog technology moment with analog voice and digital signal.ETSI has implemented the ETSI TS 102 490-DPMR and ETSI TS 102 361-DMR digital interphone protocol, but there is no research in digital land mobile communication system without a centre controller. In recent years, along with the development of communication technology, the digital land mobile communication system without a centre controller is inevitable. This paper deals with the study of call control of land mobile communication system without a central controller, and puts forward one digital scheme of call control based on land mobile communication system without a central controller.This paper introduces the technology and characteristic of digital land mobile communication system without a central controller and makes detailed description of the method and the design thought to complete the call control function. At last there are some analysis and tests based on ARM7 LPC2138 MCU which are used to prove the protocl’s feasibility and reliability in practice, and analysed QoS of the system. In contrast with analog system the digital call control protocol has more improvements and advances. Digital signal design makes the system have more prominent characteristic, expandability and practical trait. This digital call control scheme has applied to embedded development of digital land mobile communication system without a central controller.更多还原