Abstract: Internet of things combined with a variety of backbone transmission is very suitable for remote real-time monitoring, but in some areas, remote IT transmission trunk such as Internet, cable line usually does not exist, the GSM signal maybe weak or even cannot be found, in consideration of the economic point and the actual transmission environment, the message services provided by the Beidou satellite navigation system can be used. However the transmission frequency and the number of characters in each transmission sent by Beidou message are limited at present, this paper presents an effectiveness optimization mechanism of remote transmission (EMRT) that improves the efficiency of transmission sent by Beidou message services. This mechanism includes three main parts: (1)“Index compression method (ICM)”, which aims to compress redundancy indicators for the current message; (2) “Element compression method (ECM)”, which accords to the agreement agreed in advance to remove “external packaging” that known by both sides for the current indicators; (3) “Bit compression method (BCM)”, which aims to compress the first four bits for the current elements. At the same time, the effect analysis of EMRT on improving the effectiveness of transmission sent by Beidou message services are quantified, and the factors that affect the effectiveness of transmission sent by Beidou message services are analyzed too. The theoretical analysis and the actual data validation indicate that these mechanisms have a significant effect on improving the effectiveness of transmission sent by Beidou message services, and have important theoretical and practical significance to the transmission sent by Beidou message services in Chinese Beidou message services.

Key words:  Internet of things, Beidou message, remote transmission, effectiveness

摘要： 物联网结合各种主干传输很适合远程实时监测，但是在一些位置偏远地区，一般没有互联网、有线专线等基础通信的IT远程传输主干，移动信号也比较弱甚至可能没有，从经济角度和实际传输环境出发，可以采用我国北斗卫星导航系统提供的报文服务，但是目前北斗报文服务传输频度和单次传输量受到限制。针对这种情况提出了一种适用于北斗报文的提高其传输效率的远程传输有效性优化机制（effectiveness optimization mechanism of remote transmission，EMRT）。这种机制具体包括3部分：（1）针对待传记录，动态压缩记录中冗余指标的“指标压缩方法”；（2）针对待传指标，根据协议事先约定好去除双方都知道的静态“外部包装”的“要素压缩方法”；（3）针对待传要素，压缩高4位的“位压缩方法”。同时根据双方的动态数据变化量化分析了ERMT对北斗传输有效性的提高效果，并分析了影响有效性的因素。理论分析和实际数据验证表明，这些机制对提高北斗传输有效性具有显著作用，对基于我国北斗卫星的信息传输的实际应用具有重要的理论和实际意义。

关键词: 物联网, 北斗报文, 远程传输, 有效性