卫星通信组呼业务MAC层研究

组呼通信在指挥调度中有着重要作用,而在一些地面没有基站的地方,就无法正常使用。卫星通信具有无视地形,通信范围广,不易受陆地灾害影响,易于建设等优点。把卫星通信和组呼通信结合在一起的卫星组呼通信技术兼顾两者的优点,能更好的发挥指挥调度这一作用。当前卫星组呼通信采用固定频率方式,组呼成员在一个频率下进行通信,这种方式实用性不好。本文研究的是移动卫星组呼,在GMR-1系统的基础上研究了卫星组呼通信中MAC层的功能,提出了MAC-Ready-Gcc、MAC-Dedicated-Gcc这两个为了支持组呼的状态,并针对在MAC层发生的PTT竞争提出了一种回退策略。

MAC Layer of Satellite Communication Group-Calling Service

Group-calling communication plays an important role in command and dispatch, and however,is not available in somewhere without base-station. Satellite communication enjoys lots of superiorities, such as wide communication range, less susceptible to the impact of land disasters, and easy to construct. Satellite group-calling communication,integrating satellite and group-calling communication and thus combining the advantages of both communications,could play an even better role in command and dispatch. The current satellite group-calling communication adopts a fixed frequency mode, and the group-calling members communicate in a same frequency, and this method,however, is not practical. The paper discusses a mobile satellitegroup-calling. And based on GMR-1 foundation,the MAC layer function of satellite group-calling communication is studied, and the two sub-states of MAC-Ready-Gcc and MAC-Dedicated-Gcc are proposed to support the group-calling. This paper also presents a fallback strategy for the PTT competition conflict at MAC layer.