对高级在轨系统(AOS)协议的帧生成算法进行了研究,分析了在包到达率服从泊松分布的条件下,高效率帧生成算法的平均包时延均值。针对高效率帧生成算法可能使得在较长时间内没有足够多的包到达,导致帧生成时间过长,从而造成数据包时延较大的情况,提出了采用自适应帧生成算法进行解决,并给出了在不同门限值下,该算法的平均包时延均值计算公式。理论分析和仿真结果表明,自适应帧生成算法比高效率帧生成算法具有更小的平均包时延均值与方差。在实际应用中,可以根据系统的需要灵活地设置自适应算法的门限值,以获得所期望的包时延和复用效率。
The frame generation algorithms in advanced orbiting systems (AOS) protocol are studied, and the average packet time delay for the high efficiency frame generation algorithm is analyzed on the condition that the packet arrival rate obeys the Poisson distribution. On the basis of this, an adaptive frame generation algorithm is used to overcome the large packet time delay problem of the high efficiency algorithm caused by lack of enough packets' arriving in a long period of time, and a formula for calculating the average packet time delay for the adaptive algorithm is concluded. Theoretical analysis and simulation results show that the adaptive algorithm can achieve the smaller packet time delay than the high efficiency frame generation algorithm. In practical application, the threshold of the adaptive algorithm can be designed flexibly to get the desired time delay and multiplexing efficiency.