基于统计的p-坚持CSMA算法及其在电能量采集终端中的应用

Statistical p-persistent CSMA algorithm and its application in the electric energy acquisition terminal

通过对CSMA算法的研究,提出了一种基于统计的p-坚持CSMA算法。即在总线竞争不可避免的情况下,总线上的电能量采集终端发送数据的概率并非是固定不变的,而是在一个统计周期内,计算每个终端的数据发送概率,电能量采集终端根据此发送概率动态地调整p-坚持CSMA算法,在一定程度上防止了总线竞争现象的发生,降低了总线的通行量,优化了总线资源。通过分析非坚持CSMA、1-坚持CSMA、基于统计的p-坚持CSMA算法的碰撞率对比3种算法性能,验证基于统计的p-坚持CSMA算法在防止总线竞争方面的优越性。从真实现场电能量采集终端本地数据库获取的数据表明:与一般的CSMA算法比较,基于统计的p-坚持CSMA算法使终端显著改善了碰撞率性能指标。

A statistics-based p-persistent CSMA algorithm is presented through the research on the CSMA algorithm . The bus competition is inevitable , and in that case the probability of data sent by the electric energy acquisition termi-nal on the bus is not invariable , whereas that is always computed in a statistical cycle .For this, the electric energy acquisition terminal regulates the p-persistent CSMA algorithm dynamically and prevents the bus competition to a cer-tain extent .Furthermore , it reduces the traffic volume of bus and optimizes the bus resources .In an aspect of preven-ting bus competition , this paper verifies the superiority of the statistics-based p-persistent CSMA algorithm by analy-zing the collision rate and comparing the performance among the non-persistent CSMA algorithm , the 1-persistent CS-MA algorithm and the statistics-based p-persistent CSMA algorithm .The data acquired in local database of electric en-ergy acquisition terminal shows that the statistics-based p-persistent CSMA algorithm can apparently improve the per-formance of collision rate in comparison with the other CSMA algorithms .