无线ATM中基于主动容错的新型ARQ机制

A novel ARQ scheme based on active fault tolerance for wireless ATM

自动请求重传(ARQ)机制是一种常用差错控制方法。典型的ARQ机制有选择重发ARQ(SR-ARQ)和回退N-ARQ(GBN-ARQ)。针对选择重发ARQ性能高,但复杂,而GBN-ARQ实现简单,但是性能较差的问题,在GBN-ARQ机制的基础上,做出改进,利用接收数据控制字段本身的统计关联关系,设计了一种适用于无线ATM的主动容错的ARQ机制,并在性能和实现复杂度上与常规SR-ARQ和GBN-ARQ分别进行了理论和仿真对比。实验结果表明,相同条件下AFT-ARQ实现复杂度明显低于SR-ARQ,而性能上较常规GBN-ARQ机制有了显著提高,并接近于SR-ARQ。

Automatic Repeat reQuest(ARQ) scheme is one of the error control methods. There are two typical ARQ categories: the Selective Repeat ARQ(SR-ARQ) and the Go-Back-N ARQ(GBN-ARQ). SR ARQ has a much better throughput performance than that of GBN-ARQ, whereas its implementation is more complicated which results in heavy processing load. Both of the two methods can hardly satisfy the standards of wireless Asynchronous Transfer Mode(ATM). A novel ARQ scheme based on active fault tolerant is designed. It makes use of the statistical relationship of the control data from the network to recover the erroneous data. It is compared with conventional SR-ARQ and GBN-ARQ both in theories and in simulations of throughput performance. The results show that AFT-ARQ has a lower complexity than that of SR-ARQ;and it has a better throughput performance than that of GBN-ARQ,which is close to that of SR-ARQ.