Adaptive Batch Resolution Algorithm with Deferred Feedback for Wireless Systems

A batch resolution algorithm (BRA) is a channel access policy used by a group of nodes (the batch) that simultaneously generate a packet for a common receiver. The aim is to minimize the batch resolution interval (BRI), i.e., the time it takes for all nodes in the batch to successfully deliver their packet. Most of existing BRAs require immediate feedback after each packet transmission, and typically assume the feedback time is negligible. This conjecture, however, fails to apply in practical high rate wireless systems, so that the classical performance analysis of BRAs may be overoptimistic. In this paper we propose and analyze a novel BRA named Adaptive Batch Resolution Algorithm with Deferred Feedback (ABRADE), which waives the immediate feedback approach in favor of a deferred feedback method, based on a framed ALOHA access scheme. The frame length is optimized by using a dynamic programming technique in order to minimize the BRI, under the assumption that the batch size is known. Successively, we remove this assumption by coupling ABRADE with a batch size estimate module. The new algorithm, called ABRADE+, is compared against the best performing BRAs based on the immediate feedback paradigm, showing better performance both in case of partial and no prior knowledge of the batch multiplicity.