Cross-Layer Error Recovery Optimization in WiFi Networks

摘要

This paper presents a novel approach for cross-layer error control optimization in WiFi networks. The focus is on the reduction of the overhead deriving from the duplicate ARQ strategies employed at the link and transport layers. The proposed solution, called ARQ proxy, substitutes the transmission of a transport layer acknowledgement with a short request sent at the link layer. Specifically, TCP ACKs are generated based on in-transit traffic analysis and stored at the Access Point. Such TCP ACKs are released towards TCP sender upon a request from the mobile node, encapsulated into link layer acknowledgement frame. TCP ACK identification is computed at the Access Point as well as at the mobile node in a distributed way. ARQ proxy improves TCP throughput in the range of 25-100% depending on the TCP/IP datagram size used by the connection. Additional performance improvement is obtained due to RTT reduction and higher tolerance to wireless link errors.