Overheard ACK with Token Passing: An Optimization to 802.11 MAC Protocol
Distributed Coordination Function (DCF) is defined in IEEE 802.11 standard, which is widely used in practice. Despite of its wide use, it has several limitations. Because of the idle and collision times, it suffers from poor channel utilization. Besides, the control packets, particularly, ACKnowledgement (ACK), consume non-trivial amount of bandwidth. Though the number of control bits in an ACK frame is small, the added overheads like the preamble, packet header etc. make the situation worse. In this paper, the authors propose a scheme called overheard ACK where the explicit ACK frame has been eliminated by using the leverage of packet overhearing.