Explicit and implicit pipelining for wireless medium access control

In wireless networks, multiple stations contend for access to the shared channel. In the cases of collisions, the associated collision cost is much higher than wired networks since stations cannot detect the collision without explicit feedback from the receiver. For this reason, more efficient contention resolution algorithms are desired for wireless networks to reduce the collision probability among backlogged stations. With distributed multiple access control, each station usually goes through a contention resolution stage before initiating its transmission. As contention resolution stage consumes channel bandwidth without producing any goodput, ideally, we desire it to be as short as possible while reducing the possibility of collisions to as small as possible. However, in general, it is difficult to achieve an optimum tradeoff between these two desired features. In this paper, we propose to use pipelining techniques to resolve such conflicts and improve the performance of multiple access control in terms of channel utilization. We discuss several pipelining MAC schemes and present their advantages and disadvantages accordingly.