Performance evaluation of table-driven and buffer-adaptive WLANs

The random access control (MAC) technique of standard WLANs is called the distributed coordination function (DCF) [3]. DCF is a carrier sense multiple access based on collision avoidance (CSMA/CA) scheme with binary slotted exponential backoff. This exponential backoff makes the system more complex, and fairness [3−13] among the stations is a major concern. This chapter shows one possible evolution of WLANs where exponential backoff is not employed. In the new techniques herein users transmit randomly but adapt themselves to traffic conditions, thus improving throughput and delay while guarantying fairness. Users in the first technique are controlled by a table which is derived from traffic measurements (table driven). In the second, users’ transmission activities are function of their buffer contents.