The optimal configuration of the contention parameters of a WLAN depends on the network conditions in terms of number of stations and the traffic they generate. Following this observation, a considerable effort in the literature has been devoted to the design of distributed algorithms that optimally configure the WLAN parameters based on current conditions. In this paper, we propose a novel algorithm that, in contrast to previous proposals which are mostly based on heuristics, is sustained by mathematical foundations from multivariable control theory. A key advantage of the algorithm over existing approaches is that it is compliant with the 802.11 standard and can be implemented with current wireless cards without introducing any changes into the hardware or firmware.We study the performance of our proposal by means of theoretical analysis, simulations, and a real implementation. Results show that the algorithm substantially outperforms previous approaches in terms of throughput and delay.
The existing two or more stations can form a temporary network with out need of any existing network infrastructure or centralized administration. In MANETs, stations act as routers themselves, keeping route information to reach other, and stations helping forward data.Packets sent from one stations to another. A partition denotes a set of stations that have (one-hop/multi hop) communication paths between two arbitrary stations, and no path exists between any pair of stations in different partitions. If too many stations use too small CWs, then the collision rate will be very high and consequently throughput performance will be low. Similarly,if few stations contend with too large CWs, the attempt rate will be low and the channel will be underutilized most of the time, yielding a poor throughput performance also in this case. When the collision probability is far from its desired value, the...