A Cross-Layer Solution for Dynamic Selection of Data-Rate in WLAN using Traffic Differentiation

Wireless devices operating under IEEE 802.11 x standards have the ability to transmit at various data-rates. However, there is no specification in the standard for dynamically selecting a suitable value of data-rate. Numerous solutions are available, mainly from device manufacturers and research community; focusing on a particular algorithm and its suitability for the overall system. However, none of the previous designs were flexible to change their behavior with changes in traffic nature and pattern. Not all traffic types have the same requirements and so should be the behavior of underlying algorithms for data-rate control. This paper highlights various data-rate control algorithms; classifying them on the basis of several parameters and discusses their suitability for different traffic patterns. It also proposes an algorithm, specifically designed for real time services. The cross-layer framework monitors traffic nature and patterns at the transport layer and activates one of three available rate control algorithms which suits the requirements of a particular type of traffic. According to the specific design of a selected algorithm, it then selects data-rate values at runtime. The results verify the tremendous difference among the three algorithms in terms of throughput and delay and signify their usability for specific traffic types.