Demand based bandwidth assignment MAC protocol for wireless LANs

Wireless networks are being rapidly installed in enterprise networks. There are several issues that are critical with the current specifications and the prominent ones are bandwidth utilization, cell capacity, propagation delay, power efficiency and quality of service aspects of the IEEE 802.11 Medium Access Control (MAC) layer. IEEE 802.11 specifications for wireless LAN use Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) scheme. Although this scheme is widely successful due to its simplicity, it is inefficient in utilizing the physical bandwidth. Wireless media being highly limited in bandwidth and power, a Time Division Multiple Access (TDMA) may help to increase the utilization of the channel bandwidth. Many satellite networks have used Demand Assignment Multiple Access-TDMA (DAMA-TDMA), where the time slots are allocated dynamically. In this paper, a variation of this protocol has been proposed, called as Demand Based Bandwidth Assignment (DBBA) protocol. One of the main challenges that this protocol resolves is to avoid collision to the maximum extent during the demand request contention period. In order to analyze the DBBA, a test bench has been developed to simulate the traffic. Based on the simulation result, it has been observed that the proposed DBBA protocol has higher bandwidth utilization, supports larger number of stations in one cell, lesser propagation delay, more power efficient and has the ability to provide better quality of service. Since there is no collision, the efficiency of the system can be increased without affecting the overall throughput of the system.