Adaptation of MAC Layer for QoS in WSN

In this paper, we propose QoS aware MAC protocol for Wireless Sensor Networks. In WSNs, there can be two types of traffic one is event driven traffic which requires immediate attention and another is periodic reporting. Event driven traffic is classified as Class I(delay sensitive) traffic and periodic reporting is classified as Class II(Best Effort) Traffic. MAC layer adaptation can take place in terms of (i) Dynamic contention window adjustment per class, (ii) Reducing the delay suffered by difference in Sleep schedules(DSS) of communicating nodes by dynamically adjusting Duty Cycle based on Utilization and DSS delay of class I traffic, (iii) Different DIFS (DCF Inter Frame Spacing) per class, (iv) Adjusting all the three schemes proposed above simultaneously.