Adaptive MAC Scheme Ready for Delay Assurances in Wireless Networks

Providing multiple classes of delay assurances to end-to-end applications is one of the key challenges in multihop WLANs. In this paper, we propose a new scheme called delay feedback adaptive control (DFAC), which is a preparation to implement end-to-end delay guarantee in multihop WLAN. It is derived from enhanced distributed channel access (EDCA) in IEEE 802.11e. DFAC can adaptively adjust the parameters of each traffic class according to the transmission delay. We evaluate the performance of DFAC through simulation. Results show that DFAC can improve the throughput of traffic class with high priority, and provide delay assurance effectively for real-time traffic in single-hop. Then we can use DFAC to ensure the delay of traffic within the specific rang in every single-hop, adaptively adjusting the priority of each traffic classes according to the average per-hop requested time, thus the end-to-end delay assurances will come to realize on the whole path