Co-DRR: an integrated uplink and downlink scheduler for bandwidth management over wireless LANs

Abstract

Bandwidth management over wired bottleneck links has been an effective way to utilize network resources. For the rapidly emerging IEEE 802.11 wireless LAN (WLAN), the limited WLAN bandwidth becomes a new bottleneck and requires bandwidth management. Most possible existing solutions only exclusively focus on optimizing multimedia traffic, pure downlink or pure uplink fairness, or are incompatible with IEEE 802.11. This study proposes a cooperative deficit round robin (co-DRR), an IEEE 802.11-compatible host based fair scheduling algorithm based on the deficit round robin (DRR) and distributed-DRR (DDRR) schemes, to cooperate the uplink and downlink quantum calculations to simultaneously control uplink and downlink bandwidth. Co-DRR uses the standard PCF mode to utilize the contention-free period to compensate for the unfairness in the contention period. Numerical results demonstrate that: co-DRR can scale up to 100 mobile hosts even under high bit error rate (0.0001) while simultaneous achieving uplink/downlink long-term fairness (CoV<0.01) among competing mobile hosts.