A unified scheduling approach for guaranteed services over IEEE 802.11e wireless LANs

Supporting real-time multimedia applications in any network requires scheduling techniques that can provide guaranteed delay and/or bandwidth to media streams. Coordinating access to the wireless medium in an IEEE 802.11 wireless LAN is different from network layer scheduling since it requires scheduling traffic flows in a distributed manner. We introduce a new scheduling framework called multiple access hybrid scheduling (MAHS) that utilizes the concept of virtual packet and emulates stations packets in the access point in order to centralize the scheduling process. This way the main scheduling function is performed solely in the access point thus enabling the use of conventional schedulers to for scheduling both uplink and downlink packets (hybrid scheduling). We deploy a modified version of weighted fair queuing (WFQ) as this internal scheduler. Performance evaluation and analysis of the proposed framework is described in this article.