Deterministic Backoff: Towards Efficient Polling for 802.11e HCCA in Wireless Home Networks

802.11e HCCA (Hybrid coordination function Controlled Channel Access) exhibits good QoS provisioning for constant bit rate (CBR) video streams in a single collision domain. However, its performance degrades significantly for variable bit rate (VBR) video streams particularly in multi-collision domains. In addition, HCCA has the disadvantage of high complexity. In this paper, we introduce a deterministic backoff (DEB) method into the HCCA mechanism, which achieves virtual polling via carrier sense on the wireless channel. DEB inherits the merit of HCCA that achieves near collision-free channel access in single collision domain. It also exhibits robust performance in multi-collision domains. Simulation results show that DEB supports well both CBR and VBR video streams.