Contention Based Negative Feedback ARQ for VoIP Services in IEEE 802.16 Networks

In this paper retransmission strategies for real-time services over IEEE 802.16 networks are investigated. This is done in the context of VoIP using unsolicited grant service (UGS) scheduling. A mathematical model is derived for the case where the downlink channel remains constant automatic repeat request (ARQ) is analyzed in terms of bandwidth usage on the downlink as well as the uplink. A new ARQ scheme is proposed and analyzed in terms of the performance metrics packet loss rate, packet delay and link efficiency. Constraints and limitations of the scheme are also discussed