Optimal Probing of Wireless Error Prone Channels for QoS Enhancements in IEEE 802.16 Wireless MAN

Ensuring reliable and efficient packet transmission in the error prone shared radio channel is one of the ways to support QoS for integrated services in IEEE 802.16 wireless MAN network. To minimize the wasted bandwidth in transmitting corrupted packets, it is critical for the subscriber station and base station to know the channel state at and schedule the next transmission. A periodical handshake is proposed to probe the channel state for proper transmission in this paper. We built a mathematical model to determine an the optimal handshake interval. In this model, we consider the bandwidth used for transmission handshake overhead and retransmission of corrupted packets as an associated cost. Using the theory of renewal process and dynamic programming method, we obtain an optimal handshake policy under which the average cost per unit time is minimized. The numerical results are presented to demonstrate the effectiveness of our approach