A wireless channel model for support of quality of service

To facilitate the efficient support of quality of service (QoS) in third generation (3G) and fourth generation (4G) wireless networks, it is essential to model a wireless channel in terms of connection-level QoS metrics such as bandwidth, delay and packet loss ratio. However, the existing wireless channel models do not explicitly characterize a wireless channel in terms of these QoS metrics. We propose and develop a wireless channel model termed effective capacity (EC). In this approach, we first model a wireless channel by two EC functions, namely the probability of a non-empty buffer and the QoS exponent of a connection. Then, we design a simple and efficient algorithm to estimate these EC functions. The key advantages of EC channel modeling and estimation are: (1) ease of translation into QoS guarantees, such as delay bounds; (2) simplicity of implementation; (3) accuracy, and hence efficiency, in admission control and resource reservation. We illustrate the advantage of our approach with simulations which show that the actual QoS metric is closely approximated by the QoS metric predicted by the EC channel model