Fluid analysis of delay performance for QoS support in wireless networks

Providing quality of service (QoS) guarantees over wireless links requires thorough understanding and quantification of the interactions among the traffic source, the wireless channel, and the underlying error control mechanisms. In this paper, we account for such interactions in a network-layer model that we use to investigate the delay performance for an on/off traffic stream transported over a wireless link. The capacity of this link fluctuates according to a fluid version of Gilbert-Elliot´s model. We derive the packet delay distribution via two different approaches: uniformization and Laplace transform. Computational aspects of both approaches are discussed. The delay distribution is then used to quantify the wireless effective bandwidth under a given delay guarantee. Numerical results and simulations are used to verify the adequacy of our analysis and to study the impact of error control and bandwidth allocation on the packet delay performance.