An Adaptive Time slot Allocation for Statistical QoS guarantees in Wireless Networks using Cross- layer approach

Quality of Service (QoS) guarantees plays a critically important role in mobile wireless networks. For the real time services like multimedia video conference, the key QoS metric is to ensure a stringent delay-bound rather than high spectral efficiency. In this paper, a cross-layer approach is proposed to investigate the impact of physical-layer infrastructure on data-link layer QoS performance over wireless links. At the physical-layer a Single-Input-Single-Output (SISO) diversity scheme as well as Adaptive Modulation and Coding (AMC) techniques is taken into account. At the data-link layer, the focus is on how the physical-layer infrastructure influences the real-time multimedia delay-bound QoS performance. To achieve this goal, the physical-layer service process is modeled as a Finite-State-Markov-Chain (FSMC). Based on this model, the QoS performance is characterized at the data-link layer using the effective capacity approach, which turns out to be critically important for the statistical QoS guarantees over wireless links in wireless networks. The simulated results demonstrated that the proposed cross-layer model can efficiently characterize the interaction between the physical-layer infrastructure and data-link layer QoS performance.