Cross-layer optimization in QoS aware next generation wireless networks

Providing guaranteed quality-of-service (QoS) for resource-hungry multimedia applications over wireless fading channels is challenging. Traditional layered architecture fails miserably in providing the QoS requirement of high throughput, low latency demand of these kinds of applications in wireless mobile networks. Cross-layer design approaches are critical for efficient utilization of the scarce radio resources with QoS provisioning in the 4G wireless networks like WiMAX. Better system performance can be obtained from information exchanges across protocol layers, which may not be available in the traditional layered architecture. Cross-layer design approaches are critical for efficient utilization of the scarce radio resources with QoS provisioning in the WiMAX based 4G networks. Here we have proposed a cross-layer framework for WiMAX networks to optimize the system performance as well as maintaining the end-to-end QoS of individual users. As proper utilization of limited network resources is very much essential to achieve the objective of high degree of optimization, resource allocation and scheduling are important issues. We also discuss in detail the cross-layer resource allocation and scheduling scheme in the WiMAX system and propose an algorithm to cater the need of better resource management particularly for heterogeneous traffic consisting of soft and hard QoS constraints applications in 4G networks. Numerical results demonstrate a significant performance gain for the cross-layer optimization.