Adaptive Cross-layer QoS mechanism for cognitive network applications

Given limited network resources, applications, particularly those that support real-time services, must deliver an ambient quality-guaranteed service. Different applications are associated with different Quality of Service (QoS) concerns, as well as different QoS control parameters. This work discusses the QoS specifications of three wireless access technologies, 3G, WiMAX and WiFi, in the design of an ambient QoS mechanism. By exploiting the concepts of Cross-Layer and Cognition, this study integrates these environmental parameters with the sensing of spectral and received signal strength from a cognitive radio paradigm, and proposes the ambient QoS algorithm to select the best access network for services. The proposed QoS mechanism not only meets the requirements of various applications but also guarantees QoS. From the simulation results, the proposed ambient QoS mechanism outperforms existing mechanisms in real-time applications. Comparison with traditional mechanisms reveals that the proposed ambient intelligence reduces average delay time and jitter to 0.157 seconds and 0.086 milliseconds, respectively, for VoIP services, and reduces the packet loss ratio for high-definition video stream by 3.42%.