Performance analysis of dual threshold call admission control in 3G/WLAN coupled network

Future generation communication systems will provide transparent and seamless user roaming with end-to-end quality of service (QoS) guarantees. As a result, the interoperability of various communicating platforms emerges as a crucial necessity. Universal mobile telecommunication system (UMTS) and wireless local area network (WLAN) convergence network, a popular and representative interworking paradigm, provides a plethora of multimedia services to mobile users with multimode access capability. Resource allocation and call admission control (CAC) are the key management functions in the convergence network, in order to provide users with guaranteed QoS and efficient resource utilisation. In this paper, dual threshold bandwidth reservation (DTBR), a call admission control scheme is analysed for the loose, tight and hybrid coupled network. The strong feature of this scheme is that it is based on complete sharing (CS) of the overall bandwidth, which is believed to yield high radio resource utilisation while meeting guaranteed QoS. The performance parameters such as throughput, delay, voice and data call blocking probabilities are analysed for those coupling schemes.