QoS framework for IMS based heterogeneous wireless networks using mSCTP and ePDG

IP Multimedia Subsystem (IMS) is an enabling technology that are designed to provide multimedia services over heterogeneous networks. In IMS based heterogeneous networks the placement of gateway plays a vital role in enhancing the Quality of Service (QoS) and the enhanced Packet Data Gateway (ePDG) is being considered in interworking. The ePDG is realized at the edge of the network where IP Multimedia Subsystem (IMS) interacts with Worldwide Interoperability for Microwave access (WiMAX). Also, the performance of network has been enhanced by allocating priorities to mobile Stream Control Transmission Protocol (mSCTP) on per stream basis. Hence the proposed interworking system considers the impact of IMS with mSCTP and ePDG. In this paper, the performance of the network has been evaluated in terms of throughput, delay and retransmission attempts and the performance comparison is made against the conventional Transport Control Protocol (TCP) over the same network conditions. The performance evaluation shows that the proposed QoS approach improves delivery of multimedia services over heterogeneous IP access.