State aware enhancement in DCCP for multimedia handovers

The multi-radio-access enabled mobile devices have enabled the integration of fourth generation networks with the legacy technologies. However, this integration has numerous issues for the multimedia applications, such as to smoothly continue over new connection without any service disruption during vertical handover. In this paper, we propose a State-Aware Feedback extension to Datagram Congestion Control Protocol (i.e. S-DCCP) that meets the Quality of Service (QoS) requirements of multimedia applications. We consider the mobile subscribers as roaming among heterogeneous access technologies from highly unstable to more stable access environment and model their mobility patterns as uniform, pareto and exponentially distributed. We first evaluate the performance of both types of S-DCCP i.e. S-TFRC and S-TCPLike and observe end-to-end delay and packet loss during the handover process. We develop an insight that S-TFRC maintains better QoS constraints meant for multimedia traffic for various link stability environments than S-TCPLike. We then consider transmission delay, throughput and transmission rate as performance metrics and compare the performance of S-TFRC with the standard TFRC during vertical handover. Our results show that for various mobility patterns S-TFRC is capable of providing better QoS to multimedia applications than the standard TFRC as it significantly reduces the transmission delay and provides better throughput to the multimedia applications.