On reducing throughput degradation of TCP connection after vertical handover

Mobility management solutions designed for heterogeneous networks can provide seamless handover and service continuity. Thus, ongoing TCP sessions can remain active, even when mobile node handovers from one access network to another. In such seamless handover, packet loss can be avoided but TCP still undergoes through several performances degradation issues due to change of network characteristics. Throughput of a TCP connection is badly affected after vertical handover, because mobility management solutions initiates a new TCP connection or migrates the existing one, in new access network, for service continuity. If a new TCP connection is established, then it starts from slow start phase and gradually moves to a steady state, thus throughput degradation occurs. If the existing connection is migrated then TCP enters into congestion avoidance phase due to packet loss creating throughput degradation. To handle this throughput degradation, variety of solutions has been proposed in the literature. In this paper we have discussed some of these solutions that are based on end-to-end philosophy. A comparison is made on the basis of common metrics.