A study of enhanced TCP for vertical Handover using explicit congestion notification (ECN)

In current telecommunication, how to communicate on the network is one of the important issues. Handover will occur for free movement of mobile node. Cellular network has covered a wide range but has a relatively narrow bandwidth. WLAN has a wider bandwidth but a relatively narrow range of services available. Heterogeneous handover will occur for free movement of mobile node. During the handover process will have inevitably transport delay and network congestion. Currently research has progressed with Freeze-TCP and TCP Westwood. But wireless congestion and handover congestion cannot distinguish. In this paper, we propose that receiver (mobile node) determines the occurrence of the handover. Receiver received ECN marked packet and readjusts the window size according to the handover. Than sender receive handover option field and ECN marked ACK, then it sends dummy packet. In this way, problems can be solved by changing TCP header and ECN. The result of this paper is use Qualnet

I. Introduction

The wired network based on Internet environment has been developed rapidly. But now wireless network while moving on the network connection available is significant development. Network should provide the desired service to mobile user.