TCP Context Switching Scheme to Enhance Throughput by Adapting well to Vertical Handoff in Heterogeneous

Abstract

Vertical hando？？ is a new type of hando？？ that is issued when a mobile node moves over heterogeneous wireless net- works with each proving varying access bandwidth, transmission latency, and coverage. A mobile node can achieve higher through- put by accessing higher bandwidth providing wireless network. However, TCP has to experience drastic changes of the band- width and the latency due to the vertical hando？？ which must be recognized as a network congestion, and this degrades end- to-end performance. In this paper, we propose TCP context switching scheme, named Context-Switching TCP, that main- tains TCP variables separately for di？？erent types of wireless networks. Through simulations, Context-Switching TCP shows higher performance than TCP SACK for vertical hando？？. Es- pecially, it shows much higher performance gain when vertical hando？？ occurs frequently.