Graceful Degradation of Transport Layer in Mobile Internet

In mobile Internet, a handover may result in significant degradation of transmission performance. Especially in a shared medium wireless network, handover traffic which moves into a new wireless access network competes with existing traffic for available bandwidth of shared medium wireless channel. This interaction between handover traffic and existing traffic causes significant performance degradation of both of traffic. In this paper, we propose a new concept of Transport Layer Graceful Degradation. We think handover traffic should increase its available bandwidth gradually and available bandwidth of existing traffic is to be decreased slowly to bandwidth which achieves fair share of shared medium with handover traffic. In the paper, we propose a new bandwidth control method for TCP traffic which achieves our proposed concept, transport layer graceful degradation. Performance evaluation results show that our proposed scheme can improve TCP throughput performance of both handover traffic and existing traffic.