Hierarchical Mobile IPv6 (HMIPv6) can reduce the delay and the amount of signaling during handover compared with the basic mobile IPv6. However, the protocol still cannot meet the requirement for traffic that is delay sensitive, such as voice, especially in macro mobility handover. Duplicate address detection and the transmission time for the handover operation could cause high handover delay. This paper proposes a new mechanism to improve the fast handover algorithm’s efficiency in HMIPv6 network. And we present and analyze the performance testing for our proposal by comparing it with the traditional HMIPv6 fast handover algorithm. The results of simulation show that our scheme can reduce the handover delay much more than the traditional fast handover method for HMIPv6 network.
Using Markov model and the network simulator-NS, this paper studies the TCP throughput performance in wireless fading channel where the packets losses are always caused by high and burst errors. The results show that the burstiness in packet errors caused by slow multipath fading benefits Reno compared to i.i.d packet errors.
In this paper, a novel timing offset estimation algorithm of low complexity is presented, which needs a few pilots. The results of simulation prove that the system performance with timing offset correction is approximate to that over AWGN channel.
QIU Yan~1, QIN Sheng-ping~2, YUE Guang-xin~3 1.Qingdao Institute of Architecture and Engineering, Qingdao 266033, P.R. China
