Measuring the Performance of Link Layer Triggers for the Upward Vertical Handover in Heterogenous Wireless Network

The traditional handoff procedure can not meet the handoff latency demand in the upward vertical handoff. To solve this problem, a novel link layer trigger mechanism based on IEEE 802.21 standard is proposed. The performance of this new handoff scheme is evaluated in this paper. The simulation results show that link layer trigger mechanism can effectively reduce the handoff latency and packet loss. We also investigate the effects of different shrink factor ¿ on the performance of 802.21-assisted vertical handoff. It is demonstrated that choosing of a suitable link layer trigger time is of particular importance for the minimization of handoff time difference and the improvement of handoff performance.