A cross-layer partner-assisted handoff scheme for hierarchical mobile IPv6 in IEEE 802.16e systems

The design of the seamless handoff is the key issue in the next-generation mobile networks. A new broadband wireless access, called WiMAX, has been specified in the IEEE 802.16e standard document, to provide the high bandwidth and the large coverage area than the IEEE 802.11-based wireless networks. In the IP-based mobile network, mobile IPv6 (MIPv6) protocol provides the binding update message to update the mobile station's IP information for supporting the layer 3 mobility. Hierarchical mobile IPv6 (HMIPv6) protocol is proposed by employing a hierarchical network structure to reduce handoff latency. HMIPv6 protocol suffers the long handoff delay and the high packet lost in the macro mobility. This paper presents a new cross-layer partner-assisted handoff mechanism based on HMIPv6, termed as P_HMIPv6 protocol. The P_HMIPv6 protocol is a cross-layer approach by the combination of layer 2 and layer 3. The partner station (PS) is a new component with relay ability and adopted by our protocol. With the assistance of the PS, care-of address (CoA) is pre-acquired and DAD operation is pre-executed by the PS before the MS initiates the layer 2 handoff. The simulation results show that P_HMIPv6 protocol actually achieves the performance improvements in handoff delay time, packet loss rate, and handoff delay jitter. Copyright © 2009 John Wiley & Sons, Ltd.