Access Network Selection And Fast Handoffin Cognitive Wireless Local Area Network

This paper mainly studies data link layer (L2) fast handoff solution in cognitivewireless local area network (WLAN) and the access-network selection strategy. At thebeginning of this paper, the WLAN fundamentals are briefly reviewed, and then theconception of cognitive WLAN and a corresponding network management frameworkbased on1900.4are introduced. Then put forward the necessity of developing anefficient handoff scheme based on the analysis of current situation and disadvantage ofexisting WLAN handoff technology and on the management structure. In addition, theremust be an appreciate access point (AP) for the handoff execution. Although a target APcould be selected using traditional Received Signal Strength Indicator-Based(RSSI-Based) access network selection strategy, this strategy may cause someundesirable phenomena, such as network load imbalance. So, a multi-objectivecomprehensive access network selection strategy is firstly presented in this paper, whichconsiders RSSI, load and users, and takes full advantage of terminal ability empoweredby network management framework. Simulation results turn out that the strategy canmake a good balance between network throughput and load balancing. Finally, a WLANL2fast handoff scheme named dual-NIC collaboration fast handoff is presented in detail.Its project pursuant, principle and realization mechanism have been introducedrespectively. Practical performance test shows that the dual-NIC solution can get ashorter latency than traditional solution and better meet the requirements of highreal-time application, e.g. VoIP, voice or video flow-media etc.