Seamless realtime traffic handover policy for IEEE 802.16m mobile WiMAX

IEEE 802.16m standard is defining several improvements on IEEE 802.16e standard, one of them being handover (HO). This paper provides a policy to satisfy IEEE 802.16m benchmark of 150 msec or less for a hard handover (HO) between two base stations (BSs). To facilitate such fast HO, the target BSs are chosen before HO is sought. Such choice is made based on previously acquired knowledge of human mobility behavior. There are several initial ranging opportunities provided before the actual HO. Before the connection breaks with serving BS, target BS sets up its MAC states to allow instantaneous connection of service flows that are prevalent in the ongoing connection. Once the connection is broken, serving BS redirects the traffic to target BS while MSS, using the ranging parameters provided right before the connection breakup, initiates a connection request to the target BS. Several timers perform as check points so that critical operations are performed in timely manner.