Mobility support for IEEE 802.1.6d wireless networks

We study in this paper whether mobility can be supported by the 802.16d network without any change in the specification. Mobility capability involves two main issues: connection handoff and correct reception for moving terminals. We find that seamless connection handoff can be achieved within the 802.16d standard by: 1) applying some of the existing functionalities defined for the terminal initialization process; 2) devising a set of protocols for message exchanges for handoff; and 3) forwarding some of the operational parameters from the current base station to a new one via the backhaul network, instead of over the radio link. As for reception at moving terminals, our analysis of bit error rate for the OFDMA mode shows that, under typical radio conditions, the link can provide satisfactory error performance for terminal speed up to tens of kph. As a result, we show that the current 802.16d standard with our proposed technique can support user mobility.