The 802.16e adds regional roaming
(Mobile WiMAX) for broadband wireless applications up to
15 Mbps with a typical radius of around 1- 3 miles. Another
feature of the 802.16e is that it supports mobility up to 65
mph (105 km/hr) but does not provide backward
compatibility. The major feature of WiMAX is the per-flow
Quality of Service (QoS). The WiMAX has two different
modes of operation viz. the Point to Multipoint and the
Mesh. When the user is on the move and there is a need of
handoff the IEEE 802.16e-2005 has three methods to offer,
out of these one is mandatory and the other two are optional.