Nokia recently announced its plans to release phones featuring WiMAX in 2008. The current iteration of WiMAX is only able to connect when a receiver is stationary, but a new mobile revision is expected to be released by the end of 2007 . Intel spoke about mobile WiMAX evolution at the Beijing IDF , and Sprint also has plans for Mobile WiMAX.
The WiMAX technology, based on the IEEE 802.16 Air Interface Standard has already proven itself as a cost effective fixed wireless alternative to cable and DSL services. In December, 2005 the IEEE approved the 802.16e amendment to the 802.16 standard. This amendment adds the features and attributes to the standard necessary to support mobility. Mobile WiMAX is a broadband wireless solution that combines mobile and fixed broadband networks through a common wide area broadband radio access technology and a flexible network architecture. The Mobile WiMAX Air Interface uses Orthogonal Frequency Division Multiple Access (OFDMA) , I wont go into the details of it but generally it is a multiplexing technique that divides the available bandwidth into sub-carriers which are of multiple frequencies . Initial Mobile WiMAX profiles cover 5, 7, 8.75, and 10 MHz channel bandwidths for worldwide spectrum allocations in the 2.3 GHz, 2.5 GHz, 3.3 GHz and 3.5 GHz frequency bands. The WiMAX forum lists many advantages of this technology of which a few are
> High Data Rate :DL data rates up to 63 Mbps per sector and peak UL data rates up to 28 Mbps per sector in a 10 MHz channel
>High Scalability and Security
>High Mobility with Optimized Handover Schemes

Many of Nokia’s competitors have opted instead to pursue 4G alternatives to WiMAX. Sprint Nextel is at the forefront of this initiative, along with Orange, T-Mobile, Vodaphone, Motorola and KPN Mobile.

Useful links

The Wimax Forum Website

Information on 4G

Nokia WiMAX Technology

More on WiMAX Technology