WiMax refers to both the 802.16d and 802.16e standards, which IEEE said supports a variety of applications and network solutions. The WiMax label refers to a defined subset of technology specifications from the 802.16d and 802.16e standards called "profiles."

Often referred to as the mobile standard, 802.16e not only introduces mobility to broadband wireless specifications, but it also provides enhanced performance even in fixed and nomadic environments. Below I have outlined several reasons why 802.16e is the true future of WiMax.

Not backward compatible

Operators seeking to make a WiMax investment must first recognize that 802.16e is not backward compatible with 802.16d. While some 802.16d vendors propose base station equipment with additional hardware complexity or software programmability to allow a switch to 802.16e, this will not impact any 802.16d end-user devices already deployed. These 802.16d end-user devices will not operate within an 802.16e network and the imperative for low-cost end-user devices makes it prohibitive to introduce additional hardware to attempt an upgrade to 802.16e compliance. Adding upgrade capability to the base station may also result in a large cost penalty.

Additionally, an operator who deploys 802.16d and then attempts to roll in 802.16e equipment at a later date will be disadvantaged by having to split the available licensed spectrum between the two technologies. Without a true upgrade path from 802.16d to 802.16e and the necessity to preserve spectrum to support network growth, 802.16e provides the best long-term protection for an operator's WiMax investments.