There is little denying that this year will bear witness to a number of mobile WiMAX deployments or that its potential market is destined to increase in the coming years. In fact, according to the Dell'Oro Group, the mobile WiMAX market will grow by a compounded annual growth rate exceeding 50% through 2011. But are there any stumbling blocks to this growth? To answer that question, let's first take a look at some of the reasons behind its strong growth, not the least of which is its energy efficiency.

Today, the third most significant operating expense (OPEX) for cellular carriers is energy costs. These fluctuating costs are also a primary area of concern for business planners. According to ABI Research, the introduction of mobile broadband to the equation means that the energy required per subscriber, arising from increasing data uptake, will push per-subscriber energy OPEX for cellular solutions past acceptable barriers. That is, of course, unless carriers move from a traditional “cellular-only” approach to one that integrates a technology such as WiMAX.

“From a pure coverage perspective, WiMAX is twice as energy cost effective as WCDMA. When data traffic is factored into the equation, WiMAX can accommodate 11 times today's average data consumption and still be more energy cost efficient compared to WCDMA or HSDPA,” said Stuart Carlaw, director of wireless research at ABI Research.

A large number of system profiles have also helped accelerate WiMAX adoption in real-world networks. These profiles, created by the WiMAX Forum, refer to a set of parameters (e.g., frequency band, channel bandwidth and duplexing scheme) on which a WiMAX network will operate. They are based on multiple IEEE 802.16 standards: one for stationary equipment and another for mobile equipment that may be in motion while receiving or transmitting signals. Additional system profiles are expected to be added over time, based on market demand and regulation changes.

The WiMAX Forum has also significantly contributed to the growth of WiMAX via its emphasis on certification and on how much more secure WiMAX is than say early Wi-Fi. But, as ABI Research points out, “Early Wi-Fi consumers enjoyed a false sense of security until there were some well-publicized hacking exploits. There may be WiMAX customers who are similarly lulled into a false sense of security. The flaws should begin to show themselves once the first big WiMAX rollouts occur.”

The primary reasons for concern over security stem from three apparent gaps, which include:

1. User terminals. Here, encryption acceleration will be required to handle AES demands.
2. Intrusion detection. Here, intrusion detection and protection software and hardware will be needed to secure access service networks.
3. Connectivity service networks. As part of carrier back offices, connectivity service networks will require stateful firewall software or robust firewall appliances, as well as additional RADIUS servers to handle the extra load imposed by roaming clients on WiMAX authentication.

Another stumbling block for WiMAX is its lack of voice services in the short term. According to one industry analyst, voice-over WiMAX (VoWiMAX) won't likely be used much before 2009.

While the industry takes the time to address these issues, one thing remains certain. With fixed-line WiMAX here to stay and mobile WiMAX arriving in the coming years, it is now more crucial then ever for cellular carriers to develop a WiMAX strategy. Next to 3G deployment, this may be the most important decision they will need to make.