While WiMax has the potential to deliver mobile broadband services to US companies, its success will depend largely on how well and quickly the Sprint-Clearwire coalition builds out its nationwide network, says a new report from Forrester Research.

In order for WiMax to be successful, Forrester says that Clearwire will have to meet "a number of very important milestones" within the next year and a half, including service deployment, the availability of multimode devices that have separate channels for voice and data, and developing efficient pricing plans for service-level agreements.

The report says that while WiMax is taking steps toward being an enterprise-grade wireless technology, it is not deployed widely enough for companies to use as their primary mode of WAN access, and should be viewed as a solid backup option for fixed corporate WAN technologies such as MPLS.

The report also sees WiMax less as a "Wi-Fi killer" and more as an extension to current Wi-Fi-based WLANs that will fill in spaces between WLAN/Wi-Fi hotspot coverage. Thus, instead of being the primary technology used for wireless connectivity, WiMax would be used in places where Wi-Fi access is unavailable.

As far as deployment goes, Forrester expects that Clearwire's WiMax service will have "wide geographic availability in populated areas" sometime within the 2009 to 2010 timeline, and that Clearwire will reach at least 140 million people in the United States by the end of 2010. This means that for roughly two years, the technology will have little competition in the wireless broadband market, as Forrester projects that LTE won't have wide service availability until 2012.

Sprint plans to offer its first commercial WiMax services in September in Baltimore, with launches in Washington, DC, and Chicago scheduled for later in the fourth quarter. The company says other major metropolitan areas shouldn't expect WiMax to come to their cities until at least next year. Overall, Sprint's strategy is to deploy WiMax coverage in major cities, while Clearwire deploys WiMax in rural areas where Sprint doesn't have as strong coverage.

Forrester's report is the second report over the past month to take a sceptical look at WiMax's near-term enterprise potential. Roughly two weeks ago, Gartner released a report advising that enterprises hold off on investing in WiMax until the technology is more widely deployed across the United States and until vendors produce more dual-mode cellular/WiMax handsets.