It’s a milestone of sorts for mobile telecom operators: Sprint closed out Q3 08 with their much-anticipated launch of WiMAX service in Baltimore, Maryland (see Sprint to launch first WiMAX service in Baltimore ).

The commercial XOHM network marks the first deployment of a mobile WiMAX network by a Tier 1 provider (Sprint is the number three U.S. cellular operator), acting as a test case for planned Q4 WiMAX rollouts in Chicago and Washington, D.C. The service is expected to move from Sprint’s control to its WiMAX partner Clearwire by next year, after ironing out early financial and technical problems (notably with wireless backhaul).

Initially, downstream speeds will average between 2 and 4 Mbps, delivered from 180 WiMAX 802.16e base stations circling the city, with more coming online quickly. So far, the service does not support handheld devices, though Sprint reportedly expects the Nokia 810 WiMAX tablet to be the first XOHM-ready unit to go online. No word on when. Instead, PC users who want mobility can choose from an $80 USB modem from ZyXel Communications or a $60 PC card courtesy of Samsung Electronics.

Customers can choose from a three-tiered service plan, none of which carry long-term contracts. A Day pass is $10, Internet access for the home is $25 a month, while network-wide, go-anywhere coverage is $30 per month. Obviously, the degree of true mobility is dependent on the network footprint, which is in this case, just one market. Customers can also XOHM-enable two WiMAX devices of their choice for $50. A combined plan providing both residential and mobile broadband access for $55 is expected as well.

Sprint is clearly determined to shake up wireless pricing models while challenging fixed broadband providers by eliminating long-term contracts, device subsidies or rebates, and bandwidth limits on XOHM. Sprint seems to be taking a page from wireline DSL and cable modem providers’ book, with an “all-you-can-eat” approach for a fixed monthly charge, while adding the benefits of mobility. At $25 a month for home Internet access, XOHM can meet or beat competitive wireless offerings from fellow mobile operators or local/national telcos on price. For $5 more a month, plus the one-time cost of the PC modem card, users can go truly mobile within the network coverage area. That’s a good deal compared to the $60-$80 a month that wireless access via CDMA or UMTS 3G commonly runs, though it should be noted that these competitive offers usually span a much greater network footprint than the nascent Sprint/Clearwire WiMAX rollout. The disparity should even out as XOHM ramps up over the next two to three years.

For now, look for Sprint to quickly add support for more WiMAX-enabled devices, particularly on the PC side. Though clearly hand-held devices are a major part of the market demand for any wireless offering, and crucial to bundling hybrid connectivity, home-or-away mobility, it appears Sprint is targeting the mobile business user or telecommuter who works primarily from their PC first, and bring other platforms online as the network proves itself and works out any kinks. A business PC focus also allows Sprint to bundle other complementary, value-added services along with XOHM, and as user adoption picks up, make the move to more lucrative managed services as well.