Now we know. After weeks of speculation as to when Xohm, the WiMAX business unit of Sprint Nextel, would launch commercial services, Barry West, Sprint Nextel CTO and president of Xohm, finally named the month (if not the day).

Addressing conference delegates in his keynote presentation Tuesday at the WiMAX Forum Global Congress in Amsterdam, he said the first commercial Xohm service will start this September in Baltimore. “Mobile WiMAX services will follow in the Washington DC and Chicago markets during Q4 2008,” he said. “We’re already looking at other markets to launch after that.”

West says that over 575 Xohm WiMAX base station sites are on air, with a number of devices going through its own testing labs. “It’s the only [communications] technology I know where the chipset evolution for devices is going faster than the infrastructure,” he said. Talking to telecoms.com, West added. “The access devices available at launch will include a Samsung AirCard, a modem from ZyXEL, a ZTE USB dongle, the Nokia Internet tablet [N810]”, and Intel inside laptops. Others will follow.”

The original Xohm target for commercial launch was April 2008. One of the reasons publicly cited by Sprint Nextel for not making the April launch was lack of backhaul capacity. That problem has now been resolved, says West. “As we’ve sorted out the logistical issues with site deployment, we’re getting much better at securing backhaul capacity through fibre-optic and microwave links,” he says.

West also reports that Xohm’s back-office systems, responsible for billing and customer management, are nearly ready. “I’m probably two months behind where I thought I would be [on the back-office] but we are testing the software now [primarily from Amdocs] and we are very pleased with it. We can now activate a device over the air under five minutes and set up a billing relationship with the customer.”

The distribution of non-subsidised WiMAX-embedded devices through independent outlets is a key part of the Xohm business model, as is billing for customers rather than devices (the prevalent business model in the cellular world). West wouldn’t reveal any details of Xohm tariff packages in Amsterdam other than to say they would be simple to understand.

As anticipated, West poked fun at the high data-rate claims made by LTE supporters and those that branded WiMAX as a niche technology. “If its niche then it’s a global niche,” said West, referring to the fact there are now over 300 WiMAX deployments around the world.

One of the main weaknesses of LTE compared with WiMAX, argues West, is the lack of a developed chipset ecosystem. WiMAX has 23 chipset vendors while LTE chipsets are dominated by one or two companies. “LTE could wither without multiple chipset vendors,” says West.

West believes LTE will not be rolled out in any significant volumes until the 2012-13 period as operators, who have already invested a lot in HSPA, hold back on 4G investment.

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