PORTLAND, Ore.—Clearwire launched its Clear-branded mobile WiMAX service here yesterday, claiming it’s making Portland the fastest unwired city in the West.

The launch was accompanied by a marketing blitz  – new billboards, TV commercials and even cupcakes in giant bubbles situated outside the World Trade Center Plaza. The cupcakes and bubbles are featured in separate Clearwire commercials.

Clearwire CEO Ben Wolff told a room packed with journalists and analysts that the company has been working on the Portland network for the past two years. Why launch its first Clear market in Portland? Wolff, who attended law school here, explained that Portland is a tech-savvy city, home to one of Intel’s largest offices and close to Clearwire’s corporate headquarters in Kirkland, Wash. Asked if the terrain posed challenges, Wolff said it is a challenging market, between the hilly terrain, foliage and water, but the expectation is deployments will get easier in other markets, such as Phoenix.

Clearwire isn’t giving a definitive timeframe for upcoming markets, but executives have publicly talked about Las Vegas and Atlanta. Clearwire late last year closed its merger with Sprint’s Xohm WiMAX properties, and Sprint launched mobile WiMAX in Baltimore, Md., last year, making these two cities the first to have the latest WiMAX technology. Sprint also has mentioned Chicago and Boston among markets near commercial launch.

Clearwire has about 46 pre-WiMAX markets that it is in the process of converting over to mobile WiMAX. In an interview, Wolff said Seattle is one likely market to get converted in 2009. But the rate at which Clearwire will deploy new markets will be decided by the board when it meets later this month, he said. Management is composing various scenarios for the board to consider, from a fast build to a slow one and alternatives in between. The rate at which Clearwire builds out will depend on how much cash it has on hand and is able to raise. It already has $3.2 billion from investors Comcast, Intel, Time Warner Cable, Google and Bright House Networks.

Interestingly, Clearwire’s Portland tiered price plans differ from those offered in Baltimore, and Wolff said it’s likely that price plans will differ in other new markets as well. That’s one of the advantages of being a small company and something the likes of AT&T and Verizon Wireless would find difficult if not impossible to do – experiment with various price plans in different markets to see what sticks with consumers, he said.

In Portland, a mobile Internet plan runs $50 a month for unlimited usage; other plans are offered for less frequent usage, and there’s a day pass for $10. The top end of the home Internet plans is $40 a month, and customers can save $20 a month by combining home Internet and mobile Internet for the first six months of a 2-year agreement, according to a brochure.

As for launching a new network in these challenging economy times, executives at yesterday’s launch said they believe people will be looking to cut their budgets where they can, but they don’t want to give up Internet service. Wolff said he figures families spend $200 to $300 a month on collective services like broadband and residential voice service, and a customer would pay about $150 for comparable offerings from Clearwire. A Clear-branded voice service isn’t available yet but it’s in the pipeline, and VoIP services like Skype are available.