Japan's NTT DoCoMo may enter the U.S. market next year in order to capitalize on the growth in smartphone and mobile Web usage, according to a report from Japan Today.

The wireless operator has more than half of the Japanese cell phone market with more than 55 million subscribers, and it is known for having high-end handsets and mobile Internet services. The company would reportedly lease network capacity from AT&T or T-Mobile to provide its U.S. services, which would make it a mobile virtual network operator.

DoCoMo has not responded to media inquiries about the move as of this writing, but a jump into the U.S. market would enable the carrier to utilize its expertise in advanced mobile services. The company's U.S. offering would likely center around high-end devices that use 3G data networks for things like downloading apps, mobile e-mail, and other features.

An MVNO venture does pose many risks though, as recent history is littered with deep-pocketed companies unsuccessfully trying to carve out their own space in the mobile market. Disney, ESPN, Amp'd Mobile, and others all failed to build a sustainable business reselling wireless services, and these operations have been sold off, rolled into other services, or outright killed. Helio also directed its MVNO service at smartphone users who wanted always-on 3G connectivity for devices like the Ocean, but it was eventually sold at a discount rate after only garnering about 170,000 subscribers.

On the bright side, the MVNO Virgin Mobile has been able to attract a significant number of subscribers thanks to its lack of credit checks and long-term contracts, and Sprint Nextel is trying to acquire it for about $500 million.

Most companies are just starting the hard work of mobilizing workforces by bringing the software they use to smartphones. InformationWeek analyzed this issue in an independent report, and it can be downloaded here (registration required).