MarketWatch reports that Microsoft submitted a filing Monday to the Federal Communications Commission that suggests the company will soon be adding phone service to its line of Zune portable media players.

According to the filing, Microsoft and other firms will submit for the agency’s approval a prototype of a wireless device that could be used to talk over the Internet. Apple Inc. made a similar filing, although chose a different technology, in advance of announcing its iPhone in January.

In the filing, Microsoft describes a wireless device that utilizes OFDM, a technology that can be used to route digital TV and voice calls among devices. Versions of OFDM have been tested and deployed for mobile phone use by carriers. Microsoft says that the intended use of the device is “consumer broadband access and networking.”

While the FCC filing makes no mention of the Zune, Rob Enderle, an analyst with the research firm the Enderle Group, said the filing seems to indicate “an internet device or a mobile VoIP phone,” that “certainly could be a Zune derivative product.”
Speculation about the Zune phone is running rampant. According to CrunchGear, a tech blog:

By taking the proximity limitations from an otherwise sound idea and reversing them macro-syle, Microsoft opens up the Zune experience to everyone, making the ecosystem reach from coast-to-coast. The Social, as they say, goes national. We love the idea, as it really frames the concept of portable social networking in a wide, wide light.

Unfortunately for Microsoft, many analysts consider the Zune’s wireless features useless. It will take more than expanding the geographic range of the Zune’s handicapped sharing capabilities to make a Zune phone something to get excited about.