T-MobileAccording to Cult of Mac “high placed sources” are saying the iPhone may be on the T-Mobile US network as soon as this fall. Talks are said to be in advanced stages between Apple and T-Mobile and the source gives the deal an 80 percent chance of happening.

While many have suggested the iPhone would hit Verizon as soon as the exclusivity agreement with AT&T and Apple ends, the report suggest that it may be easier for Apple to add T-Mobile as a provider in the US since it operates a similar network to AT&Ts. – A point that I have also suggested would make more since.

There may be one technical hurdle, while T-Mobile and AT&T operate similar networks they operate on different frequencies. If the iPhone 4 could fully support T-Mobile’s 3G network is unknown. In order to work, the iPhone 4 would need to support the 1700 MHz and 2100 MHz bands. While the iPhone 4 technical specifications list the 2100 MHz band, there is no mention of the 1700 MHz band, however some believe that Apple may have simply omitted this information from the page.

In June Apple asked the FCC to keep quiet about the iPhone 4 for an extra 45 days. The letter to the FCC stated that the documents contained “technical and design information that has not been publicly disclosed in such marketing and that is protected by Apple as confidential and proprietary secrets.” Technical information? Like support for the 1700 MHz band? That 45 days is about up, so we could know really soon if the 1700 MHz support is there.

T-Mobile is the fourth largest mobile provider in the US and its parent company, Deutsche Telekom, carries the iPhone in Germany. [Cult of Mac]