T-Mobile and Clearwire sitting in a tree:
S-P-E-C-T-R-U-M-I-N-G
First comes 3G,
then comes 4G,
then comes the Spectrum sharing!

While this may appear ludicrous at first sight (Sprint owns majority of Clearwire, T-Mobile is looking at LTE for 4G while Clearwire builds it’s competing Wi-Max 4G network), it may be possible. The CEO of T-Mobile USA, Robert Dotson, while speaking at an investor conference in Frankfurt, had this to say-

“We continue to look at joint venture opportunities for additional spectrum… there are a number of different options we look at, (and) have been talking with cable companies, with Clearwire.”

If this hold true, T-Mobile could provide funding for Clearwire’s network build out in exchange for access to the highly valuable wireless spectrum that is needed to support T-Mobile’s LTE network.
Source- DSLReports.com