These units will initially be installed indoors first and deliver LTE-U (unlicensed) via the unregulated radio bands in use today. The gear is built by Nokia Networks and it is called Flexi Zone.
While T-Mobile said that installations would begin in earnest next year, Nokia says that the carrier has already begun deploying the Flexi Zone small cells. LTE-U is technically in a “pre-standards” phase, operating in the 5GHz band. You might be thinking that it might conflict with your home Wi-Fi, but Mr. Ray assures that T-Mobile’s LTE-U will not conflict with wireless LANs.
Part of the reason for that assurance (as well as the appeal of getting into the unlicensed space), is that there is in excess of 500MHz of unutilized, or under-utilized spectrum in the 5GHz band. That means there is great potential for delivering extremely fast throughput.
The tradeoff is that keeping everything in check within the unlicensed arena means limited coverage. However, indoor installations will be augmented by outdoor deployments where it can complement existing services.
This technology has been successfully deployed by NTT DoCoMo in Japan, called “Licensed Assisted Access,” or LAA-LTE, it uses Nokia’s Flexi Zone gear. Ericsson will be testing LTE-U small cells with T-Mobile as well. The standard will be finalized by 2016.
source: Light Reading