(Telecompaper) BT Group company EE has started the next phase of its 4G network roll-out to support Cat 9 devices. Cat 9 uses 4G+ or LTE-A technology and is available in new smartphones including the HTC M10, Samsung Galaxy S7 and S7 Edge and the Samsung Galaxy Note 7 when it is launched. To support Cat 6 devices, EE has already enabled the first stage of its 4G+ (LTE-A) network, which uses two blocks of mobile spectrum, in more than 150 UK towns and cities. The next phase to support Cat 9 devices will enable access to a third block of spectrum for high-speed 4G services on over 500 sites across these towns and cities by end-2017.