Six years after the end of the auction of 700 MHz spectrum, block A remained largely unused, although
T-Mobile USA began to deploy its extended-range LTE in 2015 on licenses purchased from Verizon Wireless and cleared of
RF interference in several areas by TV stations changing off of channel 51. This delay was caused by technical issues which were
regulatory and possibly
anticompetitive in nature. After the March 2008 conclusion of Auction 73, Motorola initiated steps to have
3GPP establish a new industry standard (later designated as band class 17) that would be limited to the lower 700 MHz B and C blocks. In proposing band class 17, Motorola cited the need to address concerns about high-power transmissions of TV stations still broadcasting on channel 51 and the lower-700 MHz D and E blocks. As envisioned and ultimately adopted, the band class 17 standard allows
LTE operations in only the lower-700 MHz B and C blocks using a specific signaling protocol that would filter out all other frequencies. Although band class 17 operates on two of the three blocks common to band class 12, band class 17 devices use more narrow
electronic filters, which have the effect of permitting a smaller range of frequencies to
pass through the filter. In addition, band class 12 and 17
signaling protocols are not compatible. The creation of two non-interoperable band classes has had numerous effects. Customers are unable to switch between a licensee deploying its service using band class 17 and a licensee that provides its service using band class 12 without purchasing a new device (even when the two operators use the same 2G and 3G technologies and bands), and band class 12 and 17 devices cannot
roam on each other's
cellular networks. US Cellular deployed a band class 12 LTE network, however not all of US Cellular's devices were able to access it. In particular, the
iPhone 5S and
iPhone 5C could not. Other wireless telecommunication providers launched LTE band class 12 networks, but have not been able to offer
smartphones that access them, instead resorting to
fixed or
mobile wireless broadband modems. As of April 2015, only three telecom providers were offering smartphones that use band 12: US Cellular, T-Mobile USA, and Nex-Tech Wireless. While smaller US telecommunication providers were upset at the lack of interoperability,
AT&T defended the creation of band 17 and told the other carriers to seek interoperability with
Sprint and
T-Mobile instead. However, in September 2013, AT&T changed its stance and committed to support and sell band-12 devices. Following AT&T's commitment the Federal Communications Commission ruled: • AT&T must fully deploy a Multi-Frequency Band Indicator (MFBI)
software feature in its 700 MHz network within 24 months of September 30, 2013. The end of the 24-month period will also commence the beginning of the band-12-capable device rollout period. • Once MFBI has been fully implemented by AT&T, AT&T shall provide LTE roaming to carriers with compatible band-12 devices. • During the first year of the device rollout period, 50% of all new unique devices will be band-12 capable. • Commencing at the conclusion of the second year of the device rollout period, all new unique devices will be band-12 capable. Consistent with these commitments, AT&T anticipates that its focus and advocacy within the 3GPP standards setting process will shift to band-12-related projects and work streams. AT&T must place priority within the 3GPP RAN committee on the development of various band-12 carrier-aggregation scenarios. Upon completing implementation of the MFBI feature, AT&T anticipates that its focus on new standards related to the paired lower-700 MHz spectrum will be almost exclusively on band 12 configurations, features and capabilities. Additionally,
Dish Network agreed to lower its maximum
effective radiated power levels on block E, which is on the lower
adjacent channel to the downlink (tower-to-user transmissions) for block A. It did this in exchange for the FCC allowing it to operate the block as a one-way service, effectively making it a broadcast, although it could still be interactive through other means. Since Dish has already been experimentally operating it as a
single-frequency network, this should not have a significant effect on whatever service it might offer in the future. == See also ==