In the transition to 5G, AT&T has focused on the 39GHz millimeter wave radio band, purchasing sizable blocks of this spectrum from FiberTower. Now, the carrier stated that its 39GHz spectrum holdings have more than doubled to 786MHz, which, in principle, should allow it to offer “at least 3Gbps download speeds” across the U.S. The big “if” in this scenario is AT&T’s ability to build nationwide towers to support this short distance mmWave bandwidth. By betting on 39GHz, AT&T will have 800MHz bandwidth in some markets.
VentureBeat reports that AT&T’s 5G+ network “is now available in parts of 35 cities and is initially being densified to provide mobile service at ‘arenas, campuses, and more,’ with fixed (home broadband) service potentially to follow.” The carrier sells only a few 5G handsets, including Samsung Galaxy S20+ and S20 Ultra 5G, but is “expected to broaden its selection later this year.”
To achieve its current bandwidth, “AT&T swapped its FiberTower holdings for auction vouchers, enabling it to target contiguous spectrum blocks across the country.” The carrier bid $2.4 billion (half from vouchers) to win the 786MHz “of nationwide 39GHz spectrum, bringing its national mmWave average to 1,040MHz, including separate 24GHz holdings.”
Although last April AT&T reported that its Netgear Nighthawk 5G hotspot reached 2Gbps on its “enterprise-focused 5G mmWave network,” its consumer 5G offering “has been disappointingly slower, offering 4G-like speeds using low band spectrum.” VB notes that, “like rival T-Mobile, AT&T has focused its consumer 5G launch on covering large swaths of land rather than on ultimate performance.”
With regard to AT&T’s 800MHz bandwidth in some markets, VB notes that this is “enough for eight 100MHz channels,” and with AT&T’s reported download speed of 1.5Gbps across four channels, it suggests “that 3Gbps should be easily attainable through all eight channels.” Speeds could be higher if a 5G device “can simultaneously access AT&T’s 39GHz and 24GHz spectrums, or the 39GHz spectrum plus low or mid band channels.”
The ability to build-out 5G tower hardware “remains a question mark,” however, since “a 39GHz signal’s ability to travel is measured in feet rather than miles, requiring significant ‘small cell’ radio hardware deployments to provide service.”
AT&T has made the decision to use its mmWave for 5G+ in urban environments “with no specific timeline for wider rollouts elsewhere,” in contrast to Verizon, which “has focused almost exclusively on millimeter wave for its initial 5G rollout.” Verizon’s service has “hit peaks in the 2Gbps range,” but VB adds that, “most of its real-world service has peaked at under 1.5Gbps, however, and the carrier has typically promised ideal performance of 1Gbps with more common speeds in the 600Mbps range.”
Microsoft Answers Amazon’s Verizon Cloud Partnership with New 5G-Enabled Azure Edge Zones, Starting with AT&T, GeekWire, 3/31/20