AT&T has submitted paperwork for Special Temporary Authority (STA) with the FCC to demonstrate 5G capabilities and propagation using the 28 and 39 GHz bands at a Hyatt hotel in Dallas.
Accompanying its application, AT&T explains (PDF) that its 5G demonstrations will involve communications between fixed base stations placed indoors in a room or open space located inside the building at 300 Reunion Blvd. in Dallas. The timeline calls for an operation start date on Feb. 1 with an end date of June 1.
The building has concrete walls and windows with coated glass, as shown in photos accompanying the application. The 5G wireless link will be set up between the base station and a maximum of two units of mobile user equipment located in the same room or area, at a distance of about 10 meters apart.
The application doesn't specify the manufacturer of the equipment, except to say there will be "multiple" suppliers.
The base station and user equipment will be operated at 3 meters and 2 meters, respectively, above floor level. A channel sounder operating in the 28 GHz band will only transmit signals that are received in the same area to demonstrate the millimeter wave propagation characteristics, the operator said.
David Wolter, AVP of Radio Technology & Architecture at AT&T Labs, whose name is on the application, told FierceWirelessTech last month that one of the things AT&T wanted to look at during its tests and field trials last year was the propagation at millimeter wave, including with Low E glass, which doesn’t play nice with millimeter wave.
They also found that foliage has a significant impact on signaling, but they were able to operate a millimeter wave system in a non-line-of-sight situation and learned there are multiple ways to address the foliage problem—with beams bouncing around, for example.
Construction materials also play a role, and there are many variables there again. The type of single-pane or double-pane glass that might be found in a home may lead to a loss of 5-7 dB; Low E glass found in an enterprise might lead to a loss of 40 dB. “The materials vary a lot in the impact,” he said. “We’re looking at all of those things to gather data as well as data that’s been public.”
Most of the testing and what’s been published through 3GPP has been based on environments in Europe and Asia, and the environments in those geographies can be quite different than in the U.S., so AT&T plans to take its measurements back to 3GPP and contribute there.
At the beginning of this year, AT&T announced it expects to be the first U.S. company to introduce standards-based mobile 5G service in a dozen markets by late 2018. Rival Verizon, which has been focused on fixed wireless, aims to strike the 5G punch first, so the race is on.