AT&T is building 5G test sites in Austin, Texas that will serve as a place for the company to test different 5G network architectures using equipment from multiple vendors. One of the testbeds is already up and running and delivering 5G services to an enterprise customer, and one test center is under construction. That site will conduct testing with about 10 customers, both residential and enterprise.
Speaking via webcast at the NYUWireless 5G Summit in Brooklyn, N.Y. this week, Dave Wolter, assistant vice president of radio technology and strategy at AT&T Labs, said these testbeds are critical to the company because AT&T can use them to test equipment and software from multiple vendors to see how they interoperate. It also allows them to test equipment outdoors, indoors, and in mobile situations.
It also gives AT&T a chance to try out different spectrum bands. Wolter said the initial 5G trials are being conducted in the 28 GHz spectrum band because equipment is available for that band. However, he said the 39 GHz band is the primary band where the company plans to deploy its fixed 5G services. The 39 GHz band equipment won’t be available until later this year.
The company also will test different types of network architectures to see how they impact the network latency as well as the economics. Wolter described the company’s early deployment of 5G, which he called option 3X. This deployment will use an evolved packet core (EPC) that will have a path for traffic between LTE and the 5G New Radio (NR).
The early deployments of 5G, Wolter said, will use an EPC, but he envisions this evolving to a next-gen core, which Wolter called option 7X. When the next-gen core is deployed, Wolter said the traffic will have a path from LTE to a next-gen core and to the 5G NR. At this point, the network will be able to take advantage of next-gen services enabled by the core. Wolter cautioned that a lot of factors will impact this network progression, such as available spectrum and the business case.
Wolter noted that AT&T is particularly interested in finding equipment that will handle access and backhaul via the same spectrum band so that the company can deploy 5G in areas where it doesn’t have fiber deployed.