AT＆T、全国的な5G、SDN制御のタイムラインを明確化

AT＆Tは、ネットワーク機能の75％を仮想化してSDNの制御下に置くという目標に「非常に近づいて」おり、CTOのAndre Fuetschは本日、投資家向け会議で「年内に簡単にヒットする」と語った。AT&T is “very close” to reaching its goal of virtualizing and putting 75% of its network functions under SDN control and will “hit it easily by the end of the year,” CTO Andre Fuetsch said today at an investor conference. The operator’s network guru also clarified that AT&T will have a nationwide 5G network running on low-band spectrum later this summer. Earlier this week, AT&T Communications CEO Jeff McElfresh misspoke when he said the operator wouldn’t reach nationwide coverage until the end of the year. “The network has become so much more dynamic so you need more agility to respond,” Fuetsch said, adding that AT&T’s core backbone network experienced a 25% surge in traffic during the first 10 days after public health restrictions were put in place across much of the country in March. “Our core backbone, which is what we call an MPLS-based network, which is under SDN control, we were able to reroute and move capacity when we needed it very quickly,” he said. “That’s the power of having software in the network.” Many of AT&T’s enterprise customers also benefited from that network framework.“We have a lot of enterprise customers that had to augment their networks, basically ours, so that they could increase their video conferencing capacity and capabilities, and a lot of that is software based,” Fuetsch said. “Instead of physically going out and having to deploy more boxes, all we had to do was just spin up more software instances to meet that demand. So that’s what SDN has done for us.” AT&T’s SDN program has yielded significant capex savings by disaggregating hardware from software and allowed “more disruptive technology to come in and frankly intercept a lot of the vendor and technology lock in that networks had in the past. When we look at how SDN networks perform on the opex side, it really enables a whole new level of automation,” Fuetsch explained.  Part of that effort also surfaced in a new development announced today by Nokia and AT&T. The vendor and operator recently performed a limited live trial of a jointly developed radio access network (RAN) Intelligent Controller based on O-RAN Alliance compliant architecture and open source software. During the trial, which ran on AT&T’s commercial 5G millimeter-wave (mmWave) network in New York City, the companies ran a series of apps at the edge on an Akraino-based open cloud platform. The second version of the Akraino Edge Stack, an open source edge computing project under the stewardship of the Linux Foundation’s LF Edge group, was released earlier this year and a third release is expected to arrive this summer.  The apps used during the recent trial were designed to improve spectrum efficiency and provide location- and use case-specific customizations, according to Nokia and AT&T. The RAN Intelligent Controller software is also available to the O-RAN Alliance community at large.  Fuetsch didn’t discuss the work with Nokia specifically, but noted that the edge is important because it opens a new arena and set of resources for app development. Prior to the development of edge computing, developers could anchor their apps to a device or the cloud, but the cloud could be up to 1,000 miles away from a device, thereby straining resources and impacted performance, he explained.  The edge is a new resource, a new location that developers can take advantage of, he said. “You don’t have to have all this compute horsepower sitting right at the device. You could now take advantage of not just the cloud compute infrastructure that could be 1,000 miles away, but something much, much closer.” AT&T’s work with cloud providers on edge computing involves the development of new use cases, including the use of computer vision technology to help retailers adapt and adhere to social distancing guidelines, Fuetsch said.  “Our 5G strategy is a multi-pronged approach,” including the use of mmWave spectrum for “little pockets around cities and venues,” low-band spectrum for widespread coverage, and sustained interest in mid-band spectrum, he said.  Mid-band spectrum is particularly scarce in the U.S. now, but the Federal Communications Commission (FCC) recently approved full-scale commercial deployment of a shared spectrum platform in the 3.5 GHz Citizens Broadband Radio Service (CBRS) band, and it’s working with satellite providers to clear mid-band spectrum in the C-Band.  “We’re very interested when that spectrum becomes available. There’s a lot of interesting dynamics I can’t get into in that spectrum that will have to be cleared out and cleared up,” Fuetsch said. “Certainly it’s going to be, in the long-term, an important part of not just our portfolio but of all carrier’s portfolios.” Finally, while AT&T encountered some supply chain issues in the early days of the COVID-19 crisis, those issues have since been resolved, according to Fuetsch. “This is a global supply chain we rely on with gear that we deploy and certainly when you look at the components that go into the network equipment, but I would say right now that has smoothed out,” he said. “We haven’t seen any real impacts to our build plans,” and there are “no significant disruptions at this time in the supply chain.”