RE: 美国3大运营商: 抛弃5G NSA
Operators May Move to Standalone 5G Faster Than Anticipated
Interestingly, test equipment makers say that operators launching the non-standalone (NSA) version of 5G in millimeter-wave spectrum such as 28GHz and 39GHz are now considering moving to the standalone (SA) 5G version more quickly because of the complexity of non-standalone 5G. In the US, Verizon, T-Mobile and AT&T are all using millimeter wave (mmWave) spectrum and NSA for their initial 5G deployments.
"In the short-term, NSA gets you up and running faster," said Paul Denisowski, product management engineer at Rohde and Schwarz North America, one of the industry's biggest vendors for testing and measurement equipment. "But then it becomes a crazy, convoluted thing to support." NSA的维护会让你抓狂
That sentiment was echoed by Sameh Yamany, CTO of test and monitoring firm Viavi. "We are seeing an acceleration in standalone," he said.
One of the big problems with NSA is the handoff from 4G to 5G because it introduces latency to the network. "A lot of carriers are realizing that in urban areas with high density, they will have handoff issues," Yamany said. The reason for the latency is that 5G networks that use mmWave spectrum have trouble maintaining a stable signal. 用微波的5G网络很难维持信号 If the network can’t find a stable 5G signal, it will push that connection to 4G, and that introduces latency. Indeed, those difficulties were recently highlighted by a report on 5G in South Korea by IHS' RootMetrics, which found that "upswitching" from 4G to 5G was adding significant latency to some users' connections.
And while the handoff issue with NSA may be fixable, Denisowski said that manufacturers are not sure how much time to spend working on NSA if operators are going to migrate quickly to standalone 5G. "As an engineer, NSA offends me because it is overly complicated," he said. "The other part is that people would like to get to standalone 5G because it is pure 5G."
Russel Lindsay, senior product manager at Anritsu, another testing and measurement company, said that wireless networks deployed in millimeter wave tend to have intermodulation issues. For example, simple things like nails or unused wires can create signal distortion. 小小的东西像手指甲和电线都会影响微波信号