Microsoft says transport latency can nullify benefits of 5G

Microsoft wants to be the global wide area network (WAN) for 5G.

Victor Bahl, chief technology officer of Azure for Operators, noted in a blog posting that while 5G offers big boosts in speed, those speeds get watered down because “every network operator ultimately depends on the internet at some point.”

He said ultra-reliable low-latency communication (URLLC) within the 5G New Radio standard is nice: its delay specification can be anywhere from one to four msec on-air latency. But he said you have to consider the context of applications, which often are interacting with users, devices and cloud services over long distances.

He said that based on the locations of the source and destination of traffic, internet latencies can vary anywhere from a single order to several orders of magnitude more than on-air 5G wireless latencies. This high latency can effectively remove all the benefits of the low-latency properties offered via the 5G network.

Microsoft would like wireless operators that run extensive national backbones to extend their WANs with Azure. And it would like smaller operators, and new operators, that do not have their own national backbones to rely on Azure’s WAN for their 5G networks.

RELATED: Microsoft makes big 5G play as AT&T moves core to Azure cloud

Azure’s pitch to 5G operators

Microsoft Azure maintains over 175,000 miles of lit fiber optic and undersea cable systems, covering close to 200 points of presence (PoPs) across 140 countries. The network is connected to many thousands of ISPs. 

“With on-air 5G latencies reaching close to the sub-ms range, wired transport latency will likely dominate end-to-end performance,” said Bahl, who added that beefing up capacity at the peering surface area and on backbone links is an expensive endeavor.

Bahl said, “We have a massive amount of spare capacity to serve 5G traffic to a broad array of new operators.”

Microsoft particularly touts its traffic orchestrator for routing network packets across the Azure WAN. It says 5G is deploying network functions in a more distributed fashion, which will need excellent orchestration.

“Our orchestrator takes control away from classic internet protocols and instead moves that control into software that we build and control for 5G traffic,” said Bahl. “We place the 5G flows that demand high performance on low-latency, high bandwidth paths to and from the internet. Network flows that are cost-sensitive are instead routed through cheaper paths. In effect, we have developed a fast-forwarding mechanism to build a 5G overlay on our existing WAN, thereby supporting a variety of 5G network slices with different wired transport properties.”