BARCELONA, Spain — Aside from 5G and the Internet of Things (IoT), the third acronym on everyone’s lips at Mobile World Congress 2017 was MEC, which stands for mobile edge computing.

But where exactly is the edge?  The answers are all over the board, but they paint a picture of network architectures, which are getting more generic.

Before the show, speaking with Nurit Sprecher, a principle architect at Nokia who’s heading up the ETSI ISG MEC group, she said, “MEC is about providing cloud computing at the edge of the network, characterized by low latency and high bandwidth. We’re talking about distributed cloud.”

As far as where the edge is located, Sprecher said it could be base stations, hot spots, small cells, in data centers, or even in routers and switches.

Rhonda Dirvin, a business development director with ARM, said, “NFV and SDN open up what you can do in the middle of the network, between the cloud and the end device. Different people call edge different things. For us, it could be a sensor.”

Edge vs. Mobile Edge Computing

Colin Kincaid, CTO of Cisco’s service provider business unit, pointed out that there’s a difference between edge computing, where the edge is likely to be at a telco central office, and mobile edge computing, where the edge is likely at a cell tower.

But the distinction between edge and mobile edge is starting to blur.

After the ETSI ISG MEC group was formed, its leaders wanted to change its name because they realized its work was not to define the computing at the edge but to work on application programming interfaces (APIs). But the group needed to keep the MEC acronym because it had already invested in the brand.

“The best one we could get was multi-access edge computing,” said Sprecher. “It shows we’re not limited to mobile; we can support multiple access technologies, wireless or wired.”

As it turns out, switching the word “mobile” to “multi-access” was propitious.

Multi-Access

At a Mobile World Congress meeting with journalists, Ericsson CTO Ulf Ewaldsson, said, “The cloud is meeting out on the access sites. Some call it edge computing. Fixed and wireless have converged in the access.”

As far as the location of the edge, Ewaldsson sees the “base station as the extreme, all the way up the stream to the cloud.”

Based on Ewaldsson’s and others’ comments, it seems better to drop the “mobile” and just refer to “edge computing.”

Whatever it’s called, the technology is ramping up in conjunction with a convergence in access technologies. Some of that convergence is being driven by the Central Office Re-architected as a Data Center (CORD) open source project. The basic concept behind CORD is to change the equipment at the central office from proprietary gear to commoditized servers, running open source software.

Telcos such as AT&T were the first to jump on board with CORD — hence the words “central office” in the name. But CORD soon formed an off-shoot project — Mobile CORD (M-CORD) — for wireless infrastructure. And even the cable company Comcast, which uses specific access technology for cable video and broadband, has joined CORD.

The cable membership organization CableLabs is also getting in on the convergence action. It recently published a white paper on NFV priorities for 5G. The purpose of the paper is to figure out the key requirements from an NFV and SDN point of view to actualize 5G. But the paper steers clear of talking about fixed access versus mobile access.

Tetsuya Nakamura, a principal systems architect at CableLabs, said, “In 5G we need to consider all the possible access networks. From a cable point of view, it’s a little hard to say mobile. Multi-access makes sense.”

And with multiple access technologies converging at CORD locations, these spots — whether they’re called data centers or central offices or cable headends — are going to be prime candidates for edge computing.

Other Edge Considerations

Cisco’s Kincaid also pointed out that the architecture of the edge will be based on geography. Networks in Europe and Asia are architected differently than in the U.S. And in locations with dense populations, the edge can be at a data center, compared with sparsely populated areas where edge devices must be located in more remote areas.

Rui Frazao, CTO with Vasona Networks, said, “The edge can be many different places.” Vasona, which is working on improving latency for video sessions, finds that central offices are a good place for its compute software. He said the edge can also be the mobile base station, but for Vasona “at a base station you would lose track of a video session. At a central office, you have a broader view.”