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5G and Wi-Fi 6 and the challenges of edge networking

Image: Hewlett Packard Enterprise

The latest generations of Wi-Fi and cellular have the speed and capacity to handle busy and complex edge networks.

With the number of edge devices already in the tens of billions and growing rapidly, the need for pervasive and fast bandwidth is obvious. The industry and standards bodies saw this coming, and the current wireless standards are built to support large numbers of devices with different kinds of network requirements.

Wi-Fi and cellular, like 5G, are often portrayed as competitive technologies. There's something to this, but it's all to the customer's benefit, and the two technologies can complement and work together.

The latest and greatest

Wi-Fi 5 and earlier versions were powerful and compelling enough to make it a dominant presence on edge networks. At the same time, Wi-Fi is mature technology and people are familiar with it. But older versions do not have the capability to support mobile communications over a long range, and older Wi-Fi deployments may not have the bandwidth needs of an ever-growing edge.

Wi-Fi 6, the latest generation, includes numerous improvements that make it better suited to large edge deployments than earlier generations of Wi-Fi. These deployments serve conventional computers and much larger numbers of devices like cameras, sensors, robots, and smart buildings. Some of these devices have high bandwidth requirements. Others use little bandwidth but require low latency, meaning they need priority access to the network.

Perhaps the most significant improvement in Wi-Fi 6 is orthogonal frequency-division multiple access (OFDMA), a technology borrowed from cellular networks. Earlier versions of Wi-Fi allow only one device to transmit at a time, but OFDMA allows bandwidth to be divided into multiple, simultaneous transmissions, making networks more responsive, especially with large numbers of users connected.

There are many other improvements in Wi-Fi 6 that improve performance on busy edge networks—for example, by making it possible to use frequencies in use by other devices without interfering.

That 5G is faster than 4G is easy to deduce from the name and is drilled into all of us by telecom advertising. In fact, 5G is capable of speeds many times those of 4G and supports low-latency connections in ways 4G can't.

But 5G wasn't designed primarily for cell phones. The real value of 5G is in Internet of Things (IoT) applications, in which connected devices with limited smarts perform tasks that require communication back to the network—such as on large farms, somewhere on a highway, or spread out through a factory or city. These are applications where Wi-Fi may not make sense, but there are also network applications for which 5G is better suited than Wi-Fi, even if both are available.

The secure edge

Because the edge is where attackers loom, Wi-Fi 6 has been architected to improve the security of Wi-Fi by requiring support for Wi-Fi Protected Access 3 (WPA3). The most important advances in WPA3 are for consumer installations, for which earlier versions of Wi-Fi security were completely broken. In WPA3, even without a password, network connections are strongly encrypted.

Enterprises can use the new WPA3-CNSA (Commercial National Security Algorithm) mode to take advantage of the strongest cryptographic protocols and be recognized by the U.S. Department of Defense and organizations that interact with it as supporting the proven Suite B TLS cipher suites profile for Transport Layer Security, developed by the National Security Agency.

Your own private cellular network

The advances in performance and flexibility in 5G will allow enterprises to build their own 5G networks to maximize efficiency in manufacturing and other complex sectors.

These networks are especially appealing to large manufacturing facilities, which have become extremely high tech and automated. For manufacturers to implement so-called Industry 4.0 technology such as robots, self-driving forklifts, AR/VR glasses, and drones, they will need the capabilities of 5G.

5G networks have both edge and core components. Both are designed to support cloud-native architectures, and both are designed as open standards, much more so than 4G. As a result, many companies have entered the market for 5G core and edge components, where in 4G, there were few vendors.

Network slicing is one feature that provides flexibility unavailable to Wi-Fi networks. Administrators (or software) can divide the physical network into multiple logical networks with assigned portions of bandwidth and specific policies and quality parameters that will be asserted.

In a factory, one slice might serve AR/VR applications that demand higher speeds, while another would serve robots, for which low latency is critical. In addition, network slices can be allocated to alleviate bottlenecks and improve throughput as workload demands dictate.

New wide-open Wi-Fi spaces

The edge got a lot bigger in 2020, at least in the U.S. and a few other countries, when the FCC issued an order to allow a large range of spectrum, about 1,200 MHz in the 5.925 GHz to 7.125 GHz (6 GHz) band, for unlicensed use.

An array of tech giants, including Facebook, Apple, Broadcom, Intel, and Hewlett Packard Enterprise, pushed for the new spectrum designation and provided research to back up its viability. The Wi-Fi Alliance has announced a new certification for the interoperability of 6 GHz-capable devices, called Wi-Fi 6E, an extension of Wi-Fi 6.

The 6 GHz band is enormous, low latency, and high speed, including seven 160 MHz channels, capable of high-definition video. Unlike 2.4 GHz and 5 GHz, the 6 GHz band has few existing applications to compete for bandwidth.

Wi-Fi and 5G can work together

In fact, Wi-Fi 6 and 5G have been designed to work together in many ways to optimize performance and user experience at the edge.

Coordination between Wi-Fi and cellular has been happening in a big way for years through Wi-Fi calling, which allows users to make and receive calls through their Wi-Fi connection, secured with IPsec tunnels, rather than through cellular radio. This arrangement often makes calls clearer and more reliable, and offloads traffic from the cellular network, but it's not without its problems.

For example, when a user walks out of a building talking on a Wi-Fi call established in the building and reaches the point where the Wi-Fi drops, a handoff of the call to cellular may fail and the call will drop.

One way 5G addresses this problem is by opening up the standards for the 5G radio access network (RAN), which is the part that the device communicates with directly. Typically, the RAN is a cell tower with antennas and electronics on and nearby it, but a 5G RAN can, in fact, be any local access network, including a Wi-Fi 6 network. It could also use one of a few Industrial IoT network protocols like LoRa, LPWAN, or Sigfox.

This approach is not commercially available yet, but it promises a compelling improvement in user experience and even IoT device performance, by allowing users on Wi-Fi to take advantage of the cellular skill at handing connections off from RAN to RAN.

The edge is delivering

The many applications running at the edge depend on reliable and high-performing connectivity at the edge. Organizations have many options to achieve this level of connectivity at the edge, and increased competition promises continuing improvements.

Wireless network engineering is a complex field. It takes expertise and modern hardware and software to get the best connections at the edge, but it's worth the investment. Modern wireless networks deliver the goods that make new and compelling edge applications possible.

Many team members at Hewlett Packard Enterprise and Aruba, an HPE company, contributed to this article: Jeff Edlund, chief technology officer; Dan Harkins, distinguished technologist; Chuck Lukaszewski, vice president and wireless chief technologist; Eldad Perahia, distinguished technologist; and Onno Harms, product management director.

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