Wi-Fi vs private 5G: a technical comparison

[NetworkExperts]

For those of you who currently rely on Wi-Fi and are curious about private 5G networks, it’s important to consider some of the technical attributes of private cellular that make it so attractive as a complement to your existing wireless networks. In this blog, we’ll look at the big three — coverage, deterministic access, and security — to better understand the differences between Wi-Fi vs private 5G.  

Coverage in private 5G networks vs Wi-Fi 

Private cellular has very good coverage compared to Wi-Fi devices that “hear” -72 dBm signals but begin to scan and roam. Private 5G CBRS devices “hear” -105 dBm signals and maintain reliable connections. The new specification is built to be able to be used at much lower signal strengths than Wi-Fi is today, so private 5G maintains a connection where Wi-Fi would begin to scan and roam. 

In addition, there are some different rules as to what the max power can be for CBRS in an outdoor area. For Wi-Fi, we know whether you're indoor or outdoor, we're going to cap that max power at 1 watt, but CBRS radios can go up to 50 watts outdoors. 

When you want to control a small number of devices spread across large geographical areas, and you need to ensure they can connect to your network and provide reliable data coverage, an outdoor CBRS radio is an attractive solution. 

Deterministic access in private 5G networks 

The next place where you really start to think about private 5G is in areas where you need deterministic access to a network. Think of it in simple terms as Quality of Service (QoS) over the air.  

Certain things like network slicing and application prioritization over the air was built into the cellular specification from the beginning. For example, cellular providers needed to provide emergency calling while users seamlessly roam at high velocity throughout a mobile network. Making sure guaranteed QoS and SLAs are in place is how cellular specifications were built back in the day and that carries into this private 5G space as well.  

There is also a difference in terms of precision. In Wi-Fi, legacy Ethernet protocols avoid collisions but use random back-off timers. Mobile Wi-Fi devices wait for a poor signal then scan for one that’s better. In comparison, with private cellular networks, the 4G/5G core centrally controls and schedules roaming and hand-off with precise timing.  

When you start looking at some wireless applications that may be getting on to your network that should have certain SLAs over wireless, private cellular may be the right answer. 

Security considerations in private 5G vs Wi-Fi  

The last thing is to think about is security. Cellular security is a little bit different than Wi-Fi. There is only one security option and that is going to be a physical SIM card or an eSIM. What's great about SIMs and eSIMs is that they are completely controlled by the enterprise. They are deployed by the enterprise and configured by the enterprise and are processors in and of themselves. When you have a SIM authenticating to a network, it's a full two-way authentication: the SIM authenticates, and the network authenticates back. The SIM is programmed with information for the user equipment to join the network, including allowed networks (home and roaming), unique identity, encryption keys, application profiles, and other information.  

SIM cards are used for authentication in private 5G vs use of credentials in Wi-Fi.  

The downside is that you need to have a SIM, so you need to have devices that can take a SIM, eSIM or iSIM, as opposed to Wi-Fi, which has very flexible authentication and encryption methods. This can be a starting point when you think about whether an enterprise private 5G network can work for you: Are your devices SIM/eSIM/iSIM capable and is that the method you want to use for security? In contrast with Wi-Fi, we have lots of flexibility, open networks, WPA3, 802.11ax or 802.11be. Both private cellular and Wi-Fi are equally secure but have very different methods to get on to the network itself. 

Learn more about private 5G and how it can complement Wi-Fi networks in the Introductory Guide to Private 5G.  

Meet blogger Sarah Heck

Sarah Heck, Ph.D., is a Consulting System Engineer with HPE Aruba Networking. She is a wireless technology expert with over 20 years of diverse industry experience designing, deploying, and supporting networks. Sarah has led efforts to drive early adoption of new wireless technologies throughout her career, including private cellular, location-based services, and WLAN technologies. Sarah is passionate about educating peers and customers on wireless technology.