October 3, 2019

Written by Nader Famili

CBRS and Wi-Fi systems have a lot in common:

  • They both can be designed and deployed independently of MNOs and MSOs
  • They both rely on the enterprise owner/manager to build it and run it
  • They both don’t need a dedicated spectrum

CBRS and Wi-Fi are both private networks. Hence, these systems can be deployed as totally closed and private systems or systems open to other users. Private systems also give the system manager the freedom to run the type of applications on them they deem necessary for their own or tenants’ business.

“So, what the difference between CBRS & Wi-Fi?”
Let’s start with Wi-Fi.

Wi-Fi is great! It’s in nearly every indoor area, it is free (most of the time), and Wi-Fi functionality is embedded pretty much in every device; handsets, laptops, or even toys.

So why would other technologies, such as CBRS, ever replace such a good thing? Here’s the answer- they won’t. They will simply complement it.

Here are some advantages of Wi-Fi:

Pervasiveness: It’s everywhere!

Simplicity: It is easy to design, deploy and manage. So much so that the enterprise IT staff has been doing it for a long time with little to no training needed.

TCO (Total Cost of Ownership): The hardware is cheap, the installation is cheap, and in most cases, there is no operating expense other than the broadband connectivity bill and a small power bill; therefore, a pretty low TCO.

Device Price: Adding Wi-Fi functionality to devices is very inexpensive due to its huge ecosystem.

So, what is the problem then, you may ask?

Well, if something is too good to be true, it is probably not completely true. Shocking as it may seem, Wi-Fi has inadequacies too.

Here are some disadvantages of Wi-Fi:

Mobility; Wi-Fi was never designed with mobility in mind. Although it offers “seamless roaming” functionality, Wi-Fi is still not as mobile as 3GPP-based systems (2-5G). (We have all had Wi-Fi calls dropped as we moved around). This is primarily due to the fact that Wi-Fi is inherently a device-based technology and not a controller-based system like 3GPP technologies. To make matters worse, not all the devices necessarily adhere to the same set of Wi-Fi standards, again, as it is the case for 3GPP devices.

Security: LTE systems are generally more secure because the identity of the user is authenticated and the data is encrypted. Wi-Fi networks, however, come in various security flavors. In open, public Wi-Fi networks, the risk of interception is high, and the data is generally not encrypted. Wi-Fi systems can also be designed and deployed to be private, password-protected, with user authentication and with advanced encryption. Generally speaking, the Wi-Fi systems are just not as secure as the 3GPP systems.

Quality of Service: The service quality on Wi-Fi connections cannot be guaranteed. Wi-Fi works in an unlicensed band where interference from other Wi-Fi networks or other interfering signal sources are common and unstoppable.

Voice: Voice over Wi-Fi (VoWi-Fi) requires low latency. However, in many cases, Wi-Fi systems and the enterprise backhauls connected to them, are not optimized very well resulting in higher latency and lower voice quality.

Offload: MNOs and MSOs love to offload their indoor traffic and/or even voice (where they have coverage deficiencies) onto the enterprise Wi-Fi system. This option is certainly cheaper and more convenient than building DAS everywhere. However, carrier offload requires a “Carrier-Grade Wi-Fi” system which is not very common in mid- to large-size facilities. Carrier-Grade Wi-Fi systems need to be designed and managed professionally, which has not been the norm up to now.

The latest Wi-Fi standard, 802.11ax, branded as Wi-Fi6, goes a long way to improve the quality, security and capacity of Wi-Fi systems. However, many of the benefits of Wi-Fi6 will not be fully realized until all the APs and all the devices are Wi-Fi6, and that will take many more years.

Making sense so far?

Now let’s talk about CBRS.

CBRS is based on 3GPP standards. Because of this, there are certain advantages that CBRS has that Wi-Fi does not.

Here are some advantages:

Mobility; CBRS has full mobility with traffic management and controlled handovers.

Security: CBRS has very secure, standard-based connections between the nodes and between devices to the nodes over the air interface.

Performance: CBRS networks will enjoy the excellent performance of the 3GPP networks with established QoS parameters

Interoperability: Most CBRS systems will be installed indoors. MNO and MSO offload will be a big deal as a source of revenue. Being the same technology, the handover between the private network and the outdoor network will be pretty straight forward.

As indicated, CBRS is a private network. A private network allows the owner to offer local applications to its customers which will be kept locally (at the edge) and not on the clouds somewhere.

The benefits of such architecture include:

  • Greater security
  • Lower latency
  • More focus on local customer needs
“So which one should I choose?!”

Let’s break it down:

If you want a system that is inexpensive, available to most people, and not necessarily operationally critical, go for a Wi-Fi system.

If you want a system that is operationally critical, needs to be secure, needs to accommodate mobility, needs to support customer-focused applications, and interaction with the macro systems is a requirement, then go for a CBRS system.

In most real-life scenarios for medium to large businesses, both systems will be needed to satisfy the various connectivity requirements of the enterprise.