What Are CBRS and Private LTE, and What Are the Use Cases?

Harald Remmert Harald Remmert, CTO, Cellular Solutions , Digi International
March 18, 2020
CBRS – Citizens Broadband Radio Service – is one of those terms you may have heard more about, especially with the advent of 5G and the broadening range of network technologies. Why is CBRS, and the parent concept behind it – Private LTE – becoming so popular?

Public LTE and Wi-Fi networks have become a necessity in modern day life.  And for some organizations, wireless has become the “fourth utility” – a resource that’s as vital as power, water and Internet connectivity.

However, there are three common scenarios where public LTE and Wi-Fi are not ideal:
  1. When these networks are not available due to coverage limitations.
  2. When they are not working well due to capacity issues.
  3. When they are not considered secure enough for the application.
A range of enterprises are increasingly looking at Private LTE networks to solve their business connectivity problems. These include industrial applications in both remote and limited access areas (such as underground) and applications in the medical, government and financial fields that handle highly sensitive data.
In this article we’ll cover the benefits of Private LTE networks and also define and explain CBRS (Citizens Broadband Radio Service), which is a version of Private LTE in the 3.5 GHz spectrum that is becoming increasingly popular in the US.

What Is Private LTE?

A Private LTE network is based on the same proven protocols and technology that public LTE networks use today.  Small cells, conceptually similar to Wi-Fi access points, are installed on-site by the enterprise or by a managed service provider to supply a dedicated wireless network that can cover tens-of-thousands of square feet.

A Private LTE network offers performance and reliability that public LTE or Wi-Fi alone can’t match, and usually at a much lower cost. It offers uninterrupted connectivity along with the ability to handle heavy traffic loads, such as data coming from thousands of IoT devices. And it offers excellent penetration, with the ability to reach through building walls and other obstacles that might block a Wi-Fi signal.


Private LTE and CBRS

Citizens Broadband Radio Service (CBRS) is a new Private LTE network option now available in the U.S. It occupies 150MHz of shared spectrum in the 3.5 GHz C-band, also known as Band 48 (B48). Traditionally, this band had been reserved for users in the U.S. military and fixed satellite service. But this spectrum has recently been approved for broader use by the FCC, opening up opportunities for a range of new applications. Industry observers have said that “CBRS will put enormous wireless networking power into the hands of organizations that have never had such a promising and affordable option before.”

Access to CBRS spectrum is shared and actively managed among three groups:
  • Tier 1. Incumbent users, primarily the U.S. Navy and satellite ground stations
  • Tier 2. Users with priority access licenses (PALs)
  • Tier 3. General authorized users (GAA)


CBRS technology is being developed and promoted by the CBRS Alliance, a non-profit industry organization of which Digi is a member. The CBRS Alliance has developed detailed specifications along with a certification program to ensure seamless interoperability for all network components.

What Are the Benefits of Private LTE?

Private LTE has several advantages over public LTE or Wi-Fi. It provides an exclusive LTE network in uncrowded spectrum. It is deployed with dedicated equipment that increases device and data capacity and includes built-in security and controls not possible in public networks. It is tailored to put the enterprise customer in control. And compared to Public LTE or Wi-Fi networks, Private LTE networks have the following advantages:
  • Privacy: In a Private LTE network, data never leaves the customer's network. This is especially important for tightly regulated industries, such as in Healthcare or Finance.
  • Security: SIM security ensures that devices have a unique identifier on the network and are properly authenticated. This gives network administrators tight control over what devices are allowed on the network.
  • Flexibility: Private LTE networks can be customized to meet an organization’s unique application needs.
  • Capacity: Private LTE networks use either dedicated or shared spectrum. And put the customer in control of the infrastructure density based on their individual needs.
  • Quality of service (QoS): Cellular technology provides improved QoS over Wi-Fi and puts the customer in control of how data traffic is prioritized, end-to-end. This allows business and mission-critical applications still to function, even in situations where other networks are overloaded or break down.
  • Latency: Deterministic latency, that is, the ability to set a fixed length of time for the transfer of data, is available with Private LTE, thanks again to full end-to-end control. Deterministic latency can be very important in factory settings where devices need to be tightly synchronized.
  • Resiliency: With Private LTE, enterprise customers can deploy additional small cells for increased resiliency and uptime. They can also allow fallback to public LTE (if desired) using the same cellular device.
  • Mobility: Mobility, which is the hand-over between Private LTE small cells, is seamless and comparable to public LTE. There’s no connection loss with private LTE as there can be with Wi-Fi.
  • Cost: While the cost of an individual small cell is higher than an Enterprise-grade access point, fewer small cells are needed to provide the same coverage as many Wi-Fi access points.  And the cost for running cables, power and the maintenance of a larger number of nodes is an order of magnitude smaller with a Private LTE infrastructure.

Setting Up a Private LTE Network

There are several ways to implement a Private LTE network:
  • The first method is via a licensed spectrum. In this case, a mobile network operator like AT&T or Verizon can “rent” a part of their spectrum to a company that wants to set up its own private LTE network. There are a variety of different bands that fall under the licensed spectrum and every country has unique laws that dictate how these bands can be used.
  • Another way to create a Private LTE network is via the shared spectrum. One example of this is CBRS, a topic we’ll cover later in this article.
  • Finally, there is the unlicensed spectrum. Here a Private LTE network can be set up in a band such as UNII-3, the same used by a Wi-Fi network. MulteFire is one example, but it is not widely used yet, but that may change in the future as part of private 5G networks.
With that in mind, here are a few of the industries leading the way in terms of Private LTE adoption.

Industries Adopting Private LTE

There is an IoT revolution happening in manufacturing as an increasing number of network-connected devices are being used on the production line. That includes everything from robots to high-precision, quality control sensors. A Private LTE network can handle all of the data that these devices generate. In the future as machine learning and AI become even more prevalent, a Private LTE network will provide the bandwidth these data-intensive programs require.

Private LTE is also becoming increasingly popular in the mining industry. An LTE network can cover a wide area, making it suitable for a mining operation spanning many square miles. A Private LTE setup can connect IoT sensors, cameras, autonomous equipment and drones on one network, unhindered by the limitations of a public network. Crucially, a private network is future-proof as it’s designed to handle the high-data requirements of a large mining fleet.

The same benefits are also helpful for ports. A port with a Private LTE network can ensure near-perfect uptime as well as consistent data transfer speeds. From docked ships to the cranes unloading them, a private network can cover an area that Wi-Fi can’t and ensure that everyone stays connected. When implemented in Rotterdam’s port, for instance, a Private LTE network was able to provide 99.99% uptime.

Apart from big industry, CBRS can bring LTE to new areas. For instance, a small town in the mountains which previously lacked good reception could install its own LTE network providing data access for local residents. Later that network could be upgraded to 5G.

A Range of Private LTE Use Cases

We have covered some of the most obvious use cases, but there are many more. When a company or organization needs to set up a localized network, and Wi-Fi is not an option, a Private LTE network may be the perfect solution. Such networks are surprisingly affordable and can cover large areas, much larger than is possible with even the best Wi-Fi hotspot.

As IoT continues its upward trend, a Private LTE network can be a heavy lifter. LTE can handle heavy traffic loads, like incoming data from tens of thousands of IoT devices. Those devices can also connect to an LTE network automatically whereas connecting to Wi-Fi requires several steps. LTE networks also have excellent penetration, reaching through buildings and other obstacles that may block a Wi-Fi signal.

Whether an organization opts to use a licensed LTE network or to set up their own on a shared band – e.g. Citizens Broadband Radio Service (CBRS) – they can expect to save money and enjoy increased reliability over the public network. Private LTE networks will see increasing adoption for a wide range of connectivity needs, in both the commercial and consumer spaces.

How Can Digi Help?

Digi International can partner with you to determine the exact right networking solution for your needs. Whether your need a highly secure, highly reliable LTE router, a Private LTE solution, or a migration path to 5G, our teams can help to assess your business requirements and determine the best fit. A Digi expert can help you navigate the options based on all of your business factors.

Learn more in our CBRS/Private LTE Standards and Technologies page. Or contact us to start a conversation.

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