What is CBRS, How Does It Work and Why Is It Necessary

CBRS stands for the Citizen Broadband Radio Service spectrum-sharing model. CBRS allows various devices to share the same spectrum band. This spectrum-sharing model makes CBRS uniquely able to offer users the ability to access a shared spectrum at different times and locations.

Spectrum-sharing increases the efficiency of the broadband radio spectrum and allows it to work in areas with low, weak, or non-existent coverage. For example, CBRS can help rural areas access reliable coverage.

The growth of spectrum sharing also allows for increased innovation within the wireless industry, as new and established companies can now offer a larger variety of services to consumers anywhere within the US. This is possible because spectrum sharing optimizes the use of existing airwaves or wireless communication channels. Users can safely and securely share the same frequency bands with improved quality and speed and reduced interference.

According to the Communications Technology Laboratory (CTL) supported by NIST, spectrum sharing is necessary because of overcrowded airwaves. The spread of smartphones, the rise of the Internet of Things, advancements in military communication systems and public safety communications, and the use of wearable devices all combine to hamper an overused group of wireless radio bands. Worst case, this constant load and interference may interrupt critical services for public safety or military response.

Key Takeaways

What is CBRS?
What is Spectrum Access System (SAS) and how does it impact CBRS?
Why is a shared spectrum necessary?
How does CBRS work?
Discover the advantages and disadvantages of CBRS
Learn how CBRS expands access to wireless connectivity
Find out how CBRS technology enables innovation and competition in the wireless space

This guide provides information on all aspects of CBRS, including its impact on wireless connectivity innovation and functionality.

What is CBRS?

CBRS operates in the 3.5 GHz band currently used by the US military, satellite providers, and other commercial users. The CBRS band partitions are as below:

Starting in 2015, the FCC commission adopted rules for shared commercial use of the 3.5 GHz band, beginning the CBRS service with a three-tiered access and authorization framework. The secured framework enables the band to also offer non-federal usages.

Here are the basics of CBRS that you need to know:

Operates in the 3.5GHz band
Standard LTE (Long-Term Evolution) radio interface
Voice, data, and text communication support
Indoor, unlicensed small cell service
Requires SAS to manage connections and interference

Who Uses CBRS and How Does it Work?

CBRS is the power behind carriers offering extended range 5G and LTE mobile and internet services, including Verizon, T-Mobile, and Xfinity to name a few. Any carrier which needs to extend their 4G LTE and 5G network capacity can buy into the CBRS spectrum.

But CBRS isn’t restricted to just commercial carriers. Even individual companies wanting to manage their own networks can get access to CBRS. For example, building management companies that need to communicate with on-site device users or manufacturing companies that need to communicate and control factory robots can use CBRS. The system works both indoors and out, so there’s less restriction on bandwidth access.

Connection providers plan to use CBRS to replace fiber access and deliver wireless service to point and multipoint connections. CBRS may be used for IoT connectivity, as a replacement for Wi-Fi, or even as a supplementary connection service to boost access to coverage. The beauty of CBRS for users looking for strong connectivity is deployment simplicity combined with higher quality and faster connection speeds.

The shared spectrum concept within CBRS opens new channels for improved communication both for high and lower-priority users. Sharing enables critical systems for public safety and military actions to function unencumbered by individual and business connectivity uses.

What is Spectrum Access System (SAS) and How Does it Impact CBRS?

SAS (Spectrum Access System) is the new technology that powers CBRS. SAS uses artificial intelligence to detect spectrum usage and manages interference within channels. CBRS offers significant advantages over existing connection systems including cable, fiber optic, and broadband.

The SAS system is a cloud-based service that allows wireless communication management of devices transmitting within the CBRS band. The SAS controls and prevents harmful interference to high-priority users of the band. To transmit within the CBRS band, companies and organizations require SAS authorization.

Here’s how the process works when a CBRS device (also known as a CBSD) seeks access to the band:

CBSDs register with the SAS administrator and then receive a unique identifier. The administrator grants the CBSD an available location and installation characteristics. CBSDs then request a grant for a portion of the band to use. When approved for the grant, the CBSD begins transmission within their assigned area of the band.

The SAS system protects high-priority users from interference by using a sensor network to detect when high-priority users are using the spectrum. For example, one high-priority user is the US Navy. When the US Navy transmits within the spectrum, their transmissions receive priority over other registered band users. Essentially, the SAS controls and manages transmissions within the band and allocates usage based on the registered user’s priority status.

Advantages and Disadvantages of CBRS

There are many advantages of the CBRS spectrum. Carriers using CBRS can reach and attract additional customers who are out of the range of other providers. More customers equal more business revenue. Additionally, carriers can improve their customer experience by providing connectivity with higher speeds and less downtime, and fewer connection interruptions. As mobile network demand continues to increase, the CBRS spectrum may become the lifeblood of a mobile network provider.

CBRS makes private LTE wireless networks economically and technically feasible. Additionally, the performance of CBRS is generally significantly higher than Wi-Fi. The CBRS spectrum can maintain connections at -120dBm with increased coverage area per radio. In other words, carriers don’t need to manage additional cabling and switching infrastructure when using CBRS. Less infrastructure management means a greater return on investment for providing connectivity to users previously out of range.

The CBRS-based LTE network enables better roaming management for connected devices. The CBRS system manages roaming instead of the device itself. By managing device roaming capability, the performance of business-critical applications that require real-time response time increases. Additionally, users have a lower risk of dropped connections and have better performing and more reliable emergency communication options.

Because SAS administrators manage interference on the band, businesses can deploy mission-critical devices using a private wireless spectrum without negative impact from external sources of interference.

Similarly, the CBRS private mobile networks can offer service level objective metrics for minimum throughput, maximum latency, jitter, and maximum packer error rate using a standard, rather than a randomly accessible, system based on each user’s device.

Other advantages to using the CBRS spectrum include:

Reduced dependency on MVNO (cable) networks
Improved connectivity access for businesses in rural and suburban areas
Reduced dependency on fixed wireless access systems (broadband)
Increased innovation and growth within the wireless provider business space

Disadvantages of CBRS include:

Interference management may impact connectivity access and speed
Connectivity speed deteriorates the further the user is from a base station
The high cost of the PAL tier may impact provider competition

Examples of CBRS in Use Today

One of the most popular uses for CBRS today is enabling broadband internet and cellular providers to better reach rural communities. In the United States, this has helped rural communities access more reliable internet connections. Perhaps most importantly, because CBRS is an established technology, providers are able to launch these new connectivity projects relatively quickly and cost-effectively.

Other projects that have incorporated CBRS include connectivity upgrades and improvements at locations including shopping malls, airports, and even local municipalities. In one case, the entire city of McAllen, Texas, partnered with a network provider to launch a CBRS wireless network to provide internet access to all its residents.

CBRS: Connectivity for the Future

CBRS enables increased access to connectivity speeds that make using the internet easier, particularly for users outside of major cities. Customers in rural and suburban areas have long suffered from a lack of providers and inadequate connection service. With an increase in innovation made possible by the CBRS spectrum, both business and individual users benefit.

The SAS administrator system ensures both the security of and access to the CBRS band. Using SAS to manage interference and transmission activity allows for the US military and other high-priority users to use connections without interruption while providing shared access to all.

Opening the CBRS spectrum to shared access improves communication access to additional users while increasing business innovation and revenue growth. Additionally, the end-user experience improves with faster and more reliable connections.

The next generation of apps created using the support of improved wireless technology that improves reliability, availability, and quality will make businesses better able to invest and grow their networks and products with less expense overall.

Planning and launching a CBRS project don’t have to be overly complex. Because the technology is well-supported, providers can launch networks relatively easily. And with the support of network experts like ATEC, CBRS is within reach of businesses of every size.

The future looks bright within the CBRS spectrum band for both individuals and businesses. Find out how this technology can help you connect today.