What is CBRS and What is the CBRS spectrum?
CBRS stands for Citizens Broadband Radio Service.
The Federal Communications Commission (FCC) approved the spectrum for CBRS (Citizens Broadband Radio Service) in 2015.
The bandwidth of the CBRS spectrum is 150 MHz.
The CBRS spectrum ranges from 3550 to 3700 MHz, with frequency allocations across the existing LTE Band 42 (3400 MHz to 3600 MHz) and LTE Band 43 (3600 MHz to 3800 MHz).
The CBRS band is Band 48, TD-LTE standard, supporting voice, SMS, and data services
The spectrum is shared and used as a shared spectrum by the U.S. government and other commercial agencies and association entities.
What is CBRS LTE?
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.
Is CBRS 5G?
While the Citizens Broadband Radio Service can be used for 4G LTE, it is ideally suited to delivering fixed or mobile 5G new radio (5GNR).
Specifically, CBRS can be employed by enterprise IT providers to build out a private LTE network supporting large warehouse facilities, sports stadiums, and remote mines.
Is the CBRS same as C-band?
The CBRS band at 3.5 GHz and the C-band both represent opportunities for U.S. wireless carriers to get access to the new mid-band spectrum for 5G.
CBRS is designed with a three-tier spectrum sharing framework. The topmost layer is the incumbent access layer, followed by the priority access layer. The final layer is the general authorized access, which includes the rest of the spectrum available for general use.
CBRS overcomes the limitations of WiFi and provides a more efficient option for large commercial enterprises. WiFi coverage and capacity are limited. CBRS provides twice the capacity and four times the WiFi range for commercial enterprises.
What is the CBRS Alliance?
The CBRS Alliance is comprised of 120 member companies.The CBRS Alliance believes that LTE-based solutions in the CBRS band, using a shared spectrum, enable building and outdoor coverage and massive capacity expansion.
In order to maximize the full potential of CBRS, the CBRS Alliance aims to build a robust ecosystem for delivering LTE-based CBRS solutions.
The mission of the CBRS Alliance is to promote LTE-based CBRS technologies, use cases and business opportunities, while driving the technology developments needed to accomplish the mission, including multi-operator LTE capabilities.
The Alliance will also establish an effective product certification program for U.S. LTE devices in the 3.5 GHz band to ensure multi-vendor interoperability.
How does CBRS' spectrum sharing allocation approach work?
What is different about CBRS compared to public network operator bands is the way spectrum is allocated to each user; CBRS does not sell spectrum over a wide area to a wide coverage operator, nor is it a completely public free trial of the band like WiFi.
Instead, usage within each building is requested and allocated individually on a case-by-case basis. If it is no longer needed, it is returned for use by others.
The process of allocating spectrum is automated, with several spectrum allocation servers (SAS) coordinating the program nationwide.
As part of the registration request, each small cell reports its horizontal location within 50 meters and its vertical location within 3 meters.
SAS uses terrain data and radio propagation models to calculate the impact on other small cells in the vicinity.
Additional outdoor radio measurement receivers (environmental sensors) are also used to assess background levels.
SAS authorizes spectrum use if the RF power density is less than -80 dBm (1×10-11 watts).
The idea is that the spectrum is a valuable national asset that should be utilized, not left dormant.
How does CBRS help the IoT?
Problem-solving applications for enterprise customers drive the continued growth of the IoT. One of the larger barriers to IoT solutions in enterprise environments is reliable and low-cost wireless connectivity.
While Wi-Fi, Bluetooth, LoRa, Zigbee, and others have previously attempted to solve this problem, CBRS (Citizens Broadband Radio Service) offers a viable alternative for enterprise IoT.
Specifically for the United States, Citizens Broadband Radio Service (CBRS) is a portion of the radio spectrum between 3550-3700 MHz.
This is a valuable area of the spectrum because it allows for good propagation (the ability to penetrate walls and get to moderate distances) and has the benefit of higher bandwidth services (such as LTE and 5G).
CBRS spectrum can be used to deploy standalone dedicated LTE or 5G networks within buildings.
Before CBRS can be used, ensuring a robust cellular network in a facility like a hospital requires the installation of an operator-specific distributed antenna system (DAS).
These systems are expensive and can only be used with one operator. CBRS systems have the potential to provide a neutral host for LTE/5G connections that will connect cellular devices (such as phones or IoT sensors) through the CBRS radio infrastructure and then to the operator’s packet core network.
For CBRS-enabled phones (not many yet), they can use these built-in networks independently of the mobile operator they use.
For example, for IoT devices in a building, using a CBRS connection may be much more reliable than trying to connect from a basement HVAC controller to a base station 2 miles away.
Citizens Broadband Radio Service Business Benefits
What is a CBRS neutral host IoT connection?
For direct cellular IoT devices installed in an enterprise (e.g., pharmacy temperature monitors in a hospital), CBRS can be used as the primary cellular connection at no cost if the device is configured to directly participate in the enterprise CBRS system.
If the enterprise provides all the components used for connectivity, there are no telecom carrier fees to pay.
Can replace Wi-Fi
CBRS 4G/5G systems use radio technology that is much more advanced than Wi-Fi and can provide 3-4 times the coverage even at the same power level.
Since security and access are controlled through the SIM card, IT teams are relieved of much of the hassle of managing Wi-Fi access and security.
Does CBRS have better performance than LoRa or Zigbee?
IoT-specific wireless technologies such as LoRa or Zigbee typically use application-layer routing designs, which means that some of the flexibility and robustness of IP networks are not available. For direct-to-IP connections (such as those enabled using CBRS 4G/5G), operations such as firmware upgrades and service changes are much easier.
What do CBRS broadband telephony and data services look like?
IoT is not a primary use case for CBRS. The ability to enhance the performance of phones in buildings is the primary value driver.
IoT becomes an add-on to the CBRS investment, at least at this stage. Wi-Fi alternatives for other devices such as laptops and TVs may emerge in CBRS-enabled buildings in the future.
What are the CBRS applications?
Good IoT applications for CBRS are those that require a lot of bandwidth and may not be battery-powered. Examples include.
1) Video surveillance or computer vision applications
2) Real-time control, building automation, HVAC
3) Push-to-talk to security, operational voice, such as voice in healthcare
4) Power-powered sensors for temperature, air quality
5) Gateway-based IoT to indoor positioning, sensors communicating with local gateways
CBRS indoor positioning example
CBRS could be a potential candidate for secure, high bandwidth backhaul and remote connectivity in future campus IoT solutions. What makes CBRS more attractive than Wi-Fi is the range it can support from a single access point, the mobility support for mobile users, and the spectral efficiency/capacity to support large volumes of traffic.
For high-reliability use cases, or in environments plagued by complex IT systems and congested unlicensed band usage (e.g. hospitals), CBRS can provide a new capability to install IoT solutions.
Indoor location systems that rely on Bluetooth or ultra-broadband often have high-frequency real-time data streaming requirements, which can be a challenge for Wi-Fi-based backhaul.
CBRS small cells connected to CBRS IoT gateway devices can provide a new way to solve the backhaul problem.
For CBRS-based IoT networks, the near-term challenges are how to handle device management (SIM-based security and resource provisioning) and the limited availability of CBRS-enabled gateways and sensors.
What are the potential barriers to CBRS?
Country-specific
CBRS is a spectrum band that exists only in the United States. However, other countries are releasing a public spectrum for unlicensed broadband wireless. The downside is that each country requires specialized radio hardware to work in a particular band.
As these bands take off, cellular module manufacturers are likely to combine them. A “private cellular only” module could be available in the next few years.
Licensing Details
CBRS is a hybrid of licensed and unlicensed spectrum. 70 MHz of the total 150 MHz band is available through auction, and mobile operators are likely to consume these bands.
The remaining 80 MHz can be used for general availability. 80 MHz is still a significant amount of spectrum needed for private cellular operations.
However, as with congestion in the 2.4 GHz band, the CBRS GAA spectrum is likely to be increasingly used as time passes.
Customer Availability
For an IoT company looking for connectivity options, CBR should be of interest, but it is really too new to rely on at this time.
Unless the application is very valuable, the cost of deploying a standalone CBRS network just for the IoT may not be justified. Waiting for customer sites to adopt CBR may be a strategy that the IoT community must adopt.
CBRS is an exciting leap forward for the U.S. public spectrum. It will be very interesting to see how it will play out for the enterprise and IoT community.
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