In modern life wireless communication plays a very important role in everybody’s life.
But due to the coverage limitations when public LTE and Wi-Fi networks are not available or not working well due to capacity issues, organisations in the U.S are looking at the option of Private LTE network which is based on CBRS which stands for Citizen Broadband Radio Service(CBRS) to fulfil their requirements.
What is CBRS
CBRS stands for Citizens Broadband Radio Service is a lightly licensed band which features a dynamic range spectrum access system (SAS) that is used to manage the allocation of frequencies in this shared range.
CBRS is a unique approach that enables most effective use of available resources and decreases the occurrences of co-channel and adjacent channel interference and also affords a three-tiered access priority arrangement.
The CBRS band is lightly licensed because each CBRS domain must include a spectrum access system, the SAS interfaces with an environmental sensing capability (ESC) system that can automatically detect the use of radar in a specific area.
CBRS can be used for 4G LTE, CBRS is ideally suited to deliver fixed or mobile 5G new radio (5G NR). Especially CBRS is used by enterprise IT providers to build-out a private LTE network that can support large warehouse facilities, sports stadiums and remote mines.
CBRS can replace existing distributed antenna systems, providing high speed data offload and in-building coverage. This is mainly important when deploying 5GNR in the GHz spectrum, where CBRS can offset the significant signal degradation experienced when traversing general construction materials.
The components supporting CBRS antenna in a particular case or a MIMO system, is referred to as a Citizens Broadband Radio Service Device(CBSD).
Each CBSD’s registers with a SAS and subsequently requests its spectrum grant. The CSBD should also identify its unique geolocation, height, whether it is deployed indoors or outside.
Difference Between Private LTE and CBRS
A Private LTE network offers performance and reliability that public LTE or Wi-Fi alone cant provide and at a very low cost.
Other hand, CBRS stands for Citizens Broadband Radio Service is a new Private LTE network option available in the U.S. CBRS occupies 150MHz of shared spectrum in the 3.5 GHz C-band, which is also known as Band 48(B48).
Private LTE provides uninterrupted connectivity along with the ability to handle heavy traffic loads like data coming from lots of IoT devices.
Private LTE provides excellent penetration, with the ability to reach through building walls and other obstacles that might block a Wi-Fi signal.
Private LTE networks are based on the same protocols that public LTE networks use today. In Private LTE network data never leaves the customer’s network.
CBRS 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, which offers opportunities for a range of new applications.
In CBRS Spectrum allocation is tiered with two relevant tiers for LTE usage:
Priority Access Licences “PAL”
PAL are non-renewable authorization to use a 10 MHz channel within the 3550-3650 MHz portion of the band. Each PAL is awarded in a competitive bid process.
General Authorised Access “GAA”
GAA are dynamically allocated 10 MHz channels within the 3550-3700 MHz portion of the band that do not conflict with any priority access licences. Any census tract can have from 80-100 MHz available for GAA usage depending on assigned PALs.
What is CBRS LTE?
The word CBRS stands for Citizens Broadband Radio Service. CBRS is a block of spectrum in 3.5GHz with a range of 150MHz to share wireless access.
The radio interface is the same as LTE in the licensed spectrum or in the unlicensed 5GHz band, the only difference with CBRS lies in spectrum assignment.
CBRS is used to lower the barrier to entry for non-traditional wireless carriers. The propagation characteristics of the 3.5GHZ spectrum plays very nicely for indoor, floor-by-floor deployment options which are rival current for Wi-Fi networks.
Because of the lower cost of PALs as compared to licensed spectrum costs, private operators now have access to 150MHz of spectrum on every floor.
What is Private CBRS LTE
Private CBRS LTE or it is also known as Band 48 is a 150MHz of prime RF real estate between 3.55GHz and 3.7GHz recently made available by the US government with a three-tiered approach to sharing.
Private CBRS LTE is affordable, high-performance indoor and outdoor private LTE networks that are not owned by the cellular carriers.
CBRS LTE shares three tiers concept as Incumbent, Private Access Licences(PAL) and General Authorised Access (GAA).
Incumbent users like the Department of Defense have prioritised access to the band anywhere, at any time.
Although their use is coordinated in such a way that minimises impacts to commercial users through a network of Environmental Sensing Capabilities (ESCs) and Spectrum Access System (SASs).
Existing users such as US Navy Radar, DoD personnel get permanent priority as well as site-specific protection for registered sites.
2. Private Access Licences(PAL)
Priority Access Licence (PAL) provides guaranteed access to spectrum for enhanced Quality of Service applications and will be treated in the similar manner as licensed spectrum at a greatly reduced cost.
Private Access Licence can be leased by anyone in 10MHz increment for 3-6 years and also are restricted geographically to enable local implementations. Organisations can pay a fee to request up to four PALs in a limited geographic area for three years.
3. General Authorised Access (GAA)
Apart from above two, the rest of the spectrum will be open to GAA use and coexistence issues will be determined by SAS providers for spectrum allocation.
General Authorised Access (GAA) is the bottom tier of CBRS and provides free access to anyone.
The same as unlicensed spectrum does today but in a much cleaner RF environment because it doesn’t suffer from the high levels of congestion associated with WiFi in the 2.4GHz and 5GHz bands.
CBRS LTE Bands
CBRS stands for Citizens Broadband Radio Service is a band i.e. band 48 of radio frequency spectra from 3.5GHz to 3.7GHz for 3 types of users.
- Incumbent Users
- Priority Access Licensees
- General Authorised Access
At the start, the CBRS band was reserved for use by the U.S Department of Defense, like U.S Navy Radar systems. But in 2015, the FCC i.e. The Federal Communications Commission dubbed the 3.5GHz band as the “innovation band” to be opened up to new mobile users.
After that the “innovation band” is now known as CBRS. CBRS opens up a major opportunity to unlicensed users and organisations who want to use 5G, LTE, or even 3GPP spectra to establish their own private mobile networks.
Every CBRS domain contains a Spectrum Access System (SAS). the SAS system is used to connects to FCC i.e. Federal Communications Commission databases and incumbent reporting systems.
The SAS also interfaces with Environmental Sensing Capability(ESC) systems. ESC systems automatically detect radar use in a particular area.
Either component supporting a CBRS antenna or antenna array is the Citizens Broadband Radio Service Device (CBSD).
The CBSD also identifies its unique geolocation, height, indoor or outdoor status, and unique call sign registered with the FCC.
To prevent interference across the three tiers, the SAS acts as a frequency coordinator that prioritises access between the Incumbent, Priority Access, and General Access Tiers.
CBRS devices can operate within the CBRS gateway and are installed on houses and businesses to help in sending video, voice, data, and IoT communications to a wired access network.
CBRS devices communicate with a router that acts as a gateway to provide Band 48 devices that operate within the 4G and 5G frameworks.
These devices use 3.6 GHz frequencies. CBRS is also supported by all the new cellular phones, such as Apple iPhones and Google Pixels. Laptops from Hewlett Packyard, Dell, and Lenovo as well as tablets from Apple, Samsung, and Zebra also support this band.
CBRS auctions allow companies to compete for Priority Access Licences or PAL. While these only make up a fraction of the equation, they are an important part. PAL auctions are good for bigger as well as smaller companies.
GAA: General Authorised Access Spectrum
General Authorised Access spectrum is the most commonly used aspect of CBRS and that is free for everyone. Anyone who wants to use it can use it as long as they are not impacting those with PAL licences, incumbent users, and those who are using it for military purposes.
GAA is the spectrum that is used by the FCC to provide people with internet upgrades and internet access when they cannot afford it on their own.
Spectrum Access System
Spectrum Access System makes sure that every user has good access to the spectrum and that the access is appropriate. The Spectrum Access System also works to provide frequency and service protection for their respective users.
Lanner’s PGN600 LTE module which is an LTE Ready Radio Modem that is used for Mission-Critical Communications.
The PGN600 module adds full support for private LTE CBRS band 48 and public safety-oriented frequencies and is also compatible with Lanner’s communication and security gateways for vehicles, industrial communication and IIoT.