Going once, going twice – sold! Over the years, spectrum auctions have raised billions of dollars in revenue for government coffers across the world. Given the insatiable appetite for mobile services, demand for spectrum has surpassed supply. That is not good news for operators, enterprises or even regulators as a shortage of spectrum stifles business growth. With 5G services just around the corner, carriers require innovative solutions to provide more spectrum rather than relying on conventional auctions and allocations.
3.5 is the magic number
With Airbnb, you share your accommodation. With Uber or Lyft, it’s your ride. So, why not share your spectrum? In 2015, the US Federal Communications Commission (FCC) established the Citizens Broadband Radio Service (CBRS) for dynamic spectrum sharing. The FCC released 150 MHz of the 3.5 GHz band for mobile broadband.
Why share? Because the government and military already use 3.5-3.7 GHz for radar systems, fixed satellite services and other applications. Commercial access to the 3.5 GHz band is great news. Network providers and carriers can look forward to growing LTE coverage and capacity while getting their ducks in a row for 5G. Businesses can use 3.5 GHz for IoT connectivity.
However, there’s one caveat: spectrum sharing can get complicated.
To make sharing as efficient and fair as possible, the non-profit Wireless Innovation Forum (WIF) formed a committee to work with industry and government bodies to collaborate on a CBRS ecosystem. It was agreed that 150 MHz would be managed by one or more spectrum access systems (SAS). Sharing the 3.5 GHz band requires three CBRS tiers:
- Tier 1: Incumbent Access: Authorized federal government users already on the 3.5 GHz band. These are priority users of military radar, ground-based radar and fixed-satellite-services.
- Tier 2: Priority Access Licenses (PAL): Following a competitive bid process, the FCC assigned the PALs. They consume the 3550-3650 MHz portion, which is frequency, service-area and geographic-area specific. Along with carriers, PALs include hospitals and utilities. PALs are also time limited and frequencies are not dynamically managed by the SAS database for automatic renewal.
- Tier 3: General Authorized Access (GAA): This group has open and flexible access to the 150 MHz band. GAAs are not required to obtain a license to use any portion of 3550-3700 MHz, as long as users from a higher tier are not using it. Frequency assignments are dynamically controlled via the SAS database where users can stipulate and agree on modifications for LTE licensed-assisted access or Wi-Fi networks based on FCC guidelines.
Making the most of the extra bandwidth
- CBRS opens up a number of lucrative commercial opportunities. Altran’s expertise in CBRS can help network operators and enterprises navigate the end-to-end architecture models and the SAS functional architecture to monetize the extra bandwidth. Here are some examples:
Some small-cell deployments are tied to specific operators that make them expensive and difficult to scale to boost coverage. A framework based on CBRS can improve in-building coverage via distributed antenna systems. Building owners, enterprises or systems integrators can deploy equipment using a neutral host radio access network (RAN) model to monetize this opportunity. What’s more, thanks to cost sharing structures between equipment companies, building owners, mobile operators and temporary licensees, there are new use cases worth exploring.
- CBRS is ideal for cable operators. They could build an LTE network, offload traffic, enter the wireless space with a mobile virtual network operator (MVNO) strategy or even consider the early stages of a 5G deployment. It might sound cliché, but the possibilities are endless.
- Enterprises can create a private LTE network, similar to Wi-Fi, to run applications on mobile devices that do not require a SIM.
- Businesses can use MulteFire-LTE for unlicensed frequency bands-to connect a variety of IoT devices. For example, a mining company could set up a private LTE network at a remote mining site and run industrial IoT applications.
- Attendees at large venues such as stadiums often find it difficult to get uninterrupted mobile data service. Businesses such as Ruckus Wireless that support CBRS can offer LTE connections using CBRS along with a neutral host. This can deliver LTE coverage with consistent data speeds to a very large number of people within a specific location.
A bold move
The CBRS ecosystem can be complex to navigate and parts of the jigsaw puzzle still need to fall into place. For example, user equipment (UE) to support 3.5GHz is not widely available in the U.S. Yet, phones from Japan, where 3.5 GHz is deployed on LTE networks can be upgraded to support LTE frequencies and access CBRS spectrum. Businesses also need to understand the SAS functional architecture and engage with the various working groups.
Similar to how the sharing economy is transforming 21st-century commerce; the FCC’s CBRS spectrum sharing initiative has revolutionized the industry and unlocked a number of opportunities for businesses and network providers. This innovative approach deserves praise as it has freed-up a significant amount of spectrum without the need for expensive auctions. It delivers flexibility to carriers and enterprises and expands coverage to consumers.