Spectrum for Private Mobile Networks

For an organization to operate a private mobile network, it needs spectrum. So, what are the choices? And what does spectrum tell us about the technology, industry structure and business models that will underpin this market?

In simple terms, there are three major options for private network spectrum:

Spectrum leased from a licensed operator. This is the most common model today. Protected use makes this attractive for high-end customers. The challenge is that it doesn't scale well to tens or hundreds of thousands of users. Mechanisms and regulations to more easily sub-lease/share licensed spectrum for private networks are in development, but for now this is a bespoke configuration, typically embedded in a deep business relationship with the operator.

Unlicensed spectrum. Classically, this means 5GHz, which is primarily used by WiFi today. For the future, 6GHz is under evaluation in the US and Europe and offers interesting options, particularly if part of the band is regulated to require synchronized sharing, which would radically improve performance when multiple users want to access the same band. In some markets, unlicensed mmWave is also an option for mobile 5G.

Locally licensed enterprise spectrum. Regulators worldwide are investigating, or already allocating, spectrum that can be locally licensed for private 4G/5G networks. For broadband services, these are typically mid-band allocations, such as CBRS spectrum (3.5GHz) in the US and 3.7-3.8GHz in parts of Europe, which offer protected use in small license areas. They are generally low-power allocations to better enable re-use.

Access to spectrum is one of the keys to unlocking the private networking market. The ability to deploy private networks without dependencies on public cellular systems or licensed operators gives enterprises greater ability to control their operations and removes friction from the market. Both unlicensed spectrum and so-called "enterprise spectrum" offer this advantage.

Dedicated enterprise spectrum offers protected use and is therefore interesting to organizations with demanding reliability and availability requirements. This applies particularly to industrial IoT applications, but also to any organization wanting to run production-critical systems with minimal risk of downtime. In a follow-up blog, I'll discuss activity in this area, and address the pros and cons of "enterprise spectrum," in more depth. For now, suffice to say that in many advanced economies, spectrum regulators are already moving to enable this market.

Unlicensed spectrum is, by design, easy to access and widely available. This is traded against the possibility that neighbors can interfere, making some organizations reluctant to rely on unlicensed for production-critical networks. Interestingly, simulations show 5G radio innovations such as Coordinated MultiPoint (CoMP), combined with good network design, can be used to achieve consistent, highly reliable performance in shared frequency bands. In the medium term, extending into 6GHz offers the potential to introduce synchronized sharing to unlicensed spectrum to significantly improve efficiency and reliability where there are multiple users.

Dedicated and unlicensed spectrum does not, however, mean there is no room for operators in this market. Heavy Reading believes spectrum will, in many cases, be decoupled from the decision about who designs, operates and maintains private networks. Already there is evidence that operators themselves see opportunities in dedicated enterprise spectrum, and several are preparing to offer managed private networks in these bands. There is also, of course, a very large market for wide-area and multi-site services that operators can offer alongside on-campus private network services.

— Gabriel Brown, Principal Analyst, Mobile Networks & 5G, Heavy Reading