Private networks have grown in importance over recent years due to their ability to offer specific features to their users not always available on a public network and rigorous controls to limit who has access to the private network and data. The private network (PN) could be a manufacturing facility, with employees and robots as the user group. The PN could be a mining operation, with access granted only to employees, autonomous vehicles, drones, and HD-video cameras. It could be a warehouse with a few employees, thousands of Internet of Things (IoT) devices, and equipment such as cameras and sensors, to track inventory. The possibilities are endless, with hundreds of LTE and 5G private cellular networks already installed worldwide and many thousands more expected in the upcoming years.
For any enterprise planning to install a private wireless network, the key decision required is a selection of the right frequency band and spectrum type. The frequency bands available for a cost-effective private network in the geographic area where the network will be used will likely be low band (< 1 GHz) or mid-band (1-6 GHz). They will need to be selected based on the band’s characteristics (such as propagation, coverage, bandwidth) and the business application needs, such as the ability to transfer significant amounts of data simultaneously (e.g., high-speed factory) or cover a large geographic area (e.g., mining operation).
The type of spectrum chosen by the enterprise will be one of four types: unlicensed, local license, shared, or public. Each has its advantages and disadvantages.
Unlicensed is free
The most straightforward private network to install will run on unlicensed spectrum, so no access fees are necessary. One example is Wi-Fi, typically operating at the 5.0 GHz band. The advantage to running your private network on unlicensed spectrum is that the spectrum is free to use; however, there are disadvantages as well. For Wi-Fi, interference is possible, as there are no rules as to who can be using the spectrum simultaneously in the same place as your network. This makes Wi-Fi a poor choice for high availability or business-critical applications that requires predictable performance.
An alternative way to run on unlicensed spectrum is with MulteFire. This technology allows the running of LTE on unlicensed spectrum, “…combining the performance benefits of LTE with the simplicity of Wi-Fi like deployments.” Although MulteFire currently only uses LTE, the MulteFire Alliance (MFA) announced in June 2021 that they were looking to support 5G networks in unlicensed bands. The MulteFire market “…is likely to grow from USD 455 million in 2020 to USD 2,119 million by 2025, at a CAGR of 36.0%.”
Enterprises can also work with telecom carriers to deploy small cell-based LTE networks that utilize unlicensed 5GHz spectrum using Licensed Assisted Access (LAA) technology.
Local licenses for private use take off in Europe
Regulators in some countries, primarily in Europe, are allocating spectrum specifically for industry. These local access licenses are not controlled by a Mobile Network Operator (MNO) but are available for private enterprises in specific areas. BNetzA, the German regulatory agency, allocated 100 MHz from 3.7-3.8 GHz for enterprises. Over 100 companies, including “Bosch, BMW, BASF, Lufthansa, Siemens, and Volkswagen” have bought licenses. The UK, France, Sweden, Hong Kong, Australia, and Japan have also allocated bandwidth for local licenses. In a first for Finland, spectrum was granted directly to a business rather than an operator,Fortum Power and Heat. In France, electronics manufacturer Lacroix will partner with Orange to deploy a private 5G network using a local license to demonstrate the “factory of the future.”
Edzcom (formerly Ukkoverkot), owned by Cellnex, is a Finnish-based company that builds and operates private LTE and 5G networks in Europe. They currently have more than two dozen installations in sites such as ports, rail, and mines. They are partnering with Nokia to jointly deliver a 5G private network for Konecranes in Finland. The network will support smart factory applications such as the use of HD cameras to “…improve load handling safety, site security, and operational integrity.”
Local access licenses “…diversifies spectrum ownership, facilitates market entry for alternative providers, and consequently provides a greater choice of network suppliers.”
Sharing spectrum could be the wave of the future
Sharing spectrum refers to two or more users having the right to use the same frequency band in the same geographic area. This differs from public networks in that an MNO is usually granted the exclusive right to use the band for a fee. With shared spectrum, multiple users are permitted to use the band. Shared spectrum differs from unlicensed spectrum in that there are rules as to who can use it and when.
A common way to implement a private network using shared spectrum in the US is with the 3.5 GHz Citizen’s Broadband Radio Service (CBRS). It is available on three tiers: the free, General Authorized Access (GAA) level, the Priority Access License (PAL), whose rights were auctioned by the FCC in 2020, with seven licenses for each county in the US, and the incumbent level, allowing existing users to keep using it. Examples of incumbents are the US Navy and fixed satellite services. The GAA users can use the band as long as no one with a PAL in that area, or an incumbent is using it, and the PAL users can use it as long as no incumbent is active. Devices know whether a specific channel is in use by communicating with a Spectrum Access System (SAS), which acts as a database to ensure seamless operations, keeping track of all devices permitted to use CBRS in a geographic area. There are several companies licensed by the FCC to operate SAS. In practice, most PAL users are assured access, as the number of non-coastal areas with incumbent users is minimal.
CBRS deployments have been seen in education, where more than one billion children in countries around the world were affected by school closures, and healthcare, where private LTE networks have helped medical personnel performing triage on the alarming number of pandemic patients seen in health centers. Deployments are also found in hotels, mining, and office buildings.
CBRS has run 4G networks almost exclusively, though there was a recent report that Ericsson and Qualcomm successfully tested 5G on CBRS.
In Europe, the “…successful commercialization of CBRS in the United States has reverberated through the wireless industry,” and many countries are looking to emulate the shared spectrum technology.
Many agree that spectrum sharing will be the future of wireless networks, including T-Mobile’s Steve Sharkey, who “… agreed with earlier panelists that spectrum-sharing will become more of the normal way of using this limited resource.”
Shared spectrum lowers the bar for entrants into private networks with lower expenses.
Public spectrum leads the private world
The vast majority of private LTE and 5G networks use public spectrum or spectrum licensed by MNOs to operate. Per Analysis Mason, more than 70% of LTE and 5G private networks use the public spectrum.
With public spectrum, MNOs set aside part of their licensed spectrum in a specific area. Third parties such as private businesses or neutral hosts can lease the spectrum and set up a private wireless network.
Conclusion
According to the GSA, there are roughly 370 companies in 45 countries where LTE or 5G private networks are in operation or are in trials. The percentage of private networks that are 5G (36%) is smaller than that of LTE as of August 2021, though the numbers are changing quickly, as 5G only held 19% of the market in October 2020. The industries that lead the market in terms of the number of private 5G networks in 2020 include manufacturing, energy and utilities, transportation, defenses, and enterprises & campuses. The future looks bright for private networks, with the private 5G market in North America forecast to grow at a CAGR of 40% between 2020-2028, from $381 million to more than $5.7 billion.
