While the enterprise has widely recognized private 4G/5G private networks with licensed and shared CBRS spectrum as a flexible means of achieving distinctive business strategies and accelerating innovation, it is still overwhelmed by its implementation cost and complexity. As the realization sinks in, enterprises are taking a fresh look at a portfolio of choices for the spectrum and associated technologies to shape their future strategies for network design. Use cases will influence its choices for its mix of spectrum and technologies.
Unlicensed spectrum is part of the mix. Shared or licensed spectrum-based private networks alone cannot serve all use cases, especially because the coveted mid-band spectrum is scarce and expensive.
There is enough unlicensed spectrum to spare to cope with the runaway demand for bandwidth in private networks. The available unlicensed spectrum is 580 MHz in the USA in the 5-GHz band and 455 MHz bandwidth in Europe. Recently, FCC added 1200 MHz in the 6 GHz band to the mix. The industrial, scientific, and medical (ISM) bands, previously used for non-communication uses, have become part of spectrum bands under the 6 GHz range for telecommunications.
The enterprise is increasingly inclined to opt for hybrid networks, including public and private wireless networks, using licensed and unlicensed spectrum to serve their diverse use case needs. It will combine them with Wi-Fi and cellular technologies to gain the most value from investments. According to a 2021 survey by Deloitte, enterprises will allocate 48% of the budget to Wi-Fi and 52 percent to cellular technologies over the next three years.
Expanded use of unlicensed spectrum for enterprise private wireless networks
Over the past few decades, Wi-Fi has been the most widely used unlicensed spectrum-based wireless networking technology for enterprises. Its latest version, Wi-Fi 6, competes with LTE and 5G in bandwidth and latency. Next-generation Wi-Fi 6 technologies are options that serve the needs of commercializing some use cases comparable to 4G and 5G at a lower cost. However, 4G/5G are better suited for business-critical and mission-critical ultra-reliable low-latency applications.
The latest generation 4G/5G cellular networks can operate in the licensed, shared, and unlicensed bands (3.5 GHz, 5.0 GHz, 6.0 GHz). Multefire operates in unlicensed and shared spectrum using 4G technologies.
Private LTE networks using the CBRS’s GAA unlicensed and PAL lightly-licensed spectrum bands have proved valuable, in local regions, for the education and healthcare sectors and in ports, agriculture, mining, and manufacturing.
Breakthrough with 5G NR-U overcomes challenges
Unlicensed spectrum has not been used for cellular networks due to the risk of interference from devices in proximity. Private cellular networks with a 5G NR-U intend to overcome challenges of interference and security, opening the way to broader adoption of unlicensed spectrum. For instance, Orthogonal frequency-division multiplexing (OFDM) is much favored as it divides individual channels into evenly spaced subcarriers, each independent of the others, minimizing interference. When needed, 5G NR aggregates the sub-carriers. The number of component channels aggregated has risen from five to eight. Consequently, a single aggregated carrier can combine up to 3.2 GHz of bandwidth.
Also, unlike Licensed Assisted Access (LAA), which leverages licensed bands for control functions and the 5GHz unlicensed band for data plan functions, standalone NR-U simplifies the processing of sensitive controls signaling, and data flows by combining them. Currently, 5G NR-U can be anchored in the licensed spectrum or not. More recently, the option to choose a standalone NR-Unlicensed spectrum for control-plane tasks and user-plane transmissions has been available to operators.
Standalone Unlicensed 5G networks have uses in a wider range of verticals and provide better performance. Some of the verticals where unlicensed 5G technology is expected to find uses are container ports, warehouses, and underground mines for the deployment of private cellular networks. According to GSA, a total of 42 operators worldwide are investing in unlicensed spectrum technologies in the form of trials, pilots, deployments, and launches.
A rush of private network offerings for hybrid networks including unlicensed spectrum
A rush of groups of new entrants are expanding the market for hybrid networks, primarily in partnerships with hyperscalers, public telecom operators, and technology companies, and are taking advantage of technological advances, such as the advent of choice of Wi-Fi 6 technologies, to take advantage of wider coverage with from the unlicensed spectrum. They also simplify the deployment process by using shrink-wrapped software for easy installation and value-added resellers for connecting with customers. Cisco, HPE, Amazon, and Microsoft are among the new kids on the block. Microsoft, for example, provides access to licensed and unlicensed spectrum for its private MEC with its Azure edge zones in collaboration with AT&T.
Cisco, for example, offers a hybrid solution that includes a private 5G solution to complement Wi-Fi 6 and Wi-Fi 6 and 6E –to meet the emerging needs of the hybrid workforce.
AT&T is collaborating with Microsoft with its Private 5G Edge that can roam to AT&T’s public network. In addition, it uses Microsoft Azure private MEC with Azure Private 5G Core to help enterprises deploy private networks on licensed or unlicensed spectrum.
Amazon provides a private network, pre-configured based on location and the capacity requirement, working with the unlicensed CBRS spectrum. Its first deployment is experimental with a private network deployment with an unlicensed spectrum on one of its fulfillment centers. An outdoor solution, it helps in accurate, safe, and convenient movement of tractor-trailers with the installation of just two small cells.
Conclusion
The initial promise of the fast growth of private networks with licensed spectrum hit a roadblock with the reality of implementation challenges. However, private networks with unlicensed and shared spectrum have renewed their growth expectations within hybrid networks. They expand the use cases, simplify deployment, and increase the channels that prospective customers can choose for firing up growth.
