As state and local governments and their partners plan to invest billions of dollars in federal funding to build broadband infrastructure, choosing the best technology will have significant long-term consequences. Federal policymakers have addressed this issue to some extent: For example, the Broadband Capital Access, Access and Deployment (BEAD) Notice on Funding Opportunity (NOFO) prefers fiber over fixed wireless.
To help state and local politicians, this report offers an engineering analysis of fixed wireless technologies and their suitability for providing broadband services in a variety of environments. The report examines a number of critical technologies and cost considerations for fixed wireless networks and, as a benchmark, for fiber to premises networks.
At a high level, the report concludes as follows:
- Fixed wireless technologies will continue to improve, but will not match the performance of optical networks – mainly because the existing and potential fiber bandwidth is thousands of times higher than wireless. Also, fixed wireless networks have inherent capacity constraints that drastically limit the number of users on the network using a certain amount of spectrum.
- Fixed wireless network coverage is adversely affected by visibility barriers (including buildings and seasonal greenery) and weather. While an optical network can physically connect each household in a service area (and provide predictable performance), for a fixed wireless network it is significantly more complex to provide visibility to each household in a service area.
- Scalability is a critical challenge for the deployment of fixed wireless networks, both technically and financially. A certain amount of wireless spectrum is able to support a certain amount of network capacity. If the number of network users increases or users need more bandwidth, the network operator must increase the spectrum (which is both scarce and extremely expensive – and may not be possible), upgrade technology or add antennas. The challenge is to design a fixed wireless network that provides sufficient, robust capacity up and down the chain and reaches all addresses in unattended areas.
- The fastest fixed wireless technologies (such as those using a millimeter-wave spectrum) are effective in providing short-range services to closely grouped households in urban and suburban environments. These technologies are largely unsuitable for serving rural communities due to the typical geographical dispersion of addresses and the lack of prefabricated structures (such as towers or roofs of buildings).
- Fiber is sustainable, scalable and renewable. It offers higher capacity, predictable performance, lower maintenance costs and longer technology life compared to fixed wireless technologies. Optical service is not compromised by line of sight problems and is not affected by capacity issues that limit fixed wireless networks.
To further illustrate the relative strengths and weaknesses of fixed wireless technologies, this report presents an analysis of the capital and operating costs of a candidate fixed wireless network compared to a candidate optical network in the same real settings. Each of the candidate networks is designed to provide full coverage of unattended housing.
While the cost analysis illustrates that the initial capital cost of fiber is higher than that of fixed wireless in many circumstances, the total cost of ownership over 30 years is comparable to optical and fixed wireless networks.
Given the above analysis, the fiber offers greater long-term value compared to fixed wireless technologies due to the long life, capabilities, scalability and flexibility of the fiber. If the state finances non-fiber technologies, such as in circumstances where the capital cost of building fiber is prohibitive or the need for maintenance cannot wait for fiber to be built, the state must take steps to protect its investment, such as requiring grantees to ensure the long-term maintenance and operation of the fixed wireless network. This can be achieved by requiring a 20-year roadmap for presentation and budget, as well as a viable full-service strategy where the line of sight is challenging.
This publication was commissioned by Communications Workers of America and prepared by CTC Technology & Energy in the spring of 2022.