5G fixed wireless access use case brings new set of testing challenges
With the 5G non-standalone (NSA) specification set for completion later this year along with the 3GPP tracking to complete the standalone 5G New Radio (NR) specification mid-2018, operators are aggressively looking to leverage pre-standard implementations of 5G fixed wireless access to pave the way to new network services.
This is an attractive route for a number of reasons. Using the high-capacity, millimeter-wave (mmWave) spectrum, service providers can deliver gigabit internet service to homes and businesses without the time-consuming and expensive process of deploying fiber to every house and premise in a given area. Think of 5G fixed wireless access as a potential solution to the last-mile problem of FTTH and FTTP. As a bonus, other services, particularly pay TV, can be delivered over the same radio link.
Another reason 5G fixed wireless access is such a draw at the moment is more forward looking. In the ultra-dense 5G networks of the future, wireless and wired networks will be highly integrated, meaning a single infrastructure location could be leveraged to support fixed wireless and mobile use cases. Further adding to the momentum is the mmWave aspect; pre-standard trials of 5G fixed wireless access provide the opportunity to gather valuable insight into the challenging propagation characteristics of the high-band spectrum. This includes how it behaves in varying geographic, weather, and foliage conditions. Moreover, it provides insight on how the spectrum connects to user equipment through different construction materials. For example, modern window glass is designed to bolster energy efficiency by utilizing reflective coatings that block UV energy. However, these coatings simultaneously block RF signals, making wireless penetration into the building difficult.
Building on initial enterprise and consumer trials in Austin, Texas, AT&T is now expanding its research around 5G fixed wireless access to Waco, Texas, Kalamazoo, Michigan, and South Bend, Indiana. In the new markets, AT&T will increase the number of end-users and the physical size of the trial networks; participants include universities, hospitals, churches, restaurants, and other small business. In addition to broadband service, AT&T is also delivering its DirecTV Now service using 15 GHz and 28 GHz spectrum. Similarly, Verizon is gradually expanding similar field trials, focused on delivery of high-speed internet access and VoIP calling to 11 cities around the country.
When these ideas of ultra-dense networks and mmWave signals join together, commercial deployments at scale will require vast networks of miniature cell sites to deliver valuable high-speed services to end users. “That means operators need more cost-effective ways to deploy millimeter-wave base stations,” Anritsu Product Manager Russ Lindsay told RCR Wireless News.
So, what does that mean for a company like Anritsu that provides a variety of test and measurement tools to the operators and turf vendors whose field technicians are tasked with commissioning, optimizing, and maintaining telecommunications sites?
“To be cost effective and scalable,” Lindsay explained, “the operators want the users to be able to self-install equipment just like with current cable TV set-top boxes. To prepare for self-installation, two things are occurring. First, network equipment providers and operators are looking to evaluate their propagation models. They need to take field-based measurements to validate that their models are accurate. Second, they need to conduct outdoor and indoor coverage mapping.”
Relative to support for the varying millimeter-wave frequencies associated with 5G fixed wireless access, Anritsu developed the Spectrum Master™ MS2760A ultraportable millimeter wave spectrum analyzer. This solution provides continuous coverage from 9 kHz up to 110 GHz to allow a field tech to test everything from the type of millimeter-wave applications discussed to things like Wi-Gig, E-band microwave links, satellite communications, and even automotive radar.
Applied to this 5G fixed wireless access use case, initially, “Maybe a tech goes and walks a neighborhood, gets an idea of what the cover may look like there, and that leads to a first round of successful installs,” Lindsay said. “From there, word spreads and people aren’t intimidated by trying to install their own equipment.”
Once deployments start to scale, operators can combine Anritsu’s ultra-portable solution with emerging drone services to perform spectrum measurements, RF inspection, and visual inspection. This same combination of technology has been successfully used to hunt for signal interference; learn more about that drone-based spectrum analysis application in Anritsu’s web series Signal Hunters.
In the context of ultra-dense, small cell networks, sites will be everywhere–light poles, utility poles, street furniture like benches and trash cans, traffic lights–everywhere. “How are you going to be able to check those?” Lindsay asked, setting up the Spectrum Master MS2760A. “It is literally light enough and has a tripod mount on the back of it that you could connect to a selfie stick, reach right up, and do a quick check on your small cells. You’ve got to have a solution that is cost-effective and easy-to-use in the field to magnitude of new field deployments.”
