Millimeter wave FWA gains ground as Verizon unveils new device
Apr 28, 2023
Slowly but surely millimeter wave is making its way into fixed wireless access (FWA) services in certain regions, driven by advances in both transmission and CPE technology, making this option cost-effective for operators in a growing range of deployment scenarios.
Among recent developments was launch of Verizon's latest 5G FWA CPE at Mobile World Congress Las Vegas, spanning mmWave, midrange and 4G, designed for operators to combine different connectivity options cost effectively for a robust FWA service, capable of switching transparently between the three bands.
Called the Verizon Receiver, this is based on the latest Qualcomm 5G Fixed Wireless Access Platform and can be combined with the operator's router to provide WiFi-based broadband access in the home just like a traditional fixed service over fiber, cable or telco DSL.
Verizon, like a growing number of MNOs, sees FWA as the most likely first source of significant revenue from mmWave, rather than the dense urban environments for which it was first proposed. In that dense scenario the greater spectral range available at higher frequencies was considered essential for meeting growing demand for capacity at high user concentrations. That may well prove to be the case, but for now most MNOs are finding that midrange frequencies have enough capacity, while also meeting demand for coverage comparable to existing 4G services.
Verizon has had its eye on FWA as a likely source of revenue from mmWave deployments from the outset, but originally built its business model around specific use cases and dense urban environments. It invested well over $1bn in mmWave in three successive mmWave auctions running up to 2020, heavily outspending its two main rivals AT&T and T Mobile.
Verizon went further still with a string of acquisitions that brought in mmWave spectrum, among other assets, including Straight Path, XO Communications and Nextlink.
For its rivals, mmWave was seen at that stage as just providing a fast leg up into 5G to establish a bulkhead for subsequent consolidation around midband spectrum. But for Verizon it was to be the mainstay of its 5G service platform, with midband and also low band spectrum filling in coverage gaps.
Verizon had underestimated the challenge of overcoming obstacles in the signal path, notably trees and buildings in dense urban environments. Coverage proved disappointing for early users of its mmWave services, which found their smartphones slipping back most of the time to lower frequencies, even when quite close to a mmWave base station. Various tests showed that mmWave coverage only extended out about 500 feet (150 meters) in many quite typical dense urban settings.
By contrast, mmWave coverage exceeded expectations in some trials of FWA in rural settings, especially in relatively flat and open terrain without many trees. It was actually the USA's fifth MNO, US Cellular, headquartered in Chicago, that in May 2021 demonstrated sustained average downlink speed of 1Gbps and peak around 2Gbps over a distance of 7 kilometers. This was achieved with extended-range functionality added to Ericsson's AIR 5322 advanced antenna system, combined with an Inseego Wavemake 5G outdoor CPE FW2010 based on Qualcomm's 5G FWA Platform including the Snapdragon X55 5G modem-RF system and QTM527 mmWave antenna module.
This range and speed could only be achieved with line of sight (LOS). Almost more significant was the additional finding that sustained average speeds of about 730Mbps down and 38Mbps up could be achieved at 1.75km without LOS, providing the terrain was not too undulating or cluttered with obstacles. This provided a realistic estimate of mmWave's potential for commercial rural FWA services.
The far greater range of mmWave in less dense settings reflects the advance of beam forming able to concentrate power in narrow channels to mitigate signal degradation through the air that tends to be greater at higher frequencies. FWA dovetails well with beamforming because both transmitting and receiving equipment are fixed, giving scope for continuous re-orientation in real time to optimize signal transmission.
Trials such as US Cellular’ s established that mmWave was at least a serious contender for FWA. But they still begged the question of how cost effective mmWave would prove to be against the wireline alternatives, in varying scenarios.
This prompted the GSA to conduct a comprehensive study comparing the total cost of ownership (TCO) of mmWave with the three principal wireline options in different regions and under varying assumptions for deployment of the underlying fiber.
The three options all have optical fiber infrastructure at least for backhaul but differ in their last mile. One is fiber all the way to the home (FTTH), the second copper-based G. Fast, or VDSL, as deployed by telcos, and the third hybrid fibrecoaxial (HFC) from cable operators. These were compared with 5G FWA network over existing 5G infrastructure served primarily by mmWave with limited sub-6 GHz spectrum available.
The main finding was that in smaller rural towns, a 5G mmWave FWA network is the most cost-effective option for delivering future-proof, next-generation broadband services in situations where fiber cables cannot be deployed over existing physical infrastructure that can be rented or shared. Such infrastructure comprises either ducting below ground or erections such as poles above ground for running fiber cables out to customer premises.
Under this scenario, a 5G mmWave FWA network would on average have 55% less TCO in Europe, 45% less in the USA and 65% less in Latin America, according to the study.
The situation is reversed when fiber can be deployed in aerial or underground infrastructure that can be shared or rented, reducing cost of FTTH which may then become more cost effective than 5G mmWave in rural towns for high-speed broadband provision. But even in those cases 5G mmWave has first mover advantage because it can be deployed more quickly than FTTH, and then scale more readily.
As the study put it: "5G FWA's faster time to market means operators can deploy improved broadband services in underserved areas before the arrival of FTTH, appealing to potential subscribers eager for improvements in network performance. 5G FWA is also an agile solution; mobile operators with an existing infrastructure base can scale 5G FWA services according to data traffic growth, by adding bandwidth and equipment to existing infrastructure."
The GSA study also teases out other factors, such as the potential for high powered indoor CPE to move the dial further in favor of mmWave for FWA by enabling customer installation without an engineer's visit. Outdoor CPE tends to enable better reception but requires a truck roll to install, while users can deploy their own indoor CPE.
The GSA then suggests that a hybrid approach might be most cost-effective in some cases, issuing subscribers far away from base stations with outdoor antennas, and indoor CPE to the rest who are closer.
The study also hints at a blurring between FWA and normal mobile service in some cases. This is already being reflected in design of some CPE and the approach of some operators.
Examples of such CPE include the Netgear Nighthawk M6 and M6 Pro mobile routers launched in April 2022 and distributed by Australia's Telstra, among others. The two differ primarily in that while both support WiFi for access to services via 5G, only the Pro version supports the latest WiFi 6E extending into the 6 GHz band. The devices have been deployed in the USA by AT&T for mobile or fixed wireless hotspots. Indeed, Netgear argues the devices are conducive for "hybrid and remote working lifestyles".
Telstra seems most interested in the potential for serving broadband to homes in a flexible package. The company has claimed a speed record using Ericsson's NR-DC software with downlink eight-component carrier aggregation (DL 8CC CA), to combine eight contiguous 100 MHz mmWave carriers with a single 100 MHz of midband spectrum, reaching 5.9Gbps on the downlink.
One caveat may be that mobile routers lack quite the same scope for optimizing mmWave signal transmission for FWA over longer distances. But there is no doubt over the potential appeal of mmWave in more remote settings for applications such as gaming that require high bit rates and low latencies. It also offers a promising route to monetization for operators such as Verizon whose initial hopes of return on large mmWave spectrum investments appeared to have foundered, at least for now, on poor coverage. Verizon has reined back promotion of its mmWave service for mobility but is stepping up efforts over FWA.