The FCC on Tuesday voted unanimously to advance changes for better use of the 70/80/90 GHz bands, including allowing smaller antennas to support wireless backhaul for 5G.
The proposed changes for smaller antennas could “help lower costs, facilitate network densification, and help support the provision of backhaul for emerging 5G services,” according to an FCC announcement on the vote.
The Notice of Proposed Rulemaking (NPRM) is seeking comment on whether there are current rules that need to be modified or new ones created so that the bands can be used to deliver broadband services on aircrafts and ships.
These bands are currently used for fixed, point-to-point communication, including wireless backhaul but have gone largely under utilized in large parts of the U.S., according to the FCC, making it a potential resource for new service offerings.
Vendors Ericsson and Nokia, alongside Avit and Comsearch, pushed for updated antenna changes, presenting their proposal in March to FCC to modify antenna rules for the 71-76 GHz and 81-86 GHz bands for 5G wireless backhaul.
According to the presentation slide deck (PDF), the main focus was that the vast densification needed for high-band 5G millimeter wave networks requires reliable backhaul on top of fiber, particularly when gear is mounted on street-level structures like light poles.
They requested lowering minimum antenna gain in the 70/80 GHz bands (E-band) from 43 dBi to 38 dBi, as well as removing co-polar discrimination requirement below 5 degrees. Relaxing mast requirements would allow for smaller 0.5-foot antennas (compared to traditional 1-foot parabolic antenna) that are compatible with ETSI Class 3 antennas. That also would harmonize with other countries, including Canada and Europe, creating a common market with the U.S., according to the presentation.
Nokia said these changes would enable enhanced microwave transport technology to support 5G backhaul where wired/fiber connections might not be available, using “smaller, lighter, lower cost , less susceptible to pole sway, and more visually attractive antennas for wireless backhaul,” according to a notice of ex parte (PDF) filed on March 16.
They stressed their proposal wouldn’t require modifications to current licensing and coordination frameworks or additional rule changes to manage interference, with Nokia stating that lowering the minimum gain could be accomplished as “a simple technical rule change.” It also noted expected customer demand.
“The simple rule change we request is long overdue and we anticipate substantial customer demand for proposed lower gain antennas once permitted in the U.S. Once our proposal is adopted by the Commission, the U.S. rules would be globally harmonized, and a global equipment ecosystem would be immediately available to U.S. carriers.”
Industry group CTIA supported the proposed antenna rule changes, noting existing rules are outdated, “unnecessarily restrictive and not well suited to support 4G LTE and 5G networks.”
“As the wireless industry adds capacity to its networks to support skyrocketing consumer demand and foster 5G deployment, it is leveraging existing infrastructure such as light poles and traffic signs for deployments, particularly in urban environments,” wrote CTIA in a May 8 filing (PDF).
When equipment is installed on light poles, the infrastructure has to deal with what’s known as “mast sway,” which can interrupt links because the antenna might move out of alignment with the transmitting antenna, CTIA noted.
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With enhancements, newer smaller antennas have wider beamwidths that can better handle mast sway and there’s less wind load, “making them ideal for the types of street-level use cases” for 4G LTE and 5G densification.
Along with federal users, parts of the bands addressed in the NPRM are currently allocated to certain fixed satellite services. To that end, SpaceX and Hughes Network Systems in separate filings urged the FCC to ensure the rulemaking considers any potential impacts on fixed satellite service (FSS) operations. That includes how changes to the antenna standards might impact opportunities for the use of the spectrum for their uses, and whether aircraft or maritime deployments would inhibit potential use of the spectrum by FSS systems.