Pivotal Commware, a startup that recently received $17 million in funding, is taking its proprietary holographic beamforming (HBF) to the streets, with plans to dramatically expand the capacity of existing 4G networks while becoming indispensable to the 5G rollout.
HBF was originally developed by several universities and readied for the market by technology incubator Intellectual Ventures, which recently spun-out Pivotal Commware in an aforementioned series A funding round that included Bill Gates as an investor. At the heart of the technology is a low-cost, low-power software-defined antenna which aims to improve upon the decades-old “phased array” beamforming technology that’s still in use today.
“Compared to HBF, phased arrays, which are often used in military applications, use a much higher cost, size, weight and power (C-SWaP) envelope,” said Brian Deutsch, CEO, Pivotal Commware, in an interview with FierceWirelessTech.
He said that HBF makes beamforming cost effective for four main markets: 1) mobile RAN, 2) rail, ship-to-shore, aviation and vehicles, 3) tactical communications for the military and government, and 4) wireless backhaul for small cells.
“The largest of these markets, RAN, faces insatiable consumer demand for data,” Deutsch said. “But it’s nearly maxed out time-slicing (TDMA) and coding techniques (CDMA) to increase spectral efficiency and throughput to deliver that data. The RAN industry acknowledges that beamforming—leveraging the spatial dimension versus time/coding dimensions—is crucial to meeting this demand, particularly at the higher, millimeter-wave frequencies being made available by the FCC and similar agencies around the world.”
To wit: At millimeter frequencies, RF signals don’t propagate as far. Beamforming addresses this shortfall by narrowing the beams to increase their propagation, and by steering them to address mobility.
As to how HBF specifically works, it can shape and steer narrow beams dynamically, so that the same frequency can be reused in adjacent beams without interfering with each other. In contrast, existing antenna sector technology used in cell towers shares wide beams across many users, in a “town-crier” model, making spectrum reuse difficult.
“Narrowing beams this way increases their gain and therefore throughput, while increasing spectral efficiency via adjacent frequency reuse,” Deutsch said. “Increasing throughput and spectral efficiency is a rare ‘twofer’ in RF engineering.”
Holographic refers to the fact that the HBF antenna is analogous to a holographic plate in an optical hologram; RF signals from a radio flow into the back of the antenna and scatter across its front, where tiny elements adjust the shape and direction of the beam.
“Better-known optical holograms use a reference wave and a holographic plate to create an object wave producing the image people see,” explained Deutsch. “For HBF, the reference wave is the RF signal from the radio, the holographic plate is the antenna surface, and the object wave is the beam.”
The company said that the technology, which can address frequency bands from 1 GHz to 80 GHz, allows carriers to put coverage where it’s required, to accommodate usage patterns (e.g. rush hour traffic, events, etc.), or in response to changing landscapes such as new buildings.
For instance, a software-defined antenna on a downtown building could blanket the streets and sidewalks below during morning and evening commutes, and then turn its beam onto an adjacent building to improve coverage there during the workday.
On the 5G front, in addition to the millimeter wave benefits, at lower frequencies beamforming addresses a growing capacity shortfall. It also aids 5G densification, maximizing frequency reuse and supporting small cells.
“HBF’s sub-microsecond beam steering allows small-cell backhaul links to stay aligned on the lower-elevation, less stable ‘municipal furniture’ such as streetlights they’re expected to occupy, and to form self-healing networks among other small cells,” Deutsch explained.
Pivotal said that it’s working on multiple projects for fronthaul and backhaul opportunities, including prototypes for two Tier 1 carriers and work with several carriers in the U.S. and in Western Europe on both 4G and 5G. And from a roadmap perspective, it’s working on projects that include tactical battlefield communications and air-to-ground inflight communications.