Pivotal takes ‘lemons’ out of mmWave to improve coverage

Pivotal Commware, a Kirkland, Washington-based startup backed by Bill Gates, released a new white paper and video to demonstrate how a Tier 1 mobile operator can use its Echo 5G and Pivot 5G repeaters to increase indoor 5G millimeter wave (mmWave) coverage while reducing deployment costs.

Pivotal doesn't mention Verizon, which is the U.S. carrier most aggressively using mmWave for its initial 5G rollouts. But the white paper explores the solution at 28 GHz, which is the band most often associated with Verizon and prior reports have connected the dots. Last month, the Wall Street Journal noted Pivotal’s presence in a Verizon-hosted demo associated with the Super Bowl.

Verizon did not immediately respond to an inquiry from Fierce but previously declined to comment about any work with Pivotal. Executives have acknowledged they’re interested in this type of gear that pulls the mmWave signal into a building or residence, as opposed to using Wi-Fi inside. Verizon's 5G Home service is currently available in only five markets.

RELATED: Editor’s Corner: Is Verizon losing its network advantage?

Pivotal’s white paper (PDF) points out how analysts and others have questioned the return on investment for operators deploying mmWave at scale.

“These are fair criticisms,” the paper states. “But deploying fewer base stations augmented by network repeater technology based on Holographic Beam Forming (HBF) tells a different story.” Namely, that the Pivotal Echo 5G and Pivot 5G, deployed in conjunction with base stations, reach more subscribers at less cost than deploying gNBs alone.

Pivotal’s technology takes advantage of mmWave’s limited propagation and other characteristics to make it all work. Repeaters used to be a dirty word in wireless because “you could easily cause two or three problems in order to fix one,” said Pivotal Commware CEO Brian Deutsch.

Signals usually are broadcast in an omnidirectional way – it’s hard to do beamforming at sub-6 GHz as the antennas would be “ridiculously large.” That happens to cause “the perfect storm, or craziness,  for spectral hygiene, because now you have a situation where to repeat that signal, you’re repeating in all directions,” he said. “What’s worse, in sub 6, the signals would propagate forever,” bouncing off buildings. 

“We took the lemons of millimeter wave,” – such as it only travels a short distance and has poor penetration – and used them to their advantage.

“Those are great things because it allows us to re-use the spectrum over and over again” and to deterministically position repeaters where they need to be. Because the frequency is so high, the antennas are super small. And it uses HBF, so it’s low cost and uses low power, he added. “We were able to take that scenario, which was kind of the perceived underpinning weakness of millimeter wave, and turn it into strengths,” he said.

Somebody recently suggested Pivotal’s competition are the high-tech companies that make phased array chips, Deutsch said, but he disagrees. The equipment Pivotal is replacing is that of Nokia and Ericsson. “Let me put it this way: I am their competitor,” he said. “I don’t know if they’re my competitor, but I am certainly their competitor.”

RELATED: Pivotal achieves 1.3 Gbps in Echo 5G field trial

Pivotal’s white paper estimates the average cost of siting a gNB, including fiber installation, at $65,000. For economic reasons, operators typically don’t want to deploy more than seven gNBs in a one-square-kilometer area. By using Pivotal’s Echo and Pivot products, deployed in conjunction with the gNB base stations, operators can reach more subscribers at less cost than deploying gNBs alone, the company says.

According to Pivotal’s modeling, the incremental cost per subscriber of adding Echoes and Pivots to achieve 80% indoor coverage is $468, versus $1,822 to achieve the same coverage from adding more gNBs.

The Echo 5G is a self-installable, on-the-window precision beamforming repeater designed to counteract the mmWave penetration, reflection and structural shadowing losses so that it can “gently flood” an interior with mmWave signal.

RELATED: Pivotal sets up shop at Luxe to show off mmWave HBF

The Pivot 5G is an outdoor network repeater that addresses mmWave coverage challenges by capturing and redirecting mmWave signals from the gNB around obstacles like buildings, according to Pivotal. By extending the range of gNBs, the Pivot 5G, can reduce gNBs capex, opex, siting costs and deployment time by minimizing the number of gNBs necessary. Plus, its small size lends itself to easier permitting and lower power consumption.

Pivotal Commware is among several companies in which Gates has invested. They each use metamaterials and HBF but are not allowed to compete in one another’s space. For example, Pivotal can’t do anything with satellites, which is Kymeta’s domain. Evolv Technology is involved in security scanners and Echodyne does radar.

Even though priorities have shifted during the COVID-19 crisis, Pivotal has been able to conduct a lot of business, with meetings shifting to telecommuting sessions, which is something telecom executives are accustomed to doing. “From that perspective, we haven’t missed many beats,” Deutsch said.