Ericsson aspires to deliver 5G connectivity without linking to the power grid by wirelessly powering base stations with lasers. To that end, the infrastructure vendor has teamed up with laser specialist PowerLight Technologies to develop the first base station wirelessly powered by a laser. The pair have demonstrated a proof-of-concept (PoC) test in Seattle.
The demonstration used PowerLight’s optical beaming laser powering a Streetmacro 6701, one of Ericsson’s 5G millimeter wave (mmWave) base stations. Talking to EE Times, Paul Challoner, head of network product solutions for Ericsson North America said of the test, “we’re delivering hundreds of watts of power over hundreds of meters… that’s the innovation.”
This modern technology is more akin to Nikola Tesla’s grandiose plans to transmit electricity over the air, proposed around 120 years ago, than the majority of today’s energy harvesting startups.
The high-powered laser converts photons into electric power via a photovoltaic panel. Such panels are used in solar power systems to convert sunlight into electricity. The same principle applies to laser power transmission. The electricity is then transmitted to the battery and distribution system in the base station.
PowerLight has been doing similar “power beaming” demonstrations with the U.S. military since 2019 but the Ericsson PoC is one of the first commercial applications to be shown off for its ground-breaking technology.
Cutting costs for 5G delivery
Delivering power via a laser to a base station will cut the time and cost required to get communications infrastructure in operation. “Actually getting power to the site is a big deal,” Challoner remarks, noting that operators will need to run cables to the site, may have to upgrade the electrical transformer and local distribution infrastructure, and may still have to wait “12 months for the city electrician.”
“Having the capability to do that wirelessly is great for enabling the worldwide rollout of 5G,” the Ericsson man opines. “It’s been a challenge in the industry for some time.”
The Ericsson/PowerLight PoC is still in the initial stages at the moment. The vendor, however, does have a plan and a roadmap to bring this technology to the market. “We see this being commercial in the next few years,” Challoner states.
One aspect of the technology that Ericsson doesn’t really want to talk about yet is exactly how much power is required for laser distribution. The test system was able to deliver hundreds of watts to power the PoC base station, Challoner notes.
Energy transmitted by laser in ‘historic’ power-beaming demonstration
“It’s not 100% efficient. Obviously, if you want hundreds of watts into the base station you have to send more than that at the origination point,” Challoner states. “But it’s efficient, and the efficiency percentage is increasing over time.”
Challoner won’t talk about exactly how efficient the laser system is now. “It’s still early technology,” he says.
Safety will clearly be a prime concern for the MNOs that will eventually be rolling out this system. The high-powered laser will be protected by a “safety curtain” of low-powered lasers that will instantly halt the transmission of the main laser if the path is crossed by a human, bird, or another object.
The lasers will be a line of sight technology that can be installed on rooftops and can be directed to multiple sites at the street level. “It’d be above the urban clutter, effectively,” Challoner says.
Over time, the Ericsson/PowerLight laser technology could be used to power a variety of other devices — such as autonomous vehicles, digital billboards, and drones — as well as base stations, Challoner stated. “Once you’ve built the laser infrastructure, then you apply that to other devices that are in that same area,” Challoner said.