Breaking Through Weather Barriers, Attochron Tackles the "Last Mile" Problem with Lasers

Breaking Through Weather Barriers, Attochron Tackles the "Last Mile" Problem with LasersMillions of people and businesses worldwide lack access to broadband internet because they lack that final connection to the internet backbone. This critical link can range from meters to kilometers, but high costs or difficulties in construction make it challenging, especially in rural and remote areas where topography is a barrier or user density is low

Breaking Through Weather Barriers, Attochron Tackles the "Last Mile" Problem with Lasers

Millions of people and businesses worldwide lack access to broadband internet because they lack that final connection to the internet backbone. This critical link can range from meters to kilometers, but high costs or difficulties in construction make it challenging, especially in rural and remote areas where topography is a barrier or user density is low. A potential solution comes in the form of "free-space optical communications" (FSO), a technology that uses lasers to transmit data through the air. This technology, first developed by NASA in the 1960s, has been touted as a potential game-changer for internet infrastructure for decades. However, it has been plagued by an unavoidable obstacle: weather. Fog, rain, even simple air turbulence can disrupt the signal, and a clear line of sight needs to be maintained between the transmitter and receiver. Thus, while FSO broadband, unlike radio signals like 5G, does not require licensing or regulation, it has not yet seen commercial success.

Now, Attochron, a Virginia-based company, claims that after over 20 years of development, it is ready to launch a commercially viable service.

Challenge of Cutting Through Fog and Rain

This July, Attochron closed a $15 million funding round. The company says it has begun low-volume production of its primary hardware product, ALTIS-7, which includes a receiver and a transmitter resembling a surveillance camera. Attochron plans to ramp up production early next year in preparation for a commercial launch. To demonstrate the technology, Attochron partnered with telecommunications company Lumen and an unnamed Fortune 200 retailer to conduct a three-month proof-of-concept trial. The laser link achieved 1.25 Gbps data speeds over a 1.5-mile (2.4 kilometer) distance. Attochron says it has achieved speeds exceeding 10 Gbps, comparable to the fastest fiber-optic business speeds.

This breakthrough is a long time coming. Established in 2002, Attochron has yet to release any products or services, a testament to its perseverance, according to CEO Tom Chaffee. He calls it "the classic example of a belief in a good idea that was not yet realized." Chaffee said that after receiving an angel round of funding in 2004, the aftermath of the dot-com bubble slowed Attochron, which was kept afloat by friends and family. "Operating funds were typically very low, sometimes only $50,000-$100,000 per year, and that had to cover everything: personnel, consultants, testing and measuring hardware," he recalls. "That situation persisted for 10 years until the business secured its first private equity funding, which was a hard-earned success that established a solid foundation of understanding of FSO physics and a team that was willing to walk through a long tunnel of challenges."

In 2012, Chaffee moved the company to its current base in Lexington, Virginia, a location that experiences frequent fog and other weather conditions that tend to be unfavorable for FSO. "We have wide variations in wind speed and rain." he says, "But here's the thing, and I don't care if you believe me or not, the clearest days are actually the hardest to get laser propagation." Chaffee explains that as the laser travels through the air, even the slightest changes in temperature or humidity can impact the beam.

In short, Attochron's technology represents two innovations compared to previous attempts at transmitting data using lasers: the use of ultra-short pulsed light instead of continuous beams and the use of broad spectra instead of narrow spectra, which significantly improves signal stability. "That's been the big breakthrough at Attochron," Chaffee says. "We have about 60 or 70 patents granted and another 200 or so pending."

Attochron is attempting to succeed where others have failed. In the early 2000s, a company called Terabeam gained attention for its plans to bring a similar technology to market but ultimately failed. Google's parent company Alphabet says it has deployed hundreds of laser broadband links for end-users in rural areas of several countries, including India, Kenya, and Fiji, through a project called Taara.

Complement, Not Replacement

Chaffee believes that there are many advantages to using lasers for the last mile problem, the first being that it is much cheaper than laying fiber optic cables. He says a typical Attochron hardware package costs only $30,000 to achieve a 10 Gbps link, while fiber optic infrastructure costs between $250,000 and $1 million and takes a long time to be approved. Chaffee says that the systems can be installed on cell towers, and deploying Attochron transmitters does not require any approval process as long as the line of sight is not blocked. He also says that the devices can be deployed in a matter of hours, not months or years.

But a $30,000 10 Gbps connection is also out of reach for the average person, so Attochron is targeting businesses. Attochron will sell the devices to broadband providers and carriers, who will install and deploy them and charge users a monthly fee.

Attochron also has its sights set on applications beyond "last mile" connectivity. Military applications, for example, could benefit from highly secure data transmission if the signal is transmitted only via laser. The technology could also be deployed near airports to address the limited capacity caused by the scarcity of radio spectrum resources.

Whether the technology lives up to the hype remains to be seen, but experts see potential. While not involved in Attochron's project, Hazem Refai, Professor of Telecommunication & Networking at the University of Oklahoma, says there are advantages to using FSO. "You don't need FCC licensing," Refai says. "You just need to shoot the laser between the transmitter and receiver. All you need is a line-of-sight path." He adds that Attochron's technology is theoretically a "big improvement" over existing technology and would be a "very good achievement" if realized.

James Osborn, Professor of Physics at Durham University in the United Kingdom and also not involved in Attochron's project, says the company's technology seems plausible in theory but there are still technological challenges because the laser pulses used are extremely short, less than a millionth of a billionth of a second. He questions whether the technology might be too complex for its intended purpose and whether there might be limitations on the achievable speeds. However, Osborn also acknowledges the technology's advantages in terms of data security and its potential to solve the "last mile" problem. "It's something to watch to see where it goes," Osborn says.

Chaffee makes it clear that Attochron is not aiming to replace existing technologies. "Some FSO companies claim that they will replace fiber. We don't say that. We say that we are complementary to it," Chaffee says. "It's really an enabling technology, not a replacement technology."