You heard it on the Terragraph: Facebook’s 1Gbps Wi-Fi breakthrough

14 Apr 2016

Facebook outpaces the telecoms industry to come up with new unlicensed spectrum technologies that bring 1Gbps speeds to cities and rural areas

Facebook is planning to transform telecoms as we know it with a new 1Gbps wireless technology it calls Terragraph, which will bring fibre-like speeds to users in dense urban areas.

As if mobile telcos and even fixed-line providers weren’t wary enough of over-the-top (OTT) social network Facebook’s ongoing shake-up of telecoms, ranging from Messenger and WhatsApp to attempting to make phone numbers defunct, things are about to get very interesting indeed.

Not only does Facebook plan to bring low-cost broadband to remote areas using flying drones, but it is building an entirely new way to connect to the internet, employing millimetre-wave technology to connect buildings in dense urban areas to the internet without fibre.

At F8 yesterday, Facebook revealed that its Connectivity Lab is working on two new terrestrial systems focused on improving the speed, efficiency and quality of internet connectivity, Terragraph and Project ARIES.

Terragraph is a 60GHz multi-node wireless system that can introduce WiGig, an enhancement of Wi-Fi that can lead to 100pc street-level coverage of gigabit Wi-Fi.

Project ARIES (Antenna Radio Integration for Efficiency in Spectrum) is a transmission technology that wants to increase the number of bits transmitted per unit of radio spectrum and which will complement the onset of 5G.

“While solutions such as GPON optical fibre can provide hundreds of megabits up to several gigabits of capacity, the high costs associated with laying the fiber makes the goal of ubiquitous gigabit citywide coverage unachievable and unaffordable for almost all countries,” said Facebook’s Neeraj Choubey.

“Similarly, conventional means of increasing the capacity of wireless networks, such as licensing more radio frequency spectrum or installing more base stations, are costly and difficult in both urban and rural areas.

Terragraph to usher in 1Gbps wireless in cities


Terragraph will bring 1Gbps speed to street level

Facebook said that 60GHz spectrum has traditionally been avoided by the telecoms industry because it absorbs high amounts of oxygen and water.

This part of the spectrum – known as V-band – is now being examined in the US as a way of deploying inexpensive nodes that can be deployed every 200 to 250 metres in built-up cities and provide inexpensive 1Gbps broadband speeds.

The technology will be intelligent enough to steer signals around interferences in big cities, such as tall buildings or high user traffic.

Choubey said that Terragraph also uses software-defined network (SDN) technology that was developed in its data centres.

“Combined with Wi-Fi access points, Terragraph is one of the lowest-cost solutions to achieve 100pc street-level coverage of gigabit Wi-Fi,” Choubey said.

Project ARIES

Facebook said that Project ARIES is the company’s focus on building spectrum efficiency into cellular networks beyond 4G and 5G.

Similar to MIMO (multiple input, multiple output) used in 4G and Wi-Fi, ARIES will facilitate the need for large arrays of antennas required in 5G networks.

Effectively, Project ARIES targets the physics challenge of future networks and makes it more affordable to deploy greater numbers of base stations.

Ultimately, it means high-speed 5G-type networks can be deployed in rural areas without the need for spectrum licensing and at much lower frequencies.

“The beamforming gain afforded by using a large number of transmit antennae may be used to overcome the large path loss associated with millimeter-wave links in urban areas,” explained Ali Yazdan Panah. “Alternatively, the beamforming gain may be harnessed at lower frequencies to provide wide-coverage connectivity to rural areas, and this is our focus.

“Given such promises, the practical and theoretical aspects of massive MIMO systems are being examined for potential beyond-4G wireless communications deployments by standardisation entities, such as the third-generation partnership project (3GPP), and by many industrial base-station and device manufacturers worldwide.”

Rollout of Terragraph and Project ARIES

Facebook said it is testing Terragraph at its Menlo Park headquarters and that it is preparing for a broader trial within the city of San Jose in California.

So far, it has been able to demonstrate 1.05Gbps bi-directional speeds across 250 metres.

“We’re working on making this technology open and interoperable via unlicensed spectrum, just like Wi-Fi itself,” Choubrey said.

Facebook also has a working testbed of Project ARIES that it says demonstrates 10-times the spectral and energy efficiency gains of 4G cellular using massive MIMO in point-to-multipoint deployments.

It said that from a recent distribution study across 20 countries, nearly 97pc of the global population lives within 40km of a major city.

“As such, we are interested in developing this technology to harness the incredible gains in providing communications to rural communities from city centres,” Panah said.

John Kennedy is a journalist who served as editor of Silicon Republic for 17 years