Accelerating rural connectivity analysis: How Fb helps deliver connectivity to hard-to-reach areas

All photos from locations in Peru, taken by our partners at Mayu Telecomunicaciones, are used here with permission. To request permission to use the photos, contact [email protected].

Facebook Connectivity’s mission is to enable better and broader global connectivity to bring more people online to faster internet. We work with others in the industry – including telecom operators, community leaders, technology developers, and researchers – to find scalable and sustainable solutions. A major research area of ​​interest is rural connectivity as many rural areas around the world still lack access to mobile connectivity and technological innovations are required. An important element of rural connectivity is backhaul, the connections that connect remote locations to the core of the Internet. The wireless backhaul with microwave radio offers a cost-effective and fast deployment compared to other options.

Nowadays the design of microwave backhaul is based on clear line of sight (LOS) requirements. In rural areas, the lack of LOS between settlements unfortunately means that a repeater or reflector has to be built, which leads to cost constraints. In this project we investigate the use of diffraction, a physical phenomenon by which some wireless signal energy is bent into the geometric shadow of the obstacle. If diffraction can be reliably predicted, it can be used to design and build wireless backhaul connections in challenging environments, reducing the need to build repeaters and making network design more efficient.

Example of a physics-based model for modeling the signal propagation that shows that part of the signal energy is diffracted into the shadow area

Illustration of how diffractive NLOS wireless links can reduce the need to build repeaters

To meet this challenge, Facebook Connectivity has developed a research partnership with partners from universities and industry. We realized that we needed field data that could be used to validate and calibrate signal prediction algorithms, improved methodologies for network design, and an assessment of the real impact on cost recovery. To facilitate knowledge sharing and collaboration, Facebook Connectivity organized a series of meetings, including a workshop in 2019. In this workshop, Omar Tupayachi Calderon (CEO of Mayu Telecomunicaciones, a rural mobile infrastructure operator in Peru) said, “Peru is incredibly diverse 60,000 rural settlements still lack broadband connections. We need your help.”

Bring rural connectivity to Peru

Universidad Politécnica de Madrid (UPM), Ohio State University (OSU), Air Electronics and Plexus Controls developed instruments for measuring signal propagation in difficult terrain and carried out systematic experiments in southern Ohio, in areas near Madrid, Spain and in the south from Ontario through, Canada. The University of Michigan, George Mason University, OSU, and MIT developed propagation models that resulted in a number of publications and open source software.

Experimental data and setups used by OSU and UPM (click to enlarge)

The complete solution set developed by Facebook comprised an end-to-end workflow for link design, network planning and site provisioning, which we publish as a service solution as a white paper in the Telecom Infra Project Network project group.

Pictures of Mayutel’s rural Peru mission (click to enlarge)

Scale the solution

In order to make the solution usable in as many parts of the world as possible, Facebook has taken a few further steps:

First, we worked with OSU and George Mason University to make a MATLAB and Python version of the Irregular Terrain Model and Longley-Rice Algorithm available as free, open source software.

Second, we expanded the collaboration to include Contract Telecommunications LTD – the makers of Pathloss, the world’s most widely used microwave link planning software – to implement the results of this project into their platform.

Third, with Plexus Controls, we have developed a drone-mounted measurement kit for field devices that allows experimenters to collect field data economically and developers of connectivity infrastructures to check the signal strength on site before building their locations. We have also developed software for data visualization and basic processing. The drone and software are designed to make field experiments and validations faster and easier than ever before.

Fourth, as the Service Solution Group, we bring our findings to the Telecom Infra Project Network.

Finally, we have expanded our partnership through collaborations with TeleworX, Internet for Todos (IpT) in Peru and Mayu Telecomunicaciones (Mayutel). IpT de Peru is a major network operator that is significantly expanding broadband access in rural parts of the country. IpT was founded in 2019 and to date has provided hundreds of broadband locations in rural areas of Peru. IpT has successfully deployed dozens of NLOS connections on its network, offering both endpoint and backbone transport connectivity. Mayutel is working with local communities in rural Peru to build telecommunications sites, deploy 4G radio systems and, for the first time, provide broadband connections to many communities.

Learn more

As we look forward to taking this solution to other parts of the world, check out our publications to learn more about the technology behind this project:

• Diffractive NLOS microwave backhaul for rural connectivity
  Julius Kusuma, Erik Boch, Philip Liddell (Facebook Connectivity)
• Development of measurement and modeling methods for diffractive wireless connections in the vicinity of LOS
  José Manuel Riera, Santiago Pérez-Peña, Marta Castiella-Fernández, Pedro Velasco-de-la-Fuente, Mateo Burgos-García, Pedro Garcia-del-Pino, Luis Mendo (Polytechnic University of Madrid, Spain), Julius Kusuma, Erik Boch (Facebook connectivity)
• Gabor frame-based economy and radiation limit conditions for parabolic wave equations
  Max Bright, Eric Michielssen (University of Michigan at Ann Arbor), Julius Kusuma (Facebook Connectivity)
• Hybrid Parabolic Equation – Integral equation solver for analyzing the propagation over long distances over complex terrain
  Eric Michielssen, Max Bright (University of Michigan at Ann Arbor), Julius Kusuma (Facebook Connectivity)
• Improving rural connectivity coverage through diffractive wireless backhaul without line of sight (NLOS)
  Julius Kusuma, Erik Boch (Facebook Connectivity)
• itmlogic: Longley and Rice’s irregular terrain model
  Edward J. Oughton (Oxford University; Cambridge University), Tom Russell (Oxford University), Joel Johnson (Ohio State University), Caglar Yardim (Ohio State University) and Julius Kusuma (Facebook Connectivity)

For more information on NLOS in the Network-as-a-Service Solutions project group at Telecom Infra Project, please see our recently published white paper on the subject. More information on the Telecom Infra project can be found on the website. You can also find more initiatives on the Facebook Connectivity website.