FOAM is a Proof of Location technology for applications needing secure location services. It enables a handshake between the location service providers and the user, proving the user’s location. Terrestrial radios and time-of-flight algorithms are used to perform localizations, and digital signatures ensure the location data cannot be spoofed. The system is completely independent of satellite-based location services like GPS.

Introduction

This has been an exciting year for FOAM. Earlier in the year, we announced the Trust Zone Program (TZP), a permissioned beta program focused on stress-testing FOAM radios (”Zone Anchors”). This beta-testing program is designed for early, qualified stakeholders aligned with the mission of the protocol to contribute to defining and refining features. The scope of refinement includes the full Proof of Location technology stack from hardware to firmware and software, our Hostel dashboard for managing Zones, and streamlining the entire onboarding process from scouting locations to installing radios, ahead of future open releases of the FOAM network.

After a busy Q3, for the the first time in FOAM’s history, there are approximately fifty FOAM radios assembled by partners forming a dozen Zones of coverage for Proof of Location testing across North America and in Europe. These radios are the “do-it-yourself” versions that can be built with off-the-shelf electronics parts. From scouting locations and assembling radios to testing and submitting results for evaluation, participant partners (”Zone Operators”) have done excellent work and continue to do so to get their Zones configured. This post is the first of a series, documenting the amazing work and progress that Trust Zone participants and the Foamspace team archived together.

*“Plug-and-play” FOAM radios that come pre-assembled are still under development, but will be the focus of a later blog post.

Scouting Locations

Before joining the program officially, applicants were required to scout locations where they could install four Zone Anchors to form a “Trust Zone”. For the beta-program, visual line-of-sight and distance of roughly 300m-4000m between each of the four locations is the recommended guideline, as well as power and internet availability.

Participants are testing in both urban and rural environments, which advances the main goal of the program to stress-test the radios in different locations and narrow down core requirements like obstructions and maximum distance. Line-of-sight between at least four Zone Anchors is especially important for the beta program because a consistent minimum of 80% packet-reception over radio across all nodes is required for localizations to be calculated.

Who is in the Trust Zone Program?

As mentioned, the Trust Zone program is designed for early, qualified testers aligned with the mission of Proof-of-Location. After reviewing a large number of applications, conducting interviews and working closely with the applicants, we onboarded a group of 12 Zone Operator teams comprised of roughly 30 individuals in total. We are excited to be working with Operators possessing a wide range of technical backgrounds and geographical locations. The expertise level ranges from tech enthusiasts to entrepreneurs and veteran professional wireless network installers. Some of the feedback from participants is below and throughout:

"The FOAM zone anchor beta program has allowed me to contribute one of the most important real-world and Web 3.0 positioning projects in all of time and space. I have followed the FOAM team since 2018 and I have witnessed the brilliance, tenacity, and perseverance of the team first hand — I trust this team unequivocally to deliver novel proof of location utility to the world.

I am incredibly grateful for the opportunity to participate in the first cohort and I suggest it for any engineers who want to help solve big problems. The team is professional, gracious, and determined. The experience is excellent and you will work directly with the best in Ethereum development, UX, hardware/electrical engineering, IoT and geospatial-tech to solve big problems.”

Required Hardware

While the Zone Anchors being utilized in the program are DIY off the shelf they still require some custom components. For the program, we developed a detailed library of documentation, called the FOAM Knowledge Base, to guide participants through the process on a remote basis.

Beta-stage Zone Anchors can be assembled with mostly off-the-shelf components that Operators obtained with provided links to Amazon and online electronics depots. Required parts included power distribution boards, LoRa transmitting chips, microcontroller boards, LTE modems (for internet-backhaul), Raspberry Pi accessories like heat sinks, weatherproof enclosures, and various cables and tools for building. In addition, our team shipped custom hardware to each beta Zone Operator, such as laser-cut PCB mounting boards, provisioned Raspberry Pis, custom FOAM FPGA Pi Hats, stencil sets for drilling, and cabling with extra weatherproofing. Procuring and shipping hardware was the least fun part of the process with supply chain delays, but everyone was excited for what came next - building the Zone Anchors!

Zone Anchors Assembled and Tested

Once Operators received all of the components, they built their Zone Anchors following a detailed assembly manual. With all the parts organized in front of the Operator, it generally took 1-2 hours to assemble each radio. The assembly process included drilling holes into the weatherproof enclosure for cable connectors, stacking electronic parts onto the Raspberry Pi, mounting the stacked PCBs on an internal board, and then connecting the various parts with cables.

The next step was to power on and connect the Zone Anchors to the internet for the first time. This was when the firmware was flashed onto the hardware, and SSH keys were applied to the Zone so each node could be remotely and securely connected to by the Zone Operator. Quick diagnostic tests were also run to ensure everything was functioning. In a minority of cases, sensitive parts like FOAM FPGA Pi Hats needed to be replaced. Check out a great video of assembly here.

From here Zone Anchors are tested outdoors at selected installation locations. This step is referred to as “pre-installation testing”, since it was required before installing the radios permanently. This testing is critical, because it verifies that each Zone Anchor was receiving sufficient transmissions from all other Zone Anchors in the Zone to calculate localizations. All four Zone Anchors had to be consistently receiving a minimum of 80% of data packets from every the initial four Zone Anchors in the Zone in order for their internal clocks to be synchronized enough to generate localizations. This technical limit is the reason for the beta-program’s distance and line-of-sight requirements. However, the results may teach us to adjust these guidelines for future releases. For example, in early testing, we have seen better penetration through thick foliage than we initially expected.

During one of the recurring monthly TZP Operator Collaboration Calls, we took time to explain pre-installation testing (slide illustrations above), while the detailed steps are additionally documented in the FOAM Knowledge Base.

Pre-installation testing also allows operators to hone in on optimal, specific spots at their locations to place their antennas (e.g. on the northwest corner of their roof). Sometimes, moving an antenna only a few feet can make a huge difference in the signal reception or transmission, even if both spots appear to have the same line-of-sight. We saw many more cases of these types of adjustments resulting in the reception improving, than operators needing to find completely new locations for their Zone Anchors.

“Building [the radios and seeing them work] is one of the more rewarding things I have ever done.”

“The Trust Zone Program has been an excellent experience…We are thrilled to be a part of initial zone testing, and are excited to begin testing the software tooling that the FOAM team has built.”

Zone Anchors Installed

Once pre-installation testing was complete, operators installed their Zone Anchors permanently, and connected the units to a consistent source of power (the pre-installation testing is often done on battery only). The Zone Anchors are “power-agnostic”, meaning they can be powered by anything with a 12V power supply, whether that is an outdoor (GFCI) electrical outlet, Power over Ethernet (PoE) or Solar. The same is true for internet, as the design supports any method of internet-backhaul, whether that is LTE modems (”hotspots”), WiFi or wired Ethernet. Of course, any available ISP can be used. There are operators using data plans from common carriers, and also teams using more decentralized options.

Once a Zone is installed, automated testing is scheduled daily. Dynamic localization experiments are next. These are aimed at localizing moving objects within a Zone. Hand-held LoRa radio transmitters developed by the Foamspace team will be localized in experiemtns. Operators will hold these transmitters and walk pre-plotted paths within their Zones to generate localization data. Different routes and paths will be tested and analyzed. The lessons learned will inform refinements to the technical stack, from hardware to firmware and software. They will also drive Zone setup procedures and guidelines for later releases of the FOAM network.

Now that Trust Zones are beginning to come online testing will start to become gamified and competitive, with leaderboards and additional rewards issued to winners of specified challenges.

“Working with the FOAM team has been an amazing experience for all of us at Athena Protocol(AP). Our work to bring integrity and equity to data collection processes involving IOT and edge computation pairs really well with the work FOAM is doing on proof of location. Relying on centralized gps services is a no go for us at AP. The types of automated incentive mechanisms us and our partners are looking to build can’t afford the fallibility of those types of legacy technologies. Participating in the TZP has been a great opportunity for us, and has connected us with other amazing projects and people working in similar spaces. Personally , I have learned a lot from the people at FOAM. Ryan and Coleman are really patient and just great to work with. We look forward to building with FOAM for a long time to come! “

Conclusion

Since the start of the Trust Zone Program operator teams have been selected and onboarded, sourced parts, and assembled, tested and hard at work installing Zone Anchors.

There is no one size replacement solution for GPS. A new ecosystem of Positioning, Navigation and Timing services is needed to complement and or work independently to back up increasing reliance on vulnerable GPS infrastructure. FOAM will be a part of this emerging ecosystem and service applications that require fraud proof location claims and interoperability with smart contracts and provide a protocol that unlocks unprecedented use cases.

The Trust Zone Program is only the beginning of Proof of Location. The following Trust Zone Program blog Update will dive deeper into localization experiments being run on Zones in the Hostel web app and outline the details and progress hardware developments for next steps for the Trust Zone Program. Stay tuned. 📻