Amateur radio stands to gain more by leveraging the Internet as opposed to fighting it. Projects such as AREDN re-purpose commercial WiFi hardware to provide Internet connectivity over ham radio bands. Sending Internet traffic over amateur radio prevents the use of encryption and any commercial data. The result is a limited use case of AREDN to emergency communications when the Internet is not available and when non-sensitive data must be sent. This doesn’t play on any of the strengths of ham radio. We believe that Delay-Tolerant Networks are a key component to the future of ham radio that utilizes our strengths instead of applying limits.
What Are Delay-Tolerant Networks?
You might be asking yourself what exactly is a delay-tolerant network and why should you care? This type of network technology works when continuous end-to-end connections cannot be guaranteed between two or more devices. Utilizing a mixture of store and forward, ad hoc networking, and high-level routing algorithms data between devices can be exchanged even when they have no continuous path to do so. Delay-tolerant networks differ from mesh networks because mesh networks provide live connectivity through changing routing paths whereas delay-tolerant networks remove the need for a continuous end-to-end connection at all.
Amateur Radio Applications
Our hobby provides plentiful methods of transferring data. By utilizing our assets consisting of HF, VHF/UHF, and microwave links along with AMSAT satellites we can provide the last mile of communications where the Internet does not reach. By connecting a delay-tolerant network to the Internet we can bridge the gap from one mile to three-thousand miles depending on the band used while utilizing the reliability and bandwidth the Internet provides. This ideology uses the Internet to strengthen our hobby.
Use Case: Remote Communications
Imagine you are camping in Joshua Tree National Park here in Southern California. There’s a great 4×4 off-road section named the Geology Tour Road and your campsite is in Pleasant Valley which is absolutely beautiful. There is a catch, however. You are surrounded by mountains and there is no cellular network connectivity whatsoever. This is off the grid.
You’re camping and want to send a picture to a friend back in Los Angeles, CA but you have no communications from the campsite. Instead of hiking to the nearest mountain top which can be dangerous and exhausting you simply wait. The Faraday radio you brought along only has a 5km radio range since the mountains block you in all directions. That’s the red circle below. A truck comes out to Geology Tour Road and is carrying a Faraday radio as well. As it passes inside your radio horizon communications are established and the image is stored inside the truck as it drives along the green line back towards Twentynine Palms, CA.
Once in Twentynine Palms, the trucks radio sends the image to a Faraday base station which then forwards the data over the Internet to your friend. This is one hour after you sent the image. Your friend responds immediately. The network knows you were in the vicinity of Joshua Tree National Park so the response is therefore routed to the area via the Internet. Along comes a second truck also carrying a Faraday radio which enters the park from Joshua Tree, CA. Our delay-tolerant network sends the response to this second truck for the ride into the park. As this second truck follows the blue line on the map above it then enters within range of your campsite radio and you receive the response. This took an hour from the time your friend responded. Two hours have passed but communications were made!
The Power of Delay-Tolerant Networks
Delay-tolerant networks cannot be compared to the Internet. They serve a completely different use case where communications are intermittent. The power of these networks is in the application of them. Ham radio’s killer app might be the use of a delay-tolerant network! In Joshua Tree there are two options to provide connectivity into the valley with one being to establish an infrastructure there and another to use delay-tolerant networks. Building infrastructure is hard, costly, and slow with traditional solutions. Ham radio can use a delay-tolerant network to expand a digital infrastructure far beyond what is feasible in the hobby today.
The Internet is extremely reliable. Cellular networks are fairing better through disasters such as Hurricane Harvey. It’s not infeasible to imagine the cellular network being less vulnerable to natural disasters as time progresses and technology marches forward. Ham radio has a place in emergency situations but that place appears to be dwindling in terms of technological capabilities. For amateur radio to establish a foothold on the forefront of technology it needs to play its strengths, not weaknesses. Delay-tolerant networking appears to be a technology that can propel the hobby to the front of the pack.
What do you think about this topic? Let us know!
Subscribe to Blog via Email
- TAPR – Delay Tolerant Networking In Amateur Radio
- Delay Tolerant Network – Car-to-Car Emergency Networking
- Ham Radio Delay Tolerant Network – Georgia Tech Paper
- NASA – Disruption Tolerant Network Website
Author: Brent Salmi
Co-founder of FaradayRF and an electrical engineer working in the aerospace industry in Los Angeles. I’m a General class amateur radio operator (KB1LQD)