Throwing this out for ideas, feedback, and help with any development required.
Establish a wireless communications network in the area pictured. Primary uses are simple communication, and updates of location for safety, weather, and mechanical issues relating to boat and overland travel.
FEATURES + PRIORITIES
- HIGH - Text/SMS messaging between devices
- HIGH - GPS Location
- HIGH - 2 people with communication devices
- MEDIUM - 7ish people with communication devices
- MEDIUM - Web or Android and iOS device access
- MEDIUM - Relay of real-time location between devices
- MEDIUM - Voice calls
- MEDIUM - Email
- LOW - Internet
- Super easy for end-users
- No paid subscriptions (decentralized)
- There is no cell coverage in this area
- Low power - There is no electrical grid in this area
- Extreme low temperatures - In winter, temperatures reach -40 (C/F), and most batteries perform poorly in this range
- Low solar - This is 65°N. In the winter, the sun is at too low an angle to clear the trees in the valley. Some sun reaches the hills, but there is often significant cloud cover in winter months.
- Low wind - Similar to solar, the locations on the river valley get low wind. There is wind that gets funneled across the hills, making wind power potentially feasible.
The red markers are locations that offer a good representation of locations which would need to receive signal. The blue markers are potential spots to drop repeaters. The black lines and numbers represent the distances between repeaters and the farthest locations on the current spec.
IDEAS + CONCEPTS
- LoRa / LoRaWAN - Long-range and low-power radio transmission in the 900mhz band. Relatively inexpensive hardware ($20-$50 ea.). Theoretical range 100+ miles line-of-sight (LOS). Practical range .5-5 miles at same elevation. Performance significantly increased with repeaters at high elevation
- The videos above can likely be simplified by using different ESP32 modules. For example: Whereas the above proofs of concept require multiple boards, the TTGO T-Beam has all the necessary components (Bluetooth, LoRA, WiFi, ESP32, 18650 LiPO holder, battery charging) integrated onto one $25 board.
- goTenna (Mesh, Mesh Plus, Pro) - This project is already existing, and would not require any development on our end to resolve the high-priority goals. They do have a free and open SDK available. On the negative side, they have low (~3.5 star) reviews on Amazon and the Android app. The devices are roughly $70 each. With an annual subscription, these can link out to the external internet, and provide SMS integration with regular phones and tracking maps.
- FRS / GMRS / Marine radio - These options could handle voice relatively cheaply. Unsure of legality of repeaters on these bands. Generally speaking, these are free and unlicensed bands. Unsure of legality of transmitting tone-based text messages on these bands.
- HAM radio - The text messaging could be handled via APRS (HAM). The huge negative is that this would require everyone using devices to have a HAM license. Another negative is that all communication must be public, totally unencrypted, and non-commercial.
- Baofeng UV-5R radios for FRS / GMRS / HAM - Inexpensive radios which can be programmed to work in licensed or unlicensed bands. We already have 2 at camp, and potentially have access to 3 more at no cost. Repeaters can be built with 2 radios. In theory, 2 repeaters (for a total of 4 radios) could be installed, and this could scale uup to any number of users simply by adding 1 radio per user.
- AREDN - Decentralized network which also can connect to internet. Uses relatively easy to acquire WiFi networking equipment. Works in bands which require HAM license. Can be used for all normal internet protocols for voice, chat, email, media streaming, etc.
- LibreMesh (or other community WiFi mesh) - Works on standard WiFi access points with custom open source firmware based on OpenWRT/LEDE. Can be used for all normal internet protocols for voice, chat, email, media streaming, etc.
We already have FRS / GPRS / Marine radio working, but without repeaters at higher elevations, the range is not very useful. It wouldn’t be very difficult to build a couple UV-5R repeaters to provide full coverage in the required area. We would have to look into the legalities of repeaters for the various spectrums not requiring licenses. Also, the relatively high power use of these radios would likely mean that the system would fail in the winter due to freezing batteries.
Adding the simplest LoRa implementation to the radio option in the preceding paragraph may be the simplest and most open/flexible path. The rub here is that it would require significant hardware and software development time and energy. I think this is withing our capabilities, but it may not be “worth it”.
Adding goTenna Mesh devices to the radio option above would be the simplest, but may ultimately be unstable. This would require at least 2 devices to mount as repeaters. The power use may be low enough to work in the winter when batteries begin to fail.