The network consists of multiple battery powered base stations and a single central controller that has an Internet connection. All of the base stations receive location data from trackers on VHF and have an UHF link radio for communication between base stations. The network is able to relay data from remote base stations through multiple hops so that all the location data is eventually received by the central node and sent to a web server.
Both the VHF and UHF parts use radio hardware and communication protocols specifically designed for needs of the system. New protocol designs are being planned to increase capacity to handle more trackers and to increase range of the radio links. Some parts of the current and future radio systems could possibly be used for other IoT, M2M and sensor network applications as well.
The schematics and board layouts have been attached to the project entry.