Since our system uses submaps, the range of the map can be anything in terms of ultrasound coverage. Submaps ≈ cells.

Think about our system in terms of cellular networks: your cellular network’s cell can be from a tiny 50-meter or so picocell to a large tens of kilometers macrocell – depending on the band, base station, height of the antennas, environment, surroundings, etc. What is the “range” of the cellular network? – it can be virtually anything, depending on the number of cells and their coverage. The same is with our system. The “range” of the map in terms of ultrasound can be anything. If you want to cover the whole underground country, it is possible.

Therefore, normally, when we talk about the range, we talk about the range within a submap for ultrasound. 

However, for radio, we talk about the range in terms of the map because the modem controls all beacons within its radio range since the system works in a star architecture. And on the opposite. If the modem cannot reach the beacon over the radio, it cannot control it. The radio range of the modem-beacon link limits the size of a map. Thus, if you want to increase the radio range of the system, you need to first improve your modem’s antenna. Thus, you will increase the range toward all beacons.

In order to have networks of practically unlimited size, we use super-mops. They are the maps of maps. Super-Modems of each map are controlled by a super-super-modem of a super-map via a backbone that can rely on multiple physical interfaces from 4G/5G to WiFi and even RS485. See more in the Multi-Modem Architecture.