Since the Helium network started there have been many issues with miners spoofing or faking their locations. In other words there are people who are gaming the system for more rewards.
What does spoofing mean and how do people fake their locations?
The Helium app allows you to assert your location. It actually uses the GPS on your phone to determine where you are located.
However you can override this setting and enter your location manually.
A spoofer will ‘place’ miners at a remote location where there are no other miners other than their own. That way the miners only talk to one another. So while the miners can actually be physically located in China (for instance) they appear to be in Belgium. Here is an example of that.
There was something very suspicious about this hotspot as someone noticed that all the Received Signal Strength Indicator (RSSI) and Signal-to-Noise Ratio (SNR) readings were a little too perfect.
Typically these measurements vary by quite a bit on account of radio frequency propagation in the real world. In practice radio signals are subject to interference, fading and other such effects. It’s not the same as sending signals across a cable.
*RSSI is a measure of the received signal strength in dBm or deciBel referenced to one milliwatt. The idea of RSSI extends to all wireless networks. For example RSSI is a parameter that’s monitored in Ring devices.
The greater the distance between two hotspots, the lower the RSSI. Use the free space path loss calculator to get an ideal estimate of received signal strength.
Signal-to-Noise Ratio is the ratio between the signal power and noise power at the receiver.
Variations occur as a result of the signal bouncing off objects both mobile and stationary in a dynamic propagation environment. Signal variations can be 10 dB or more. Even as high as 20 or 30 dB. This is no different than what you experience in your cell phone network for instance. A signal might be strong in one area but very weak in another that’s close by.
When you get RSSI and SNR readings that never vary – it’s a sign that the signals are not being transmitted over the air – but by a cable connected between the transmitter and the receiver. That was very likely the case with this miner.
Fortunately Helium has now started maintaining a denylist. As the name suggests, a denylist is a list of hotspots that are denied or refused connectivity to the block chain. As a result, they cannot earn HNT.
When you see a hotspot like the one above, you can report it. The people at Helium will then look into the reported hotspot. In the case of Tricky Lava Lemur this was done and now it’s not earning anything.
You are encouraged to use the Helium denylist to report any miners that you suspect of being spoofed. A human being actually looks into these before banning a miner.
A better solution would be to conduct some kind of periodic RF drive test to determine whether a miner is actually at the location its reported to be at. A drive test is a type of verification procedure where a GPS-enabled vehicle drives around a city. While driving, it records signals from hotspots along with their locations. A periodic test will then confirm the geographic location of every hotspot and prevent spoofing.
If the miner is not at the location then it can be automatically added to the deny list. This will deter location spoofing for sure.
The Helium organization is far from implementing this and as a result, we have to rely on user location reporting.
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[2] Directional Antennas for Helium