Heard of this a little while ago, guess its still around.
Haven't been exposed to it myself yet, but its one reason I tend to have the bandwidth meter up when I expect I could possibly encounter players (ctrl+b, i think)
It displays uploading bandwidth and downloading bandwidth, as soon as a player share instance with you this jumps from a couple of KB/s to a few Mb/s, and is as such functional as an early warning system since you would only see players if they where otherwise in sensor range (at most 7km, if I remember correct).
In Mobius this simply means time to say hi in local chat
It also helps to quickly diagnose broken wings/instances etc.

Hey I'm Thor -
People call me Bob.
Rule 1: Pillage. Then burn.
Rule 2: No such thing as overkill, as long as there are reloads.