I'm of the opinion that communication is essentially we currently call cellular networking, and that it works the same. There is one hitch... in the future there is no voice, its all data. (Its already pretty impressive how little communications is based on voice.)
From the rule book, Page 243, Complex Action: Trace Icon.. I dunno, its wireless, I'd make it vaguish, a sphere, 100 meters X noise? Jacking in physically, should be 100% accurate to the location of the jack, but cables come in all lengths.
Now the fun begins, seeing who's there. Remember Folks wanting to be hidden can probably do it. You'd need a decker\rigger capable of locating icons, and sending a fast drone to go hunt. Perhaps its a regular vehicle containing a variety of drones like MCT Flys, and perhaps a few aggressive drones. Now this is a physical perception issue. Unless he Decker\Rigger is there it would be impossible to distinguish if someone else was using that icon in the area. (Maybe the decker\rigger is in one such vehicle, like a one man copter, so he can go and see the icons there.)
By the rules, I don't think there is a way to safely do this with automated drones. Specifically the drone would need to have Decker skills like Matrix perception, and that's not possible. A truly obnoxious opponent would possibly put a wrapper on his icon, or even the truly devilish would do that to all the icons near by. Even more devilish do it at place full of people jacked in.
True Story: 15 years ago, Ricochet Communications was used for one such network hack. The FBI was trying to catch someone making illegal stock trades. They located the gear approximately on the network, then got out and looked. (In this case they used the company's wireless engineer and an RF sniffer.) They quickly converged on a shipping container with a power feed from a nearby pole. The container contained... a short cable to a another wireless device.