How do wireless hotspots, routers etc. go about displaying their name to devices in their range? For example, when you open your laptops network center and see named wireless connections: linksys-xxx, DIR-xxx etc. How is this message displayed exactly from technology point, what are the processes involved?

Also, would it be somehow possible to display an image or other data besides text in the same fashion? If so, would it require altering hardware or something else?

Finally, is it possible to programmatically decrease the range of your router's signal?

  • Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
    – Ron Maupin
    Aug 11 '17 at 2:35

How is this message displayed...

APs broadcast their presence via a beacon frame every 100ms. (by default. this can be disabled: "hidden SSID", and the timer adjusted.)

Would it be somehow possible to display an image or other data...

No. The beacon contains no such fields. It's purpose is to announce the availability of networks and the capabilities of the AP.

Is it possible to programatically decrease the range of your router's signal?

Most systems do have a power level setting. Consult the documentation for your specific brand of AP.

  • 3
    To be accurate, you cannot disable beacon frames. "Hidden SSID" only causes the SSID field in the beacon to use a NULL value.
    – YLearn
    Jan 1 '15 at 7:00
  • Perhaps a "bug", but I have devices that allow the beacon timer to be zero. And they do, in fact, stop broadcasting beacons. They will send a beacon in response to a probe, but otherwise are silent. (Not that I recommend messing with that timer.)
    – Ricky
    Jan 3 '15 at 0:14
  • 1
    Bug or poor design. Operating without a beacon is non-standards based operation.
    – YLearn
    Jan 3 '15 at 0:15
  • I'll go with "old" -- the one I'm thinking of is an atmel micro-controller glued to a pcmcia wireless card. I see dd-wrt won't let you set it to zero anymore.
    – Ricky
    Jan 3 '15 at 0:22
  • Old doesn't negate the fact that operation in opposition of the standards is either a bug or poor design. It just makes it an old bug or an old poor design decision.
    – YLearn
    Jan 3 '15 at 19:17

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