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IEEE 802.11 detector keychain

Oh, the connectivity!
  (+21, -1)(+21, -1)(+21, -1)
(+21, -1)
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IEEE 802.11 is a standard commonly used for wireless communication on local area networks. Wireless devices that use it can't connect to the net unless they're in an area that has the right flavor of IEEE 802.11 coverage.

Consequently, wireless devices usually have LEDs that indicate that the device is detecting IEEE 802.11 coverage (or that at least it's worth trying.)

I want this in a key chain form factor.

It doesn't have to actually implement the layer, just tell me whether it's worth plonking down my bags / getting out the palm pilot and booting.

(This is a spin-off from a device that an friend of a friend brought back from Japan - a LED in an amulet that lights up when a cellphone right next to it rings, for detecting rings in noisy places.)

jutta, Jun 21 2000

[dwater]'s link http://www.flukenet...Testers/WaveRunner/
[hippo, Sep 29 2002]

MiniStumbler http://netstumbler....cid=1&orderby=hitsD
A NetStumbler client for the Pocket PC. It's free. [bristolz, Sep 29 2002]

Wi-Fi detector ring http://www.gizmodo....tor-ring-031912.php
[jutta, Jul 21 2005, last modified Jul 04 2006]

thinkgeek: $59.99 http://www.thinkgee...ts/electronic/7374/
[jutta, Jul 04 2006]


       one of the neatest uses for the cell-detecting systems (which, by the way, have gotten down to the size of fake fingernails, LED included) was for airline stewardesses checking for illegaly operating cellphones during takeoff. walking up and down the isle, she would be able to detect some of the once-a-minute check-ins the cellphone would make with the base station...
bear, Jun 22 2000

       I've got one of those....cept the LED is in the aerial so when it rings, the LED blinks. Powered by field induction from the transmitter.
likwidnarkotix, Nov 21 2000

       Really, it shouldn't be IEEE 802.11-specific.   

       You probably couldn't do this in a fingernail, but a key fob would be OK: create a small device with enough smarts to recognize all of the major wireless signals (different forms of cell phone coverage, IEEE 802.11/802.11b, Bluetooth, old and new Ricochet, GPS, other satellite signals, ...) and activate blinkenlights appropriately.   

       Unfortunately, there's a technical problem. The cell phone detectors work by simply detecting the high-power signal from the cell phone (which is answering the cell tower to say "Yep, I'm here, I'm ringing, don't pass the call off to voice mail quite yet"). A hypothesized 802.11 detector (let alone my more general hypothetical device) would have to pick up much weaker signals.   

       Worse yet, a cell phone ring detector can simply look for any energy in a certain band. However, 802.11 shares the unlicensed ISM band (2.4GHz) with lots of other unrelated protocols. So this keychain *would* have to implement an awful lot of the physical media layer just to tell one kind of spread-spectrum digital noise from another.   

       Of course, what I *really* want is a headset I can put on that will let me visually *see* these signals. Using wireless gadgets, I often feel like a blind man with a photometer. I develop all sorts of voodoo about how different kinds of walls block various transmissions, and "shadows" and "reflections" and "multipath", and the locations of towers and the directionality of their antennas and so on... for once, I'd like to put on some glasses and *see* all this stuff.
egnor, Nov 22 2000

       I have also thought such a device would be useful. I use 802.11b on my laptop, and with places like Starbucks and various airport waiting areas, and even some airplanes promising to broadcast 802.11b, it would be great to see if there is indeed an 802.11b network availible before digging out the laptop.   

       egnor is correct, this device would have to implement at least some aspects of the layer to detect if it is a public network, or if it is encrypted (and you need a password to join), or even if it is hidden and you need to know the name of the network to even detect it on the laptop.   

       I would be happy if such a device was palm sized.   

       Did you mean to say laptop instead of palm pilot? Because I personally would be happy if this device was palm sized.   

       Actually, with the right software, and this springboard module   


       you could have a hand held 802.11b detector.   

       (if you did indeed mean palm, mea culpa. Is the above card the method that you are using to get to an 802.11b network from the palm?)
dodono, Jun 21 2001

       Hmmm, how about this? Get 10 of the cell phone signal strength detectors. Put a filter each of them, passing the bandwidth of one of the frequencies used in 802.11 frequency hopping. To improve accuracy & avoid random microwaves, you could put in some sort of timer/adder/magic so that the LED wouldn't blink unless the RF was toggled at a certain rate. When all of those LEDs on your hat,belt or laptop case start blinking it's time to pull out the laptop & see what flavor of spread spectrum is in the neighborhood.   

       Or you could go the other route & have some sort of docking station for your 802.11 card. It could be smaller than the pilot & have just enough smarts to put the card into sniffer mode & look for an arp string. How big is your keychain?
tenhand, Jun 22 2001

       (FWIW, the high speed (11mbps) version of 802.11 is direct-sequence, not frequency-hopping.) I think your device would be a better indicator of 802.11 if only one of its LEDs were blinking, indicating a single 802.11 cell. If they're all blinking, it probably indicates a more wideband signal, like bluetooth or a leaky microwave oven.
wiml, Jun 22 2001

       I have been skipping round Asia; in various airports and hotels, and even shopping malls.   

       I would love for there to be an 802.11b detector, but I haven't found any such thing to be available.   

       I'm sure it wouldn't take too much more than the size of a PCMCIA card to implement this.   

       Personally, I'd like it to be on a wrist watch - I was about to ask Casio to do one....perhaps I will.
dwater, Sep 29 2002

       Found this: [Admin: URL moved to 'Links' list] which might do the job, albeit at a cost.
dwater, Sep 29 2002

       Or download a copy of ministumbler and run it on a pocket pc.
bristolz, Sep 29 2002

       I'm just paging randomly through old ideas here, and I stumbled on this one from 2000.   

       I own two.   

       Isn't technology wonderful? Let's all give Jutta a hand here and speculate what else is going to get Baked as time passes!
gisho, Jul 04 2006

       does that mean, now that it's baked, that it becomes an M.F.D. ?
xenzag, Jul 04 2006

       No. "Baked" isn't grounds for deletion; only "widely known to exist" (at the time of inception) is. I.e., the poster needs to get out more. Not that this isn't true for most of us.
jutta, Jul 04 2006

       Browsing categories, I clicked this to check if somebody had already said it was baked. Then I noticed it was posted way back in 2000. I haven't heard more than a single mention of such a device since before 2007 (when the iPhone came out). (That mention was in the novel Little Brother (2008).)
notexactly, Nov 14 2015


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