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WLAN Visualization Meets GIS Mapping

Posted by ryuzaki0 on from the pat-metheney-meets-wifi dept.

martin dodge writes "The Wireless Ntwork Visualization Project (Univ. of Kansas) has an interesting alternative to just dot maps of wlan base stations. These guys are mapping out the zone of availability using gis. nice maps using aerial photographs backdrops as well. If you are interested, check out other ways of mapping 802.11b network infrastructure. "

4 of 86 comments (clear)

  1. Re:I love it! by Chairboy · · Score: 3, Interesting

    I have a question about the specific mechanics of this: What is the behaviour of 802.11b cards passing multiple nodes at high speed?

    If you're driving down a highway with continuous 802.11b coverage and all the APs are set up to allow external access using some common agreed upon collection of settings (no WEP, a standard network name, etc), how well would a card support switching from AP to AP within seconds of each other?

  2. my little project at UCSD by ghamerly · · Score: 4, Interesting

    Last year i took my laptop & gps & a few perl scripts and mapped out the wireless access at my campus (UCSD). I made some maps too. Pretty fun!

    http://www.cs.ucsd.edu/~ghamerly/wireless.html

  3. Secuirty related questions. by Matey-O · · Score: 3, Interesting

    Can anybody comment on the following:

    Linksys (and other folks) have a flag that disables the SSID broadcast 'feature' of their basestations.

    According to netstumbler.com:
    "Linksys' latest firmware update for WAP11 includes closed network support. It disables the SSID beacon broadcast and as a result no longer shows up on either the Boingo or CyberPixie roaming clients, nor on Apsniff or NetStumbler network discovery tools. "

    Is this REALLY a security 'adder' or can folks discover the network in other ways?

    Our .11b network has 128wep, MAC list restriction, and SSID broadcast turned off. I realise that someone can sniff the traffic and decrypt the packets by cracking WEP, but this would otherwise prevent them from doing something ON the network, right?

    We're investigating adding our VPN to the mix, but it's a non-trivial network topology change for a group that really doesn't have sensitive data.

    --
    "Draco dormiens nunquam titillandus."
  4. Re:I love it! by GoRK · · Score: 3, Interesting

    I have actually done seamless roaming while streaming video at 75mph with the breezecom equipment. I believe that technically very high roaming speeds are possible with more dense configurations of AP's.

    The first problem is that the breezecom stuff is FHSS which is a little bit easier to "roam" than DSSS, simply because you can hear neighboring AP's without having to switch channels as you do with DSSS, thus you know more about neighboring AP's.

    The next problem is that the network has to be specially designed to support roaming clients. It has to have intelligence on the ethernet side of the AP's to teach the network about roaming client routing, so that packets always get to where they need. In large WLAN's, AP's are all rarely connected via a 100mbps backbone or the like. They are often connected with layer 3 switches, or worse -- routers, such that roaming is near impossible anyway without using special client software that implements MobileIP (or even ipv6)

    The final problem with the way that breezecom does it is that their roaming is proprietary. The AP's preauthenticate clients before they show up, saving time after switching. It's not compatible with 802.11, though "regualr" 802.11 FHSS cards can indeed roam on breezecom equipment.

    The fast roaming modes do not work on the breezecom direct sequence 802.11b equipment. You must be going 5mph or practically 10mph to roam seamlessly (ie without a data stream interruption) on this equipment.