how do you set up wifi to cover large area with lots of hosts?

Discussion in 'Networking' started by BlahBlahYouToo, Mar 8, 2012.

  1. BlahBlahYouToo

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    lets say one needs to accommodate 1000+ users and a square mile (school campus for instance). how would you set that up?

    you can't use a consumer WAP/router right?
    those are only good for ~254 hosts, so I'm assuming there's a more professional grade WAP that allows you to connect more hosts.

    and to cover that area, would you just scatter them evenly across the campus?
     
  2. drebo

    drebo Diamond Member

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    Any WAP is good only for about 30 connected hosts. Any more than that, and you're going to see a lot of retransmits and collission avoidance will take way too long.

    What you'll need to do is a propagation study to see how the AP signals propagate through the buildings. You'll probably want a denser deployment with less powerful signal per AP, depending on the expected densities and breakdowns of where you expect clients to be, etc.

    Decide if you want L2/L3 mobility and seamless roaming. Decide how much you want to spend. You'll definitely want a unified wireless solution.

    If you go Cisco, you'll be spending $100k on a project of that size, easy, between WLCs, APs, WCS licensing, and other required infrastructure upgrades. More if you want mesh/outdoor APs.

    If it's all indoor, you could go with a cheaper system like Ubiquiti UniFi...way, way cheaper, but has its own general issues.
     
  3. rsutoratosu

    rsutoratosu Platinum Member

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    This is good to know, so say its the same square mile, how much "access points" do you need to deploy ? I know like cablevision out here and time warner has wifi in the city but its always pretty weak, like certain area does not have good coverage.

    In a sq mile, how many of those do you need to wire up and where would you put it ? like on a post by itself, attach to exterior of buildings ? lamp post ? etc ?
     
  4. spidey07

    spidey07 No Lifer

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    I'd slam in over 100 APs with cisco lightweight solution and strongly encourage 5 Ghz. You typically don't want more than 10-12 clients on a single AP radio. It would be one large IP address space, a /21 or a /20. For outdoor areas the cisco outdoor APs are incredible - you can do wireless mesh so no need to wire them up. All others would be wired. For outdoor you'd typically hop on a street light for power.

    As far as where to place the APs, predictive modeling and site survey would determine where to put them. But this is really pretty standard stuff for something like that, the system can scale to 1000s of APs in a campus environment - it's all a single system.
     
  5. imagoon

    imagoon Diamond Member

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    Both Cisco and Aruba do well in this area (see Spidey's post.) I have personally found that it is best to wire as many as you can but mesh works out for the others.
     
  6. mammador

    mammador Platinum Member

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    Have multiple subnets, on a /24 subnet mask. this should be enough IP addresses for the entire campus, also to be scalable.

    Set up multiple access points in the campus, and to a survey to see where to place them. As for the wiring/configuration, just use basic Cat 6 cabling towards a centralised router.

    It may be best to have each major building on a seperate subnet. You may also need to speak with your IT Dept. regarding spare addressing space. I presume it's an IP version 4 block you're using, so ask them if there are any spare private blocks (in classes A or C) available.
     
  7. spidey07

    spidey07 No Lifer

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    Actually you want it all one single big subnet to support roaming. There really isn't any need to break it out as broadcast and multicast traffic is handled specially by the controllers as opposed to typical bridging. Just make it one big happy wireless network. That's the beauty of controller based wireless - it's all one big seamless managed system.
     
  8. AD5MB

    AD5MB Member

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  9. spidey07

    spidey07 No Lifer

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    Mesh is typically applied where it's too expensive to cable. Normally for outdoor. Mesh ap also have options for fiber or hfc networks. Plus it burns up spectrum got the back haul wireless links.
     
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