Outdoor setup critique and antenna ideas wanted

Discussion in 'Networking Issues' started by Team140, Oct 17, 2005.

  1. Team140

    Team140 Network Guru Member

    Hey gang,

    I'm looking to setup a wireless network between three buildings that are perfectly in sight of each other. Here's a quick and dirty diagram of what I'm looking at:

    The primary location is where the cablemodem and primary WRT54G will be located. The other two locations are 800' and 400' away and at a 45* window from the viewpoint of the primary WRT54G. I will be using WRT54Gs at all locations.

    I was able to walk to the 800' location with my laptop and was still able to connect to the WRT54G's configuration page, although the signal was very low. The 400' location has a decent signal.

    Each location will probably house one wired PC, although I may make them wireless just to make installation easier. I'd also like to be able to keep wireless at each point so I can meander around with my laptop and connect anywhere.

    I'll probably use DD-WRT on all three and set them up WDS style.

    Any comments on the specifics for this installation for the WDS configuration?

    What about antennas? How well do the Linksys 7dB antennas increase range? Any suggestions for antennas or anything to make the system pretty reliable? It doesn't have to be critical, but having to adjust something or reboot routers every day would suck.

    Thanks in advance!
  2. Team140

    Team140 Network Guru Member

    no input from anyone?
  3. crawdaddy

    crawdaddy Network Guru Member

    if the stock antennas work that well, adding the 7db antennas would only improve it. Also, since they are omnis, you can roam around with ur laptop all u want in the area.
  4. mesu55

    mesu55 Network Guru Member


    I ran similar tests both with the standard antenna and the 7db. I got fair results at 4 to 600 ft. but not enough to trust it as a good connection.

    You will not need much in the form of high gain but directional will do you well.

    I have a triangle network with each point 1600 to 2000 feet apart.
    I must use point B as a repeater since the other two points do not have a clear LOS. I have NO Internet so none of my units use the WAN port.

    I run a 15db grid antenna (point C output 40MW) using WDS to connect to Point B about 1600 ft. away with very good results. I still need to tweak to see if it gets better but I am transfering files both ways at up to 11 Mbps.
    The 15db Grid antenna cost was about $70.00

    Then my data goes through the POINT B bridge and the final result is about 5.6 Mbps.

    Point B output 30MW is a 90 deg 17db Panel antenna ( about $170.00) and is point to multipoint to points C and A which is about 1800 ft. away.

    Point C is a 12db Omni w/3 degree downtilt with output of 40MW.
    Omni cost was about $69.00

    I am using the DDWRT22r2 firmware so I can get more flexibility overall. My WRT54G units are 1 Ver2.0, 1 Ver 2.2, and 1 Ver 3.0.

    ALL are set to be wired and wireless LAN/AP and use WDS to bridge the distances. Of course my areas have different AP needs so a grid for AP is not the best solution if you want area coverage.

    HINT To get the CORRECT MAC addresses to use in your WDS settings, go to the status/wireless window in DDWRT firmware. Get the MAC shown there, NOT the mac shown on the box. This mac will be 2 digits higher than on the box.

    For your needs a small directional panel antenna should work or the grid.

    For securety the small beamed directionals will lessen the area coverage and focus your power where you need it.

    I am no expert but this seems to work so far.

    hope this helps,


    Thanks in advance![/quote]
  5. Team140

    Team140 Network Guru Member

    Thanks guys, I was hoping I wasn't imagining things when piecing it together in my head and seeing it work like I expect.

    I'll probably pick up the other APs in the next day or so and see how they perform before I spend the $60 on the Linksys antennas. The more I look, the more I find semi-directional antennas with double digit gain for the same, or less money.
  6. Team140

    Team140 Network Guru Member

    Here's an updated schematic. I finally got the cablemodem fired up today (just moved here) so I didn't have fast access to my fileserver 400 miles away.


    A wired multifunction printer and VOIP adapter will be added at a later time to Skynet-1
  7. Team140

    Team140 Network Guru Member

    Just an update, the mesh is working much as expected, but I do have a concern about security. With WEP enabled, the routers refuse to talk to each other. I may try some of the other methods tomorrow. Anyone have any tips?

    (From Skynet-1)
    WDS Signal (Skynet-3): 00:13:10:..... rssi -81
    WDS Signal (Skynet-2): 00:14:BF:..... rssi -83
    SSID  	MAC  	Channel  	Rssi  	noise  	beacon  	cap  	dtim  	rates
    Skynet-3	00:13:10:.....	6	-74	-86	100	1	0	12(g)	
    Skynet-2	00:14:BF:.....	6	-80	-86	100	1	0	12(g)
    (From Skynet-2)
    WDS Signal (Skynet-3): 00:14:BF:..... rssi 0
    WDS Signal (Skynet-1): 00:0F:66:..... rssi -70
    SSID  	MAC  	Channel  	Rssi  	noise  	beacon  	cap  	dtim  	rates
    Skynet-1	00:0F:66:.....	6	-74	-90	100	1	0	12(g)	
    Skynet-3	00:13:10:.....	6	-80	-90	100	1	0	12(g)
    (From Skynet-3)
    WDS Signal (Skynet-2): 00:14:BF:..... rssi 0
    WDS Signal (Skynet-1): 00:0F:66:..... rssi -9
    SSID  	MAC  	Channel  	Rssi  	noise  	beacon  	cap  	dtim  	rates  	
    Skynet-1	00:0F:66:.....	6	-72	-96	100	1	0	12(g)	
    Skynet-2	00:14:BF:.....	6	-86	-96	100	1	0	12(g)	

    Skynet-2 and Skynet-3 do not communicate at the moment as the location of the router at Skynet-2 is in a temporary location that's completely blocking the line of sight to Skynet-3.

    I do want to get this mesh secured, but it's not a super high priority as I'm in a tiny town and the closest wireless I've found while wardriving was 6 miles away :)
  8. crawdaddy

    crawdaddy Network Guru Member

    are you still running the stock antennas with those links? I need to make the longest link possible with a 9db omni, I just have no clue how far I can make with it.
  9. Team140

    Team140 Network Guru Member

    Yup. Everything is stock out of the box except the firmware is bumped to DD-WRT v23b2 and they're running at 84mw.

    How far do you HAVE to link or is it just a test to test the limit of your setup?
  10. crawdaddy

    crawdaddy Network Guru Member

    I need to make the link go as far as possible. I'm trying to build a wifi network that covers miles of area. I'm using high-gain directional antennas for the backhaul, and as high gain as I can find omnis for clients. I'll bump the power up as high as possible without losing connection integrity. I don't have an exact figure for how far I have to hit with the omnis, but it needs to be as much as possible, including shooting through walls to clients.
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