ship to shore network

[jalange]

Hello;

I would like suggestions regarding designing a ship to shore 802.11b network. This project will involve multiple research vessels (3) that will require wireless connectivity back to our campus. We would like multiple 'hot spots' (3 or 4 areas) on the lake that the ships would move between. This means that in addtion to the 3 ships I need at least 3 antennas pointing out over the lake. I can create these zones using sector or yagi antennas, but I am unsure of if or how I could get a vessel to 'roam' between the bridge units. Should there be 1 root bridge on each ship with multiple non/root clients on shore? Or perhaps the reverse, 1 non/root client on each ship and multiple roots units on shore. How do I handle the SSIDs? Can there be 3 root bridges with the same SSID that connect to a vessel as it enters a specific hot spot? At this point in time we were considering having all the bridges on a single ip subnet, perhaps multiple subnets will be needed?

Any ideas regarding antennas, bridges, access points or how to handle the multiple bridges would be welcome.

Jeff

[tcross3]

You just need one ip subnet. As far as the ap go you should put the roots on shore for stability. If the shore aps are within radio range of each other then only one root would be needed. The the ship ap will reconnect when the roam in to the coverage area of another ap. You can use ap1200 series with yagi which will have a narrow beam, longer distance or a dish for a wider beam, shorter distance.

Hope this helps. Post how this works.

[adamt]

I agree with everything that tcross has said except for using the ap1200's. jalange had said that they would use a briged network, and I'd recommend BR352's (They may not be sold anymore though, and there successor is the BR1410, which is 802.11a).

Then on each ship that you would like to allow connectivity, you would use the same subnet, and SSID, with the bridge. Then you could either use a wired or wireless connection on each ship.

If you would go the BR1410 route you would find that you can get alot better distance with 802.11a, since 802.11a's speed cap is 54Mbp/s whereas 802.11b is 11Mbp/s.

So technically speaking you could shoot your 802.11a signal a good mile out to sea (over the lake) with decent connectivity, but the problem that mostlikely would arise is that you would have to have a pure signal, which in this case would mostly be at a half mile and in.

You would then in this case need:

a BR1400 series bridge with an AP on each ship if you want to go wireless on the ship, otherwise a switch/hub/router for the wired network.

Although this senario would probably work, you could also use the AP1220 Access Points, on Shore and using a patch antenna, either a Cisco or Maxrad, (both are the same just different prices and different vendors). But this would almost certainly require you to be close to docking and / or docked at the harbor to get a good enough signal.