newbie questions

[erikmt]

Hello,

I'm setting up wireless internet access for my parents resort, 22 log cabins spread over 10 acres or so. I've got it working (sort of) using 2 D-Link 900+, one as an ap and one as a repeater. The AP has a directional (cell-patch) antenna that points to the repeater which has a 12 db omni.. The ap is at the front of the resort, the repeater/omni is right in the center of the resort.

I'm currently getting a good signal at about 80% of the resort. Both the AP and the Repeater are set at 22 mb.

My question is, will I get better range if I lower the ap setting to 11 mb or even 5.5 mb? It's connecting to a 1.5 mb dsl line so I'm not worred about absolute speed on the wireless, mostly better range.

I'm also going to try and raise the omni 10 feet or so to see if that helps, there are lots of trees. Any other suggestions?

Also, any idea which of these different modulation techniques will give the best range:


* Barker (1Mbps/0db)
* Barker (2Mbps/3db)
* CCK (5.5Mbps/5.5db)
* PBCC (5.5 Mbps/1.5db)
* CCK (11Mbps/8.5db)
* PBCC (11Mbps/4.5db)
* PBCC (22Mbps/8.5db)


Thanks.

-Erik

[M/Q]

That is an interesting setup. I am surprised that it is working that well. How far apart are the two DLink's? And you have cabins all over a 10 acre area that are able to connect? I would not change anything with the two nodes. What are you using for the client side? In the more trouble some locations adding an external antenna to the client might be the easiest answer. Raising the antenna up is not always a good idea. You might start to lose some of the closer clients if the vertical coverage angle not large enough.

As for the bandwidth setting I would allow the nodes to determine it automatically. You have it somewhat backwards. The AP will downshift to the next lower bandwidth setting if the signal strength is not sufficient to allow a good solid link with no resending of frames. By you adjusting the bandwidth down just removes the nodes opportunity to use the best available speed.

[erikmt]

Hello,

As far as the clients, I'm testing it right now with A D-Link DWL-120+ usb, and a DWL-810+ bridge. I just borrowed a linksys pmcia card that I'm going to play with tonight.

We are either going to let people use their own equipment if they have it, or we will loan or rent out usb adaptors or bridges.

There isn't anything too close to where the omni is, but some of the property is higher, so I'm going to try raising the omni and see if that makes it better or worse. There are also a lot of trees that I'm dealing with in one area.

I may try to add another repeater with an external antenna in the worst spot if I can get a connection from the AP there.

I need to get my gps out and measure some stuff tonight, but I think the distance between the omni and the ap is about 300-400 feet.

The area where the cabins are isn't 10 acres, probably only 5, the whole resort is 40 acres but we have only built out 10 of it so far.

The resort is http://www.northfortyresort.com if you are interested.

We are in our slow season now so I've got a month or so to get this all ironed out.

Thanks for any advice.

-Erik

[M/Q]

You may want to try some of these on the bridges and USB clients. They work very well.

http://osiris.urbanna.net/antenna_designs/projects/template/

[erikmt]

I need to keep things as simple as possible for the customers so I don't think that antenna will work. I'm sure we'd get some strange looks if we started giving those to guests!

If I understand how the 900+ works, every repeater reduces the total bandwith by 50%. So with 1 repeater I'm down to 5.5 mb (starting at 11), so I could add another 2 repeaters ( where I can get a signal from the ap) and still be at 1.375 mbs (best case senario).

Is there any reason why I couldn't use an ap to a bridge to another ap? Rather than trying to repeat the main signal, I could have 2 ap's bridged wirelessly? Then if necessary I could put a repeater on each of the ap's and still have 5.5 mb connections?

My main goal is to have good coverage and still be above my dsl speed.

Learning, learning, learning...

-Erik

[M/Q]

Actually you are at 5.5 right from the start with 11b, as the management overhead uses 50% of the bandwidth. You are right about the losing 50% per hop and repeating also adds quite a bit of overhead itself. It would be interesting to see what the actual bandwidth was on your system. Using a bridge and an AP is what I would recommend as the best approach. You do not loss the repeater induced bandwidth at all that way. You just have to have the AP and bridge on two non-interfering channels. I better make sure you mean a AP wired to a bridge and then wireless to another AP. Repeating also requires a much stronger signal to make a acceptable link. So I would recommend eliminating the repeating if possible and use AP/bridge combinations where ever you need them and have them all point to one node that is the access to the main network.

[erikmt]

Thanks for your help.

This is what I'll try:

Hard wired ap (channel 6), wireless to bridge hard wired to second ap (channel 1 or 11)

Then I guess I could add a repeater to either AP if it was necesarry to get better coverage in a certain area.

-Erik