i'm looking to setup an 802.11b link over Wellington harbour, between a building on Featherston St and a house above Oriental Parade. I have two questions:
1) is it possible (below $800), taking into consideration the water interference
2) What kinda antenna would I need? I've googled a bit and found that yagi directional antennas are what I want, but what gain would I need?
3) Can I use a say, 16dBi yagi on the oriental parade end, and a smaller gain antenna in the office building?
i have a citylink connection. i want to get it to a house above oriental parade install+ongoing costs of getting it installed at the premises is way too high, versus capital cost of wireless
I'm also looking at this but a bit further in distance. Is there a problem going over water, I want to go across harbour. I wouldn't have thought water would make much of a differnece.
There is a useful calculator for signal loss with distance here http://www.ydi.com/calculation/free-space-loss.php
Thats a really short haul and can be done with yagis or anything else. Directionals are much better though. If you have $800 budget then you should be able to afford 19 or 24 dish antennas. I think 24s are $200 and you should be able to get 2x APs and pigtails for $400.
Thats a really short haul and can be done with yagis or anything else. Directionals are much better though. If you have $800 budget then you should be able to afford 19 or 24 dish antennas. I think 24s are $200 and you should be able to get 2x APs and pigtails for $400.
where would you recommend I purchase these from? (preferably in NZ)
also.. i though yagi's _were_ directional antennas?
I think Shadow sells all you need. Are you going to mount outdoor? Figure out your cable lengths etc.http://shop.borg.net.nz
forgive me for being stupid, but how do i do that? I've read that long cable lengths between antenna and AP/wireless card are really bad for signal loss -- how do I do it effectively?
You want to put your AP as close as possible to the antenna. You could put the AP in a waterproof box and then run DC power to the box. The box would be right next to the AP.
The other way to do it is to use good coax like LMR400 so there is no signal lose from the AP to antenna. You can comfortably go 10m. The 10m might set you back $80 dollars though.
You want to put your AP as close as possible to the antenna. You could put the AP in a waterproof box and then run DC power to the box. The box would be right next to the AP.
the box would be right next to the...antenna you mean?
Quote:
The other way to do it is to use good coax like LMR400 so there is no signal lose from the AP to antenna. You can comfortably go 10m. The 10m might set you back $80 dollars though.
sweet - I didn't know how far I could go without any loss. thanks. now I just have to get my head around the various types of connectors
There is always loss. You will see about 3db lose with pigtails and 10m LMR400 but you can afford to lose that easy if you use 24db antennas.
You need to chose an AP type first I'd say. There are plenty to chose from. Have a look at the Dlink 2000AP. These bridge together and are 11g. Might be too pricy though.
okay.. just out of interest, how about the dlink dwl810? would this work? if you wouldn't recommend this one, why not? otherwise, i was going to go with the dwl-900AP, seems alot of people are using these
are there any AP's which output more power than typical? (all I've seen is 15dB output)
I was thinking of using a cantenna at each end -- from what various people have said, all I need is a 12dBi gain antenna
Second option being a borg waveguide at one end, and a parabolic dish at the other end, the logic being that having two dishes makes it hard to line up.
I have access to a GPS receiver -- how would I use this to line up two parabolic dishes? Using a map and compass?
Yeah that would work according to the specs. It go for the DWL900 over that though as there are a lot more out there and people are getting good results. If you want cheap 11b then Shadow has an AP which can be used as a bridge as well as an AP. Its well under $200 from memory.
You are far better to go for a directional antenna over anything else. Not only will you get better gain but you will also get a lot less interference.
There are APs that are 17db+ but they are prity rare and you don't need the power. If you go for a 15db AP and a 19db dish antenna it would be a good solution.
sweet. since one end is in an office, i can't really put a dish inside. what could I use? It's going to have to sit on the header (which runs right along one side of the buliding, the side which has LOS to the end point)
Trvln: he could just use a 180 waveguide for the office though for ease of setup, right? I mean, an antenna is gonna be a bit of a monstrosity sitting on a desk somewhere :P
There is always loss. You will see about 3db lose with pigtails and 10m LMR400 but you can afford to lose that easy if you use 24db antennas.
You need to chose an AP type first I'd say. There are plenty to chose from. Have a look at the Dlink 2000AP. These bridge together and are 11g. Might be too pricy though.
Based on what I have seen with mine I would suggest staying away from these till the firmware matures a little more.
I am about to try a sustained test with my 2 NZ purchased revision B hardware and see if its more stable then the revision A ones I imported. Not hopefull however.
I would stick with dwl-900ap+s for now, they are stable, and have the max power firmware, but Im pretty sure that would put you well over the legal limit with 24 dB antennas
I would stick with dwl-900ap+s for now, they are stable, and have the max power firmware, but Im pretty sure that would put you well over the legal limit with 24 dB antennas
How do I obtain updated/'max power' firmware? or is the latest already on it?
After getting all the parts (thanks to Andrew for supplying them - apart from a delivery issue all arrived reasonably quickly) I set it up, and managed to get ~4MBit half-duplex.
I'm gonna try orientating the antennas differently (24db grid+Borg twinfire) this week (horizontally polarised) and see if that helps.
802.11 link over Wellington Harbour 
install+ongoing costs of getting it installed at the premises is way too high, versus capital cost of wireless
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