View Full Version : Wireless LAN project

13th June 2004, 09:34 PM
I have never used a wireless LAN before, so I may sound like a horrible newbie, but please, bear with me :P

I want to setup a wireless LAN for the purposes of:
Melbourne PubliC Wireless LAN
Swinburne Uni about 4km away
RMIT Uni around 3km away
Home network
Access to home LAN in park which is about 500m away

And I'd also have my wired LAN consisting of:
My desktop
Girlfriend's desktop
File server
Test/dev box

I've quickly drawn the following diagram to represent the network topology I think would be suited here.


Would I need seperate antennas for each wireless network, or can I have the one

What would be the best way to go about this?
I think I can get away with a high powered omni directional antenna that would cover the area within my home and the park adjacent.

I assume I need a seperate network card for each network I want to connect to. So I'd need to consruct an AP with 4 network cards in it. Would that also mean I need 4 seperate antennas for each wireless card, or can I have one antenna for all of them? (depending on wether an omni would reach the signal I want, otherwise I assume I'd need multiple directional antennas).

But yeah.. anyone have any suggestions as how I should go about this or things I should read?

13th June 2004, 11:31 PM
Althought something like this is possible. It will be difficult and expensive...I would only assume.

The gain required from these antennas would be huge...well, above the regulatory dB rating for private use.

Because of this, licensing will more then likely be requred.

The antenna will be large, expensive outdoors types and of course, security will be a major issue.

One thing that I am not too certain about is that the signal from Swinburn, and Melb Wireless, will that be from other wireless access points? well, either way, their signal strength will have to be high enough to allow the signal to travel 3km's.

Other then this, I cannot really think straight, having a terrible time with this flu I got.


14th June 2004, 06:53 AM
I'm not too sure what you want to do here with regards to the RMIT/Swinnie/melb wireless bits. Do you want to broadcase your home network to include these places?

And if so....why?

I do not see the point of doing this. RMIT already has wireless hotspots setup in the cafe. And I'm sure you can find many a cafe in melbourne with an unprotected wireless network. I'm sure swinnie will have a wireless setup sometime soon.

Why not just expand you smoothwall box to include a bit more than just a basic linux box and setup your own ftp server as well. That way you can access the files you will need while away from any other network via ftp.

14th June 2004, 09:41 AM
Originally posted by Quamen@Jun 14 2004, 06:53 AM
I'm not too sure what you want to do here with regards to the RMIT/Swinnie/melb wireless bits. Do you want to broadcase your home network to include these places?
RMIT and Swinburne have their own wireless networks. I want to be able to access it from home, not access my home network from on campus :)
That way all my notes and stuff I do in class isn't far away, rather than e-mailing, copying to disk, or using that stupid NetStorage thing. I'd also get free internet useage via the University ;)

Melbourne wireless is a public LAN where many users around Melbourne have created a network, for sharing, umm, resources :P

On my LAN, there is a fileserver which runs an FTP server on it already, so I don't need to set up a seperate one.

23rd January 2005, 02:28 AM
decryption is right. The maximum EIRP legal output of 2.4 GHz ISM wireless equipment is 4 W. This is regulated by the ACA.

It is unlikely that the airport cards common in most Macs would exceed 60 mW, and even with a 25 dBi grid antenna this will be well under the 4 W limit. Thus with commodity wireless hardware and a little effort you can cover distances of up to 25 km, with a reasonable level of reliability, given good line of sight. You can buy 200 mW access-points for around $200 now.

On a slightly different subject, does anyone know how to change the regulatory domain of an Airport card in a G4 Powerbook? Is it a soft setting, or does it require a firmware change? I bought my PowerBook in the USA, and I would like to be able to use all the legal channels here.

23rd January 2005, 08:08 AM
The pic you posted with your post don't work... So I can't see it to comment :)

23rd January 2005, 10:00 AM
decryption, check out the following website, you may wish to ask these guys some questions, they have a major wireless setup covering alot of Darwin:


It won't be as expensive as you think, however as a student it will be :)

23rd January 2005, 10:06 AM
This is a very old idea that got thrown to the side as silly and impractical. Ignore it :P