Setting up a long distance wireless hotspot

I'm looking into setting up a wireless hotspot between 6 users with a maximum distance between us being 1.5km, which is not exactly line of sight. We are wanting to be able to connect with laptops and pda's so directional antennas are out of the picture. So far we are thinking along the lines of having a dedicated computer running Mikrotik router OS, then connecting that to a one watt amplifier and a 15 dBi omnidirectional externally mounted antenna. What sort of coverage would i expect to get from this equipment and are there any foreseeable problems you could think of?

Thanks
Evan

I was browsing trademe and found this aution. High Speed Long Range Wireless Internet Transmiter for sale - TradeMe.co.nz - New Zealand

This guy is boasting that his equipment can create a hotspot upto 40km and that it's even possible to connect from 1km away with a ordinary usb wifi dongle. Now thats what i want to do, only on a smaller scale and price of cource.

Now hes talking about the secret of WiFi, now whats that all about?

Well I've got $700ish to spend on equipment and i need my hotspot to be around 1.5km without the use of directional antennas, so far i've set up an antenna mast and installed Mikrotik router OS on a 400mhz computer. What else would i need? and is this even possible?

I have a 2.1Km non-LoS connection with grid arrays and can still connect to the AP.
At point "A" I have a WAP54G with Mustdie firmware (84mw). The AP is mounted on a 30' mast with the 24db grid array (hills). I can connect with my laptop in my lounge at the opposite end of the house in a 90deg angle from the direction it is pointed. At the other end we have a similar setup but the AP is mounted on an ordinary antenna hockey stick with the grid array. We don't connect wirelessly at that end. The APs are in B Mode only for stability of signal. We still run VoIP across them.

Grids are around $120 (gowifi). WAP54G around $199 (dse) retail.

Even if you were to put a WAP54G on the roof with your grid and wired a second WAP54G in the house for wireless connection it would still be a cheap option.

Regards

Fred

Well I've spent the money and built the network. However thinking about it now, A better investment would of been one of thoes wimax networks. Which would have been the perfect solution for roaming within the 1.5km radius with a laptop or umpc as the client doesn’t have to have a huge directional antenna.

However the networking is working just fine with wireless G. Just for the people who are interested our wireless network is running with the following equipment..

The base station is running off a 600mw PCI wireless card connected to a 15dbi Omni directional antenna. Then the clients either have 19dbi die cast reflector antennas or 12dbi panel antennas hooked up to Linksys WRT54G APs running custom ddwrt firmware.