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Idgit
Feb 11th, 2004, 03:48 AM
Maybe a little of topic, but here goes....

I am interesting in creating a private wide area network. The network will cover an area of about 1 mile in diameter (line of sight). It must be able to support a max of 50 users, some with light physical obstruction (trees, walls), but most user have a clear line of sight.

The server would be at the center of of star formation, the main access point. The question at hand is how to extend the range of the current wireless technology so that users within the 1 mile circle could have wireless access of maybe 10 mbps (at leat 1 mbps) data transfer.

Its seems that this would be pretty difficult, since most wireless lan cards and wireless access points are pretty limited in range and power. I thought maybe it would be possible to use about 5 or 6 distributed access points with range extenders. Each distributed access point would have about 10 users locally. Each of these local access points must have a connection with the main access point, the server.

A major limiting factor is cost. Running fiber is almost impossible.

I am not sure if this is even possible, my knowledge of wireless is very limited.

Any ideas on where to start looking at hardware that may be capable of meeting these requirements..., anyone???

Thanks:wave:

Merrion
Feb 11th, 2004, 05:04 AM
Fixed users or mobile?

Idgit
Feb 11th, 2004, 06:09 AM
All users would be at fixed locations, all destop pc's.

Idgit
Feb 13th, 2004, 05:43 AM
Who is Idgit? Ooops, I'm an Idgit:D :D :p ;) :rolleyes:

Idgit
Feb 13th, 2004, 07:54 PM
Here is some info I dug up, anyone here have any exp. with this type of networking?

http://www.dailywireless.org/modules.php?name=News&file=article&sid=173

http://www.dslreports.com/forum/dslalt

Idgit
Feb 14th, 2004, 12:48 AM
Try to set some detailed goals:

1) 2.4Ghz system to deliver unlicensed wireless services 1-2 miles at a speed 1-6 Mbps.

2) Server Access Point - Three mast-mounted 12dB gain flat panels that cover the area in 120 degree sectors, each driven with their own AP...three, Senao outdoor Access Points or Zcomax Access Points based on a 200mw (+23dB) PC Card (assumed sensitivity @ 2Mbps about -93dBm). Total about $1200-1500

3) Average Client: 180mW Zcomax card with a USB Adapter which plugs into an external 12dB flat panel or (if necessary) a 18 dB flat panel. Total about $200 per client.


Range = 1.5-2 miles with +25.8 dB Fade Margin

Is this a feasable setup?

Any comments....?:wave:

Idgit
Feb 14th, 2004, 01:19 AM
Another observation, the local area has virtually no exsisting wireless activity:D

plenderj
Feb 17th, 2004, 03:17 AM
What you want to do is try to split up everything into locations.

So each location would be a small LAN.
Each LAN :
Have all systems wired into a 10/100(/1000) switch if possible.
Failing the ability to lay cable, then use normal wireless technology. Use WEP with some encryption key - WEP_KEY_N (where N is the index of that LAN (i.e. the first lan, N=1, second lan, N=2 etc.)).
So this LAN can then operate independantly of the others.

Next, to connect that LAN to the others, use a directional antenna connected to a wireless access point on top of the building in which that LAN resides. The access point would also be wired into the access point or switch controlling that LAN.
The directional antenna would point towards a centra location, where you might have a number of antennae.
You would use the access point as a bridge - normally you can use Access Points in bridge mode, whereby you specify the MAC address of the desination access point to merge networks together.

Repeat this process for each segmented LAN.
At the central location, or at one of the LANs, you would have your PDC (primary domain controller (A Windows NT, 2000 or 2003 Server)) to authenticate users on the network etc.

You could also run DHCP on the PDC, or, which would give better network performance, run a DHCP server, or enable DHCP on the access points at each location. Each individual LAN would be using a different wireless encryption key - so the DHCP servers should not interfere with eachother.

That is how I would do it :)

Idgit
Feb 17th, 2004, 03:54 AM
Excellent! (maybe this was the wrong forum for this post, hehe)

I am using a Windows 2000 PDC currently with DHCP server running. Here I am planning to install a 50 foot grounded mast with the 3 flat panel antenna's in 120 degree segments.

This will add some length to the 3 cables coming in to the main building, some cable loss will be introduced.

With this in mind:

Transmitter: 12dB gain flat panel @ 200mw (50 foot mast)
Clients: 12dB gain flat panel @ 180mw

assming sensitivity @ 2Mbps about -93dBm

Can a 1.5-2 miles range with +25.8 dB Fade Margin be maintained under normal conditions?

Thanks for the detailed layout... still worried about power...:D

plenderj
Feb 17th, 2004, 04:37 AM
Well obviously athmospheric conditions will effect the performance of your network. Can you move the antennae/dishes any closer, or perhaps put one in-between as a booster?

plenderj
Feb 19th, 2004, 05:02 AM
Might be of interest ?
http://www.d-link.com/products/?pid=35

Idgit
Feb 19th, 2004, 12:26 PM
Thanks for the info... d-link seems to provide a power and affordable unit. I will look into this unit in more detail.

Thanks again for your effort:wave:

DiGiTaIErRoR
Feb 20th, 2004, 01:42 AM
You can get devices to place on the phone lines(around $100/each) which will enable UHF transmissions over a wideband area. The bandwidth is similar to that of DSL, several Mbps.

The devices cut off the low-frequencies while retaining the UHF. Basically it's your own DSL. And you'll have the ability to setup a WAN, or your own BSP.