Question : 150+ user wireless network with 300m linear spread

I am overseas and have recently adopted a satellite internet system.  I have two distinct issues with the system.

Situation:  The network is intended to support 150 wireless users.  The users are in three distinct areas.(b1, b2, and b3).  b1 is the tallest building and thus supports the satellite.  b2 is 120 meters from b1.  b3 is a group of 4 buildings spaced within a 75 meter square and is approx. 75 meters to its center from b2.

The satellite contract reads 4.0 mbs down/1.0 mbs up with a 2/1 contention ratio.

Currently there are two networks defined NET1 and NET2.

Current hardware is as follows:
At b1:
Satellite and Nera Satlink 1000 - b1
Linksys WTR54GX4 - acting as an access point in b1
Linksys WTR54GS V3 - acting as an access point in b1
Linksys WTR54G V5 -   b1 this router defines NET1
Linksys WAP54G - located in b1 connected to a DLink 10 dBi panel antenna oriented towards b2

At b2:
Linksys WRT54G V2.2 - This router defines NET2 connected to a DLink 10 dBi panel antenna oriented towards b3
Linksys WAP54G - configured as a bridge

At b3:
WAP54G v3.1
WAP54G v3.0
WAP54G v3.0
WAP54G v3.0

1.  Network stability - The network is inherently weak between the bridge.  I believe this issue to be because of limited line of sight to the antenna attached to the bridge and the panel antenna broadcasting from b1.  Additionally we are seeing problems between the second panel antenna and the access points in b3 due to the same issue.

2.  Bandwidth - the contract reads that contention ratio is 2/1.  However, we are not seeing speeds  I believe the issue is that with the current hardware (specifically the routers) we are only able to have 19 concurrent wireless users per router.  This is particularly an issue in the b2 to b3 configuration because we have one router handling over 100 users.

I am a programmer and not a network administrator.  Thus my knowledge is very basic.  Please feel free to ask questions and clarify this issue.  I am looking for someone who has had experience in either developing a wireless solution for 150+ users and/or someone that has experience in developing wireless access over a 300 meter linear spread.

Thank you for your help.

Jack.

Answer : 150+ user wireless network with 300m linear spread

With your number of users, I agree that you should dedicate AP's to the duty of bridge, even if the AP's are capable of dual function (bridge and AP).  Without seeing your layout, I suspect that the buildings are located such that you would be best served by a bridge between B1 and B2 and a separate bridge between B1 and (one of the buildings of) B3.  Both these bridges should be built with AP's dedicated to the bridging function, and should be equipped on each end with high gain antennas, preferably external ones, carefully and firmly installed.  Metal exterior buildings (like trailers) hurt wireless signal strength.  Once you get the signal into B2, use regular AP's to provide access to users.  B3 is another matter, can you cable between them?  If so, cable an AP in each of the B3 buildings and cable it back to a switch connected to your B3 bridge.

4MB download really isnt much for 150 users.  I am not surprised they are complaining about speed.  2/1 contention ratio sounds wonderful and expensive.  If you have performance doubts, run a test from a single local workstation.  Also note that Cisco recommends no more than 24 users per access point.

Your situation sounds complicated enough that you really should get a qualified network wireless installer to review it and give you a quote.  You are trying to build a commercial network with hobby grade equipment.

In your situation, what would I do if I had to do this myself?  That depends on:
How much money do I have?
How much time do I have?
What are the consequences of downtime when I kill the system to reconfigure?
Are there any local network geeks I can tap for help?
Are there any local RF geeks I can tap for help?

Here are some thoughts:

1.  Test the satellite speed.  Connect only 1 workstation to the sat terminal, and do some speed testing.  If not satisfactory, get the vendor started on fixing it.

2.  If your users can stand it, temporarily kill B3.  Try using the two flat panel antennas and 2 WAP54G's to set up a good bridge between B1 and B2.  Orient the antennas carefully toward each other, both horizontally and vertically.  Connect the B2 end of this bridge to B2's access point(s).  If this improves performance in B2, then set up another bridge between B1 and B3 (if LOS allows) using similar equipment.

This really is quite complicated.