Outdoor Wireless Network Hardware

I'm trying to setup an outdoor network that would need to cover a little less than half a mile. I have a TrendNet TEW-412APBO access point and a TEW-OA14DK directional 14db antenna. I seem to be getting a usable signal to about 400 yards, but nothing past that. The gain on the antenna makes me think that the signal should be better, but it doesn't seem to be that much better than an a standard home wireless AP.

On the receiving end, I have no power to setup a point-to-point network. Plan is to have somebody with a tablet PC on that end. I have been testing the reception using a Dell Inspiron 6400 laptop with built in wireless (no means of attaching an additional antenna to the laptop itself).

The land being covered is flat, no buildings but a few trees. I have the directional antenna mounted on a wall about eight feet off the ground, with a clear line of sight to the target receiving point.

Any thoughts or help on this? Is the Trendnet Outdoor AP the problem?

Thanks in advance for your reply.

The TEW-412APBO is supposed to have a built in 9dB antenna and the TEW-413APBO is supposed to be the one with the connection for an external antenna.
http://downloads.trendnet.com/TEW-41...EW-413APBO.pdf
You say you have a few trees, are they in the path of your signal? Even though you appear to have line of sight you still need to have the signal path x metres above any obstructions, ie no obstructions within the "Fresnel zone" or you would have to find some extra gain. With a completely flat ground and no obstructions the antennas on both ends would need to be a minimum of 10ft high.
Link calculator
Link Calculator : Wifi Extreme, Outdoor Wireless Systems
The laptop wifi card has an inadequate antenna and probably a not very high power output so in order to send a reliable signal to the trendnet you would probably need an 8->10dB directional antenna. You will probably only be able to use a speed of 11Mbs over that distance as well.
You could look for a USB wireless adapter with a detachable antenna that you could replace and mount the adapter and antenna on a mast.
If you have a play with the Link calculator you will get some idea of the antennas you may need.
Although they say a margin of 10dB is acceptable this gives around a 90% reliability so if you require a greater reliability look for around 20dB in both directions.
The data sheet for the 413 has the rx sensitivity figure.
You will need to look up the data sheet for the wireless card you are going to use for it's sensitivity.

By using an outdoor AP unit with the radio and antenna outside you area will be covered no problem, This unit is under $200 range and will solve your problems,ASU-24005g
2.4GHz, 802.11g, Fighter Outdoor Long Range WLAN


ASU-24005g---Zigwire