I'm hoping for an EE response but fihart might have the experience. My house is 7200 sq ft with the Linksys WRT300N located in the geographical center of the house (center room, middle floor). I have desktops and game consoles linked wirelessly on the upper two floors with 80 to 100% signal, but 1 MBps to 270 MBps depending on location. My issue is the desktop on the ground floor. Regardless whether I position it below the router (less than 3 meters) of across the room I can't connect to the network although the signal strength is 83 to 100% by scanner and MetManager. I've tried PCI card adapters (Linksys), USB adapters (linksys) and a high gain Alfa USB adapter (500 mW and 9dBi antenna) all without success. The high gain finds the netowrk, records 85% signal strength but claims it is too weak to connect. Irony: my two laptops equipped with internal and PCMCIA adapters (Linksys and other) will connect perfectly anywhere on the ground floor with signal strength 83% and connection speed 108 MBps.
My guess is the duct work in the ceiling causes interference of the signal, yet why can the PCMCIA cards connect fine while any other on the desktop can't connect? I mapped the ground floor with a signal scanner for best location, yet none work for connection. The router is configured with DHCP enabled and auto channel select, MAC address filter and non-broadcast SSID.
I configured all adapters to dynamically connect, auto channel select, loaded MAC addresses in filter table and supplied the SSID name. The adapters (all) see the network, connect rarely with a low connection speed and can't get to the Internet. The PCMCIA cards on the laptops are configured exactly the same and they connect to the network fine and to the Internet at 108 MBps speed or better. Is there a solution to the connection problem like Cat5e to repeater on ground floor, Ethernet to ground floor desktops or another system like the slower HPNA and CoAX?
I'm still puzzled why PCMCIA cards work fine while high gain antenna bus adapters can't pull in enough connectivity. Explanation?
My God, you know more about this stuff than I do !
The only thing that justifies my presence is the knowledge that hi-gain antennas work by increased directionality -- maybe if there are obstructions a multidirectional device is preferable.
Remember also that signal strength indicators are a very rough guide to signal strength but not to signal quality.
Your description of a signal scanner is spot on. I wish someone would offer a scanner that would constantly ping the networks, then calculate the per cent of connectivity. That type of a device could actually show areas of interference. My high gain antenna does not work in any orientation toward the router (accounts for direct connection and reflected connection off of walls). Still, I would think the device would certainly have the power to connect vs the smaller PCMCIA card.
Other than installing a microwave burst antenna on my router, I doubt any adapter for a desktop will capture the signal (high enough energy to cook eggs). Besides doing a Cat5e wiring of my house the only possible solution would be to get a bus PCMCIA reader for the desk system. Any other ideas?