Another option is to use 5Ghz wifi. There is much less noise & far more
bandwidth on the spectrum. Plus on Band B 5Ghz, you can kick out upto 1W
EIR, which can range pants loads more than 2.4Ghz. 5Ghz also permeates
walls & large obstructions better. It would however mean refitting
everything that wants wifi to do 5GHz (which isn't a lot of things).
The idea of range extenders is generally a bad idea, as others said you
will half it's speed on each new point. However, there is some clever
meshing kit available from Ubiquity
http://www.ubnt.com/ which can mesh
multiple AP's slightly more cleverly than SOHO WDS. Nanostations are
especially nice, as they have a spectrum analyser built-in, as to "see"
the noise on wifi channels properly, not like inSSIDer or kismet, but
actually spectrum (including other devices using the 2.4GHz range).
Some access points can share SSID/PSK, sit on different channels and not
bridge/point to point with one another, but when you move out of range
of one into another, your wifi client will have to reauth, causing a
momentary blip in connectivity. However, if their LAN is on the same
VBC/Subnet, the blip will be mere seconds & could allow to resume
connectivity (as DHCP will most likely give that MAC the same IP again).
I use a setup like this for the house wifi, residents downstairs get AP
downstairs, upstairs the one upstairs etc. & it works almost flawlessly.
However, not all AP's will let this happen, they will fight for the
client and _will_ cause elevated noise on the 2.4Ghz spectrum.
