I live in a basement flat with stone walls. Getting a signal to the router is nightmare and so I ordered a AWUS036HN external network card after reading several reviews.
Wifi cards mention two statistics about their performance, namely the gain of the antenna and the power of the unit.
1) As far as I can make out gain is the same as directionality, i.e. more gain does not necessary = better signal. If we have a high gain antenna (high directionality) that means we transmit in a very narrow field of vision but transmit with more power in that direction. Can we conclude from this that antenna gain only modifies our ability to transmit and says nothing about the device's ability to receive?
Edit: just read this "Due to reciprocity, these two effects are equal - an antenna that makes a transmitted signal 100 times stronger (compared to an isotropic radiator), will also capture 100 times as much energy as the isotropic antenna when used as a receiving antenna. As a consequence of their directivity, directional antennas also send less (and receive less) signal from directions other than the main beam. This property may be used to reduce interference."
2) Card power seems to just indicate the amount of transmit power. So how does a higher power card help us to receive very weak wifi signals?
I can see how a card with a highly directional antenna would enable one to transmit to a remote location and receive from a remote location, but how on earth does a higher power card make reception better?