Airport Extreme distance

Hello Tokai. Welcome to the Apple Discussions!

Can an AirPort Extreme 802.11n be expected to have a reach of about 1500 feet?

Possibly, but the "advertised" range of the 802.11n AirPort is "twice the range" of the 802.11g model. That model had an "advertised" range of 150' for 802.11b and 50' for 802.11g ... so, doing the math, you could expect a range of around 300' ... and this would be unobstructed (both no obstacles nor Wi-Fi interference) range.

Now that doesn't mean your experience may not be better or worse. Some have reported getting connectivity up to a 1/4-mile when the base station was placed high over head. In one case from the balcony on a high-rise apartment.

And if this is at the maximum it might work....would the signal be too weak to expect much from it?

I believe the maximum "advertised" range takes into consideration a useable signal to maintain either the 802.11b or 802.11g standard, 11 Mbps or 54 Mbps respectively. Beyond the "advertised" range limits you can expect the signal to drop off proportionately.

Or should an AirPort Express or something like that be used at the far end?

Using additional base stations will NOT increase the signal, but instead, repeat the signal at the strength that it receives it. To be useful, you would want to place the additional base station within a 20dB Signal-to-Noise (SNR) range to have relatively good signal performance. However, when extending base stations wirelessly in a WDS, the bandwidth performance will be halved for each base station added to this WDS.