I was downtown Ottawa on the Friday, eating at a restaurant that had power, since we had none at home. (at least, when we arrived they had power...) What I noticed is that my GSM (Fido/Microcell) had very poor reception, and I frequently didn't get a signal. My conclusion - they don't have all of the transponders on generator backup, so they have less capacity during a blackout. Repeating this design for IP telephone would not be a good idea :-)