okay, quick internet search. Not sure if you can mount it to your exterior wall outside the windows (like many residents here do) legally, but if you have a patio...
if you're in an apartment setting and the landlord is adamant that he will not extend permission to allow mounting a dish on the roof, you may have a perfectly legal option. if you have a balcony/patio which is exclusively under your control, you have the right, not the privilege, as protected by the u.s. federal telecommunications act of 1996, to install a dish in that area regardless of the landlord's wishes. (exclusivity means only you, other residents of your flat, or your guests, with your permission, are the only people who would have access to this area.) you cannot legally attach to a railing if the landlord objects, but a five gallon plastic pail and a couple of sacks of quick-setting concrete make a very stable mount to set on the balcony/patio flooring for a dish. jig a four foot length of 1-1/2" diameter pole (galvanized electrical conduit is ideal.) in it while it sets, give it 24 hours to set well, attach the dish at the top of the pole, and you should be good to go. total expense for materials should be under $15.00. note, though, that this is under u.s. law. canada may be different.