What speed does your ISP claim it provides ? Assuming it's 16mbp, I wouldn't be surprised to see that halved by wireless because it's a duplex system.
But 1mbp would seem rather slow -- so I would try the usual remedies. Experiment with channels because some may work better than others in your environment. If you can detect neighbouring wifi change to a channel 5 stops from the strongest neighbour. Relocate cordless phone base or video sender away from computer or router.