A 0-degree phase starts up and to the right. Down and to the right is a 180-degree phase. This would mean that 2400 baud is about the MAX you could get on a modem. Its actual max is 3000 but 2400 became an acceptable standard. Used for radio.
Waves bounce well.
Suceptable to static because a spike caused by lightning or interference alters the height of the wave. Compress and expand the waves. Not suceptable to spikes because height of the wave is not measured. FM waves dont bounce well because they become compressed. You get 4 bits from a single QAM wave, so you can get 19200 from this.