Automatic repeat request (ARQ) Break large files into packets FILE PKT PKT PKT Check received packets for errors Use a feedback channel to request retransmissions Retransmit packets containing errors acket Receive ACK
Sampling Given a continuous time waveform, can we represent it using discrete samples? How often should we sample? Can we reproduce the original waveform?
Sampling Sampling provides a discrete-time representation of a continuous waveform Sample points are real-valued numbers In order to transmit over a digital system we must first convert into discrete valued numbers