In packet switching, the bandwidth of the transmission medium is shared between multiple communication sessions, in contrast to circuit switching, in which circuits are preallocated for the duration of one session and data is typically transmitted as a continuous bit stream.
[3] Network design can achieve two major results by using packets: error detection and multiple host addressing.
[4] Communications protocols use various conventions for distinguishing the elements of a packet and for formatting the user data.
In order to provide mono compatibility, the NICAM signal is transmitted on a subcarrier alongside the sound carrier.
This means that the FM or AM regular mono sound carrier is left alone for reception by monaural receivers.
Making the NICAM bitstream look more like white noise is important because this reduces signal patterning on adjacent TV channels.