07-05-2014, 12:19 PM
Bandwidth Utilization: Multiplexing and Spreading
Bandwidth Utilization.ppt (Size: 1.73 MB / Downloads: 306)
MULTIPLEXING
Whenever the bandwidth of a medium linking two devices is greater than the bandwidth needs of the devices, the link can be shared. Multiplexing is the set of techniques that allows the (simultaneous) transmission of multiple signals across a single data link. As data and telecommunications use increases, so does traffic.
Interleaving
The process of taking a group of bits from each input line for multiplexing is called interleaving.
We interleave bits (1 - n) from each input onto one output.
Data rate matching
Multilevel: used when the data rate of the input links are multiples of each other.
Multislot: used when there is a GCD between the data rates. The higher bit rate channels are allocated more slots per frame, and the output frame rate is a multiple of each input link.
Pulse Stuffing: used when there is no GCD between the links. The slowest speed link will be brought up to the speed of the other links by bit insertion, this is called pulse stuffing.