A term used to describe any
data/
voice connection with a
bandwidth of less than 2.048Mb/s.
This figure is arrived at by calculating ther
maximum data throughput of a
PCM cable when using in a
System X exchange.
- A System X exchange samples the analogue signal 8000 times a second
- Each sample is digitised into 8 bits
-
Each PCM carries 32 channels of information, so:
8 x 8000 x 32 = 2048000 b/s or 2.048Mb/s
This is obviously a UK only definition, as the US telephone network uses a different exchange architecture