This TS defines the structure of the physical layer (layer 1) of the BSS-MSC interface for supporting traffic channels.
Use of the physical layer for supporting Signalling System No.7 signalling links is covered in TS 48.006
The physical layer is the lowest layer in the OSI Reference Model and it supports all functions required for transmission
of bit streams on the physical medium.
For the present document only digital transmission will be considered, the use of analogue transmission is a national
full Table of Contents for TS 48.004 Word version: 15.0.0