the main functions of S1 interface layer 1 are
as following:
·
Interface to physical
medium;
·
Frame delineation;
·
Line clock extraction
capability;
·
Layer 1 alarms
extraction and generation;
·
Transmission quality
control.
Protocol specification
3GPP TS 36.411 - Evolved
Universal Terrestrial Radio Access Network (E-UTRAN); S1 layer 1