3 Definitions and abbreviations
37.4623GPPIuant interface: Signalling transportRelease 17TS
For the purposes of the present document, the following terms and definitions apply.
ASCII character: A character forming part of the International Reference Version of the 7-bit character set defined in ISO/IEC 646:1991 represented as one octet
Octet: 8 bits as used in ISO/IEC 13239 
Device type: One octet identifying the type of a device
Unique ID: A concatenation of the vendor code (2 octets) and a 1 to 17 octets long unit specific code (e.g. serial number) exclusive for each secondary device from the vendor to whom the vendor code is assigned. The vendor code is placed in the left-most (most significant) position of the unique ID. The vendor to whom the vendor code is assigned is responsible for ensuring the uniqueness of the unique ID for each device.
Vendor code: A unique ASCII 2-character code assigned to each vendor in AISG v2.0 .
Reset: A process by which the device is put in the state it reaches after a completed power-up
SecondaryPayloadTransmitLength: The maximum length of the INFO field of an HDLC I-frame in the direction secondary device to primary device.
SecondaryPayloadReceiveLength: The maximum length of the INFO field of an HDLC I-frame in the direction primary device to secondary device.
For the purposes of the present document, the following abbreviations apply:
CRC Cyclic Redundancy Check
DISC Disconnect (frame type)
DM Disconnected Mode (frame type)
FCS Frame Checking Sequence
FI Format Identifier
FRMR Frame Reject (frame type)
GI Group Identifier
GL Group Length
HDLC High-Level Data Link Control
I Information (frame type)
INFO Information (field name)
NAK Non Acknowledgment
NRM Normal Response Mode
PI Parameter Identifier
PL Parameter Length
PV Parameter Value
RET Remote Electrical Tilting
RETAP Remote Electrical Tilting Application Part
RNR Receive Not Ready (frame type)
RR Receive Ready (frame type)
SNRM Set Normal Response Mode (frame type)
TMA Tower Mounted Amplifier
TMAAP Tower Mounted Amplifier Application Part
TWA Two Way Alternate
UA Unnumbered Acknowledgement (frame type)
UNC Unbalanced Operation Normal Response Mode Class
XID Exchange ID (frame type)