Glossary of terms

1PPS	One Pulse Per Second
AAI-48	48-bit Administratively Assigned Identifier
AAI-64	64-bit Administratively Assigned Identifier
ACK	Acknowledgement
ADEV	Allan deviation
AP	(Wireless LAN) Access Point
ARB	Arbitrary
ARTC	Arbitrary Reference Time Clock
AV	Audio/Video
AVB	Audio/Video Bridging
BBU	Base Band Unit (upper-layer processing within a basestation; equivalent to the CPRI term REC)
BC	Boundary Clock (see T-BC)
BITS	Building Integrated Timing Source
BMC	Best Master Clock
BMCA	Best Master Clock Algorithm
BPSK	Binary Phase Shift Keying
BTS	Base Transceiver Station (the basestation name for a 2G network, e.g. GSM)
CAN	Controller Area Network
CDMA	Code Division Multiple Access
CES	Circuit Emulation Service
CID	Company ID
CMI	Coded Mark Inversion
CMLDS	Common Mean Link Delay Service
CP	Communication Profile (according to IEC 61784-1:200710)
CPF	Communication Profile Family (according to IEC 61784-1:2007)
CPRI	Common Public Radio Interface (a specification for radio over fibre produced by the CPRI consortium, www.cpri.info)
CRAN	Centralised Radio Access Network (sometimes used to refer to Cloud RAN, although this is more general concept than Centralised RAN)
CSMA/CD	Carrier Sense Multiple Access with Collision Detection
CSN	Coordinated Shared Network
CTC	Channel Time Clock
cTE	constant Time Error
CU	Centralised Unit (higher-layer processing within the basestation)
DAN	Dual Attached Node
DANH	Dual Attached Node with HSR protocol
DSL	Digital Subscriber Line
DSLAM	Digital Subscriber Line Access Multiplexer
dTE	dynamic Time Error
DU	Distributed Unit (lower-layer processing within the basestation)
E2E	End-to-End
EC	Equipment Clock
eCPRI	enhanced Common Public Radio Interface (a specification for radio over a packet network, e.g. Ethernet or IP, produced by the CPRI consortium, www.cpri.info)
EEC	Ethernet Equipment Clock
EEC	synchronous Ethernet Equipment Clock
eEEC	enhanced Ethernet Equipment Clock (the enhanced SyncE clock defined in G.8262.1)
ELI-48	48-bit Extended Local Identifier
ELI-64	64-bit Extended Local Identifier
eNodeB	evolved NodeB (basestation name for a 4G network, e.g. LTE)
EPC	Evolved Packet Core (the core network in 4G)
EPON	IEEE 802.3 Ethernet passive optical network (as specified in IEEE Std 802.3-2008)
ePRC	enhanced Primary Reference Clock (defined in G.811.1)
ePRTC	enhanced Primary Reference Time Clock (defined in G.8272.1)
eRE	Radio Equipment (eCPRI term for the physical-layer processing within the basestation; equivalent to the RRU or RRH)
eREC	Radio Equipment Controller (eCPRI term for the higher-layer processing within the basestation; equivalent to the combination of a CU and DU)
ESMC	Ethernet Synchronization Messaging Channel
ESS	Extended Service Set
ETH	Ethernet MAC layer network
ETY	Ethernet PHY layer network
EUI-48	48-bit Extended Unique Identifier
EUI-64	64-bit Extended Unique Identifier
FCS	Frame Check Sequence
FDD	Frequency Division Duplexing
FFM	Flicker Frequency Modulation
FFO	Fractional Frequency Offset
FM	Frequency Modulation
FPC	Floor Packet Count
FPM	Flicker Phase Modulation
FPP	Floor Packet Percent
FPR	Floor Packet Rate
FTM	Fine Timing Measurement
G.hn	ITU-T G.9960 and ITU-T G.9961
GBAS	Ground Based Augmentation System
GbE	Gigabit Ethernet
GM	Grandmaster (see T-GM)
GMT	Greenwich Mean Time
gNodeB	The basestation name for a 5G network
GNSS	Global Navigation Satellite System (generic name for the various satellite-based navigation and time distribution services, e.g. GPS, GLONASS, Beidou etc)
GPON	Gigabit-capable Passive Optical Network
GPS	Global Positioning System
gPTP	generalized Precision Time Protocol (see PTP)
HRM	Hypothetical Reference Model
HRPD	High Rate Packet Data
IANA	Internet Assigned Numbers Authority
ICV	Integrity Check Value
HSR	High availability Seamless Redundancy
IP	Internet Protocol
IPv4,6	IPv6 Internet Protocol version 4 / 6
IRNSS	Indian Regional Navigation Satellite System
IS	Integration Service
ISO	International Organization for Standardization
ISS	Internal Sublayer Service
IWF	Inter-Working Function
JD	Julian Date
JDN	Julian Day Number
LAN	Local Area Network
LCI	Location Configuration Information
LLC	Logical Link Control
LTE	Long Term Evolution
LTE-A	Long Term Evolution – Advanced
M2M	Machine to Machine
MAC	Media Access Control (according to IEEE Std 802.3-2005)
MACsec	Media Access Control security
MAFE	Maximum Average Frequency Error
MA-L	MAC Addresses Large
MA-M	MAC Addresses Medium
MAN	Metropolitan Area Network
MA-S	MAC Addresses Small
MATIE	Maximum Average Time Interval Error
max\|TE\|	Maximum absolute Time Error
MBMS	Multimedia Broadcast Multicast Service
MBSFN	MBMS based on Single Frequency Network
MD	Media-Dependent
MDEV	Modified Allan Deviation
MII	Media-Independent Interface
MIMO	Multiple Input Multiple Output
MJD	Modified Julian Day
MLME	MAC Layer Management Entity (IEEE 802.11)
MPCP	MultiPoint Control Protocol (IEEE 802.3)
MPDPDU	MPCP Data Unit (IEEE 802.3)
MTIE	Maximum Time Interval Error
NE	Network Element
NIST	National Institute of Standards and Technology (see www.nist.gov)
NodeB	The basestation name for a 3G network, e.g. UMTS
NRZ	Non-Return to Zero
NTP	Network Time Protocol
NUI-48	48-bit Network Unique Identifier
NUI-64	64-bit Network Unique Identifier
OAM	Operations, Administration and Maintenance
OC	Ordinary Clock
OFD	Observed Floor Delay
OLT	Optical Line Terminal (IEEE 802.3)
ONT	Optical Network Terminal
ONU	Optical Network Unit (IEEE 802.3)
OSC	Optical Supervisory Channel
OSSP	Organization-Specific Slow Protocol
OTN	Optical Transport Network
OUI	Organizational Unique Identifier (allocated by the IEEE)
P2P	Peer-to-Peer
PAM	Pulse Amplitude Modulation
PDV	Packet Delay Variation
PEC	Packet-based Equipment Clock
PDU	Protocol Data Unit
PEC-S	Packet-based Equipment Clock Slave
PHY	Physical layer (according to IEEE Std 802.3-2005)
PICS	Protocol Implementation Conformance Statement
PLL	Phase-Locked Loop
PM	Phase Modulation
PNT-F	Packet Network Timing Function
PP	Packet Processing
ppm	parts per million
PPS	Pulse Per Second
PRC	Primary Reference Clock
PRTC	Primary Reference Time Clock (defined in G.8272)
PSN	Packet Switched Network
PTP	Precision Time Protocol (defined in IEEE1588)
PRP	Parallel Redundancy Protocol
QZSS	Quasi-Zenith Satellite System
RE	Radio Equipment (CPRI term for the physical-layer processing within the basestation; equivalent to the RRU or RRH)
REC	Radio Equipment Controller (CPRI term for the upper-layer processing within the basestation; equivalent to the BBU)
RF	Radio Frequency
RRH	Remote Radio Head (physical layer processing within a basestation; another name for the RRU; equivalent to the CPRI term RE)
RRU	Remote Radio Unit (physical layer processing within a basestation; another name for the RRH; equivalent to the CPRI term RE)
RT-DSLAM	Remote Terminal-Digital Subscriber Line Access Multiplexer
RTT	Radio Transmission Technology
RTT	Round-Trip Time
RWFM	Random Walk Frequency Modulation
SA	Security Associations
SAI-48	48-bit Standard Assigned Identifier
SAI-64	64-bit Standard Assigned Identifier
SBAS	Satellite Based Augmentation System
SDH	Synchronous Digital Hierarchy
SEC	SDH Equipment Clock
SFD	Start Frame Delimiter
SM	State Machine
SNTP	Simple Network Time Protocol
SOF	Start of Frame
SSM	Synchronization Status Message
SSMB	Synchronization Status Message Byte
SSU	Synchronization Supply Unit
STA	Station
STM	Synchronous Transport Module
STM-N	Synchronous Transport Module-N
SyncE	Synchronous Ethernet
TAI	Temps Atomique International (international atomic time)
T-BC	Telecom Boundary Clock (defined in G.8273.2)
TC	Traffic Class
TC	Transparent Clock (see T-TC)
TDD	Time Division Duplexing
TDEV	Time Deviation
TDM	Time Division Multiplexing
TDMA	Time Division Multiple Access
TD-SCDMA	Time Domain Synchronized CDMA
TE	Time Error
TG	Task Group
T-GM	Telecom Grandmaster (defined in G.8273.1)
TIE	Time Interval Error
TLV	Type, Length, Value (according to IEEE Std 802.1AB)
ToD	Time of Day
ToS	Type of Service
TS	TimeStamp
T-TC	Telecom Transparent Clock (defined in G.8273.3)
T-TSC	Telecom Time Slave Clock (defined in G.8273.2)
UCMM	UnConnect Message Manager
UCT	UnConditional Transfer
UDP	User Datagram Protocol
UDP/IP	User Datagram Protocol (see IETF RFC 768 B5) / Internet Protocol
UI	Unit Interval
UTC	Coordinated Universal Time
UTC	Universal Time Co-ordinated
UTRA	Universal Terrestrial Radio Access
VCO	Voltage Controlled Oscillator
VLAN	Virtual Local Area Network
WCDMA	Wideband CDMA
WDM	Wavelength Division Multiplexing
WFM	White Frequency Modulation
WG	Working Group
WiMAX	Worldwide Interoperability for Microwave Access
WLAN	Wireless Local Area Network
xDSL	x-type Digital Subscriber Line
xPON	x Passive Optical Network

Relationship between fronthaul terms

BTS	2G term for a basestation
Node B	3G term for a basestation
eNodeB	4G term for a basestation
	Generic terms	CPRI terms
	BBU	REC	Upper layer processing (i.e. not physical layer) within a basestation
	RRU, RRH	RE	Physical layer processing (i.e. radio layer) within a basestation
gNodeB	5G term for a basestation
	Generic terms	eCPRI terms
	CU	eREC	Higher-layer processing within a basestation
	DU	eREC	Lower-layer processing within a basestation
	RRU, RRH	eRE	Physical layer processing (i.e. radio layer) within a basestation

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