Reference Manual

Glossary
IMSI International Mobile Subscriber Identity
INIT Initial
INT Internal
IOG Input/Output Group
IOM Internal Operation and Maintenance bus
IR InfraRed
IS Interface Switch
IWD InterWork Description
JTC Joint Technical Committee
LAPD Link Access Procedures on D-channel
LAPD is the data link layer (layer 2)
protocol used for communication between
the BSC and the BTS on the Abis
interface.
Abis layer 2 is sometimes used
synonymously with LAPD.
LBO Line Build Out
LED Light Emitting Diode
LLB Line Loop Back
LNA Low Noise Amplifier
Local bus The local bus offers communication
between a central main RU (DXU) and
distributed main RUs (TRU and ECU).
Local mode When the RU is in Local mode, it is not
communicating with the BSC.
Local/Remote switch A switch used by the operator to order the
RU to enter Local or Remote mode.
LOF Loss Of Frame
Logical Channel A logical channel represents a specified
portion of the information carrying
capacity of a physical channel.
GSM defines two major categories of
logical channels:
TCHs Traffic CHannels, for speech or
user data
EN/LZT 720 0008 P2A
2001-11-28
477 (485)
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