Ericsson RBS 2106 Reference Manual page 279

Description
The RBS receives four access bursts and performs demodulation
according to the previously stored channel mode. Channel decoding is
performed according to /GSM:05.03:5.3.1/. The RBS performs the
following PDCH measurements produced per access burst by the
decoder:
•
•
•
•
A PCU Frame is created, consisting of the four decoded access bursts
and the PDCH measurements. The PCU Frame is then transmitted on
Abis Interface.
27.3.4 Continuous Timing Advance Update
Purpose
Continuous Timing Advance Update specifies the functionality for
updating of the timing advance values, using the logical channel
PTCCH/U and PTCCH/D scheduled on PDCH according to /
GSM:05.02/.
Preconditions and Initiation
The function is inititated when a CHANNEL_ACTIVATION message
with element "Activation Type" = Packet Channel is received on Abis
RSL interface.
Description
The RBS receives an access burst on PTCCH/U on air interface. The
access burst is demodulated, decoded /GSM:05.03:5.2/ and the timing
advance value is determined. The timing advance value is updated in
the next PTCCH downlink block following the access burst. PTCCH
downlink block is according to /GSM:04.04:7.4f/.
The RBS performs coding /GSM:05.03:5.2/ and transmits the PTCCH
downlink block on nominal power by four normal bursts on PTCCH/D.
EN/LZT 720 0008 P2A
2001-11-28
Burst quality
Frame quality
CRC
Access delay
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GPRS, Physical Link Layer
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