Reference Manual

GPRS, Physical Link Layer
Description
The RBS receives a PCU Frame on Abis interface and checks for
errors. The RLC/MAC Block and the control information channel
mode, coding scheme and power level is extracted from the PCU frame.
A radio block is created by encoding the RLC/MAC Block according to
the given coding scheme /GSM:05.03:5/. The information of channel
mode is stored to be applied on the next block uplink /
GSM:05.02:6.3.2.2.1/.
The Radio Block is transmitted by four normal bursts on air interface
using the received power level.
27.3.2 Radio Block Reception
Purpose
Radio Block Reception specifies the funtionality for uplink transport of
RLC/MAC Block.
Preconditions and Initiation
The function is initiated by a PCU frame of type PCU-DATA-IND,
received on Abis GSL interface.
Description
The RBS receives a Radio Block (four normal bursts) on air interface
and performs demodulation according to the previously stored channel
mode. Deinterleaving and channel decoding is performed according to
received steal flags /GSM:05.03:5/.
The RBS performs the following PDCH measurements on a block basis:
•
Block quality
• CRC
•
RX level
•
Access delay
A PCU Frame is created, consisting of the RLC/MAC Block and the
PDCH measurement. The PCU Frame is then transmitted on Abis
Interface.
27.3.3 Access Burst Reception
Purpose
Access Burst Reception specifies the functionality for uplink transport
of Random access.
Preconditions and Initiation
The function is initiated by a PCU frame of type PCU-DATA-IND,
received on Abis GSL interface.
276 (485)
EN/LZT 720 0008 P2A
2001-11-28
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