Operational Conditions - Ericsson CME 20 R6.1 Reference Manual

The synchronization of the RF transmission is in compliance with
requirements in /GSM:05.10/ for GSM 900 and GSM 1800, and /
PCS:7/ for GSM 1900.
20.3.2 BCCH Carrier Filling
The output power for a transmitter sending the BCCH frequency is
constant and equal to the nominal output power, except for the power
ramping between bursts, see /GSM 05.08:7.1/ for GSM 900 and GSM
1800 and /PCS:6.5.1/ for GSM 1900.
During idle timeslots dummy bursts are transmitted, the dummy burst is
defined in /GSM:05.02:5.2.6/.
20.3.3 Transmitter Filling
The RBS can be configured for transmitter filling. All transmitters
serving a cell are then configured with a filling level which transmits
dummy bursts in the idle timeslots.
Transmitter filling is not configurable for synthesized frequency hopping
transmitters.
Transmitter filling is not configurable for transmitters configured for
DTX.
Transmitters configured for BCCH carrier are not affected by the filling
level.
20.3.4 TX–Diversity
In order to improve the downlink performance, the BTS can be
configured for transmitter diversity. Two transmitters connected to
different antennas are then transmitting with maximum power on the
same frequency. One of the transmitters has its bursts forwarded in
time two bits compared to the other. The MS receiver signal processing
will then contribute to a downlink performance gain of 3–5 dB.
Transmitter diversity is initiated when the first transmitter is configured
on A-bis to a nominal power value 2 dB higher than the maximum
nominal power defined for the RBS, and no Operation & Maintenance
Link is established to the second transceiver.
If any transmitter goes down, then the other transmitter will also be
taken out of operation.
20.4

Operational Conditions

20.4.1 Capabilities
The transmitter can control the output power as defined by the Base
Station Power Control function.
The transmitter is capable of frequency hopping as defined by the
Frequency Hopping function.
EN/LZT 123 2697 R5A
1998-08-13
© Ericsson Radio Systems AB
— All Rights Reserved —
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