Rohde & Schwarz CMU-K20, Operating Manual

Page: 241 / 646

CMU-K20/K21/K22/K23/K24
Signalling: Connection Control
1115.6088.12 4.163 E-12
Remote control
CONFigure:BSSignal:FM:DEViation <Frequency>
Mode
The
Mode
softkey defines the BS Signal configuration after a connection has been
set up:
BCCH or TCH
Switch off BCCH after the connection has been established. This
means that in the
Call Established
and
TBF Established
states,
all timeslots are available for the TCH. This is particularly useful
for BER tests on packet data channels; see section
BER Tests of
PDTCHs: BLER and DBLER
on p. 4.120 ff.
BCCH and TCH
Maintain BCCH after the connection has been established. The
BCCH occupies timeslot 0 but also blocks the two adjacent
timeslots (no. 7 and 1) for TCHs: Only timeslots 2 to 6 are
available for BS signal traffic channels.
Note: If option CMU-B95, Additional RF Channel, is fitted, the Aux TX signal
can be used for the BCCH (see
4.168 ). With this signal configuration
all timeslots are available for the TCH, even though the BCCH can be
maintained to ensure a stable connection. The
Mode
softkey is hidden.
Remote control
CONFigure:BSSignal:CCH:MODE BATC | BOTC
The following BCCH settings are provided by the Main TX generator or the Aux TX generator (with
Option CMU-B95), depending on the settings in the table-oriented
BS Signal
tab (see Aux TX section
on p. 4.168 )
.
BCCH
Level
The
BCCH Level
softkey sets the absolute level (in dBm) of the BCCH control
channel used for synchronization of the mobile. The value range for
Level
depends
on the RF output selected and of the external attenuation set.
Remote control
CONFigure:BSSignal:CCH:LEVel:ABSolute <Level>
RF
Channel
The
RF Channel
softkey selects the GSM channel number of the BCCH control
channel. For an overview of GSM channels see section
Control of Input and Output
Signals
on page
4.69
. In GSM900 the CMU can use all three sub-bands (P-GSM,
E-GSM, R-GSM), so care must be taken that the MS supports the selected
RF
Channel.
Remote control
CONFigure:BSSignal:CCH:CHANnel <CCHChannel>
Note: After a handover the BS Signal tab no longer shows the current
Mode, BCCH Level
and
RF Channel
but displays "from other network", indicating that the values of the origin
network have been left unchanged. Display of the current values is restored by returning to
the target network or setting up the connection again.
The right half of the BS Signal tab contains the following TCH settings:
Slot
Mode
The
Slot Mode
softkey set the mobile station under test to either
Single Slot
or
Multislot
operation. As soon as a call is established the slot mode can no longer be
changed and the softkey is disabled (grayed). The
Multislot
setting changes some
of the other softkeys in the
BS Signal
tab (see section
Softkey-oriented Version: MS
Multislot
on p. 4.157 ). It will come into effect only if the BS under test is capable of
multislot operation (i.e. if it supports HSCSD or GPRS).
深圳德标仪器
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