Rohde & Schwarz CMU-K20, Руководство по эксплуатации

Страница: 246 / 646

Signalling: Connection Control
CMU-K20/K21/K22/K23/K24
1115.6088.12 4.168 E-12
service) or
TEST
(packet data main service) signalling states. It is automatically
reset (switched off) each time that the connection is released.
A test case using the random frequency offset for determining the EGPRS usable
receiver input level range is described in standard 3GPP TS 51.010-1.
Remote control
PROCedure:BSSignal:FM:DEViation:RANDom:ENABle ON | OFF
Aux TX
If option CMU-B95,
Additional RF Generator,
is fitted, the CMU provides a second
RF signal Aux TX that can be used for the BCCH to set up and maintain a
connection (circuit switched or packet data main service). The following Aux TX
signal parameters can be set:
Channel Type
Switch the Aux TX signal on or off. If Aux TX is switched
Off
, the
Main TX
generator provides both the TCH and the BCCH.
Level
Aux TX signal level. This defines the
BCCH Level
of the softkey-oriented
BS Signal
tab if Aux TX is used for the BCCH. The Aux TX level is
independent of the
Main TX
level.
RF Channel
Aux TX channel number. This defines the
BCCH Channel
of the
softkey-oriented
BS Signal
tab if Aux TX is used for the BCCH.
The Aux TX channel must be different from the TCH channel.
Note: After a handover the BS Signal tab no longer shows the current Aux
TX settings 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.
Remote control
CONFigure:BSSignal:CCH:AUXTx:CHANnel
CONFigure:BSSignal:CCH:AUXTx:CHTYpe
CONFigure:BSSignal:CCH:AUXTx:LEVel[:ABSolute]
Tips for using the Aux TX signal:
The main purpose of the Aux TX signal is to ensure a stable connection
(continuous BCCH), while the Main TX signal provides a TCH in all 8 timeslots.
This is particularly useful for packet data channels. The following hardware-related
restrictions should be kept in mind:
•
The RF output connector RF 3 OUT is not available if Aux TX is used. Selecting
RF 3 OUT in the AF/RF tab of the
Connection Control
menu causes an error
message.
•
The Aux TX channel must be different from the TCH channel. If a conflicting
frequency is set, the CMU displays a notice box indicating that the setting will be
auto-corrected. Conflicting frequency settings may occur in the
BS Signal
tab
(TCH Channel, BCCH Channel, RF Channel, Hopping sequence Lists) but also
indirectly when a connection is set up
(Signal On, Main Service)
or a
Power/PCL
measurement is performed.
If equal TCH and BCCH channel numbers are needed for a particular test, it is still
possible to select the multislot mode
TCH or BCCH
(see p. 4.163 ) in order to obtain
a TCH in all 8 timeslots.
Hopping
sequence List ...
The table section
Hopping Sequence List...
configures the four frequency hopping
sequences A, B, C, and D. Configured hopping sequences can be selected via the
Hopping
softkey in the signalling state
Call Established
(see section
Softkey-
深圳德标仪器
135-1095-0799