Rohde & Schwarz CMU-K20, Operating Manual

Page: 247 / 646

CMU-K20/K21/K22/K23/K24
Signalling: Connection Control
1115.6088.12 4.169 E-12
oriented Version: Single Slot Mode
on page 4.162 ).
In GSM networks, frequency hopping is primarily used for error protection in the radio
transmission path. It consists of periodically switching over the transmission channels (except
BCCH) to other carrier frequencies. The frequency changes after each radio frame so that
the dwell time on each carrier frequency is 4.615 ms ("slow" frequency hopping).
Frequency hopping is controlled by the network: The BTS transfers a hopping sequence
(hopping list) to the mobile station. From this list, the mobile station calculates the radio
frequency channel for each TDMA frame number according to an algorithm described in
GSM 05.02.
Four standard hopping lists
A, B, C,
and
D
are defined as default sequences, see
command description in chapter 6. All four lists can be modified by entering up to
64 channel numbers. If a shorter list is desired,
Off
can be entered for the unused
channel numbers.
Remote control
PROCedure:SIGNalling[:CSWitched][:TCH][:SSLot]:
FHOPping:SEQuence
CONFigure:BSSignal[:CSWitched][:TCH][:SSLot]:FHOPping:A
CONFigure:BSSignal[:CSWitched][:TCH][:SSLot]:FHOPping:B
CONFigure:BSSignal[:CSWitched][:TCH][:SSLot]:FHOPping:C
CONFigure:BSSignal[:CSWitched][:TCH][:SSLot]:FHOPping:D
Network Parameters (Connection Control – Network)
The
Network
tab defines various parameters of the network that the CMU reports to the mobile station.
Some functions of the menu depend on the
Main Service (Circuit Switched
or
Packet Data (GPRS)
operating mode) and most parameters can no longer be set after the
Call Established
signalling state is
reached. As a consequence, settings may be disabled or even hidden in some operating modes of the
CMU/MS test system. Exact information is provided in the command description in chapter 6 of this
manual.
The present chapter describes the parameters related to circuit switched operation of the mobile
phone. Tests in
Packet Data (GPRS)
mode require option CMU-K42. They are described in section
Network Parameters (Connection Control – Network)
on p. 4.197 ff.
The CMU provides a softkey-oriented version of the
Network
tab and a table-oriented version with
extended functionality. The
Network
hotkey toggles between the two versions if it is pressed
repeatedly.
Softkey-oriented Version
The softkey-oriented version of the
Network
tab selects the following traffic channel parameters:
•
The channel coding and transmission rate
(Traffic Mode)
•
The bit pattern that the CMU transmits to the MS
(Bit Stream)
深圳德标仪器
135-1095-0799