
WCDMA Signaling
R&S
®
CMW-KG4xx/-KM4xx/-KS4xx
44
User Manual 1173.9657.02 ─ 11
Test and loop modes
Various tests, especially receiver tests, require that data is looped back by the UE.
Several loop modes are defined in 3GPP TS 34.109. Only loop mode 1 and 2 are rele-
vant for bidirectional radio bearers. For reduced signaling only loop mode 2 is used.
With or without loop, RMC connections are always set up in test mode, i.e. without
alerting.
Loop Mode 1
Loop Mode 2
Loopback point
Above layer 2
Effectively on transport layer (higher lay-
ers in Transparent Mode)
Data looped back
RLC/PDCP SDUs
Transport block data and CRC bits
Special settings
RLC modes "transparent" and "acknowl-
edged" are available
UL CRC can be enabled or disabled, see
below
UL Cyclic Redundancy Check (CRC) options:
●
UL CRC disabled:
UE performs no CRC. Received DL CRC bits are added to the UL transport block.
Symmetric DL/UL data rate and asymmetric DL/UL transport block size.
●
UL CRC enabled:
UE performs CRC check and sends resulting UL CRC bits to the tester. Received
DL CRC bits are discarded.
Symmetric DL/UL data rate and symmetric DL/UL transport block size or
asymmetric DL/UL data rate and asymmetric DL/UL transport block size.
Loops are required for the "WCDMA Signaling BER Measurement", see especially
chapter 2.2.18.1, "BER, BLER and DBLER Tests"
2.2.11.2
Signaling Radio Bearer (SRB)
The data content of the SRB is defined on transport channel level in 3GPP TS 34.108.
The most important layer 1 parameters are shown in the following table, depending on
the data rate.
SRB 1.7 kbps
SRB 2.5 kbps
SRB 3.4 kbps
SRB 13.6 kbps
DPCH Slot Format
0
6
4
8
Transmission Time
Interval
80 ms
40 ms
40 ms
10 ms
Coding Type
Convolution coding
Convolution coding
Convolution coding
Convolution coding
Coding Rate
1/3
1/3
1/3
1/3
Rate Matching
attribute
155
256
155
155
Size of CRC
16 bits
12 bits
16 bits
16 bits
TFS (TF0, TF1)
0 x 148 bits,
1 x 148 bits
0 x 100 bits,
1 x 100 bits
0 x 148 bits,
1 x 148 bits
0 x 148 bits,
1 x 148 bits
General Description
深圳德标仪器
135-1095-0799