Rohde & Schwarz CMU-K20, Руководство по эксплуатации

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GPRS Signalling and EGPRS
CMU-K20/K21/K22/K23/K24
1115.6088.12 4.200 E-12
and coding schemes MCS1 to MCS9. Puncturing means that
bits in the radio blocks are removed after channel coding in
order to reduce the amount of transferred data and enhance the
useful data rate. The puncturing schemes are selectable so that
it is possible to test their influence on measured quantities, e.g.
bit error rates. Moreover, it is possible to test incremental
redundancy with a definite initial puncturing scheme; see below.
3 different puncturing schemes (PS) are defined. The
modulation and coding schemes MCS3, MCS4 and MCS7 to
MCS9 can be combined with 3 PS, the remaining modulation
and coding schemes with 2 PS only.
For schemes MCS1 to MCS6, four normal bursts carry one RLC
block. For the remaining schemes MCS7 to MCS9, four normal
bursts carry two RLC blocks. The puncturing schemes for the
two blocks can be set individually.
Incremental
Redundancy
Enable or disable Incremental Redundancy RLC mode for the
downlink; see background information below.
With enabled incremental redundancy, the CMU uses the
selected puncturing scheme as initial puncturing scheme but
cyclically changes the puncturing scheme if data blocks must be
retransmitted. This setting corresponds to normal operation of
the BTS in the network.
With disabled incremental redundancy, the puncturing scheme is
fixed. This setting is suitable for layer 1 tests at fixed
transmission parameters.
PC Meas. Chan.
Channel type (BCCH or PDCH) that the mobile uses to
determine the received signal strength and quality. The PC
Meas. Channel parameter corresponds to the GPRS power
control parameter
PC_MEAS_CHAN
in the system information
SI 13 Rest Octets (GSM 04.18).
USF
Update State Flag in the range 0 to 7 to be set in the blocks
transmitted to the MS in GPRS test mode.
USF Duty Cycle
Defines the percentage of downlink GPRS radio blocks
containing the USF assigned to the MS. This setting can be
changed in
TBF Established
signalling state only, after the
selected USF is actually assigned to the MS under test.
100 % assigned
means that all blocks contain the assigned
USF.
0 % assigned, 100% random
means that each USF (0 to
7) except the assigned one is used with a probability of 1/7.
12.5
% assigned, 87.5 % random
means that each USF including the
assigned one is used with a probability of 1/8.
This setting can be used to check whether the USF BLER
depends on the transmitted USF.
Extend. Dyn.
Alloc.
Enable or disable Extended Dynamic Allocation of the mobile.
Extended dynamic allocation is an optional medium access
mode (3GPP TS 04.60).
With the
Auto
setting the CMU checks whether the mobile
supports Extended Dynamic Allocation by evaluating the
GPRS
Extended Dynamic Allocation
message received during the
GPRS Attach. Extended Dynamic Allocation is enabled only if
the mobile supports this feature.
Number of PDUs
Number of Protocol Data Units (PDUs) that the MS is to transmit
in the uplink during GPRS test mode A.
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