The HSDPA block error ratio (BLER) measurement can only be performed on a
Radio Bearer Test Mode
connection with a
12.2k RMC + HSDPA
or 12.2k RMC + HSPA. To perform the HSDPA BLER measurement, the test set sends blocks of data to the UE on the downlink HS-PDSCH(s). The data sent on the downlink HS-PDSCH(s) is determined by the
HS-DSCH Data Pattern
FDD Test "HS-DSCH Data Pattern"
FDD Test Operating Mode
). The test set then monitors the positive acknowledgments (ACKs) and negative acknowledgments (NACKs) sent by the UE on the uplink HS-DPCCH.
The UE is required to respond to every block of data directed to it with either an ACK or NACK. If it does not respond to a block in its assigned TTI, the test set logs the event as a statistical DTX (statDTX). Also, if the UE responds to a block with data other than all 1s (ACK) or all 0s (NACK), the TTI is treated as a statDTX. StatDTXs are considered block errors, and are included in the BLER calculation. You can specify how the test set responds to statDTXs using the statDTX Reception Behavior setting.
In addition to ACK/NACK information, the uplink HS-DPCCH also carries channel quality indicator (CQI) information. The test set analyzes the CQI values sent by the UE and reports the Median CQI .
operating mode the test set does not provide radio bearer setup control of the UE. You must configure the UE to synchronize to the test set, demodulate the downlink HS-SCCH and HS-PDSCH channels and generate the appropriate uplink HS-DPCCH (see
Synchronizing the UE to the Test Set's Downlink to Make Measurements
Once the UE begins transmitting its HS-DPCCH, the test set requires a finite amount of time to acquire and decode the UE's signal. If you initiate the HSDPA BLER measurement while the test set is still acquiring the UE's signal, the measurement will report statDTXs until it finishes its acquisition and begins demodulating the HS-DPCCH. To avoid an incorrect HBLER result, it is recommended that you wait approximately 2 seconds after the UE begins transmission of its HS-DPCCH before initiating the HBLER measurement (the amount of time required varies depending upon your test configuration).
Sets the number of blocks to test during the measurement. See Blocks to Test Specified Per Serving Cell for more information about setting the number of blocks to test with active DC-HSDPA connections.
When DC-HSDPA is configured (the
Current Secondary Serving Cell Status
, and the
Blocks to Test Specified Per Serving Cell
is set to
, then this setting is not used, and the actual number of blocks to test for the measurement is determined by the
DC-HSDPA Serving Cell Blocks to Test
DC-HSDPA Secondary Serving Cell Blocks to Test
GPIB Command: SETup:HBLerror:COUNt
On, then the number of blocks to test for the serving cell is determined by DC-HSDPA Serving Cell Blocks to Test and the number of blocks to test for the secondary serving cell is determined by DC-HSDPA Secondary Serving Cell Blocks to Test .
Off, then the number of blocks to test for each serving cell is not predicted, but the total number of blocks to test for the serving cell and the secondary serving cell is determined by Number of blocks to test .
GPIB Command: SETup:HBLerror:COUNt:DCHSdpa[:STATe]
GPIB Command: SETup:HBLerror:COUNt:DCHSdpa:SERVing
GPIB Command: SETup:HBLerror:COUNt:DCHSdpa:SECondary
. If you set
, ensure that the
value is greater than the time the measurement needs to measure the desired
Number of blocks to test
The trigger source for this measurement is always protocol-based (see Trigger Source Description ).
This result reports the data throughput of the HSDPA connection. 3GPP TS 34.121 F.6.3.1 defines Information Bit Throughput R as "the sum (in kilobits) of the information bit payloads (excluding the 24-bit HS-DSCH CRC) successfully received during the test interval, divided by the duration of the test interval (in seconds)."
Each time the test set receives an ACK from the UE, it increments a counter called "totalBits" by the size of the data block (in bits) that was positively acknowledged. Each time the test set transmits a data block on the HS-PDSCHs, it increments a counter called "blocksTransferred" (a transmission of a new block of data or retransmission of an old block of data both count as a block transmission). Each time the test set does not transmit a block in a TTI it increments a counter called regDTX.
Results are provided for the serving cell, secondary serving cell and combined dual cell with an active DC-HSDPA connection. However, when
Blocks to Test Specified Per Serving Cell
Information Bit Throughput
for the combined dual cell is not available. This is because the blocks to test for each serving cell are configured independetly and the transmit time for each serving cell is not equal. Therefore, the overall time to complete the transmission of the total blocks in the dual cell cannot be calculated exactly.
CQI frequency distribution (frequency/CQI): 1/10, 3/11, 5/12, 4/13, 2/14
Cumulative CQI frequency distribution (cumulative freq/CQI): 1/10, 4/11, 9/12, 13/13, 15/14
value occurs at (15-1)/2 = 7 occurrences, which lies between a CQI value of 11 and 12. The
value in this example is thus 12.
The expected power into the test set must be set in order to maintain the link with the UE. This is done using the UE Target Power setting or by using manual receiver power control and specifying the expected power level. See Receiver Control .
Manual Operation: How Do I Make an HSDPA Block Error Ratio Measurement?