Loopback Bit Error Ratio Measurement Description; How Is A Loopback Bit Error Ratio Measurement Made; Mobile Station (Ue) Control During Fdd Test Mode Operation; Input Signal Requirements - Agilent Technologies 8960 Series Reference Manual

Loopback Bit Error Ratio Measurement Description

How is a Loopback Bit Error Ratio measurement made?

When the test set measures loopback bit error ratio, it sends a known data pattern on the downlink dedicated
traffic channel (DTCH) to a mobile station (UE) that is configured in loopback mode 1 (see 3GPP TS 34.109.
v3.1.0). The mobile station decodes the data and re-transmits it on the uplink DTCH. The test set analyzes the
uplink data to see how closely it matches the data bits originally sent on the downlink. The measurement
result is the ratio of incorrectly received bits to the total bits sent to the UE, expressed at a percentage (%).
This measurement is typically performed at low cell power levels to measure the sensitivity of the mobile
station's receiver; the lower the level of signal that the mobile station can receive and still correctly decode the
data, the better the sensitivity. The receiver sensitivity test is described in 3GPP TS 34.121, section 6.2, v3.2.0,
Reference Sensitivity Level. This measurement can also be used for the Maximum Input Level test, 3GPP TS
34.121, section 6.2, v3.2.0.
The number of data bits to send during the measurement is selectable by the user. However, the actual
number of bits used to analyze the data is always the largest even multiple of the number of bits needed to fill
a DTCH transport block for the transmitted format. For the 12.2 kbps reference measurement channel (RMC)
used in FDD Test operating mode, the transport block is 244 bits.

Mobile Station (UE) Control During FDD Test Mode Operation

The FDD Test operating mode does not provide radio bearer setup control of the mobile station (UE) for test
mode operation. The operator must configure the mobile station in loopback mode 1 and synchronize it to the
test set's downlink signal in order to make this measurement in FDD Test operating mode. Refer to
Operating Mode" .
The uplink transport format must include both the DTCH and the DCCH; however, only the DTCH
information is used for the loopback bit error ratio measurement.

Input Signal Requirements

• The expected power into the test set must be set in order to maintain the link with the mobile station. This
is done using the MS Target Power setting or by using manual receiver power control and specifying the
expected power level. See

Trigger Source

The trigger source is always protocol.

Related Topics

"Programming a Loopback Bit Error Ratio Measurement"
"Loopback Bit Error Ratio Troubleshooting"
"Receiver Control" .
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Loopback Bit Error Ratio Measurement Description
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