GSM Frame Erasure Rate (FER) Measurement Description

How is the FER Measurement Made?

The test set measures FER by sending a Layer 3 message that does not require a Layer 3 response from the mobile station. It does require acknowledgment in the form of an RR frame from the mobile station. When the test set does not receive the RR frame in acknowledgment, it retransmits the Layer 2 message. The test set counts the number of times it resends Layer 2 messages.

The test set uses an MM Information message with all the optional fields omitted for the Layer 3 message.

You can make the Frame Erasure Rate Measurement on a full-rate FACCH channel (FACCH/F) or a half-rate FACCH channel (FACCH/H).

Operating Considerations

The FER measurement can only be performed in Active Cell Operating Mode.

The connection type must be Auto.

FER Measurement Parameters

• Samples to Test - The number of samples to be taken by the measurement.
• Minimum Frame Interval (FACCH/F)- The minimum interval between FACCH frames (full rate) being sent to the mobile station.
• Minimum Frame Interval (FACCH/H)- The minimum interval between FACCH frames (half rate) being sent to the mobile station.
• Trigger Arm - (See Trigger Arm (Single or Continuous) Description .)
• Measurement Timeout - (See Measurement Timeouts .)

FER Measurement Results

• Integrity Indicator - (see Integrity Indicator )
• Frames Sampled - The count of samples tested.
• Frames Erased - The count of frames requiring retransmission by the test set.
• Frame Erasure Rate - The ratio of Frames Erased to Frames Sampled.

Related Topics

Programming a Frame Erasure Rate (FER) Measurement

How Do I Make a Repeated SACCH Frame Erasure Rate (FER) Measurement?

SETup:FFERate

FETCh:FFERate

Test Adherence to Standards