False transmit format detection ratio (FDR) is a performance metric used in UMTS networks to measure how often a receiver incorrectly identifies the transport format of an incoming signal. A high FDR indicates that the receiver is misinterpreting the coding scheme or payload size, leading to dropped frames and increased error rates. Engineers monitor this ratio during base station testing to ensure reliable decoding under poor signal conditions.
Heard on the job
The FDR is spiking on sector three whenever the signal-to-noise ratio drops below the threshold.