This value reports the percentage of frames dropped over the past minute on a specific AP radio because its transmit queue was full. Admins use it as a direct indicator of QoS overload, since a sustained non-zero drop ratio means the radio can't keep up with offered traffic and end users will notice packet loss. For example, a ratio of 15 means 15% of frames were discarded in the last minute, which would justify tuning QoS policy or adding capacity.