1. A wireless communication apparatus operable to transmit packet via a wireless communications channel, the wireless communication apparatus comprising:processor circuitry configured to:
determine if the channel is clear for use using a clear channel assessment, CCA, parameter which governs sensitivity of sensing a clear channel; and
control the CCA parameter based on a transmission performance of the wireless communication apparatus by monitoring performance of the wireless communication apparatus in terms of successful transmission by the wireless communication apparatus to intended destinations,
the processor circuitry is configured to determine transmission performance on the basis of a rate of failure of transmissions to reach their intended destinations,
the processor circuitry is configured to determine if a transmission has failed to reach its intended destination and thence to determine if the failure of that transmission to reach its intended destination is likely to be the result of a collision with another transmission in the channel, and
the processor circuitry is configured to classify a failure in accordance with its likelihood of being due to a collision with another transmission in the channel, the classifier being operable with reference to channel information regarding past conditions of the channel.