A transceiver apparatus and a method comprise detecting means for detecting messages, wherein the detecting means comprises a first detector arranged to operate over a first detection period and which output indicates the beginning of a message with a first detection probability, and a second detector arranged to operate over a second detection period and which output indicates the detection of the beginning of a message with a second detection probability. The second detection probability is higher than the first detection probability and the transceiver apparatus is arranged to receive the message if the second detector indicates detection of the beginning of a message.