A device comprising: a transceiver operable in a first or second mode and configured to receive packets from a remote device, each packet comprising an indication of whether or not the remote device has a further packet to transmit, wherein: in the first mode the transceiver: (i) sends a polling message in response to receiving the indication of a further packet for transmission; and (ii) listens for that further packet; and in the second mode the transceiver: (i) does not send a polling message in response to receiving the indication of a further packet for transmission; and (ii) listens for packets regardless of whether a received packet indicates that there is a further packet to transmit or not; and a controller configured to monitor an activity level for the transceiver and cause the transceiver to operate in the first or second mode in dependence on the activity level.