A device capable of communicating according to a wireless communications protocol, the device comprising: a transceiver 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, the transceiver being operable in a first mode or a second mode, wherein: in the first mode the transceiver is configured to: (i) send a polling message to the remote device in response to receiving the indication of the remote device having a further packet to transmit; and (ii) listen for that further packet; and in the second mode the transceiver is configured to: (i) not send a polling message to the remote device in response to receiving the indication of the remote device having a further packet to transmit; and (ii) listen for packets regardless of whether a received packet indicates that the remote device has a further packet to transmit or not; and characterised in that the device further comprises: a controller configured to: monitor an activity level for the transceiver by measuring the number of packets received over a period of time that indicate that the remote device has further packets to transmit; compare the activity level with a threshold; and cause the transceiver to operate in the first mode or the second mode in dependence on said comparison. a transceiver 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, the transceiver being operable in a first mode or a second mode, wherein: in the first mode the transceiver is configured to: (i) send a polling message to the remote device in response to receiving the indication of the remote device having a further packet to transmit; and (ii) listen for that further packet; and in the second mode the transceiver is configured to: (i) not send a polling message to the remote device in response to receiving the indication of the remote device having a further packet to transmit; and (ii) listen for packets regardless of whether a received packet indicates that the remote device has a further packet to transmit or not; and in the first mode the transceiver is configured to: (i) send a polling message to the remote device in response to receiving the indication of the remote device having a further packet to transmit; and (ii) listen for that further packet; and in the second mode the transceiver is configured to: (i) not send a polling message to the remote device in response to receiving the indication of the remote device having a further packet to transmit; and (ii) listen for packets regardless of whether a received packet indicates that the remote device has a further packet to transmit or not; and characterised in that the device further comprises: a controller configured to: monitor an activity level for the transceiver by measuring the number of packets received over a period of time that indicate that the remote device has further packets to transmit; compare the activity level with a threshold; and cause the transceiver to operate in the first mode or the second mode in dependence on said comparison. monitor an activity level for the transceiver by measuring the number of packets received over a period of time that indicate that the remote device has further packets to transmit; compare the activity level with a threshold; and cause the transceiver to operate in the first mode or the second mode in dependence on said comparison.