A mobile device comprising: a transceiver for accessing a packet-based network; a screen; communication processing apparatus coupled to the transceiver and screen, for conducting a packet-based video call with a remote device via a channel established over the packet-based network; and a sensor for sensing a spatial state of the mobile device; wherein the communication processing apparatus is coupled to said sensor and is configured so as to detect, during the video call, whether said mobile device is in a first spatial state or a second spatial state, characterized in that: the first spatial state comprises said mobile device being held in a video capture position; the mobile device comprises a rear-facing camera arranged to generate data for an outgoing video signal of the video call; the communication processing apparatus is configured to, when the mobile device is in a rear-facing video capture mode and held in the video capture position, enable outgoing video functionality of the video call, so as to transmit to the remote device data generated by the rear-facing camera as the outgoing video signal, but to suppress incoming video functionality of the video call; and the communication processing apparatus is configured to suppress both the incoming and the outgoing video functionality when in the second spatial state. a transceiver for accessing a packet-based network; a screen; communication processing apparatus coupled to the transceiver and screen, for conducting a packet-based video call with a remote device via a channel established over the packet-based network; and a sensor for sensing a spatial state of the mobile device; wherein the communication processing apparatus is coupled to said sensor and is configured so as to detect, during the video call, whether said mobile device is in a first spatial state or a second spatial state, characterized in that: the first spatial state comprises said mobile device being held in a video capture position; the mobile device comprises a rear-facing camera arranged to generate data for an outgoing video signal of the video call; the communication processing apparatus is configured to, when the mobile device is in a rear-facing video capture mode and held in the video capture position, enable outgoing video functionality of the video call, so as to transmit to the remote device data generated by the rear-facing camera as the outgoing video signal, but to suppress incoming video functionality of the video call; and the communication processing apparatus is configured to suppress both the incoming and the outgoing video functionality when in the second spatial state. the first spatial state comprises said mobile device being held in a video capture position; the mobile device comprises a rear-facing camera arranged to generate data for an outgoing video signal of the video call; the communication processing apparatus is configured to, when the mobile device is in a rear-facing video capture mode and held in the video capture position, enable outgoing video functionality of the video call, so as to transmit to the remote device data generated by the rear-facing camera as the outgoing video signal, but to suppress incoming video functionality of the video call; and the communication processing apparatus is configured to suppress both the incoming and the outgoing video functionality when in the second spatial state.