A communication system for supporting machine type communication within a cellular communication network is described in which a communication device is allocated a permanent offline area in which the communication device is expected to be located whilst not attached for communication within the network. The communication device identifies a cell in which the communication device is currently located and determines whether or not the cell forms part of the permanent offline area or a temporary offline area that comprises a previously visited cell that is not part of the permanent offline area. If these areas do not comprise the cell in which the communication device is currently located, the communication device attaches to the network and communicates information identifying the cell in which the communication device is currently located to the network.