An apparatus (1; 11) for use in a communications system in which terminals of the system can communicate with each other via a network infrastructure of the system and/or in a direct mode of operation in which terminals can communicate with each other without the communication passing via the network infrastructure, the apparatus (1; 11) comprising: means for providing a direct mode operation repeater function and/or a gateway function for a terminal or terminals (2, 3, 5, 6; 12, 13, 14) of the communications system; and characterised by means for allowing a user (9; 16) of the apparatus (1; 11) to participate in a call for which the apparatus (1; 11) is providing and/or is to provide a repeater and/or gateway function; and by further comprising: means for, when the user (9; 16) of the apparatus (1; 11) wishes to transmit in an ongoing call or to initiate a call for which the apparatus (1; 11) is providing and/or is to provide a repeater function, signalling to all the other participants in the call as if the signalling originated from a terminal operating in a direct mode of operation via the repeater function that the apparatus (1; 11) is providing and/or is to provide; and/or means for, when the user (9; 16) of the apparatus (1; 11) wishes to transmit in an ongoing call or to initiate a call for which the apparatus (1; 11) is providing and/or is to provide a gateway function, signalling to all the other participants in the call as if the signalling originated from a terminal operating: via the network infrastructure and the gateway function that the apparatus (1; 11) is providing and/or is to provide; or in a direct mode of operation via the gateway function that the apparatus (1; 11) is providing and/or is to provide; and wherein the means for providing the direct mode terminal function and the repeater function and/or a gateway function comprise an internal signalling interface which may be linked at layer 1, layer 2, or layer 3 or any other layer of the International Standards Organisation Open System Interface Basic reference model. means for providing a direct mode operation repeater function and/or a gateway function for a terminal or terminals (2, 3, 5, 6; 12, 13, 14) of the communications system; and characterised by means for allowing a user (9; 16) of the apparatus (1; 11) to participate in a call for which the apparatus (1; 11) is providing and/or is to provide a repeater and/or gateway function; and by further comprising: means for, when the user (9; 16) of the apparatus (1; 11) wishes to transmit in an ongoing call or to initiate a call for which the apparatus (1; 11) is providing and/or is to provide a repeater function, signalling to all the other participants in the call as if the signalling originated from a terminal operating in a direct mode of operation via the repeater function that the apparatus (1; 11) is providing and/or is to provide; and/or means for, when the user (9; 16) of the apparatus (1; 11) wishes to transmit in an ongoing call or to initiate a call for which the apparatus (1; 11) is providing and/or is to provide a gateway function, signalling to all the other participants in the call as if the signalling originated from a terminal operating: via the network infrastructure and the gateway function that the apparatus (1; 11) is providing and/or is to provide; or in a direct mode of operation via the gateway function that the apparatus (1; 11) is providing and/or is to provide; and means for, when the user (9; 16) of the apparatus (1; 11) wishes to transmit in an ongoing call or to initiate a call for which the apparatus (1; 11) is providing and/or is to provide a repeater function, signalling to all the other participants in the call as if the signalling originated from a terminal operating in a direct mode of operation via the repeater function that the apparatus (1; 11) is providing and/or is to provide; and/or means for, when the user (9; 16) of the apparatus (1; 11) wishes to transmit in an ongoing call or to initiate a call for which the apparatus (1; 11) is providing and/or is to provide a gateway function, signalling to all the other participants in the call as if the signalling originated from a terminal operating: via the network infrastructure and the gateway function that the apparatus (1; 11) is providing and/or is to provide; or in a direct mode of operation via the gateway function that the apparatus (1; 11) is providing and/or is to provide; and via the network infrastructure and the gateway function that the apparatus (1; 11) is providing and/or is to provide; or in a direct mode of operation via the gateway function that the apparatus (1; 11) is providing and/or is to provide; and wherein the means for providing the direct mode terminal function and the repeater function and/or a gateway function comprise an internal signalling interface which may be linked at layer 1, layer 2, or layer 3 or any other layer of the International Standards Organisation Open System Interface Basic reference model.