A Personal Area Network Security Domain (PSD) (50) is formed between PDA (52), mobile terminal (54), PC (56) and printer (58). The PSD (50) allows the sharing of resources between the devices within the PSD. If the devices within the PSD (50) are located remotely from one another, communication between those devices will be performed via mobile or cellular telephone network (66) and the Internet (68). For each set or association of similarly located devices within the PSD (50), one of those devices will be a gateway device. The gateway device is a device that is configured to communicate with an external communications medium (mobile network (66) or the Internet (68)). Data transmissions to other devices within the PSD are channelled through the relevant gateway. In another embodiment resources are shared between the two separate PSDs (of which may or may not be remotely located with respect to one another) by means of data exchanges between the respective gateway devices of the two PSDs.