Communications systems

A method of enabling communication between a plurality of telecommunications networks, the method including:

• providing subscriber terminals of each network with a respective publicly-known telephone number for allowing communications to be addressed to each subscriber terminal;
• associating selected subscriber terminals of each network together in a group such that those subscriber terminals can address communications to one another using a respective code allocated to each of the selected subscriber terminals;
• and
• maintaining a database of the codes and corresponding publicly-known telephone numbers of all of said networks and providing to one of said networks a publicly-known telephone number corresponding to a code of a subscriber terminal of another one of said networks to allow communication from a subscriber terminal of said one of the networks to be addressed to a subscriber terminal of said other of the networks using the code of the latter subscriber terminal.

A communications system, comprising:

• a plurality of telecommunications networks;
• and
• an IMP system,
• wherein the communications system:
• provides subscriber terminals thereof with a respective publicly-known telephone number for allowing communications to be addressed to each subscriber terminal;
• allows selected subscriber terminals thereof to be associated together in respective groups;
• and
• is configured to determine whether a communication from a terminal is for a member of a particular one of said groups,
• and wherein the IMP system maintains a database of the groups for each of said networks and enables at least one of special charges and services to be provided for communications between at least one of members of the same group and members of different groups.