Telecommunications system

A signalling agent for use in a telecommunications system, the telecommunications system including a main network and a mobile network, the mobile network including a plurality of portable communication devices and router means arranged in use for routing data to and from the portable communication devices, the main network including a plurality of spaced apart attachment points to which the mobile network can attach in order to communicate with the main network, and a plurality of directory agents, wherein the portable communication devices each have a directory agent associated therewith, each directory agent storing routing information for routing data to the or each mobile communication device associated with that directory agent, wherein the signalling agent is configured to send a respective update message to each directory agent in response to a signalling message from which signalling message it can be inferred that the point of attachment of the mobile network has changed, each update message including updated routing information such that on receipt of the updated routing information, each directory agent can update the routing information thereof to take into account the changed point of attachment of the mobile network.

A network including:

• a plurality of directory agents, each directory agent storing routing information for routing data to a respective mobile communication device of a mobile network;
• a plurality of spaced apart attachment points to which, in use, a mobile network can attach in order to communicate with the main network;
• and, a signalling agent, the signalling agent being configured to send a respective update message to each directory agent in response to a signalling message from which signalling message it can be inferred that the point of attachment of the mobile network has changed, each update message including updated routing information such that on receipt of the updated routing information, each directory agent can update the routing information thereof to take into account the changed point of attachment of the mobile network.

A method of operating a network which includes a signalling agent, a plurality of directory agents each of which stores routing information for routing data to a respective mobile communication device associated with that directory agent, and a plurality of spaced apart attachment points to which a mobile network having a plurality of portable devices can attach in order to communicate with the main network, the method including the steps of:

• (i) storing an indication of the identity and/or network location of each directory agent associated with a portable device;
• (ii) receiving, from the mobile network, temporary address information indicative of the current point of attachment of the mobile network;
• and, (iii) in response to receiving the temporary address information, using the stored indication of identity and/or network location to send an update message to each directory agent, the update messages each including updated routing information such that on receipt of the updated routing information, each directory agent can update the stored routing information thereof so as to take into account the changed point of attachment of the mobile network.