Method, subject terminal device, target terminal device, data content server, system and computer programs for maintaining and updating data contents

A method of updating data contents in at least one target terminal device, comprising the steps of:

• detecting a data content change relating a subject terminal device;
• transmitting an identifier for a changed data content to at least one target terminal device;
• receiving the transmitted identifier with the at least one target terminal device;
• and
• determining in the at least one target terminal device, based on the received identifier for the changed data content, whether data content corresponding to the identifier already exists in its memory.

A target terminal device, comprising:

• a first memory;
• a first receiver configured to receive an identifier for a changed data content;
• first determining means configured to determine, based on the received identifier for the changed data content, whether data content corresponding to the identifier already exists in the first memory;
• a first transmitter configured to transmit a request for the changed data content if the data content corresponding to the identifier does not exist in the memory, wherein the first receiver is configured to receive the requested changed data content;
• and
• applying means configured to use the data content in the first memory the identifier of which corresponds to the received identifier if the changed data content exists in the first memory, or to use the received changed data content received by the first receiver if the changed data content does not exist in the first memory.

A data content server for maintaining and updating data content information, wherein the server comprises:

• a second memory configured to store a plurality of data contents;
• a second receiver configured to receive a data content change message from a subject terminal device, the data content change message comprising at least one of a changed data content and an identifier for the changed data content;
• and
• a second transmitter configured to transmit the identifier for the changed data content to at least one target terminal device.

A system of maintaining and updating data contents in communication network, comprising:

• at least one data content server;
• at least one subject terminal device connected to the at least data content server;
• at least one target terminal device connected to the at least data content server;
• the at least one target terminal device comprising a first memory;
• a first receiver configured to receive an identifier for a changed data content;
• first determining means configured to determine, based on the received identifier for the changed data content, whether data content corresponding to the identifier already exists in the first memory;
• a first transmitter configured to transmit a request for the changed data content if data content corresponding to the identifier does not exist in the first memory, wherein the first receiver is configured to receive the requested changed data content;
• and applying means configured to use the data content in the first memory the identifier of which corresponds to the received identifier if the changed data content exists in the first memory, or to use the received changed data content received by the first receiver if the changed data content does not exist in the first memory;
• and
• the at least one data content server comprising a second memory configured to store a plurality of data contents;
• a second receiver configured to receive a data content change message from the at least one subject terminal device, the data content change message comprising at least one of a changed data content and an identifier for the changed data content;
• and a second transmitter configured to transmit the identifier for the changed data content to the at least one target terminal device.

A subject terminal device, comprising:

• a third memory;
• third determining means configured to determine an identifier for a changed data content;
• a third transmitter configured to transmit a data content change message to a data content server, the data content change message comprising the identifier for the changed data content;
• and
• a third receiver configured to receive a request for the changed data content if data content corresponding to the identifier does not exist in the memory of the data content server, wherein the transmitter is configured to transmit the changed data content stored in the third memory to the at least one data content server.

A computer program comprising code adapted to perform the following steps when executed on a data-processing system:

• receiving an identifier for a changed data content from a data content server;
• and
• determining, based on the received identifier for the changed data content, whether data content corresponding to the identifier already exists in a memory;
• wherein if the data content corresponding to the identifier does not exist in the memory, requesting the changed data content corresponding to the received identifier from the data content server;
• and
• wherein if the data content corresponding to the identifier already exists in the memory, using the data content corresponding to the received identifier.