UPnP-based network system and control method thereof

A Universal Plug-and-Play (UPnP)-based network system comprising:

• a controlled device which provides a description change advertisement service and a unique device name (UDN) of the controlled device;
• and
• a control point which stores the UDN of the controlled device and performs subscription of the description change advertisement service;
• wherein the control point receives an event message, including the UDN of the controlled device, for the description change advertisement service transmitted by the controlled device, determines that the controlled device is a previously existing controlled device in the UpnP-based network system based on the stored UDN and the UDN included in the event message, and transmits a message for requesting a description file to the previously existing controlled device,
• wherein the previously existing controlled device generates the event message for the description change advertisement service if a service provided by the previously existing controlled device is changed, wherein the service provided by the previously existing controlled device being changed comprises a new service being added to the previously existing controlled device and an existing service of the previously existing controlled device being deleted,
• wherein the previously existing controlled device transmits the event message in response to an update to services provided by the controlled device.

A method of controlling a Universal Plug-and-Play (UPnP)-based network system, the method comprising:

• storing, at a control point, a unique device name (UDN) of a controlled device;
• transmitting an advertisement message including the UDN of the controlled device from the controlled device;
• determining, at the control point, that the controlled device is a previously existing controlled device in the UPnP-based network system based on the stored UDN and the UDN included in the advertisement message;
• determining, at the control point, whether an extension header included in the advertisement message transmitted from the previously existing controlled device is changed;
• and
• if it is determined that the extension header is changed, transmitting a message for requesting a description file from the control point to the previously existing controlled device,
• wherein the extension header comprises information on a change of a service provided by the previously existing controlled device, wherein the change of a service comprises a new service being added to the previously existing controlled device and an existing service of the previously existing controlled device being deleted,
• wherein the previously existing controlled device transmits the advertisement message in response to an update to the extension header.

A method of controlling a Universal Plug-and-Play (UPnP)-based network system, the method comprising:

• storing, at a control point, a unique device name (UDN) of a controlled device received from the controlled device;
• performing, at the control point, subscription of a description change advertisement service provided by a controlled device;
• generating, at the controlled device, an event message, including the UDN of the controlled device, for the description change advertisement service and transmitting the event message to the control point;
• determining, at the control point, that the controlled device is a previously existing controlled device in the UPnP-based network system based on the stored UDN and the UDN included in the event message and
• transmitting a message for requesting a description file from the control point, having received the event message, to the previously existing controlled device,
• wherein the event message is generated for the description change advertisement service by the previously existing controlled device if a service provided by the previously existing controlled device is changed, wherein the service provided by the previously existing controlled device being changed comprises a new service being added to the previously existing controlled device and an existing service of the previously existing controlled device being deleted,
• wherein the previously existing controlled device transmits the event message in response to an update to services provided by the controlled device.