Method and apparatus for synchronizing device providing content directory service with device not providing content directory
Provided is a method for synchronizing contents included in devices in a Universal Plug and Play (UPnP) network. A control point device, which contains local content but cannot provide a content directory service, converts information regarding content objects of the control point device into Digital Item Description Language Lite (DIDL-Lite) format, and manages a mapping table, thereby performing synchronization with a device such as a UPnP media server providing a content directory service, without loading a separate protocol stack.
1. A synchronization method for synchronizing a first Universal Plug and Play (UPnP) device with a second UPnP device in a UPnP network, the method comprising:
generating, by the UPnP first device, a synchronization document comprising an identifier that specifies an object to be synchronized from among the content objects of the first UPnP device and the second UPnP device and information regarding a synchronization policy for synchronizing content directory services that provides metadata of contents;
providing the synchronization document to the second UPnP device; and
synchronizing the first UPnP device and the second UPnP device based on the synchronization document, update information of the first UPnP device regarding the content objects of the first UPnP device to be synchronized, and information indicating a location from which the update information of the first UPnP device may be obtained by the second UPnP device,
wherein the first UPnP device provides no content directory service and the second UPnP device provides a content directory service,
wherein a format of the synchronization document is Digital Item Description Language Lite (DIDL-Lite), and
wherein the information indicating the location comprises a Uniform Resource Identifier (URI).
2. The synchronization method of claim 1 , further comprising:
requesting, from the second UPnP device, update information regarding the content objects of the second UPnP device to be synchronized;
updating content objects of the first UPnP device to be synchronized, based on the update information received from the second UPnP device in response to the requesting.
3. The synchronization method of claim 2 , further comprising:
transmitting an update information message regarding the content objects of the first UPnP device designated in the synchronization document as objects that are to be synchronized in the synchronization document, and the update information message comprising a message for requesting synchronization in accordance with the synchronization document, to the second UPnP device,
wherein the message for requesting synchronization includes at least one of the update information of the first UPnP device, and the information indicating a location from which the update information of the first UPnP device may be obtained by the second UPnP device.
4. The synchronization method of claim 2 , further comprising:
transmitting an update information message regarding the content objects of the first UPnP device designated in the synchronization document as objects that are to be synchronized in the synchronization document, and the update information message comprising a message for requesting synchronization in accordance with the synchronization document, to the second UPnP device,
wherein the message for requesting synchronization includes information indicating that the message for requesting synchronization is transmitted from a UPnP device providing no content directory service.
5. A computer-readable recording medium having embodied thereon a computer program for executing the method of claim 1 .
6. The synchronization method of claim 1 , further comprising:
converting information, regarding content objects of the first UPnP device that are to be synchronized with the second UPnP device, into information with a predetermined format recognizable by the content directory service of the second UPnP device,
wherein the synchronization document is generated based on the information with the predetermined format.
7. A synchronization apparatus for synchronizing a first Universal Plug and Play (UPnP) device with a second UPnP device in a UPnP network, the synchronization apparatus comprising:
a synchronization document generator which generates a synchronization document comprising an identifier that specifies an object to be synchronized from among the content objects of the first UPnP device and the second UPnP device and information regarding a synchronization policy for synchronizing content directory services;
a synchronization document providing unit which provides the synchronization document to the second UPnP device; and
a synchronization performing unit that synchronizes the first UPnP device and the second UPnP device based on the synchronization document, update information of the first UPnP device regarding the content objects of the first UPnP device to be synchronized, and information indicating a location from which the update information of the first UPnP device may be obtained by the second UPnP device,
wherein the first UPnP device provides no content directory service and the second UPnP device provides a content directory service,
wherein a format of the synchronization document is Digital Item Description Language Lite (DIDL-Lite), and
wherein the information indicating the location comprises a Uniform Resource Identifier (URI).
8. The synchronization apparatus of claim 7 , wherein the synchronization performing unit requests, from the second UPnP device, update information regarding the content objects of the second UPnP device to be synchronized, and updates the content objects of the first UPnP device to be synchronized, based on the update information received from the second UPnP device in response to the request.
9. The synchronization apparatus of claim 8 , wherein the synchronization performing unit transmits an update information message regarding the content objects of the first UPnP device designated in the synchronization document as objects that are to be synchronized, the update information message comprising a message for requesting synchronization in accordance with the synchronization document, to the second UPnP device and wherein the message for requesting synchronization includes at least one of the update information of the first UPnP device, and the information indicating a location from which the update information of the first UPnP device may be obtained by the second UPnP device.
10. The synchronization apparatus of claim 8 , wherein the synchronization performing unit transmits an update information message regarding the content objects of the first UPnP device designated in the synchronization document as objects that are to be synchronized, the update information message comprising a message for requesting synchronization in accordance with the synchronization document, to the UPnP second device, and wherein the message for requesting synchronization and the request for update information include information indicating that the message for requesting synchronization is transmitted by a UPnP device providing no content directory service.
11. The synchronization apparatus of claim 7 , further comprising:
an information conversion unit which converts information, regarding content objects of the first UPnP device that are to be synchronized with the second UPnP device, into information with a predetermined format recognizable by the content directory service,
wherein a synchronization document generator generates the synchronization document based on the information with the predetermined format.