Abstract: Provided are a method and apparatus for limiting a content usage authority scope of a client by using metadata in an Internet Protocol Television (IPTV) service. The method performed by a metadata server adds control information to the metadata and transmits the metadata, wherein the content usage authority scope of the client is defined in the control information. The client of a user limits a content control operation according to a user input by using the control information extracted from the metadata.

Abstract: Provided are a method and apparatus for notifying a specific device, which requests a service, of an event if the event relating to the service occurs in a home network. An event notification message that is multicasted in the home network includes a device ID that requests a service relating to an event, and devices discard the event notification message when the device ID included in the event notification message is not identical to IDs of the devices, thereby preventing all devices that are not related to the service from being notified of the event relating to the service.

Abstract: Disclosed are an information storage medium having recorded thereon service information regarding a broadcast service to provide additional content, the information storage medium having recorded thereon information for receiving a trigger while the broadcast service is received, information for selecting additional content to be inserted to the broadcast service in correspondence to the received trigger, and a locator for receiving the additional content, a method of providing additional content by using the same, and a digital broadcast reception apparatus.

Abstract: Disclosed are an information storage medium storing metadata for providing additional content during a broadcast program, the metadata including information indicating whether to insert second additional content instead of first additional content, which is underlying additional content of the broadcast program, and a locator of the second additional content, a method of providing additional content by using the same, and a digital broadcast reception apparatus.

Abstract: Provided are method and apparatus for searching for a second device relaying at least one IPTV service included in the same residential network as a first device, wherein the searching is performed by the first device, and receiving the IPTV service provided from outside of the residential network through a found second device.

Abstract: Provided are a method and apparatus by which a first entity receives information about one or more Internet Protocol Television (IPTV) service providers or information about one or more IPTV services from a second entity by using a Session Initiation Protocol (SIP) message.

Abstract: A channel-switching method and apparatus are provided. The channel-switching method includes switching from a first channel to a second channel, outputting a partial video corresponding to the second channel on a screen while main data of the second channel is being buffered to be output, and outputting the main data of the second channel on the screen.

Abstract: Provided are a method of receiving metadata including keywords related to content data and searching for supplementary data by using the keywords after the content data is reproduced, and an apparatus therefor. The method comprises receiving content data to be reproduced; receiving metadata including at least one keyword related to the content data; and searching for supplementary data related to the content data by using the at least one keyword included in the metadata. According to the present invention, metadata may be accessed during reproduction of content data or after the content data is completely viewed by using a keyword table, and supplementary data may be easily found in a television (TV) browser, by displaying the keywords as recommended keyword buttons.

Abstract: A system, apparatus, and method of providing a personal broadcasting service according to scheduling are provided. The system for providing a personal broadcasting service includes a producer client which produces and transmits a broadcasting schedule, a broadcasting server which establishes a broadcasting channel according to the broadcasting schedule and provides broadcasting content produced by the producer client through the broadcasting channel, and a viewer client which receives the broadcasting content through the broadcasting channel.

Abstract: A channel-changing method is disclosed. The method includes receiving broadcast signals consisting of multiple packets, extracting frames using packet-identification information on the packets, and storing the extracted frames by channels, and outputting frames corresponding to the channel requested by a user among the stored frame.

Abstract: Multimedia content is provided continuously for multiple users each potentially moving to a different place while enjoying it together. The system includes a network for transmitting preferably IP-format data, a first device for outputting particular multimedia content received through the network, and a second device for outputting a second multimedia content prepared for, and received upon requesting, continuous provision of the particular multimedia content through the network. A contents server delivers the particular multimedia content and the second multimedia output to the first and second devices, respectively. The second multimedia content consists of the part of the particular multimedia content remaining to be transmitted at the point of time at which the second device requested the continuous provision of the particular multimedia content.