Abstract: Provided is a mobile device for a personalized service including: a media receiving unit acquiring broadcasting contents during expressing in a broadcast viewing terminal device; and a comparing unit generating a media ID based on the broadcasting contents acquired in the media receiving unit, comparing the generated media ID with a media ID in a media ID list received from a media ID server to identify a channel ID, and transmitting a personalized service request message including the identified channel ID and a user ID to a personalized information providing server to request a personalized service.

Abstract: A continuous connectivity-lacking network environment-based node apparatus, node management apparatus, communication system, and node management method are provided. The node management apparatus includes a communication unit configured to receive node information from the mobile node through an additional communication network, which is separate from a continuous connectivity-lacking network, and transmit contact information generated by a control unit regarding one or more neighboring nodes of the mobile node to the mobile node via the additional communication network; and the control unit configured to generate the contact information based on the node information received by the communication unit. Accordingly, it is possible for the mobile node to quickly set a communication link and search for any neighboring communicable node.

Abstract: Disclosed is a system of transporting multimedia based on network, and more particularly, to an apparatus for inserting, transporting and extracting a timestamp through a network protocol. A network timestamp is transported without changing a preset transport standard such as a UDP, an RTP and a MPEG-2 standard by adding a packet having a timestamp, which is used to compensate for network jitter and used for synchronization, to a packet stream transported through a UDP or an RTP.

Abstract: A multicast communication method, a multicast communication apparatus and a multicast communication system in a network environment lacking a continuous connectivity. The source node device selects a group leader device which is able to forward data to group member devices belonging to a multicast group, and forwards the data to the selected group leader device, thereby reducing traffic between node devices, improving network reliability and saving the communication cost.

Abstract: Disclosed is a system of transporting multimedia based on network, and more particularly, to an apparatus for inserting, transporting and extracting a timestamp through a network protocol. A network timestamp is transported without changing a preset transport standard such as a UDP, an RTP and a MPEG-2 standard by adding a packet having a timestamp, which is used to compensate for network jitter and used for synchronization, to a packet stream transported through a UDP or an RTP.