Abstract: A method of configuring a multicast agent and a 1:N overlay multicast network considering a wireless local area network (WLAN) environment of the same are provided. The method includes: a session manger generating a first database with entries of multicast agents subscribing to a session and multicast agents that have applied for subscription to a session but have not been confirmed for normal operation; a multicast agent generating a second database with entries of a path from the root of a tree to which the multicast agent belongs, a hierarchical relation in the tree, the list of probed neighboring nodes, and a list of not-probed neighboring nodes; the multicast agent subscribing to the overlay network; obtaining information on neighboring multicast agents; setting a multicast agent which is determined to be optimal based on the obtained information, as a parent node; and if a multicast agent providing a tree improved from the current tree is found, changing the parent node.

Abstract: A method for providing an IM (Instant Messenger) based personal broadcasting service includes when a lower node in a first group requests an upper node in the first group to transmit a broadcasting content, transmitting, at the upper node in the first group when a lower node in first group requests an upper node in the first group to transmit a broadcasting content, the broadcasting content to the lower node in the first group, and transmitting, at the lower node in the first group that receive the broadcasting content, the broadcasting content to a lower node in a second group where the lower node in the first group operates as an upper node.

Abstract: Provided are a relay multicast system and method for providing efficient group communication services. In the relay multicast system, each multicast feeder can make a peer to open connection with multicast feeders in other classes by selecting an optimal multicast feeder based on available resources of each relay multicast feeder in order to efficiently form a data forwarding route of a relay group. Also, in order to form a relay channel, the relay multicast system negotiates and uses a most appropriate channel between hops, not a data forwarding channel unified in a session or group. Also, in order to forward data to a specific group, the relay multicast system connects local multicast domains, in which it is possible to multicast or broadcast on a small scale as in a local area network (LAN) or a company network in which multicast members of the group are included, without changing an existing 1:1 unicast based Internet infrastructure.

Abstract: A system for providing a session initiation protocol based conference service includes: a conference host terminal that produces requests to setup a call using identification information, to make a registration of participants to be invited to a conference session using a conference identifier, and to initiate the conference session using the conference identifier; a plurality of conference participant terminals as the participants that participate in the conference session; and a conference server having the identification information.

Abstract: Provided is a method and apparatus for configuring and managing an overlay multicast data delivery tree in a transmission network having a SM (session manager) and at least one MA (multicast agent).

Abstract: Provided is a method in which a tracker configures a notification condition on the basis of an authorization policy predetermined by a trackee so that a location information server provides a customized location tracking service according to the notification condition. The method includes: (a) registering an authorization policy of a trackee in order to determine whether a location tracking service requested by a tracker will be accepted; (b) configuring a customized location information notification condition by a tracker; (c) requesting the customized location tracking service by the tracker; and (d) providing the customized location tracking service by a location information server on the basis of the configured authorization policy and the customized location information notification condition.

Abstract: A wireless multicasting service method using a relayed transmission scheme is provided. In the wireless multicasting service method, a mobile node moves from a first wireless network to a second wireless network. Then, the mobile node performs a new joining request to a mobile multicast agent managing a multicasting service in the second wireless network. If the mobile node receives a joining approval for the new joining request, the mobile node performs a secession request to a previous mobile multicast agent managing a multicasting service in the first wireless network.

Abstract: Provided is a method in which a tracker configures a notification condition on the basis of an authorization policy predetermined by a trackee so that a location information server provides a customized location tracking service according to the notification condition. The method includes: (a) registering an authorization policy of a trackee in order to determine whether a location tracking service requested by a tracker will be accepted; (b) configuring a customized location information notification condition by a tracker; (c) requesting the customized location tracking service by the tracker; and (d) providing the customized location tracking service by a location information server on the basis of the configured authorization policy and the customized location information notification condition.

Abstract: It is possible to filter spam of diversified Internet protocol (IP) multimedia applications, since it is possible to provide spam filtering services suitable for various processing methods of calls of the IP multimedia applications and media features in an application server layer without changing a structure of IP multimedia service network by classifying calls of IP multimedia application services based on service features, checking policy information of the calls classified based on the service features, filtering spam so as to determine whether the call is spam through dynamic filtering mechanism for each application service, and transmitting the call to a lower network by determining a suitable processing method based on the checking result of the policy information or the filtering result, so as to filter IP multimedia spam in an application server in a network for providing various real-time IP multimedia application services.

Abstract: Disclosed herein is a method of constructing and managing an overlay multicast tree on the Internet. The overlay multicast tree includes a sender, one or more receivers and one or more agents for relaying data. At the first step, a new participant requests access to the overlay multicast tree from a tree manager while transmitting network characteristic information thereof to the tree manager. The second step is determining an optimal parent node in consideration of the network character information of the new participant having requested access at the first step and network characteristic information of agents participating in a currently constructed overlay multicast tree, and transmitting information of the determined parent node to the new participant. The new participant establishes data channels on the basis of the information of the determined parent node at the third step.

Abstract: Disclosed herein is a method for synchronizing user registration information in an inter-domain. In this synchronization method, the current position information of a random user is registered through a register message when the user moves from one user agent to another. An up-sync message is transmitted upstream of a tree structure and a down-sync message is transmitted downstream of the tree structure when user registration information is created or changed. The synchronization of the user registration information is carried out in upper and lower session initiation protocol servers/registrars having received the up-sync and down-sync messages, respectively.

Abstract: A routing apparatus for guaranteeing Quality of Service (QoS) in the Internet, includes a QoS edge routing unit for receiving a request for allocating resource from a transmitting node, setting a path at a QoS data rate by signaling; at least one QoS core routing unit for receiving a request for allocating resource from the QoS edge routing unit at a transmitter, setting a path at a QoS data rate by signaling; and a QoS edge routing unit at a receiver for receiving a request for allocating resource from the QoS core routing unit, setting a first path at a QoS data rate by signaling.

Abstract: Disclosed herein is a method of constructing and managing an overlay multicast tree on the Internet. The overlay multicast tree includes a sender, one or more receivers and one or more agents for relaying data. At the first step, a new participant requests access to the overlay multicast tree from a tree manager while transmitting network characteristic information thereof to the tree manager. The second step is determining an optimal parent node in consideration of the network character information of the new participant having requested access at the first step and network characteristic information of agents participating in a currently constructed overlay multicast tree, and transmitting information of the determined parent node to the new participant. The new participant establishes data channels on the basis of the information of the determined parent node at the third step.

Abstract: A load distribution is performed between session initiation protocol (SIP) servers in an intra domain.

Abstract: Disclosed herein is a method for synchronizing user registration information in an inter-domain. In this synchronization method, the current position information of a random user is registered through a register message when the user moves from one user agent to another. An up-sync message is transmitted upstream of a tree structure and a down-sync message is transmitted downstream of the tree structure when user registration information is created or changed. The synchronization of the user registration information is carried out in upper and lower session initiation protocol servers/registrars having received the up-sync and down-sync messages, respectively.