Abstract: As a result of performing a comparing and determining process of determining the relationship among the bandwidth of distributed data in real time in a local group, the incoming data bandwidth to the local group, and the outgoing data bandwidth from the local group, the increase/decrease management and the connection management of each terminal device in the local group are performed. The comparing and determining process compares, for example, a sum of the total sum of the terminal possessed transfer bandwidths and the incoming data bandwidth from other groups to the local group with a sum of the value obtained by multiplying the bandwidth of distributed data in the local group by the number of terminal devices in the local group, the outgoing data bandwidth from the local group, and a predetermined determination margin.

Abstract: A data distribution system can select paths easily with flexibility when paths are generated. In the data distribution system, a management device includes a node bandwidth information acquisition unit to acquire and hold information on data transmission-enabled bandwidth of each of the plurality of nodes on the network; a content rate acquisition unit to acquire and hold a bandwidth for content to be distributed; a bandwidth splitting information acquisition unit to acquire and hold bandwidth splitting information, which is a splitting ratio to split the content to be distributed into a plurality of bandwidths; and a connection destination decision unit to determine a connection destination of the content to be distributed, which is split based on the bandwidth split information being held in the bandwidth splitting information acquisition unit.

Abstract: As a result of performing a comparing and determining process of determining the relationship among the distribution data band of the data distributed in real time in a local group, the incoming data band to the local group, and the outgoing data band from the local group, the increase/decrease management and the connection management of each terminal device in the local group are performed. The comparing and determining process compares, for example, a sum of the total sum of the terminal possessed transfer bands and the incoming data band from other groups to the local group with a sum of the value obtained by multiplying the distribution data band in the local group by the number of terminal devices in the local group, the outgoing data band from the local group, and a predetermined determination margin.

Abstract: A data distribution system can select paths easily with flexibility when paths are generated. In the data distribution system, a management device includes a node bandwidth information acquisition unit to acquire and hold information on data transmission-enabled bandwidth of each of the plurality of nodes on the network; a content rate acquisition unit to acquire and hold a bandwidth for content to be distributed; a bandwidth splitting information acquisition unit to acquire and hold bandwidth splitting information, which is a splitting ratio to split the content to be distributed into a plurality of bandwidths; and a connection destination decision unit to determine a connection destination of the content to be distributed, which is split based on the bandwidth split information being held in the bandwidth splitting information acquisition unit.

Abstract: A push-to-talk data transmission device that creates and manages groups of participating terminals dynamically. A PoC data transmission device is deployed to support push-to-talk sessions in a prescribed area. This device has a data transmitter that broadcasts a group profile repetitively in the prescribed area. The group profile is a set of parameters that prompt terminals in the prescribed area to send back their respective unique identifiers to join a push-to-talk session. A counter in the PoC data transmission device counts the number of responses returned from the terminals, and the data transmitter broadcasts a new group profile if the number of responses has reached a predetermined threshold.

Abstract: A method for duplicating a home agent including an address correspondence maintaining unit for maintaining a destination address of a mobile terminal in correspondence with a home address of the mobile terminal, and a transferring unit for encapsulating an IP packet addressed to the home address of the mobile terminal and transferring the encapsulated IP packet to the destination address of the mobile terminal is disclosed. The method includes the steps of setting a home agent address, which is the same as a home agent address of an operation system home agent, to a standby system home agent, and receiving a location registration request, which is sent from the mobile terminal and addressed to the operation system home agent, with the standby system home agent.