Abstract: A transmission apparatus includes a first transmission section for transmitting communication data using a first communication path in which band control is performed using a dedicated band and an undedicated band; a second transmission section for transmitting communication data using a second communication path in which priority control is performed depending on the priority of communication data; a switching control section for performing switching between the transmission using the first transmission section and the transmission using the second transmission section; and a parameter setting section for setting communication parameters for performing communication using the second communication path in the case that switching is performed from the transmission using the first transmission section to the transmission using the second transmission section.

Abstract: A transmission apparatus includes a first transmission section for transmitting communication data using a first communication path in which band control is performed using a dedicated band and an undedicated band; a second transmission section for transmitting communication data using a second communication path in which priority control is performed depending on the priority of communication data; a switching control section for performing switching between the transmission using the first transmission section and the transmission using the second transmission section; and a parameter setting section for setting communication parameters for performing communication using the second communication path in the case that switching is performed from the transmission using the first transmission section to the transmission using the second transmission section.

Abstract: It is an object of the present invention to receive/play a streaming immediately after a switching not to disconnect it when a terminal for receiving the streaming is switched from a first receiving terminal to a second receiving terminal A communication method of switching a receiving terminal of a streaming to which a rate control using TFRC is applied from a first receiving terminal to a second receiving terminal, includes a deciding step of deciding whether or not a route on a network between a transmitting terminal of the streaming and the first receiving terminal is identical to a route on the network between the transmitting terminal and the second receiving terminal, and a transferring step of transferring history information of a packet loss that the first receiving terminal is managing to the second receiving terminal when it is decided that both routes are identical.

Abstract: A packet transmitting method wherein an explicit multicast packet can be transmitted with the consumption of communication bands of broadcast media being suppressed. According to this method, a link level multicast is used to transmit an explicit multicast packet only to next hop nodes that, even when receiving the explicit multicast packet through the link level multicast, will not output the same packet to the broadcast media, while a unicast is used to transmit an explicit multicast packet to the other next hop nodes.

Abstract: When the routing function of router becomes disabled, a routing stop message is multicast to all terminals and another router in a LAN. If another router can provide the routing function, a routing start message is multicast to all terminals and the other router in the LAN. This method allows the terminals in the LAN to switch the default router at a predetermined timing according to both messages, thus minimizing the default router switching delay time and the packet loss.

Abstract: A radio communication device includes a reception unit for receiving a route request message from another radio communication device, a route control message processing unit for judging whether the received route request message is addressed to itself or not, a route request message management unit for deciding a delay amount for delaying response transmission or relay forwarding with regard to the route request message according to an operating state of the radio communication device when the route request message is not addressed to itself, and a delay processing unit which performs response transmission or relay forwarding to the route request message when the delay amount time has expired. Thus, a route selected giving preference to radio communication devices having a preferable operating state can be obtained.

Abstract: It is an object of the present invention to receive/play a streaming immediately after a switching not to disconnect it when a terminal for receiving the streaming is switched from a first receiving terminal to a second receiving terminal A communication method of switching a receiving terminal of a streaming to which a rate control using TFRC is applied from a first receiving terminal to a second receiving terminal, includes a deciding step of deciding whether or not a route on a network between a transmitting terminal of the streaming and the first receiving terminal is identical to a route on the network between the transmitting terminal and the second receiving terminal, and a transferring step of transferring history information of a packet loss that the first receiving terminal is managing to the second receiving terminal when it is decided that both routes are identical.

Abstract: A packet transmitting method wherein an explicit multicast packet can be transmitted with the consumption of communication bands of broadcast media being suppressed. According to this method, a link level multicast is used to transmit an explicit multicast packet only to next hop nodes that, even when receiving the explicit multicast packet through the link level multicast, will not output the same packet to the broadcast media, while a unicast is used to transmit an explicit multicast packet to the other next hop nodes.

Abstract: A router includes a multicast packet transmitting unit that multicasts the identifier of the router periodically, a relay determining unit that determines whether a received data packet should be relayed to a router in another segment, an order determining unit that determines, on the basis of information included in multicast packets from the other routers, the router to which the data packet shall be transferred, and a packet relaying unit that, when the data packet is not relayed, notifies the transmission source which transmitted the packet as to the router selected by the order determining unit to be the relay destination and then transfers the data packet to the selected router. A router suitable for relaying the packet is thus selected. Since switching of the relay router may be performed by following the router redirection message, it is unnecessary to add a new function to a terminal.

Abstract: Between network connection apparatuses connected to each other by use of a virtual redundant arrangement, a first network connection apparatus that is in a standby state receives an advertisement message from a second network connection apparatus that is active as a network connection apparatus, and uses a priority comparing section to compare its own priority with the priority in the received advertisement message. When its own priority is higher, the first network connection apparatus uses a master down timer comparing section to compare the remaining time of a master down timer with the time as weighted in accordance with its own priority and resets the timer for a shorter time.

Abstract: Provided are a service-type recording section for recording a characteristic of a service to be utilized by the mobile communication device and an interface recording section for recording an externally-connecting interface type of within a network and a characteristic thereof. The interface decision section selects at least one or more of interfaces satisfying a service request and notifies it to a mobile router possessing an externally-connecting interface. Due to this, in case there is a link status change in the external interface of the mobile router, the mobile communication device is allowed to swiftly switch the external interface and continue communication. Moreover, congestion can be avoided from occurring in communication between the mobile communication device and the mobile router during switchover.

Abstract: When connected to an external network, a mobile router checks an address 0table if a home address is allocated. If it is not allocated, the mobile router derives the address of a position management server from a position-management-server address table and sends an allocation request message to the position management server. The position management server receives an address management table listing addresses to be allocated to each mobile network and the allocation request message sent from the mobile router, searches the address management table for an unused address, and sends an allocation permission message to the mobile router to automatically allocate a home address to the mobile router.

Abstract: A packet routing method for quickly reorganizing a path from a transmission source terminal to a destination terminal. A radio receiver part (103) detects, from a decrease of the field intensity or the like, a cut-off of a communication with a communication device using a radio signal to directly transmit packets. A control part (105) determines whether the local terminal device including it is the packet destination radio terminal device or the packet transmission source radio terminal device. When it is determined that the communication with a communication device using the radio signal to directly transmit packets is cut off and that the local terminal device is the transmission source radio terminal device, a radio transmitter part (104) broadcasts a request signal of path restoration addressed to the packet destination communication device.

Abstract: A packet routing apparatus that simultaneously implements prompt route recovery and continuation of communication by an optimal route. A radio reception section (103) receives a radio signal including packet data received in a transmission/reception antenna (101) via a circulator (102). Further, the radio reception section (103) detects disconnection of an adhoc network by a decrease in electric filed strength of a signal from a communicating party. A radio reception section (104) transmits a radio signal including a route search packet, route response packet or the like from the transmission/reception antenna (101) via the circulator (102). When the adhoc network is disconnected, a control section (105) performs processing of route recovery for transmitting a route search packet to a destination wireless adhoc terminal, while performing route reconstruction processing for reporting route disconnection to a transmission source wireless adhoc terminal.

Abstract: A radio communication device includes a reception unit for receiving a route request message from another radio communication device, a route control message processing unit for judging whether the received route request message is addressed to itself or not, a route request message management unit for deciding a delay amount for delaying response transmission or relay forwarding with regard to the route request message according to an operating state of the radio communication device when the route request message is not addressed to itself, and a delay processing unit which performs response transmission or relay forwarding to the route request message when the delay amount time has expired. Thus, a route selected giving preference to radio communication devices having a preferable operating state can be obtained.

Abstract: A router device includes a lower-layer information acquisition section for acquiring connection information of whether or not connected with a base station in an external network from a lower layer, and a route judgment section for transferring the received packet to the base station in the case of being connected with the base station and judging a transfer destination by looking up a routing table in the case of not being connected with the base station, when receiving a packet destined for a terminal in an external network from a radio terminal device in a same local network. Because the received packet is transferred to the base station during connection with the base station, the packet can be transferred to the external via the router intended by the terminal. Furthermore, the load in the local network can be reduced.

Abstract: When the routing function of router becomes disabled, a routing stop message is multicast to all terminals and another router in a LAN. If another router can provide the routing function, a routing start message is multicast to all terminals and the other router in the LAN. This method allows the terminals in the LAN to switch the default router at a predetermined timing according to both messages, thus minimizing the default router switching delay time and the packet loss.

Abstract: A router includes a multicast packet transmitting unit that multicasts the identifier of the router periodically, a relay determining unit that determines whether a received data packet should be relayed to a router in another segment, an order determining unit that determines, on the basis of information included in multicast packets from the other routers, the router to which the data packet shall be transferred, and a packet relaying unit that, when the data packet is not relayed, notifies the transmission source which transmitted the packet as to the router selected by the order determining unit to be the relay destination and then transfers the data packet to the selected router. A router suitable for relaying the packet is thus selected. Since switching of the relay router may be performed by following the router redirection message, it is unnecessary to add a new function to a terminal.

Abstract: A router device includes a VRRP (Virtual Redundancy Router Protocol) realizing a virtual router device for operating a plurality of router devices virtually as one router device. The router device further includes a virtual router processing section for executing virtual router processing and a virtual router information processing section for extracting virtual router information upon reception of a virtual router information message and performing setting necessary for operation as a virtual router. When performing a new connection to a local area network, the virtual router information can be automatically set. Thus, it is possible to significantly reduce the load required for building a virtual router system by manual setting conventionally performed by a management operator.

Abstract: Physical router devices report router status information to a router priority calculation device via a local network. According to the router status information reported, the router priority calculation device calculates priority of each physical router device and reports the priority to the physical router devices via the local network. According to the priority reported, the physical router devices decide one master router and a backup router other than this from a plurality of physical router devices. Thus, by utilizing the priority obtained from the router status information on the physical router devices, it is possible to automatically and flexibly constitute a virtual router device.