Abstract: The present invention provides a packet communication system including a mobile host, a home agent, a correspondent host, and a mobility agent, where the mobility agent operates in such a way that when the mobile host is in an active mode and has no need for buffering packets, the mobility agent forwards packets received from the home agent or the correspondent host to the mobile host; and alternatively, in the case when the mobile host is in an active mode, but requires buffering of packets, the mobility agent buffers the packets, and further in the case when the mobile host is in an idle mode, the mobility agent buffers the packet and notifies the mobile host of arrival of the packet, in order to prevent the loss of a packet addressed to a mobile host thus decreasing the traffic and the transmission frequency of Binding Update packets.

Abstract: A mobile communication system comprises a plurality of transfer devices configured to transfer packets to a visited position of a mobile terminal, a plurality of connection management devices arranged in a network and configured to connect to the mobile terminal, and a mobile terminal including a detection unit configured to detect the transfer device, and a communication unit configured to connect to the connection management device, and transmit/receive packets to/from the transfer device detected by the detection unit via the connection management device.

Abstract: There is disclosed a link manager comprises detecting unit for detecting what link is installed; managing unit for defining a plurality of link metrics indicating characteristics of each link detected and managing data corresponding to the respective link metrics on a table; and selecting unit for selecting a link having link metrics complying with a given condition.

Abstract: A packet transmission system includes a home agent providing a home link and a home address to a mobile node, one or more access routers, each providing a foreign link and a c/o address to the mobile node, and one or more mobility support routers that relay a packet to the destination between the mobile node and the home agent or a counterpart correspondent node. When the mobile node moves into a new foreign link, the corresponding access router transmits a registration request to the home agent and/or the correspondent node. When acquiring a registration request on the way to the destination, each mobility support router stores an entry having the home address of the mobile node and the c/o address contained in the registration request, and produces and transmits a new registration request updating the c/o address to its own address.

Abstract: The present invention provides a single carrier/DS-CDMA packet transmission method wherein a predetermined time slot is assigned to reservation demand packet transmission in regard to a spreading code, and the reservation demand packet and data packets are time-multiplexed for transmission. An uplink packet transmission method in a multi-carrier/DS-CDMA mobile communication system is also provided, wherein frames are set up in each communication channel of a subcarrier, time slots which are time-segments of the frames are set up further, and a mobile station spreads a packet to be transmitted by a spreading code and the information signal is transmitted to a base station in a predetermined time slot.

Abstract: A configuration comprises a destination address extracting/rewriting device 4 for extracting a destination address of a packet; a common-route packet extracting device 8 for extracting two or more packets having a common route at least in part of routes to their respective terminals from a plurality of packets, based on their extracted destination addresses; an aggregate packet creating device 9 for aggregating the plurality of packets having the common route at least in part of the routes to create an aggregate packet including information of each of the packets; a destination address giving device 10 for giving the aggregate packet a destination address so that the destination address of the aggregate packet is an address of an adjacent node on the common route; and an aggregate packet routing device 11 for routing the aggregate packet, based on the destination address.

Abstract: The present invention provides a single carrier/DS-CDMA packet transmission method wherein a predetermined time slot is assigned to reservation demand packet transmission in regard to a spreading code, and the reservation demand packet and data packets are time-multiplexed for transmission. An uplink packet transmission method in a multi-carrier/DS-CDMA mobile communication system is also provided, wherein frames are set up in each communication channel of a subcarrier, time slots which are time-segments of the frames are set up further, and a mobile station spreads a packet to be transmitted by a spreading code and the information signal is transmitted to a base station in a predetermined time slot.

Abstract: A mobile unit capable of communication using a plurality of communication subsystems including a usability determination section to determine usability of the plurality of communication subsystems at the current location of the mobile unit. The mobile unit also includes a communication subsystem selection section for selecting a communication subsystem whereby the current location of the mobile unit can be measured with highest accuracy. A mobile telephone network communication section in the mobile device then measures the current location of the mobile unit and transmits the result of determination of usability, together with information indicating the current location, to an information provision server. Then, the mobile unit is able to look up the result of determination of usability from a plurality of mobile units that is stored in the information provision server.

Abstract: A mobile communication system can implement broadcasting control that generates broadcast information autonomously in a distributed manner, thereby obviating the need for an RNC (Radio Network Controller). Each base station has an IP address and a base station multicast address. Each base station sends its own system information to all base stations using the multicast address. Each base station generates its broadcast information from its own system information and the system information received from other base stations. Thus, it can generate the broadcast information autonomously in a distributed manner without using the RNC.

Abstract: The present invention improves receiving quality compared to the prior art even if instantaneous control of transmission power is not executed. A mobile station MS#0 measures signal level received from surrounding base stations and determines to which base stations it is to be connected in order to satisfy a desired downlink receiving quality (step S1). The mobile station MS#0 notifies a radio network control station RNC of the desired based stations to which the mobile station is to be connected (step S2). Upon receiving the notification from the mobile station MS#0, the radio network control station RNC duplicates a downlink transmitted signal for the mobile station MS#0, if any, and transmits it to the selected base stations (step S3). The mobile station MS#0 receives signals transmitted by the base stations (step S4) and synthesizes these signals (step 5), thereby satisfying the desired downlink receiving quality.

Abstract: Efficient paging control is achieved in a communication system that selectively provides one of communication services implemented by integrating a plurality of communication systems. Before transmitting a downlink signal to a terminal, a gateway requests each of the communication systems to transmit a paging signal to the terminal. Receiving the paging signals transmitted from the communication systems, the terminal selects a communication system A with the lowest communication cost in accordance with communication cost information contained in the paging signal. The terminal sends a request for connection to the selected communication system A. As a result, the communication system A transmits the downlink signal to the terminal.

Abstract: The mobile station visiting a location registration area at the present time plans to move to another location registration area at a future time. The mobile station sends the moving schedule information to the location management agent in a prescribed format to notify it of the scheduled destination. Receiving the moving schedule information, the location management agent learns the location registration area corresponding to the scheduled destination among the plurality of location registration areas. The location management agent sets a moving schedule flag in the location registration database in accordance with the moving schedule information with that format, which is received from the mobile station, and makes an additional registration of the moving time and the destination location registration area. Then, at the future time, it updates the location registration database, thereby making a new location registration.

Abstract: A retransmission control method is provided. In the method, all base stations perform error judgment for a signal sent from a mobile station 1. Then, first and second base stations send results of error judgment to a third base station which is a communication partner of the mobile station 1. The third base station sends NACK for requesting retransmission to the mobile station 1 only when every result of error judgment of the first and second base stations indicates that there is an error.

Abstract: A mobile unit 10 according to the present invention is capable of communication using a plurality of communication subsystems. Usability determination section 13 determines usability of the plurality of communication subsystems at the current location of the mobile unit 10 based on the electrical field intensity of a wireless LAN and the electrical field intensity of a mobile unit telephone network. A communication subsystem selection section 14 selects a communication subsystem whereby the current location can be measured with highest accuracy, of the communication subsystems that are determined as being usable. For example, if the mobile telephone subsystem is selected, the mobile telephone network communication section 15 infers the current location of the mobile unit 10 and transmits the result of determination of usability, together with information indicating the current location, to the address of an information provision server 20.

Abstract: The present invention provides a packet communication system has a mobile host, a home agent, a correspondent host, and a mobility agent, wherein the mobility agent operates in such a way that in the case of an active mode and no need for buffering of packet, the mobility agent forwards a packet received from the home agent or the correspondent host, to the mobile host, that in the case of the active mode and necessity for buffering of packet, the mobility agent buffers the packet, and that in the case of an idle mode, the mobility agent buffers the packet and notifies the mobile host of arrival of the packet, in order to prevent the loss of a packet addressed to a mobile host, to decrease the traffic of Binding Update packets, to decrease the transmission frequency of Binding Update packets where the mobile host sends or receives no packet for a long period of time, and to send a packet a destination of which is a node present at a mobile network.

Abstract: A mobile communication system comprises a plurality of transfer devices configured to transfer packets to a visited position of a mobile terminal, a plurality of connection management devices arranged in a network and configured to connect to the mobile terminal, and a mobile terminal including a detection unit configured to detect the transfer device, and a communication unit configured to connect to the connection management device, and transmit/receive packets to/from the transfer device detected by the detection unit via the connection management device.

Abstract: A configuration comprises a destination address extracting/rewriting device 4 for extracting a destination address of a packet; a common-route packet extracting device 8 for extracting two or more packets having a common route at least in part of routes to their respective terminals from a plurality of packets, based on their extracted destination addresses; an aggregate packet creating device 9 for aggregating the plurality of packets having the common route at least in part of the routes to create an aggregate packet including information of each of the packets; a destination address giving device 10 for giving the aggregate packet a destination address so that the destination address of the aggregate packet is an address of an adjacent node on the common route; and an aggregate packet routing device 11 for routing the aggregate packet, based on the destination address.

Abstract: A packet transmission system includes a home agent providing a home link and a home address to a mobile node, one or more access routers, each providing a foreign link and a c/o address to the mobile node, and one or more mobility support routers that relay a packet to the destination between the mobile node and the home agent or a counterpart correspondent node. When the mobile node moves into a new foreign link, the corresponding access router transmits a registration request to the home agent and/or the correspondent node. When acquiring a registration request on the way to the destination, each mobility support router stores an entry having the home address of the mobile node and the c/o address contained in the registration request, and produces and transmits a new registration request updating the c/o address to its own address.

Abstract: A mobile communication system can implement broadcasting control that generates broadcast information autonomously in a distributed manner, thereby obviating the need for an RNC (Radio Network Controller). Each base station has an IP address and a base station multicast address. Each base station sends its own system information to all base stations using the multicast address. Each base station generates its broadcast information from its own system information and the system information received from other base stations. Thus, it can generate the broadcast information autonomously in a distributed manner without using the RNC.

Abstract: The present invention provides a single carrier/DS-CDMA packet transmission method wherein a predetermined time slot is assigned to reservation demand packet transmission in regard to a spreading code, and the reservation demand packet and data packets are time-multiplexed for transmission. An uplink packet transmission method in a multi-carrier/DS-CDMA mobile communication system is also provided, wherein frames are set up in each communication channel of a subcarrier, time slots which are time-segments of the frames are set up further, and a mobile station spreads a packet to be transmitted by a spreading code and the information signal is transmitted to a base station in a predetermined time slot.