National Institute of Information and Communications Technology, Incorporated

National Institute of Information and Communications Technology, Incorporated Administrative Agency

Mitsubishi Denki Kabushiki Kaisha

Hitachi-kokusai Electric Inc.

Kddi Corporation

Communications Research Laboratory, Independent Administrative Institution

Masugi Inoue

Khaled Mahmud

Mikio Hasegawa

Homare Murakami

Gang Wu

Akira Idoue

Hidetoshi Yokota

Udana Bandara

Hiroyuki Morikawa

Takeshi Kubo

Satoshi Yasuda

Takashi Sakakura

Nobuyasu Shiga

Ved Kafle

Kohta Kido

Kiyohide Nakauchi

Yoneo Watanabe

Koji Yamaoka

The time of transmission and reception between stations A and B is exchanged, and any deviation in time is calculated in a corresponding manner in the stations. Using the transmission time TXA from station A to B, the transmission time TYB from station B to A, the time TXB of a clock at station B in a transmission from station A to station B, and the clock time TYA at station A in a transmission from station B to A, the following are measured in sequence: 1) station A records the time TXA at which TXA and TYA were transmitted, 2) station B measures the time TXB at which TXA and TYA were received, 3) station B records the time TYB at which TXB and TYB were transmitted, and 4) station A measures the time TYA at which TXB and TYB were received, the transfer time between stations A and B being derived at each station on the basis of the average of the increase &#x394;TXB-A from TXA to TXB and the increase &#x394;TYA-B from TYB to TYA, or the deviation in time for a transfer between stations A and B being determined by subtracting the increase &#x394;TXB-A from the transfer time. The transmission time TXA from station A to B may also be measured using a reflection signal from a transmission terminal.

Method for detecting synchronization deviation between communication stations

A home node and a destination node, which are specified by node identifiers, acquire locators thereof and mapping of the node identifiers and the locators, prior to communication, and they are transmitted after the address of a packet specified by the node identifier is rewritten by the locator at the time of communication. Because roles of the node identifier and the locator are separated, the communication method is suitable for mobile communication and multi-homing. In addition, the communication method makes it possible to reduce use amount of global addresses, and thus solve an address exhaustion problem.

Packet communication method using node identifier and locator

An analog signal input/output system in which an analog signal input terminal converts an input analog signal to a digital signal and transmits the digital signal to a host computer via a network, while a digital signal generated by the host computer is transmitted through the network to an analog signal output terminal and converted therein to an analog signal to be outputted. Two connections of upstream and downstream sockets between the host computer and the analog signal input/output device. These connections are selectively used to provide communication of control signals and data. Exemplary analog signals include input signals from a microphone, output signals to a speaker, and input/output data to/from a sensor, a measuring device and the like.

Analog signal input/output system using network links

The present invention is a wireless communications system for simultaneously establishing a basic access network and a wireless access network using at least two kinds of wireless communication networks. The basic access network executes signaling communication in which communication is controlled so as to be continuously switched, whereas the wireless access network executes data communications other than the signaling communication. According to the system of the present invention, networks can be continuously switched by setting multicast for temporarily flowing data to the basic access network.

Wireless communications system

A location information server system for acquiring the status of a user terminal in wireless communication network, comprising: a plurality of sensor means capable of communicating through a network; a priority database to location information from each sensor means; location information selecting means for selecting a location information having a high priority from overlapping location information with reference to the database; and a sensor information integration processing means which integrates acquisition information from at least two sensor means of the sensor means for acquiring the location information and the sensor means for acquiring identification information of a user terminal, and acquires the user terminal position wherein information from each means is accumulated in the location information server as terminal location information database and the location information server means includes a location information providing means capable of providing the sensor information to a predetermined network server which switches communication in the user terminal.

Location information server system and wireless communication system using the same

A gateway (GW) and a plurality of foreign agents (FA) are connected in a ring-like manner, and the procedures of (1) the GW receiving an IP packet, addressed from a corresponding node CN to a mobile node MNa; (2) the GW transferring the packet to a link Lin one direction; (3) an FAtransferring the received packet to a link Lin the same direction; (4) FAfurthermore transferring the received packet to a link L, connected to MNa, if the destination address of the received packet is already registered in the visitor list; (5) an FAtransferring the received packet to a link Lin the same direction; (6) FAfurthermore ending the process as it is if the destination address of the received packet is not registered; and (7) the GW discarding the received packet.

Mobile network and communication method thereof

It is an object of the present invention to provide a communication system to provide a communication system which requires no special application for a correspondent node and has a service handoff function enabling a transfer destination terminal device to be freely used, and its configuration equipment. In order to realize this, the communication system includes a correspondent node delivering communication data which can be executed by a predetermined application, a proxy server device which receives the communication data from the node to execute the application, and transfers the service to a transfer destination terminal device, the transfer destination terminal device outputting the service, and a user terminal device, wherein the user terminal device transmits control information to the proxy server device, and thereby the proxy server device switches the transfer destination terminal device to perform service handoff.

Communication system having service hand-off function, user terminal device, transmission destination terminal device, and proxy server device

The present invention is a wireless communications system for simultaneously establishing a basic access network and a wireless access network using at least two kinds of wireless communication networks. The basic access network executes signaling communication in which communication is controlled so as to be continuously switched, whereas the wireless access network executes data communications other than the signaling communication. Then, a wireless communication terminal is provided with a position obtaining means and sends position information to a server, thereby it is possible to switch to an optimum network.

Wireless communication system for switching different wireless communication networks

The present invention is a wireless communications system for simultaneously establishing a basic access network and a wireless access network using at least two kinds of wireless communication networks. In the basic access network, there are executed signaling communication for obtaining available network information based on the position information of a terminal and communication by SIP (Session Initiation Protocol) for executing exchange of a subscribe request signal between terminals and negotiation of communication. This arrangement makes it possible to connect between terminals by a media application on peer to peer.

A data communication method and apparatus for a mobile network. A destination foreign agent (FA) recognizes a MAC address of an MN. The FAregisters the MAC address of the MN in a handoff request message (FHReq), and the FAfeeds the FHReq onto a transfer network. Each of foreign agents (FAs) receives the FHReq, registers an IP address corresponding to the MAC address in the FHReq when the MAC address is registered in a binding list of the FAs themselves, and feeds the IP address onto the transfer network. The FAreceives the FHReq, and temporarily registers the MAC address and the IP address in the binding list of the FAitself. The FAtransfers data sent from a homw agent (HA) to the MN, based on the information which has been temporarily registered.

Mobile network, and data communication method therefor

The present invention is intended to provide, for a wireless communication system originally having a calling function, a wireless communication system enabling an audio communication service or the like which requires a calling function, and to provide a wireless communication system which reduces power consumption of a wireless terminal when it is in a standby mode. A communication party, which is a calling side, a network to which the communication party is connected, and a wireless LAN base station, a pager base station, and a pager controller which are connected to the network, and a PC, which is a wireless communication terminal, constitute the present invention. The PC includes a wireless LAN card and a pager card. This forms the present invention.

Radio communication method, radio communication system, wide area radio communication base station, and radio communication terminal

Upon recovery of communication, this recovery is detected by communication recover detector and then optimal times duplicated pseudo acknowledgements calculated by arithmetic unit are transmitted from ACK transmitter. During normal state, advertisement is made in small value of advertised receive window size and immediately after recovery state, advertisement is made in expanded window size.

Packet communication method and proposal node

In a multiservice wireless communication system according to the present invention, a location managerof a multiservice terminaldetects its own position with a GPS receiver interface. The location manager sends the detected positional information to a management servervia a common-signaling wireless network base stationin which respective multiple service zones serviced by multiple wireless systems overlap in a common-signaling wireless zone and acquires information on available wireless systems as a response to that. A network selecting sectionselects a wireless system that most matches selecting conditions from the acquired available wireless systems and performs communication via the interfacesandthat operate the selected wireless system.

Growing community of inventors

Tokyo, Japan

Masugi Inoue