Ntt Docomo, Inc.

Sony Corporation

Atsushi Iwasaki

Shinichi Isobe

Ken Igarashi

Takashi Koshimizu

Kenji Nishimura

Takayuki Takeda

Tatsuya Kubota

Shinichi Ohtsubo

Youichi Matsumura

Tsuyoshi Futami

Motoshi Tamura

Takatoshi Okagawa

Akimichi Tanabe

Masahiro Sawada

Shin-ichi Isobe

Takeshi Ihara

Makoto Koushiro

A mobile communication network system () is disclosed. The network system comprises a transport network () including a plurality of routers (), and a network control apparatus () for controlling mobility of a mobile node (, MN), characterized in that the network control apparatus () comprises a mobility managing unit (LRM) for managing information (CDT) of a correspondent node (, MN) communicating with the mobile node (, MN); the mobility managing unit (LRM) comprises a boundary router detecting unit for detecting that the mobile node (MN) moves and reaches a boundary of a router (AR) managed by the mobility managing unit (LRM) itself; and a correspondent node information forwarding unit for forwarding the information (CDT) of the correspondent node (MN) to a neighbor mobility managing unit (LRM) having a similar structure, when it is detected that the mobile node (MN) reaches a boundary of a router (AR) managed by the mobility managing unit (LRM) itself.

Mobile communication network system and a mobility managing unit

An imaging device includes a detector that repeatedly carries out a series of operation of generating an evaluation value to evaluate the degree of focusing of a position after driving of a lens toward one end part in the drive range of the lens, and detects the evaluation value of a position that is closer to the end part than the position of the evaluation value of the highest degree of focusing and is immediately adjacent or adjacent across a predetermined number of positions to the position of the evaluation value of the highest degree of focusing. The imaging device further includes a drive controller that makes the series of operation be repeatedly carried out toward the other end part in the drive range of the lens, and drives the lens to a position of a degree of focusing not smaller than the detected evaluation value.

Imaging device, imaging method, and program

An imaging apparatus includes: a supplying section configured to supply a driving command for driving at least a portion of a lens in a specific direction to a focal-point adjustment device for changing or adjusting a focal-point distance in accordance with power supplied to the focal-point adjustment device; and an inference section configured to infer a position, at which the lens is located after being driven in accordance with the driving command in the specific direction, on the basis of the driving command supplied to the focal-point adjustment device and on the basis of error information serving as information on an error of a driving quantity by which the lens driven by the focal-point adjustment device is moved.

Image apparatus, imaging method and program

A communications system is provided which can search for information about a communications device that is not registered in a network by designating time. The search system, which includes a plurality of communications devices, gateways and an entity management server, can execute a search method. The entity management server stores in a storage device the identification information of the communications device sent from the gateways with establishing correspondence with notification time. The entity management server receives from a mobile terminal the identification information of the communications device and designated time. The entity management server searches for the identification information stored in the storage device at the designated time, and identifies the location information of the gateways corresponding to the identification information included in the search request.

Search system of communications device

A mobile communication systemaccording to the present invention comprises handover control apparatusand radio terminal unit. The handover control apparatuscontrols handover of a radio terminal unitbetween access routers-provided in respective base stations-for radio communication with the radio terminal unit. The handover control apparatuscounts the number of relay routers for every candidate access router-for a destination of the radio terminal unit, from a gateway deviceand determines a COR on the basis of the number of relay routers for every access routerthus counted.

Handover control apparatus, relay router, gateway apparatus, access router, base station, mobile communication system, and handover control method

Rerouting of packet exchanges by a mobile terminal is controlled so as to be optimized on a real time basis to prevent network resources from being wasted by redundant routing. In an initial state a route of data from a mobile communication terminal M to a CN, which is a communication partner, is a route R. Then, an access router (AR)acquires the number of hops of data received from the CNby the mobile communication terminal M. As the mobile communication terminal M now performs a handover to under the command of the AR, the route will change to a route R. Then the ARdetects that the route becomes redundant by the fact that the number of hops acquired after the shift is greater than the pre-shift number of hops received from the AR, and invokes control to reroute to a route R, which provides the optimal routing.

Method, terminal and router for detection of trigger to rerouting

In a configuration provided with routers-and gateway deviceconnected above edge routers-provided in respective base stations in a hierarchical structure and configured to perform relaying of data to the base stations, a routeris specified as a relay router, which is a COR closer to a radio terminal unit out of CORs where all paths from an edge routerbefore movement of the radio terminal unitand from each of all edge routersas destination candidates to CNof a communication correspondent intersect. This makes it feasible to readily decrease the handover transaction time.

Handover control apparatus, radio terminal device, edge router, router, mobile communication system, and handover control method

When a radio terminal unitundergoes a handover between base stations, a previous edge routerhaving been connected to the radio terminal unit, out of edge routersprovided in respective base stations, provides an instruction to instruct a relay router, under which the edge routerand every edge routerin the base stationas a candidate for a destination of the movement are connected, to buffer data from a correspondent node, and instructs the relay router to forward the data buffered in the relay routeraccording to the instruction, to the radio terminal unitafter the movement, after completion of the handover, whereby the buffered data is forwarded to the radio terminal unit. This implements forwarding packet data through the optimal path to the radio terminal unit after the movement in the handover control and achieves effective utilization of network resources and reduction of handover transactions.

Handover control apparatus, base station, edge router, relay router, radio terminal unit, mobile communication system, and handover control method

Handover control apparatus, relay router, gateway apparatus, access router base station, mobile communication system, and handover control method

A mobile communications system is disclosed that includes a first local routing manager (LRM) providing a first network in which a mobile terminal is currently located, a second local routing manager (LRM) providing a second network in which a counterpart terminal communicating with the mobile terminal is currently located, and a home routing manager (HRM) managing correspondence between the unique home address of the counterpart terminal and the second network. The first LRM has a controller that acquires address information of the counterpart terminal from the second LRM, via the HRM, when the first LRM does not have the address information, and communication means that transmits the address information of the counterpart terminal to a router of a new cell in the first network when the mobile terminal moves into the new cell.

Mobile communications system and routing management apparatus used in the mobile communications system

A digital video signal is transmitted via a communication system which can transmit digital data through an asynchronous communication line (ATM communication line) or the like and, at the same time, voice information for the working communication and information such as computer information are transmitted by using the communication system. The user of a first data transmitting apparatus sets up the character data etc. for communication on the terminal. The set character data is multiplexed in the predetermined transmission packet together with the audio and video data output from the VTR device and transmitted via an ATM communication line 2 to a second data transmitting apparatus. In the second data transmitting apparatus, the character data is demultiplexed from the transmission packet and displayed on for example the display device of the personal computer. In place of the character information, also voice information can be transmitted by a telephone set. In this way, the users of both data transmitting apparatuses transmit and receive the working communication information by using the communication line for transmitting the digital video signal.

Growing community of inventors

Yokosuka, Japan

Atsushi Iwasaki