Nippon Telegraph and Telephone Corporation

Rikagaku Kenkyusho

Inter-University Research Institute Corporation Research Organization of Information and Systems

Other

Fujifacom Corporation

Komatsugawa Chemical Engineering Co., Ltd.

Ichiro Inoue

Shigeo Urushidani

Teruyuki Nagamune

Kaori Shimizu

Isao Endo

Nobuaki Matsuura

Hisashi Kojima

Tomonori Takeda

Kazuhiro Takizawa

Kohei Shiomoto

Tatsuya Iwakura

Michihiro Aoki

Kozo Inoue

Takashi Miyamura

Takashi Kurimoto

Keisuke Kabashima

Ikuzo Kagami

Tadashi Nohira

Shinji Endo

Susumu Suga

Shoji Aizawa

Rie Hayashi

Noburu Takematsu

The path management controllerrefers to resource informationincluding reservation statuses of working paths and advance reserved paths that are set in every link, so as to calculate a route for setting a new path and set this path in this calculated route. If the route for setting this new path cannot be obtained (1) because of a shortage of residual bandwidth of a link of interest, the path management controllerrefers to the resource reservation informationof working paths and advance reserved paths and calculates an alternative route for another existing path used in the link of interest, and moves this path to the calculated alternative route. On the other hand, if the route for setting this new path cannot be obtained (2) because there is no continuous bandwidth sufficient for setting this new path in the link of interest, the path management controllerrefers to the resource reservation information regarding working paths and advance reserved paths in the link of interest in the resource information, so as to execute the time slot rearrangement.

Path management control method, path management control program, path management controller and path management control system

An optical network has: sections for establishing optical paths; a plurality of optical edge routers for connecting external IP networks to the optical network (); and a plurality of optical cross connects, for connecting the optical edge routers by the optical paths, having switching sections with respect to an optical pulse unit. In the optical network, each of the optical edge routers has both of: (1) an optical network control instance (INSp) for maintaining topology information in the optical network and switching/signaling the optical paths; and (2) an IP network instance (INSi) for maintaining a routing table in each of the external IP networks and activating routing protocols between the external IP networks and the IP network instance. By doing this, it is possible to realize a multi-layer cooperative function and provide highly safe optical networks, etc.

Optical network, optical edge router, program thereof, cut through method, and edge router

A route switching method for switching a route in a core network that accommodates service networks including user node apparatuses by use of a server storing path information that includes, in every time frame, a route for a working path and a route for a backup path to be switched over from the working path, both of the working path and the backup path established between two boundary node apparatuses each of which is located on a boundary between the service network and the core network. The server calculates, in response to the connection request from the user node apparatus, a route for a working path and a route for a backup path, and requests the boundary node apparatus to establish this working path. The server can send the route for the backup path to the boundary node apparatus before a failure occurs in the core network. The boundary node apparatus establishes the working path in response to the establishment request for establishing the working path from the server, and can perform a quick recovery by switching over the working path to the backup path when a failure occurs in the core network.

Route switching method, server, boundary node apparatus, route switching system, and route switching program

A plurality of pieces of information about a link (hereinafter referred to as 'link information'), which are stored in a common DB, are categorized in accordance with the VPN related to each piece of link information. VPNID, which is information for identifying each VPN, is added to each piece of link information which has been categorized. The link information for the same VPNID is extracted from the link information to which the VPNID for the common DB is added so as to be contained in the corresponding VPNDB. By doing this, it is possible to realize a path design for the customer easily by providing the network information in the VPN provider and the network information of the customer network while realizing a high scalability.

VPN communication control device, communication control method in VPN, and virtual dedicated network management device

An unscheduled terminal unit is prevented from being connected to conference communication or a scheduled terminal unit is prevented from being not connected to the conference communication, and security of the conference communication is improved, and also, a conference server for interconnecting many terminal units is connected to a private branch exchange and reservation tables for using the conference server are provided in order to surely charge users for conference communication service. When an incoming call for requesting connection of the conference communication comes to the private branch exchange, the validation is identified by whether the incoming call has been registered in the reservation tables or not, and the connection is rejected for the invalid incoming call.

Conference communication system

In a turbidimeter for measuring a turbidity of a test solution to be measured i.e. culture solution in a fermentation apparatus, a semiconductor laser diode and a semiconductor photodiode are integrally arranged in a detection portion of the turbidimeter in such a manner that a laser beam emitted from the semiconductor laser diode is made incident upon the semiconductor photodiode through the test solution. Moreover, a protection circuit for the semiconductor laser diode and the semiconductor photodiode is also arranged in the turbidimeter to cut off a current flowed therethrough when an environmental temperature becomes above a predetermined temperature. Therefore, the turbidimeter can be made small in size and light in weight, and the turbidity can be measured accurately over wide range.

Turbidimeter employing a semiconductor laser diode and a photodiode

Disclosed is an improved turbidimeter or instrument for measuring the concentration of a suspension using diffuser means for converting incident light into diffused light before passing through a suspension. The use of diffused light improves the linearity of the optical density vs. concentration characteristics over a relatively wide range.

Instrument for measuring concentration of substance in suspension

This invention relates to an apparatus for automatically sampling a clarified test solution from a suspension to be tested, which comprises two filtering tubes being immersed in the suspension, a circulator connected to the one tube, and a sampling cell connected to the circulator and the other tube. The suspension is sucked by the circulator and filtered through the one tube. The filtered and clarified test solution is sampled in the sampling cell and the residual test solution is returned to the suspension through the other tube. A flow direction of the test solution is reversed at intervals so that the filtering tubes are not blocked by suspending solids.

Autosampler

Growing community of inventors

Tokyo, Japan

Ichiro Inoue