Patents Assigned to Hitachi Communication Technologies, Ltd.
  • Patent number: 7341144
    Abstract: A case includes a case body, a lid, hinges supporting the lid on the case body and a waterproof seal placed on the joining surface of the case body. The lid can be turned for closing on the hinges so as to compress the waterproof seal perpendicularly to the joining surface of the case body. Each hinge is provided with a hinge pin having opposite cylindrical end parts and an offset middle part defining a groove together with the cylindrical end parts. The grooves of the hinges permit first knuckles formed integrally with the lid to sink therein so that the lid held with its joining surface parallel to the joining surface of the case body can be moved toward the case body perpendicularly to the joining surface of the case body to compress the waterproof seal perpendicularly between the joining surfaces of the lid and the case body. The hinge pin is restrained from coming off by the first knuckles when the first knuckles are engaged in the groove.
    Type: Grant
    Filed: February 18, 2005
    Date of Patent: March 11, 2008
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Takeshi Tajiri, Osamu Kamimura, Yasushi Kimura
  • Patent number: 7330470
    Abstract: A boundary node router determines whether a received packet includes a SIP message and a REGISTER message, and, if so, adds its router identifier to a REGISTER message which includes a user identifier and a user terminal identifier, sent from a user terminal, and sends the message to a SIP server. The SIP server has a user management table which stores the user terminal identifier, the router identifier of a router which serves the user terminal, and a predetermined Quality of Service type, in association with each user identifier. The SIP server extracts a user identifier, a user terminal identifier, and a router identifier from a received REGISTER message, and updates the user terminal identifier and the router identifier corresponding to the extracted user identifier, to the extracted user terminal identifier and the extracted router identifier.
    Type: Grant
    Filed: January 12, 2005
    Date of Patent: February 12, 2008
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Hiroaki Nakazawa, Atsushi Tachikawa
  • Patent number: 7315543
    Abstract: Disclosed is a packet-switched communication apparatus (DNS proxy server) receiving and forwarding messages which are used to obtain an address corresponding to a domain name assigned to a device connected to a network from the domain name and to obtain such a domain name from the address. The communication apparatus comprises mapping retaining means for retaining mappings between network-dependent parts of addresses which are used in a first network and address translators; address translator selecting means for selecting an address translators, based on an address included in a received packet; address obtaining means for obtaining a substitutive address to replace the address included in the received packet from the selected address translator; and address replacement means for replacing the address included in the received packet by using the obtained substitutive address.
    Type: Grant
    Filed: January 16, 2004
    Date of Patent: January 1, 2008
    Assignee: Hitachi Communications Technologies, Ltd.
    Inventors: Keisuke Takeuchi, Hidenori Inouchi, Yukiko Takeda, Katsunori Takahashi
  • Patent number: 7310519
    Abstract: A base station control portion selects one or multiple signals in accordance with the state of radio waves from signals received through multiple communication paths. A wireless communication apparatus communicates with a wireless terminal and a wired communication network at multiple frequencies. In response to a request for software upgrading from a network management device, the wireless communication apparatus selects one frequency, controls the state of transmission waves of a wireless interface such that a communication path in which a communication service is being provided can be switched to another communication network without interruption, rewrites software for each wireless interface to software received through a wired interface in advance, and returns the state of transmission waves of the wireless interface. Thus, the software can be upgraded without blackouts of the communication service to the wireless terminal.
    Type: Grant
    Filed: January 19, 2005
    Date of Patent: December 18, 2007
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Koichi Okita, Ryosuke Kurata
  • Patent number: 7286539
    Abstract: A packet forwarding apparatus for connecting a plurality of user terminals to an ISP management server has a management table indicating the relationship between a connection port identifier and specific header information in association with the MAC address of each of the user terminals so that, in a communication protocol procedure executed between each of the user terminals and the ISP management server prior to communication with a wide-area network, the packet forwarding apparatus discards a packet for the user terminal when it is determined that the specific header information cannot be assigned to the user terminal based on the management table.
    Type: Grant
    Filed: February 27, 2006
    Date of Patent: October 23, 2007
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Munetoshi Tsuge, Ryo Nakamura, Toshiyuki Saito, Yasunari Shinohara
  • Publication number: 20070195758
    Abstract: A communication system using PPP in which a plurality of layer 3 protocols are defined has a problem. PDSN cannot judge which of layer 3 protocols is equipped in a terminal, and NCP phase processes corresponding to all layer 3 protocols of the system are executed. This increases the number of PPP packets transmitted/received between the terminal and PDSN, which prolongs a connection time. In the invention, a new procedure of the NCP phase process is established in a communication system, by which the terminal firstly notifies a layer 3 protocol to PDSN and thereafter the NCP phase process is executed. PDSN waits for a notice of the layer 3 protocol from the terminal, selects the corresponding layer 3 protocol from the layer 3 protocols according to the notice, and executes the NCP phase.
    Type: Application
    Filed: February 25, 2005
    Publication date: August 23, 2007
    Applicant: HITACHI COMMUNICATION TECHNOLOGIES, LTD.
    Inventors: Hitomi Teraoka, Naruhito Nakahara
  • Patent number: 7254160
    Abstract: A radio receiver handles a transmitted Walsh sequence having a code length of “m” as a two-dimensional array of “a” rows and “b” columns, and performs a fast Hadamard transform process having a code length of “a” in the row direction. The absolute values of the results are added in the column direction, and a Walsh number having the maximum receiving power is selected to determine a Walsh sequence having a code length of “a.” Then, only the identified column is extracted, and a fast Hadamard transform process having a code length of “b” is applied in the column direction.
    Type: Grant
    Filed: February 12, 2003
    Date of Patent: August 7, 2007
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Kiyoshi Kawamoto, Manabu Kawabe, Shiro Mazawa, Tomoyuki Ono
  • Patent number: 7251230
    Abstract: A radio communication system having a base station and a plurality of radio terminals, wherein each radio terminal having a transmission request transmits a reservation packet at arbitrary timing through a reservation channel in accordance with a CDMA scheme, and the base station assigns a traffic channel and a time slot to be used to each radio terminal requesting a reservation through a reply packet outputted onto a reply channel. On the reservation channel, a short spreading code corresponding to a matched filter is applied.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: July 31, 2007
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Hironari Masui, Yasuo Ohgoshi, Takashi Yano, Nobukazu Doi
  • Patent number: 7239813
    Abstract: A bit synchronization circuit composed of a multiphase data sampling unit for converting each received burst data sets to multiphase data trains, a phase determination unit for generating a control signal indicating an optimum phase data train, an output data selector for selectively passing optimum phase data train indicated by the control signal, and a data synchronization unit for converting the optimum phase data train to a data train in synchronization with a reference clock. The phase determination unit repeatedly detecting the optimum phase data train during the same burst data set is received. When optimum phase varies, the output data selector dynamically switches the optimum phase data train to be supplied to the data synchronization unit.
    Type: Grant
    Filed: September 4, 2003
    Date of Patent: July 3, 2007
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Yusuke Yajima, Toshihiro Ashi, Tohru Kazawa
  • Patent number: 7218818
    Abstract: A dispersion compensating fiber whose chromatic dispersion is positive and a negative dispersion compensating fiber whose chromatic dispersion is negative are prepared, and division-multiplexed optical signals, after being guided to either dispersion compensating fiber to once shift the whole wavelength band to positivity or negativity, are subjected to fine adjustment with a dispersion compensating fiber of a reverse sign.
    Type: Grant
    Filed: July 28, 2005
    Date of Patent: May 15, 2007
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Yasuyuki Fukashiro, Hiroyuki Nakano, Tetsuya Uda, Tooru Hirai
  • Patent number: 7194258
    Abstract: A base station control portion 200 selects one or plural signals from signals received by plural settable communication paths in accordance with the state of the wave. A wireless communication apparatus 110 communicates with a wireless terminal 300 and a wired communication network. When the wireless communication apparatus 110 receives a request for upgrading software from a network management device 250, the wireless communication apparatus 110 controls the state of the transmission wave of a wireless interface so as to switch a communication path in which communication services are being provided to another wireless communication apparatus 110 without blackouts, rewrites the set software to software having been received through a wired interface in advance, returns the state of the transmission wave of the wireless interface and upgrades software without blackouts of the supply of communication services to the wireless terminal 300.
    Type: Grant
    Filed: October 3, 2005
    Date of Patent: March 20, 2007
    Assignee: Hitachi Communication Technology, Ltd.
    Inventors: Koichi Okita, Ryosuke Kurata
  • Patent number: 7190952
    Abstract: A base station control portion 200 selects one or plural signals from signals received by plural settable communication paths in accordance with the state of the wave. A wireless communication apparatus 110 communicates with a wireless terminal 300 and a wired communication network. When the wireless communication apparatus 110 receives a request for upgrading software from a network management device 250, the wireless communication apparatus 110 controls the state of the transmission wave of a wireless interface so as to switch a communication path in which communication services are being provided to another wireless communication apparatus 110 without blackouts, rewrites the set software to software having been received through a wired interface in advance, returns the state of the transmission wave of the wireless interface and upgrades software without blackouts of the supply of communication services to the wireless terminal 300.
    Type: Grant
    Filed: October 3, 2005
    Date of Patent: March 13, 2007
    Assignee: Hitachi Communication Technology, Ltd.
    Inventors: Koichi Okita, Ryosuke Kurata
  • Patent number: 7149301
    Abstract: A repeating device 14 for relaying the call to a plurality of receiver telephones 12a–12c that are connected to a local area network, comprising a function for requesting a reply to the plurality of receiver telephones 12a–12c asking their availability to receive a call, a function for selecting the destination of the call out of the receiver telephones 12a–12c that responded, and a function for notifying the address of the selected receiver telephone 12a to the caller telephone 22a. Further, the present repeating device comprises a function for receiving the transfer request from a user.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: December 12, 2006
    Assignees: Hitachi Communication Technologies, Ltd., Telecom Kiki, Ltd.
    Inventors: Takahiro Yoshida, Masaru Noji, Takahiro Sasaki, Tadashi Saito
  • Publication number: 20060019651
    Abstract: A wireless communication system and its test method capable of executing a test of the wireless communication apparatus from a remote place by using a terminal generally used in wireless communication systems are implemented with a low-cost configuration and a simple procedure. A terminal obtained by installing a test AP on a general terminal that is used in general wireless communication systems and that can execute APs via a communication network is placed in a coverage area of a wireless communication apparatus. A maintenance center for the wireless communication system activates the terminal. The terminal executes the test AP and conducts communication with the maintenance center by using control signals and test signals for testing wireless communication system. A test is executed by measuring an actual communication state of the wireless communication system.
    Type: Application
    Filed: December 21, 2004
    Publication date: January 26, 2006
    Applicant: Hitachi Communication Technologies, Ltd.
    Inventors: Tsutomu Uchida, Koji Hayata, Hideo Aoe
  • Publication number: 20050288025
    Abstract: A radio communication system includes a grouping unit for grouping a plurality of base stations into a plurality of groups (Soft Handoff Groups) and a determining unit for selecting base stations belonging to one and the same group selected from the groups produced by the grouping unit and for determining the base stations as base stations to send communication packets to an access terminal.
    Type: Application
    Filed: January 19, 2005
    Publication date: December 29, 2005
    Applicant: Hitachi Communication Technologies, Ltd.
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Patent number: 6977999
    Abstract: A call agent(CA) connects a IP telephone and a public switching telephone on the basis of a called-destination telephone number which corresponds to received reverse-charging service number from the IP telephone; a reverse-charging service control apparatus causes an exchange to stop charging; the CA and the reverse-charging service control apparatus calculate a charging information items, respectively; and generate a fee information by setting a charged party information so that a sum of fees in an IP network and a public switching telephone network may be charged to the called-destination telephone number, and transmit the fee information to an IP/PSTN charging management apparatus on a called destination side; and generate other fee information so that a fee in the network on a call origination side may be charged to a business company of called destination, and transmit the fee information to the apparatus on a call origination side.
    Type: Grant
    Filed: August 10, 2004
    Date of Patent: December 20, 2005
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Yusuke Honda, Satoshi Matsuhashi, Kouichi Shimizu
  • Publication number: 20050224508
    Abstract: A case includes a case body, a lid, hinges supporting the lid on the case body and a waterproof seal placed on the joining surface of the case body. The lid can be turned for closing on the hinges so as to compress the waterproof seal perpendicularly to the joining surface of the case body. Each hinge is provided with a hinge pin having opposite cylindrical end parts and an offset middle part defining a groove together with the cylindrical end parts. The grooves of the hinges permit first knuckles formed integrally with the lid to sink therein so that the lid held with its joining surface parallel to the joining surface of the case body can be moved toward the case body perpendicularly to the joining surface of the case body to compress the waterproof seal perpendicularly between the joining surfaces of the lid and the case body. The hinge pin is restrained from coming off by the first knuckles when the first knuckles are engaged in the groove.
    Type: Application
    Filed: February 18, 2005
    Publication date: October 13, 2005
    Applicant: Hitachi Communication Technologies, Ltd.
    Inventors: Takeshi Tajiri, Osamu Kamimura, Yasushi Kimura
  • Publication number: 20050141528
    Abstract: A media gateway built in an exchange comprises a media gateway control unit connected to a control unit of the exchange, a first protocol processing unit for executing a call connection procedure according to a first call control protocol with an IP call connection controller on the IP network, and a second protocol processing unit for executing a call connection procedure according to a second call control protocol with the IP call connection controller. The media gateway control unit instructs the first protocol processing unit to start call connection processing in response to a call connection command from a PSTN telephone, aborts the call connection processing of the first protocol processing unit when receiving a connection protocol change command from the IP call connection controller before completing the call connection according to the first protocol, and instructs the second protocol processing unit to execute call connection processing.
    Type: Application
    Filed: July 27, 2004
    Publication date: June 30, 2005
    Applicant: Hitachi Communication Technologies, Ltd.
    Inventors: Satoshi Matsuhashi, Toshiyuki Matsuda
  • Publication number: 20050113028
    Abstract: A radio communication terminal, being used in a radio communication systems in which the transmission rate varies depending on radio wave conditions and communication statuses of other users, comprises a reception module which receives packets transmitted by a base station in an idle state of the radio communication terminal, a signal processing module which estimates a transmission rate available in communication based on the packets received by the reception module, and a display module which displays information indicating the transmission rate estimated by the signal processing module.
    Type: Application
    Filed: January 30, 2004
    Publication date: May 26, 2005
    Applicant: Hitachi Communication Technologies, Ltd.
    Inventors: Tsutomu Uchida, Hiroshi Tamaribuchi, Hideo Aoe, Masato Inagaki
  • Publication number: 20040246991
    Abstract: An IP address translator comprising: SIP-ALG message processing unit for assigning a virtual IP address in a process of establishing a session between an IPv4 apparatus and an IPv6 apparatus via a SIP server; an address translation table for storing a relation between an IPv4 address and a virtual IPv6 address, a relation between an IPv6 address and a virtual IPv4 address, and filter information in association with each of the virtual addresses; and a processor for performing address translation on the IPv4 and IPv6 packets according to the address translation table, wherein header information of received packets is checked on the basis of the filter information before the address translation to discard a packet which does not adapt to the filter information.
    Type: Application
    Filed: August 22, 2003
    Publication date: December 9, 2004
    Applicant: Hitachi Communication Technologies, Ltd.
    Inventors: Akihito Tsuzuki, Noriyuki Sueyoshi