Patents Assigned to NTT Mobile Communications Network, Inc.
  • Publication number: 20060251038
    Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.
    Type: Application
    Filed: April 6, 2006
    Publication date: November 9, 2006
    Applicant: NTT Mobile Communications Network, Inc
    Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
  • Publication number: 20060199578
    Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.
    Type: Application
    Filed: March 28, 2006
    Publication date: September 7, 2006
    Applicant: NTT Mobile Communications Network, Inc.
    Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
  • Publication number: 20060194583
    Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.
    Type: Application
    Filed: March 30, 2006
    Publication date: August 31, 2006
    Applicant: NTT Mobile Communications Network, Inc.
    Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
  • Publication number: 20060178167
    Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.
    Type: Application
    Filed: April 4, 2006
    Publication date: August 10, 2006
    Applicant: NTT Mobile Communications Network, Inc.
    Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
  • Patent number: 7082310
    Abstract: Among cellular radio communication systems, there are those in which a plurality of businesses, e.g. businesses A, B and C share a designated frequency band, and each business provides radio communication services using respectively allotted frequency bands. In this type of radio communication system, there are cases in which mobile stations belonging to different businesses use channels which have adjacent frequencies, in which case adjacent channel interference of a large interference level is produced. Therefore, in this radio communication system, of the frequency bands allotted to each business, the adjacent frequency bands which are adjacent to frequency bands allotted to other businesses are allotted to low power communications, while non-adjacent frequency bands which are not adjacent to frequency bands allotted to other businesses are allotted to high power communications.
    Type: Grant
    Filed: July 29, 2003
    Date of Patent: July 25, 2006
    Assignee: NTT Mobile Communications Networks, Inc.
    Inventors: Tomoaki Hirayama, Tadao Takami, Kiyohito Nagata
  • Patent number: 6977903
    Abstract: Disclosed is a mobile communication system including a network constituted of at least one switching center and a plurality of base stations, and a mobile station which communicates with the base stations simultaneously. The system permits varying transmission delay between the switching center and the base stations according to the type of services available to the mobile station. The object of the present invention is to propose a communication which permits varying transmission delay according to the type of service currently employed, and to promptly recover a synchronization state even if an out-of-sync state happens. To attain the object, a memory means (mobile switching center processor 32) stores transmission delay characteristics corresponding to services which are available to the mobile station.
    Type: Grant
    Filed: December 25, 1997
    Date of Patent: December 20, 2005
    Assignee: NTT Mobile Communications Network, Inc.
    Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Satoh, Hiroki Morikawa, Fumiaki Ishino
  • Patent number: 6963551
    Abstract: A signal transmission method checks, when detecting an occurrence of a communication request, whether the communication request is a high speed communication (step S302). In the case of the high speed communication, it checks whether the number of current high speed communications (m) plus one is greater than the upper limit (mmax) of the high speed communication (step S312). If greater, it cancels the request as a call loss (S316), and sets to a variable a the ratio (h) of the rate of the high speed communication to that of a low speed communication. If the communication request is the low speed communication, it sets one to the variable a (step S304). It compares n plus a with nmax (step S306), where n is the total number of all the current communications, a is the value associated with the communication request, and nmax is the upper limit of the number of communications acceptable in a bandwidth, all of which are expressed in terms of the number of the low speed communications.
    Type: Grant
    Filed: April 19, 1999
    Date of Patent: November 8, 2005
    Assignee: NTT Mobile Communications Network, Inc.
    Inventors: Shinji Uebayashi, Seizo Onoe, Minami Ishii, Takehiro Nakamura
  • Patent number: 6912394
    Abstract: A radio channel assignment judgement method and a radio channel control device in a mobile communication system, capable of preventing a rapid tolerance degradation with respect to the identical frequency interference associated with a degradation of a receiving level of a communication channel that is caused, for example, by a moving of the mobile station, are disclosed.
    Type: Grant
    Filed: February 16, 2000
    Date of Patent: June 28, 2005
    Assignee: NTT Mobile Communications Network Inc.
    Inventors: Kazunori Obata, Akihiro Maebara, Tooru Nakamura
  • Patent number: 6871302
    Abstract: The writing address supply part 210 supplies writing addresses for writing the bits forming bit sequences corresponding to the header H contained in a frame to be transmitted or stored and bit sequences corresponding to the data D, into the operating memory 220. The reading address supply part 230 alternately supplies to the operating memory 220 a plurality of addresses for reading a plurality of continuous bits corresponding to the header H from the operating memory 220, and an address for reading 1 bit corresponding to the data D from the operating memory 220, and reads the bit sequence such that the bits forming the bit sequence corresponding to the header H are scattered and arranged within the bit sequence forming the data D, from the operating memory. In accordance with such an interleaving device, it is possible to individually randomize frames according to their constituent data, and it is possible to transmit the bits that make up such data in a format which is most suited for said data.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: March 22, 2005
    Assignee: NTT Mobile Communications Network, Inc.
    Inventors: Toshiro Kawahara, Toshio Miki, Sanae Hotani, Takashi Suzuki
  • Patent number: 6847928
    Abstract: A decoding processing portion 11 of a speech decoder 10 is provided with an emphasis processing portion 15 for performing an emphasis process on signals to be processed (excited signals) SPC generated from coded speech signals BS. A counter portion 17 counts the number of times code errors occurred in successive frames of the coded speech signal BS, and outputs the successive frame error number. When the successive frame error number outputted form the counter portion 17 is less than or equal to a preset reference successive frame error number, a first switch SW1 and second switch SW2 are set to an emphasis processing portion 15 side. Accordingly, the signals to be processed SPC generated from various parameters included in the coded speech signals are supplied through the switch SW1 to the emphasis processing portion 15 of the decoding processing portion 11 to perform an emphasis process.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: January 25, 2005
    Assignee: NTT Mobile Communications Network, Inc.
    Inventor: Nobuhiko Naka
  • Patent number: 6842442
    Abstract: A DS-CDMA transmission method capable of improving the accuracy of channel estimation using pilot symbols by eliminating cross-correlation between pilot symbols inserted into code channels in CDMA multiplexing carrying out fast signal transmission. In each frame assembler, the pilot symbols, which are used for channel estimation for coherent detection, are inserted into coded information data on code channels at fixed intervals, and then the data is modulated by the modulator. The modulated data symbols in each code channel from the modulator are spread by the spreading modulator, the pilot symbols are spread using a spreading code, whereas the information symbols are spread using different spreading codes assigned to respective code channels. The spread signals of the code channels are summed up by the adder to be transmitted.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: January 11, 2005
    Assignee: NTT Mobile Communications Network, Inc.
    Inventors: Koichi Okawa, Koji Ohno, Mamoru Sawahashi, Shinji Uebayashi, Yukihiko Okumura
  • Patent number: 6804507
    Abstract: When a page message containing a caller ID is received from a caller, a call back message containing one of prepared response messages is transmitted to a call number associated with the caller ID. For this, the system displays the prepared response messages and prompts the user to select one of them. A call back message is compiled from a call back number associated with a caller ID contained in the page message and the selected response message. The call back message is transmitted to the call back number. The compilation of call back message is performed such that the format of call back message is adapted to the type of the caller's communication device associated with the caller ID.
    Type: Grant
    Filed: October 3, 2002
    Date of Patent: October 12, 2004
    Assignees: Matsushita Communication Industrial Co., Ltd., NTT Mobile Communications Network, Inc.
    Inventors: Hironari Ishikawa, Hitoshi Itakura, Hisashi Nakagomi
  • Patent number: 6801515
    Abstract: A call admission control method and a mobile station device for a CDMA mobile communication system which is capable of not damaging a communication quality of a mobile station in communication even under a situation of large traffic, suppressing a possibility for degrading a communication qualities of mobile stations in communication with surrounding base stations sufficiently low, and improving efficiency without increasing the control signal traffic.
    Type: Grant
    Filed: August 27, 1998
    Date of Patent: October 5, 2004
    Assignee: NTT Mobile Communications Network Inc.
    Inventors: Yoshihiro Ishikawa, Yasuyuki Watanabe, Takaaki Sato
  • Patent number: 6744784
    Abstract: A variable length frame transmission method making it possible to accurately and easily establish synchronism at the receiver side without redundancy of system under an environment in which a code error easily occurs. In a transmitter, a variable length frame division section 1 divides a variable length frame f into code strings f1 and f2 having a length ratio of 1:1. A first synchronization flag addition section 3-1 adds a synchronization flag S1 to the head of the code string f1 and a second synchronization flag addition section 3-2 adds a synchronization flag S2 to the head of the code string f2. The synchronization flags have contents different from each other, but they have the same length. Code strings having synchronization flags are multiplexed by a changeover switch 4 and formed into a variable length frame. A series of variable length frames obtained from the changeover switch 4 are transmitted to a receiver as serial data.
    Type: Grant
    Filed: December 29, 1998
    Date of Patent: June 1, 2004
    Assignee: NTT Mobile Communications Network Inc.
    Inventors: Nobuhiko Naka, Toshiro Kawahara
  • Patent number: 6741837
    Abstract: A base station 422 of a second system performs communication using a frequency adjacent to a frequency employed by communication between a base station 412 and a mobile station 414 of a first system. When the mobile station 414 is close to the base station 422, the communication of the base station 422 undergoes interference by the leakage power of the mobile station 414. To avoid the interference, the transmission is halted of the mobile station 414 of the first system, which provides the interference by the leakage power.
    Type: Grant
    Filed: July 30, 1999
    Date of Patent: May 25, 2004
    Assignee: NTT Mobile Communications Network, Inc.
    Inventors: Etsuhiro Nakano, Yoshihiro Ishikawa, Masafumi Hata, Minami Ishii, Seizo Onoe
  • Patent number: 6738411
    Abstract: An exclusive OR of outputs from a plurality of shift stages of an M-series generator is formed, thereby obtaining an M-series which has a desired delay, which in an example is a three bit delay with respect to the output code from the generator. Similarly, outputs from a plurality of shift stages are combined and an exclusive OR thereof is formed to provide another delayed M-series. An exclusive OR of each output from the simultaneously delayed code generator and an output from another M-series generator is formed, thus simultaneously obtaining a plurality of Gold code series.
    Type: Grant
    Filed: March 16, 1999
    Date of Patent: May 18, 2004
    Assignee: NTT Mobile Communications Network Inc.
    Inventors: Shinsuke Ogawa, Hirofumi Takagi, Akihiro Higashi
  • Patent number: 6728305
    Abstract: A CDMA radio receiver includes a plurality of reception fingers for effecting a dispreading of a received signal with a plurality of spread codes to derive received data. The receiver includes a plural code generator for simultaneously generating and supplying spread codes to the plurality of reception fingers, and a controller for designating a plurality of spread codes which are to be generated and supplied to the plural code series generator and for specifying to which finger they are to be supplied. The plural code series generator includes a shift register having a plurality of shift stages in which a first initial value is loaded by the controller and adapted to be subject to a shift operation in synchronism with a clock.
    Type: Grant
    Filed: June 21, 2002
    Date of Patent: April 27, 2004
    Assignee: NTT Mobile Communications Network, Inc.
    Inventors: Shinsuke Ogawa, Hirofumi Takagi, Akihiro Higashi
  • Patent number: 6728322
    Abstract: A sequential decoder for use in broadband mobile communications and a receiver including the sequential decoder. The sequential decoder computes likelihood values by referring to histories of paths to reduce the required computational effort. The paths include signal points having small tap coefficient values in an equalizer with a transversal filter, and may also include paths within a constraint length which are old in time.
    Type: Grant
    Filed: February 4, 2000
    Date of Patent: April 27, 2004
    Assignee: NTT Mobile Communications Network, Inc.
    Inventors: Takahiro Asai, Tadashi Matsumoto
  • Patent number: 6724806
    Abstract: A transmission method for implementing variable rate transmission. Part of the baseband processing of a transmitter based on a CDMA transmission scheme is described. A transmitted information sequence in the form of a digital signal is phase modulated by a phase modulator 105. An orthogonal code generator 101 selects, in response to rate information of the transmitted signal, the orthogonal code to be generated. The bit rate of the orthogonal code the orthogonal code generator 101 generates is double the maximum transmission rate. The modulated transmitted signal is multiplied by the orthogonal code corresponding to the rate information with a multiplier 103. The transmitted signal, which is multiplied by the orthogonal code corresponding to the rate information, is further multiplied by a spreading code sequence with a multiplier 104 to be spread into a CDMA signal, and is transmitted under power transmission control based on the rate information.
    Type: Grant
    Filed: January 15, 1999
    Date of Patent: April 20, 2004
    Assignee: NTT Mobile Communications Network, Inc.
    Inventors: Yukihiko Okumura, Fumiyuki Adachi
  • Patent number: 6714908
    Abstract: A speech decoder 10 comprises a decoding processing portion 11 and an amplification process control portion 12. Here, the decoding processing potion 11 is a device for decoding a received coded speech signal (bitstream) BS and outputting a decoded speech signal SP. Additionally, the amplification process control portion 12 monitors the state of occurrence of frame errors in the coded speech signal BS, and when the number of successive frame errors exceeds a predetermined reference frame error number, outputs amplification instructions for a predetermined number of frames after the successive frame errors disappear. As a result, instead of codebook data DCB obtained by a decoding process of the decoding processing portion 11, amplified codebook data DACB are supplied to a synthesis filter portion 17, and is written into the codebook decoder 18 of the decoding processing portion 11 as new original codebook data DCBO.
    Type: Grant
    Filed: December 29, 1999
    Date of Patent: March 30, 2004
    Assignee: NTT Mobile Communications Network, Inc.
    Inventor: Nobuhiko Naka