Patents by Inventor Akihiro Maebara
Akihiro Maebara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8315596Abstract: A transmission process restriction method according to the present invention includes the steps of transmitting a notification information notifying of a restriction rate for each access class and a restriction rate for each traffic class, causing the mobile station to determine a restriction rate of the mobile station on the basis of the notification information received by the mobile station, an access class of the mobile station, and a traffic class of the mobile station, causing the mobile station to compare a random number generated by the mobile station to the restriction rate of the mobile station, and causing the mobile station to decide whether or not to block the connection request transmission processing in accordance with a result of the comparison.Type: GrantFiled: October 23, 2008Date of Patent: November 20, 2012Assignee: NTT DoCoMo, Inc.Inventors: Kazunori Obata, Kazuya Nomura, Mikio Iwamura, Yasuhiro Kato, Akihiro Maebara
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Patent number: 8111664Abstract: A communication path switching system including a wireless base station having a function of wireless communication with a mobile station and a function of relaying data transmitted from the mobile station over a wireless communication path; and plural transmission apparatuses having a function of wired communication with the wireless base station and capable of establishing respectively a wired communication path to be used to relay the data transmitted from a mobile station toward another mobile station. One wired communication path from the wireless base station to one transmission apparatus is switched to another wired communication path from the wireless base station to another transmission apparatus without re-establishing a wireless communication path between the mobile station and the wireless base station.Type: GrantFiled: October 3, 2005Date of Patent: February 7, 2012Assignee: NTT DoCoMo, Inc.Inventors: Masafumi Masuda, Akihiro Maebara, Masayuki Koshino, Yasuhiro Kato
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Patent number: 7860505Abstract: A mobile communication system includes an extension transmission/reception server configured to transmit/receive user data transmitted/received between mobile stations to/from a base station by using an extension transmission/reception transmitting/receiving the data within a radio access network, and the base station configured to transmit/receive the user data to/from the extension transmission/reception server.Type: GrantFiled: June 4, 2004Date of Patent: December 28, 2010Assignee: NTT DoCoMo, Inc.Inventors: Mayu Yamada, Akihiro Maebara, Masayuki Koshino, Masafumi Masuda, Seizo Onoe
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Publication number: 20100273496Abstract: A transmission process restriction method according to the present invention includes the steps of transmitting a notification information notifying of a restriction rate for each access class and a restriction rate for each traffic class, causing the mobile station to determine a restriction rate of the mobile station on the basis of the notification information received by the mobile station, an access class of the mobile station, and a traffic class of the mobile station, causing the mobile station to compare a random number generated by the mobile station to the restriction rate of the mobile station, and causing the mobile station to decide whether or not to block the connection request transmission processing in accordance with a result of the comparison.Type: ApplicationFiled: October 23, 2008Publication date: October 28, 2010Applicant: NTT DoCoMo, Inc.Inventors: Kazunori Obata, Kazuya Nomura, Mikio Iwamura, Yasuhiro Kato, Akihiro Maebara
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Patent number: 7634293Abstract: A mobile communication system includes a first base station configured to be controlled by a first radio network controller, and provide an address of an extension transmission/reception device to user data received from a first mobile station, and the extension transmission/reception device configured to be controlled by the first radio network controller or a different second radio network controller, and provide an address of a second base station, which is controlled by the second radio network controller, to user data received from the first base station.Type: GrantFiled: November 5, 2004Date of Patent: December 15, 2009Assignee: NTT DoCoMo, Inc.Inventors: Masafumi Masuda, Akihiro Maebara, Masayuki Koshino, Mayu Yamada
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Publication number: 20090141674Abstract: A communication path switching system comprises a wireless base station (21) having a function of wireless communication with a mobile station (11) and a function of relaying data transmitted from the mobile station over a wireless communication path; and plural transmission apparatuses (41, 841) having a function of wired communication with the wireless base station and capable of establishing respectively a wired communication path to be used to relay the data transmitted from a mobile station toward another mobile station. One wired communication path from the wireless base station (21) to one transmission apparatus (841) is switched to another wired communication path from the wireless base station (21) to another transmission apparatus (41) without re-establishing a wireless communication path between the mobile station and the wireless base station.Type: ApplicationFiled: October 3, 2005Publication date: June 4, 2009Applicant: NTT DoCoMo, Inc.Inventors: Masafumi Masuda, Akihiro Maebara, Masayuki Koshino, Yasuhiro Kato
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Patent number: 7088960Abstract: Disclosed is a mobile communication system whereby, to reduce the connection time, a mobile station closely located to a base wireless station is permitted to continue to use a common channel for exchanging signals, and to suppress an increase in interference, an individual channel is set for a mobile station located near the edge of a cell, and to obtain a stabilized communication quality and to prevent an increase in the connection time, the probability that the transmission power will reach an upper limit is reduced. When communication between a mobile station and a wireless base station is started, the wireless base station measures the transmission power and the communication quality in the communication with the mobile station and the utilization ratio for a common channel, and compares the obtained values with predetermined threshold values. When the obtained values are lower than the threshold values, the wireless base station continues to use the common channel for signal transmission/reception.Type: GrantFiled: June 23, 2003Date of Patent: August 8, 2006Assignee: NTT DoCoMo, Inc.Inventors: Yasuhiro Kato, Takehiro Nakamura, Seizo Onoe, Akihiro Maebara, Yutaka Ohto, Shinji Ueda
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Patent number: 7039413Abstract: While a plurality of cellular mobile communication systems have their respective service areas regionally overlapping each other in part, a mobile station is configured to perform a standby for calling or communication while selecting one of the plural systems in the overlapping areas, and is arranged as follows: the mobile station preliminarily stores cell information notified of by a base station and indicating whether the mobile station is transferable to each surrounding cell while maintaining the current system; when the arrival of transfer timing to a surrounding cell is detected, the mobile station extracts the information about the pertinent cell and judges whether the surrounding cell is a transferable cell, based on the cell information; when the surrounding cell is a transferable cell, the mobile station transfers to the surrounding cell; when the surrounding cell is not a transferable cell, the mobile station directly transfers to a cell of a different system.Type: GrantFiled: October 23, 2002Date of Patent: May 2, 2006Assignee: NTT DoCoMo, Inc.Inventors: Masafumi Masuda, Akihiro Maebara, Hidetoshi Yazaki, Hiromu Niiyama, Takashi Nagano
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Patent number: 6983039Abstract: Each communication is classified into any one of a plurality of communication types in advance. A plurality of threshold values used for determining whether or not the resources are to be allocated are set up in advance. The plurality of threshold values differ from each other according to the communication types and a predetermined number of divided traffic amount ranges such that a difference in ease of resource allocation between the communication types increases as a traffic value increases. When a communication connection request is made, the traffic of communication being executed is measured. A threshold value is selected according to the communication type of a communication associated with the connection request and the measured traffic. Whether or not resources maybe allocated to the communication associated with the connection request is determined based on the selected threshold value and the measured traffic.Type: GrantFiled: June 4, 2003Date of Patent: January 3, 2006Assignee: NTT DoCoMo, Inc.Inventors: Yoshihiro Ishikawa, Akihiro Maebara, Seizo Onoe, Yoshitaka Hiramoto
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Patent number: 6912394Abstract: 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: GrantFiled: February 16, 2000Date of Patent: June 28, 2005Assignee: NTT Mobile Communications Network Inc.Inventors: Kazunori Obata, Akihiro Maebara, Tooru Nakamura
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Publication number: 20050136950Abstract: A mobile communication system includes a first base station configured to be controlled by a first radio network controller, and provide an address of an extension transmission/reception device to user data received from a first mobile station, and the extension transmission/reception device configured to be controlled by the first radio network controller or a different second radio network controller, and provide an address of a second base station, which is controlled by the second radio network controller, to user data received from the first base station.Type: ApplicationFiled: November 5, 2004Publication date: June 23, 2005Applicant: NTT DoCoMo, Inc.Inventors: Masafumi Masuda, Akihiro Maebara, Masayuki Koshino, Mayu Yamada
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Publication number: 20050014498Abstract: A mobile communication system includes an extension transmission/reception server configured to transmit/receive user data transmitted/received between mobile stations to/from a base station by using an extension transmission/reception transmitting/receiving the data within a radio access network, and the base station configured to transmit/receive the user data to/from the extension transmission/reception server.Type: ApplicationFiled: June 4, 2004Publication date: January 20, 2005Applicant: NTT DoCoMo, Inc.Inventors: Mayu Yamada, Akihiro Maebara, Masayuki Koshino, Masafumi Masuda, Seizo Onoe
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Patent number: 6819661Abstract: Base station generates a mobile station identifier which indicates a mobile station that a data signal is addressed thereto, and a head slot having a data signal when there is a data signal that has a length to be able to transmitted using one slot of a TDMA radio channel. When there is a data signal that has a length to be not able to transmitted using one slot, base station generates a head slot and continuous slots which contain at least a part of data signal. Base station transmits the head slot by using the starting slot which located at predetermined position every mobile station on the TDMA radio channel, and transmits the continuous slots by using slots which follow the starting slot. Mobile station receives the starting slot, and stops reception if the starting slot is not the head slot. If the starting slot is the head slot, the mobile station judges the mobile station identifier.Type: GrantFiled: June 10, 1997Date of Patent: November 16, 2004Assignee: NTT DoCoMo, Inc.Inventors: Ichiro Okajima, Akihiro Maebara, Atsushi Murase, Katsumi Kobayashi, Tadao Takami
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Publication number: 20040009776Abstract: Each communication is classified into any one of a plurality of communication types in advance. A plurality of threshold values used for determining whether or not the resources are to be allocated are set up in advance. The plurality of threshold values differ from each other according to the communication types and a predetermined number of divided traffic amount ranges such that a difference in ease of resource allocation between the communication types increases as a traffic value increases. When a communication connection request is made, the traffic of communication being executed is measured. A threshold value is selected according to the communication type of a communication associated with the connection request and the measured traffic. Whether or not resources maybe allocated to the communication associated with the connection request is determined based on the selected threshold value and the measured traffic.Type: ApplicationFiled: June 4, 2003Publication date: January 15, 2004Applicant: NTT DoCoMo, Inc.Inventors: Yoshihiro Ishikawa, Akihiro Maebara, Seizo Onoe, Yoshitaka Hiramoto
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Publication number: 20040005898Abstract: Disclosed is a mobile communication system whereby, to reduce the connection time, a mobile station closely located to a base wireless station is permitted to continue to use a common channel for exchanging signals, and to suppress an increase in interference, an individual channel is set for a mobile station located near the edge of a cell, and to obtain a stabilized communication quality and to prevent an increase in the connection time, the probability that the transmission power will reach an upper limit is reduced. When communication between a mobile station and a wireless base station is started, the wireless base station measures the transmission power and the communication quality in the communication with the mobile station and the utilization ratio for a common channel, and compares the obtained values with predetermined threshold values. When the obtained values are lower than the threshold values, the wireless base station continues to use the common channel for signal transmission/reception.Type: ApplicationFiled: June 23, 2003Publication date: January 8, 2004Applicant: NTT DoCoMo, Inc.Inventors: Yasuhiro Kato, Takehiro Nakamura, Seizo Onoe, Akihiro Maebara, Yutaka Ohto, Shinji Ueda
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Publication number: 20030087637Abstract: While a plurality of cellular mobile communication systems have their respective service areas regionally overlapping each other in part, a mobile station is configured to perform a standby for calling or communication while selecting one of the plural systems in the overlapping areas, and is arranged as follows: the mobile station preliminarily stores cell information notified of by a base station and indicating whether the mobile station is transferable to each surrounding cell while maintaining the current system; when the arrival of transfer timing to a surrounding cell is detected, the mobile station extracts the information about the pertinent cell and judges whether the surrounding cell is a transferable cell, based on the cell information; when the surrounding cell is a transferable cell, the mobile station transfers to the surrounding cell; when the surrounding cell is not a transferable cell, the mobile station directly transfers to a cell of a different system.Type: ApplicationFiled: October 23, 2002Publication date: May 8, 2003Applicant: NTT DoCoMo, Inc.Inventors: Masafumi Masuda, Akihiro Maebara, Hidetoshi Yazaki, Hiromu Niiyama, Takashi Nagano
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Publication number: 20020044543Abstract: Base station generates a mobile station identifier which indicates a mobile station that a data signal is addressed thereto, and a head slot having a data signal when there is a data signal that has a length to be able to transmitted using one slot of a TDMA radio channel. When there is a data signal that has a length to be not able to transmitted using one slot, base station generates a head slot and continuous slots which contain at least a part of data signal. Base station transmits the head slot by using the starting slot which located at predetermined position every mobile station on the TDMA radio channel, and transmits the continuous slots by using slots which follow the starting slot. Mobile station receives the starting slot, and stops reception if the starting slot is not the head slot. If the starting slot is the head slot, the mobile station judges the mobile station identifier.Type: ApplicationFiled: June 10, 1997Publication date: April 18, 2002Inventors: ICHIRO OKAJIMA, AKIHIRO MAEBARA, ATSUSHI MURASE, KATSUMI KOBAYASHI, TADAO TAKAMI
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Patent number: 6157837Abstract: An object of the present invention is to reduce the control time required when a channel handover is performed in a mobile communication system. The conventional system has such shortcomings that a long time is required for re-designating a channel when a channel handover procedure results in failure. Particularly, in the common access type system, there is such a problem that since a channel handover is required to be performed several times during a channel handover procedure, an extra time is required for performing the handover procedure. The present invention has a plurality of base stations for covering the service area, and a mobile station for performing a communication with the base stations through radio channels.Type: GrantFiled: January 21, 1997Date of Patent: December 5, 2000Assignee: Ntt Mobile Communications Network Inc.Inventors: Yasuhiro Kato, Akihiro Maebara, Ichiro Okajima, Kazuo Sugiyama, Koji Sasada
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Patent number: 6084966Abstract: A transmitted signal is enciphered or concealed to thereby prevent interference, even when data indicative of the receiver terminal is made public because of the use of a common access channel. In the transmitter, in a random-number bit adder 6, a random-number .alpha. (digital signal) generated by a random-number generator 5 is inserted into a transmitting data signal DA generated by a transmitting data generator 1, and the resultant is outputted as a signal (DA, .alpha.). An encipherment processor 2 enciphers the signal (DA, .alpha.) and outputs it as a signal (DA, .alpha.)'. In the receiver, this signal (DA, .alpha.)' is deciphered into (DA, .alpha.), and the random-bits .varies. are removed from (DA, .alpha.) to restore the signal DA.Type: GrantFiled: April 8, 1996Date of Patent: July 4, 2000Assignee: NTT Mobile Communications Network, Inc.Inventors: Akihiro Maebara, Katsumi Kobayashi, Ichiro Okajima, Noriko Uchida, Shinji Uebayashi
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Patent number: 6021516Abstract: In a communication system having a transmission station which transmits the data signal and a receiving station which receives the data signal, the transmission station consists of an adding means for adding an error detecting code showing a position of a transmission error, which occurs on said data signal, in said data signal to said data signal and a retransmission means for retransmission of a part in said data signal when said receiving station requests the retransmission of the part in said data signal. The receiving station consists of a judgment means for judging a position of the transmission error in said data signal on the basis of the error detecting code which is added by the adding means and a request means for requesting the retransmission of the part containing the transmission error in the data signal on the basis of the position of the transmission error.Type: GrantFiled: January 21, 1997Date of Patent: February 1, 2000Assignee: NTT Mobile Communications Network, Inc.Inventors: Ichiro Okajima, Akihiro Maebara, Katsumi Kobayashi, Koji Sasada, Hiroyuki Hattori