Patents by Inventor Fujio Watanabe

Fujio Watanabe 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).

  • Publication number: 20080031179
    Abstract: A method supports scalable and reliable multicast in a wireless network with a large bandwidth-delay product. In this method, acknowledgement packets from different receivers experiencing the same number of data packets lost are assigned the same time slots. This method can be combined with other loss recovery techniques, such as forward error correction (FEC) recovery, proactive protection, feedback suppression and collision detection. Scalability is achieved as bandwidth usage relates only to the number of packets transmitted, rather than the number of receivers.
    Type: Application
    Filed: October 12, 2007
    Publication date: February 7, 2008
    Inventors: Xia Gao, Fujio Watanabe, Gang Wu, Ravi Jain, Toshiro Kawahara
  • Patent number: 7321587
    Abstract: A method for maintaining a quality of service in a wireless communication network is introduced. A reservation is created in a first data path between a home agent and a first foreign agent for data flow between the home agent and a wireless terminal. When the wireless terminal associates with a second foreign agent, a quality of service supportive second data path may be created between the first foreign agent and the second foreign agent. The data flow may be routed over the first and second data paths to maintain the quality of service for the data flow. A wireless communication network may include first downstream and reverse tunnels coupling a home agent and a first foreign agent, each tunnel having a reservation to maintain a quality of service. Second downstream and reverse tunnels may couple a home agent and a second foreign agent.
    Type: Grant
    Filed: November 15, 2002
    Date of Patent: January 22, 2008
    Assignee: NTT Docomo, Inc.
    Inventors: Xia Gao, Moo R. Jeong, Fujio Watanabe, Gang Wu
  • Publication number: 20070233863
    Abstract: Apparatuses and methods are disclosed herein for implementing dormant mode with paging in a WLAN. Power savings in the computing device and reduction in traffic across the network are achieved by requiring a computing device to inform the WLAN of its location only when it crosses a paging area boundary or is to receive IP traffic. Dormant mode with paging is implemented in a protocol that supports dormant functionality and paging functionality but does not itself provide methods or standards for implementing such functionality, such as the IEEE 802.11. The methods and apparatuses disclosed herein provide the methods needed to implement dormant mode with paging in such a protocol. Generally, the methods and apparatuses for implementing dormant mode with paging basically include (1) establishing paging areas; (2) communicating access group information to a computing device; and (3) locating a computing device.
    Type: Application
    Filed: May 24, 2007
    Publication date: October 4, 2007
    Inventors: Daichi Funato, Fujio Watanabe, Toshio Miki
  • Patent number: 7236475
    Abstract: A system and method for monitoring subnet relations in a wireless communication system is disclosed. A wireless communication device is provided and is located in a first subnet. When the wireless communication device executes a handoff to a second subnet, a mobility agent server notifies a virtual operator server of the handoff. As a result of the handoff, a subnet relation is created between the first subnet and the second subnet that is stored and later used to control how the wireless communication device uses power by placing network interface systems that cannot be used in a power-saving mode.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: June 26, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Fujio Watanabe, Jingjun Cao, Shoji Kurakake
  • Publication number: 20070140157
    Abstract: A method and a system discover a wireless LAN network for a multi-mode handset in a power-efficient way. The method extends stand-by time for the cellular and wireless LAN multi-mode handset, taking advantage of that fact that the cellular interface demands less energy from the battery than the wireless LAN (WLAN)-based interface in such a handset. The method therefore uses the cellular interface as an always-on proxy for the wireless LAN interface to receive the initial packets of a communication session, and uses the initial packet or packets to activate the handset's interface with the wireless LAN.
    Type: Application
    Filed: December 13, 2006
    Publication date: June 21, 2007
    Inventors: Guangrui Fu, Fujio Watanabe
  • Publication number: 20070133448
    Abstract: A method for power saving in an ad hoc wireless computer network determines an optimal ATIM message exchange window. The method (a) determines an effective number of nodes that participate in exchanges of ATIM messages during an ATIM window; (b) using the effective number of nodes, calculating a length for a data frame transmission window; and (c) calculates a length for the ATIM window using the calculated data frame transmission window. In one instance, the method determines the effective number of nodes based on the number of senders of ATIM messages. In another instance, the effective number of nodes is determined based on both senders and recipients of the ATIM messages. The method may determine the effective number of nodes from a number of successful ATIM message transmissions in a given time period. The calculated ATIM window size can be provided as an initial value to other methods that dynamically adjust the ATIM window size.
    Type: Application
    Filed: November 28, 2006
    Publication date: June 14, 2007
    Inventors: Xia Gao, Moo Jeong, Fujio Watanabe
  • Patent number: 7161914
    Abstract: A network selection system that includes a mobile terminal in communication with a first network, a second network in communication with the first network and an application layer triggering mechanism that determines which one of a plurality of triggers is required in a certain set of circumstances to provide a particular application.
    Type: Grant
    Filed: April 11, 2002
    Date of Patent: January 9, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Shahid Shoaib, Fujio Watanabe, Jingjun Cao, Shoji Kurakake
  • Publication number: 20060285528
    Abstract: Methods are disclosed to support power saving states of a beacon station in an ad hoc wireless local area network (WLAN). Some of the methods allow exchanging power management information among stations in the wireless network and to allow beacon station handovers. In some methods, always-on stations are given a higher priority to become a beacon station or a beacon station handover destination. The methods achieve good power saving while minimizing beacon handover frequency.
    Type: Application
    Filed: June 16, 2006
    Publication date: December 21, 2006
    Inventors: Xia Gao, Fujio Watanabe, Moo Jeong
  • Publication number: 20060285527
    Abstract: Methods for increasing power saving in a station that sends or receives frames in an ad hoc wireless network (e.g., IBSS), while allowing the station to enter a power-saving mode quickly upon completion of scheduled tasks. At the same time, a method of the present invention allows two stations in the ad hoc wireless network to infer each other's power management mode without requiring an ATIM/ACK exchange between the STAs within an ATIM window. Consequently, a station may enter a power-saving mode promptly without impairing the station's ability to receive packets. In one embodiment, a “more data” field is used between stations to exchange information. Stations with various computation abilities provide information under different time constraints. The stations may enter power-saving modes that send multicast/broadcast frames or use promiscuous mode within an ATIM window.
    Type: Application
    Filed: June 16, 2006
    Publication date: December 21, 2006
    Inventors: Xia Gao, Fujio Watanabe, Moo Jeong
  • Publication number: 20060198325
    Abstract: A method supports scalable and reliable multicast in a wireless network with a large bandwidth-delay product. In this method, acknowledgement packets from different receivers experiencing the same number of data packets lost are assigned the same time slots. This method can be combined with other loss recovery techniques, such as forward error correction (FEC) recovery, proactive protection, feedback suppression and collision detection. Scalability is achieved as bandwidth usage relates only to the number of packets transmitted, rather than the number of receivers.
    Type: Application
    Filed: October 14, 2004
    Publication date: September 7, 2006
    Inventors: Xia Gao, Fujio Watanabe, Gang Wu, Ravi Jain, Toshiro Kawahara
  • Publication number: 20060155860
    Abstract: Apparatuses and methods are disclosed herein for implementing dormant mode with paging in a WLAN. Power savings in the computing device and reduction in traffic across the network are achieved by requiring a computing device to inform the WLAN of its location only when it crosses a paging area boundary or is to receive IP traffic. Dormant mode with paging is implemented in a protocol that supports dormant functionality and paging functionality but does not itself provide methods or standards for implementing such functionality, such as the IEEE 802.11. The methods and apparatuses disclosed herein provide the methods needed to implement dormant mode with paging in such a protocol. Generally, the methods and apparatuses for implementing dormant mode with paging basically include (1) establishing paging areas; (2) communicating access group information to a computing device; and (3) locating a computing device.
    Type: Application
    Filed: January 19, 2006
    Publication date: July 13, 2006
    Inventors: Daichi Funato, Fujio Watanabe, Toshio Miki
  • Patent number: 7072657
    Abstract: A method of coordinating the handoff of a mobile carrier between a first access network and a second access network. The method including establishing a contract between a user of a mobile carrier and a hyper operator and attempting a hand off from a first access network that the mobile carrier is currently operating within to a second access network, wherein the attempting includes authenticating at the hyper operator only that the user may have access to the second access network via the contract. Handing off to the second access network if the authenticating is successful.
    Type: Grant
    Filed: April 11, 2002
    Date of Patent: July 4, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Fujio Watanabe, Shahid Shoaib, Jingjun Cao, Shoji Kurakake
  • Publication number: 20060111103
    Abstract: In a fast active scanning wireless network apparatus and method for quick determination of available access points (20), information about a candidate set of available access points (20) is obtained, and a candidate access point is identified from the candidate set. A mobile station (10) then queries the candidate access point with a probe request that designates the candidate access point as a sole responder. The probe request prevents other access points from contending for the medium of communication between the mobile station and the designated sole responder access point by excluding the attempt by other access points (20) to transmit probe responses. The apparatus and method thus increases the probability of a fast and successful probe request from the mobile station and subsequent response from the designated access point (20). The designated access point may also respond with a probe response of high priority, preventing intervention of communication.
    Type: Application
    Filed: April 2, 2004
    Publication date: May 25, 2006
    Inventors: Moo Jeong, Fujio Watanabe, Toshiro Kawahara
  • Publication number: 20060092888
    Abstract: Active scanning method in a wireless network for fast determining available access points (106, 806) using inter-AP (Access Point) communication is described. In the scanning method, a mobile station (102, 802) sends Probe Request for Proxy frame to the current AP (104, 804) serving the mobile station (102, 802). In response to the Probe Request for Proxy frame, the current AP (104, 804) send Proxy Probe Request packet to the appropriate APs (106, 806). In response to the Proxy Probe Request packet, the neighbor APs (106, 806) send Probe Response frame to the mobile station (102, 802) on its operating channel. Since the mobile station (102, 802) moves to the channel being examined after sending the Probe Request for Proxy frame, it receives the Probe Response frame if it is in the coverage area of the neighbor AP (106, 806). The content of Probe Response frame provides the mobile station (102, 802) with the information to be used in handoff decision and network join procedures.
    Type: Application
    Filed: May 20, 2004
    Publication date: May 4, 2006
    Inventors: Moo Ryong Jeong, Fujio Watanabe, Toshiro Kawahara
  • Patent number: 7031709
    Abstract: One aspect of the present invention regards a method of coordinating the handoff of a mobile carrier between a first access network and a second access network, the method including handing off from a first access network that the mobile carrier is currently operating within to a second access network and building a physical access network topology based on the handing off without input from either the first access network or the second access network.
    Type: Grant
    Filed: October 1, 2002
    Date of Patent: April 18, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Fujio Watanabe, Jingjun Cao, Toshio Miki
  • Publication number: 20060079233
    Abstract: One aspect of the present invention regards a method of coordinating the handoff of a mobile carrier between a first access network and a second access network, the method including handing off from a first access network that the mobile carrier is currently operating within to a second access network and building physical access network topology based on the handing off without input from either the first access network or the second access network.
    Type: Application
    Filed: October 4, 2005
    Publication date: April 13, 2006
    Inventors: Fujio Watanabe, Jingjun Cao, Toshio Miki
  • Patent number: 7020440
    Abstract: A location update system for updating a location of a mobile terminal. The system includes a paging area with a mobile terminal present within the paging area, a domain area with the mobile terminal present within the domain area and a paging location update server that is communication with the mobile terminal and updates a location of the mobile terminal and updates the domain area.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: March 28, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Fujio Watanabe, Gang Wu
  • Publication number: 20060023686
    Abstract: Channel scanning for wireless networks, such as Wireless Local Area Networks (WLANs), generally provides a wireless station with the information on the available WLAN resources, such as the frequency band and the maximum transmission power. The present invention provides safe and fast domain-aware channel scanning, enabling a wireless station to comply with applicable local regulations, in spite of the possibility of domain changes, with short channel-scanning time. Fast channel scanning is accomplished by active channel scanning if valid domain information is available and there is no possibility of domain change. Also, domain-independent channels, if any, are first scanned using active scan to get domain information faster.
    Type: Application
    Filed: September 6, 2005
    Publication date: February 2, 2006
    Inventors: Moo Jeong, Xia Gao, Fujio Watanabe, Gang Wu
  • Publication number: 20050232200
    Abstract: A method and communication system for supporting dormant mode are described. In one embodiment, the communication system comprises a wireless station operable in a power savings mode and group of access points. Each group of access points comprises one or more access points with at least one group of access points having at least two access points. Ranges for the one or more access points in each of the groups define a paging area for each group, wherein one access point uses a paging channel for paging the wireless station when the wireless station is in the power savings mode and is in the paging area associated with the one access point.
    Type: Application
    Filed: June 14, 2005
    Publication date: October 20, 2005
    Inventors: Moo Jeong, Fujio Watanabe, Toshiro Kawahara
  • Patent number: 6944457
    Abstract: The present invention relates to a communication system comprising devices (2a-2d) having means for short range communication using a certain frequency band. The frequency band is divided into communication channels. In the communication system some of said communication channels are predefined for establishment of the connection and other communication channels are predefined for data transfer between at least two devices. The present invention also relates to a communication device for communication in a communication system, the device having means for short range communication using a certain frequency band, which is divided into communication channels. The present invention further relates to a method for performing communication in a communication system comprising devices, which have means for short range communication using a certain frequency band, which is divided into communication channels.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: September 13, 2005
    Assignee: Nokia Corporation
    Inventors: Petteri Alinikula, Mauri Honkanen, Pertti Huuskonen, Antti Lappeteläinen, Jarno Leinonen, Arto Palin, Aarno Pärssinen, Visa Smolander, Jukka Reunamäki, Juha Salokannel, Fujio Watanabe, Heikki Huomo