Patents by Inventor Chih C. Tsien
Chih C. Tsien 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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Publication number: 20100103840Abstract: Briefly, in accordance with one embodiment of the invention, a device may dynamically select a frequency on which to communicate on a wireless local area network by determining which channels are available and which are unoccupied, for example using a received signal power level measurement. A linear folding algorithm may be used to select an available channel at a midpoint in a larger gap between occupied channels. In the event there are multiple larger gaps of the same size, the larger gap at the higher frequency may be selected.Type: ApplicationFiled: December 23, 2009Publication date: April 29, 2010Inventors: Chih C. Tsien, Jiewen Liu
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Patent number: 7583975Abstract: In a wireless network communications device, transmit power levels may be interactively adjusted to dynamically maintain a desired level of network loading and/or data throughput within the network in a changing network environment.Type: GrantFiled: March 8, 2004Date of Patent: September 1, 2009Assignee: Intel CorporationInventors: Adrian P. Stephens, Chih C. Tsien
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Patent number: 7415262Abstract: An access point in a wireless network receives link margin values from associated access points. The access point determines sensitivity values for the associated access points and determines a lower access point output power value from the sensitivity values. Beacons are transmitted at full power and remaining frames are transmitted at the lower access output power. A new access output power may be determined periodically, or when a station associates or disassociates.Type: GrantFiled: March 29, 2004Date of Patent: August 19, 2008Assignee: Intel CorporationInventors: Jiewen Liu, Chih C. Tsien
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Patent number: 7392016Abstract: A method includes monitoring a variable-rate data communication channel to determine its signal-to-noise ratio, and adjusting the data transmission rate of the variable rate data communication channel based on its signal-to-noise ratio.Type: GrantFiled: May 12, 2005Date of Patent: June 24, 2008Assignee: Intel CorporationInventors: Chih C. Tsien, Jiewen Liu
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Patent number: 7359727Abstract: A communication station performs closed-loop transmit power control and adjusts its transmit power level based on an access point sensitivity, a path loss and/or a link margin variation. An average received power level of orthogonal frequency-division multiplexed (OFDM) subcarriers of an OFDM channel may be measured at the communication station, and the path loss may be estimated from an access point transmit power level and the measured power level. The communication station may request an access point's transmit power level and link margin from the access point prior to estimating the path loss. The communication station may calculate the access point sensitivity by subtracting the path loss and the access point link margin from the communication station's transmit power level. The link margin variation may be estimated from an access point transmit power variation, an indoor path loss variation, and/or a receiver power measurement error of the communication station.Type: GrantFiled: December 16, 2003Date of Patent: April 15, 2008Assignee: Intel CorporationInventors: Chih C Tsien, Jiewen Liu
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Patent number: 7346364Abstract: Transmit parameters are adjusted for a wireless device based on link margin. In at least one embodiment, link margin is calculated as a difference between a received power level and receiver sensitivity.Type: GrantFiled: October 29, 2003Date of Patent: March 18, 2008Assignee: Intel CorporationInventors: Chih C. Tsien, Jiewen Liu
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Patent number: 7328037Abstract: Briefly, a method to control data transmission rate and transmission power level of a mobile unit is provided. The method may include varying a data transmission rate value based on a difference between a received signal strength and a receiver sensitivity value and reducing the transmission power level when transmission is at the highest data transmission rate.Type: GrantFiled: December 9, 2002Date of Patent: February 5, 2008Assignee: Intel CorporationInventors: Chih C. Tsien, Jiewen Liu
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Patent number: 7295827Abstract: A mobile station in an 802.11 wireless network dynamically adjusts a number of 802.11 beacon intervals to sleep based on a power savings level and a required wake-up time to receive packets from an access point. The power savings level is based on data traffic activity in a current period. The mobile station wakes up to receive a beacon, and if a beacon is not received, the mobile station sleeps for one additional beacon period.Type: GrantFiled: March 31, 2004Date of Patent: November 13, 2007Assignee: Intel CorporationInventors: Jiewen Liu, Chih C. Tsien
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Patent number: 7289056Abstract: A managing wireless communication device assigns channels of a channel set to associated wireless communication devices. The associated wireless communication devices monitor the assigned channels for in-band signals including radar signals and report detections to the managing wireless communication device. The managing wireless communication device resets a timer associated with a channel when a report is received from one of the associated wireless communication devices. The timer may indicate how long the associated channel has been radar free.Type: GrantFiled: March 24, 2005Date of Patent: October 30, 2007Assignee: Intel CorporationInventors: Jiewen Liu, Chih C. Tsien
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Patent number: 7245877Abstract: Briefly, in accordance with one embodiment of the invention, a mobile unit may detect and connect to a wireless local area network, contemplating worldwide multiband networks and multiple regulatory domains, with a shorter searching time.Type: GrantFiled: August 12, 2003Date of Patent: July 17, 2007Assignee: Intel CorporationInventors: Jiewen Liu, Chih C. Tsien
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Patent number: 7155230Abstract: A receiver in a wireless communication system detects a possibly interfering radar signal, and uses dynamic frequency selection to switch to a non-interfering channel. The power level and the channel of the radar signal may be detected. When a radar signal that exceeds a predetermined power level is detected, the receiver may be tuned until the channel of the radar signal matches the communication receiver channel. The communication receiver may then be tuned to a higher quality channel to mitigate or avoid interference between communication signals and the radar signal.Type: GrantFiled: August 19, 2002Date of Patent: December 26, 2006Assignee: Intel CorporationInventor: Chih C. Tsien
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Patent number: 6959171Abstract: A method includes monitoring a variable-rate data communication channel to determine its signal-to-noise ratio, and adjusting the data transmission rate of the variable rate data communication channel based on its signal-to-noise ratio.Type: GrantFiled: February 28, 2002Date of Patent: October 25, 2005Assignee: Intel CorporationInventors: Chih C. Tsien, Jiewen Liu
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Publication number: 20040203762Abstract: A mobile unit may operate within an ad-hoc network by listening for information broadcast from a device on the network pertaining to regulatory information. If the mobile device receives regulatory information, the transmitter of the mobile unit may be arranged to transmit within regulatory restrictions. If no regulatory information is received after a predetermined period, the transmitter of the mobile unit may be arranged to transmit at a predetermined safe power level on a clear channel in a common frequency band. The predetermined safe power level may be determined to be in compliance with a known regulatory restriction.Type: ApplicationFiled: October 15, 2002Publication date: October 14, 2004Inventors: Jiewen Liu, Chih C. Tsien
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Publication number: 20040110470Abstract: Briefly, a method to control data transmission rate and transmission power level of a mobile unit is provided. The method may include varying a data transmission rate value based on a difference between a received signal strength and a receiver sensitivity value and reducing the transmission power level when transmission is at the highest data transmission rate.Type: ApplicationFiled: December 9, 2002Publication date: June 10, 2004Inventors: Chih C. Tsien, Jiewen Liu
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Publication number: 20040033789Abstract: A receiver in a wireless communication system detects a possibly interfering radar signal, and uses dynamic frequency selection to switch to a non-interfering channel. The power level and the channel of the radar signal may be detected. When a radar signal that exceeds a predetermined power level is detected, the receiver may be tuned until the channel of the radar signal matches the communication receiver channel. The communication receiver may then be tuned to a higher quality channel to mitigate or avoid interference between communication signals and the radar signal.Type: ApplicationFiled: August 19, 2002Publication date: February 19, 2004Inventor: Chih C. Tsien
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Publication number: 20030166394Abstract: A method includes monitoring a variable-rate data communication channel to determine its signal-to-noise ratio, and adjusting the data transmission rate of the variable rate data communication channel based on its signal-to-noise ratio.Type: ApplicationFiled: February 28, 2002Publication date: September 4, 2003Inventors: Chih C. Tsien, Jiewen Liu
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Patent number: 5438683Abstract: An automatic level control circuit for cellular telephone transmitters which is compatible with both existing analog cellular service and expected next generation digital TDMA service. The circuit automatically and dynamically changes modes to maintain communication when a mobile subscriber moves from one type of service to another. In a first mode of operation, which is compatible with existing analog cellular service, the circuit provides a closed loop negative feedback circuit which produces a control signal for continuously controlling the output power level of the transmitter amplifier. In a second mode of operation, which is compatible with proposed digital TDMA service, the circuit operates to alternately close the negative feedback loop during the periods when the transmitter is permitted to transmit (assigned TDMA frames) and open the loop during other periods when the transmitter is turned off. When the loop is opened, the invention temporarily stores the magnitude of the control signal.Type: GrantFiled: September 19, 1994Date of Patent: August 1, 1995Assignee: NovAtel Communications, Ltd.Inventors: Willem G. Durtler, Kiomars Anvari, Chih C. Tsien