Cisco Technology, Inc.

Other

Ndssi Holdings, LLC

Applied Signal Technology, Inc.

Daryl Arnold Kaiser

Timothy S Olson

Ian L Sayers

Kirshnam Raju V Datla

Bretton Lee Douglas

Sheausong Yang

David E Halasz

Wenfeng Huang

Richard D Rebo

Arnold M Bilstad

Jonathan S Leary

Howard Pines

Pejman D Roshan

John Z Deng

Sujai Chari

Phillip L Kelly

Stephen McGrath

Determining the location of a station in a wireless network including determining path losses between the wireless station of unknown location and at least some access points at known locations. The determining includes receiving measurements from the wireless station of unknown location, and measuring the received signal strengths as a result of respective transmissions from at least some of access points at known respective transmit powers and known or determined locations to obtained measured path losses. The method further includes determining a location for the wireless station using the measured path losses and a calibrated path loss model.

Radiolocation using path loss data

Determining the location of a station or potential rogue access point in a wireless network including accepting an ideal path loss model and calibrating the ideal model using path loss measurements between access points at known locations. The calibrating determines a calibrated path loss model between the access points. The method further includes determining path losses between the wireless station of unknown location and at least some of the access points. In the case the wireless station is a client station, the determining includes receiving measurements from the wireless station of unknown location measuring the received signal strengths as a result of respective transmissions from at least some of the access points at known respective transmit powers. In the case the wireless station is an potential rogue access point, the determining includes receiving measurements from at least some of the access points measuring the received signal strength at each of the access points resulting from transmission by the potential rogue access point for each of a set of assumed transmit powers for the potential rogue. The method further includes determining the likely location or locations of the wireless station using the measured path loss and the calibrated path loss model.

Methods and systems of a receiver selecting a subset of plurality of frequency hopping bands for synchronization of the receiver are disclosed. One method includes the receiver determining a receive signal quality metric for each band of the plurality of frequency hopping bands, and selecting at least one synchronization band as a subset of the plurality of frequency hopping bands for synchronization based on the receive signal quality metric of each of the plurality of frequency hopping bands.

Synchronization band selection of a frequency hopping wireless receiver

A method, an apparatus, and a software program to implement a method to detect a rogue access point of a wireless network. The method includes maintaining an AP database that includes information about managed access point (APs) and friendly APs, including the MAC address of each managed AP. The method further includes sending a scan request to one or more managed APs, including one or more of a request for the receiving managed AP to scan for beacons and probe responses and a request for the receiving managed AP to request its clients to scan for beacons and probe responses. The method further includes receiving reports from at least one of the receiving managed APs, a report including information on any beacon or probe response received that was sent by an AP. For each beacon or probe response on which information is received, the method analyzes the information received in the report about the AP that sent the beacon or probe response, the analyzing including ascertaining if the MAC address of the AP that sent the beacon or probe response matches a MAC address of an AP in the AP database to ascertain whether or not the AP is a potential rogue AP or a managed or friendly AP.

Method, apparatus, and software product for detecting rogue access points in a wireless network

A system for providing a fast access channel is disclosed. The system includes a transmitter configured to transmit a first long contention symbol and one or more subsequent long contention symbols. The first long contention symbol is followed by the subsequent long contention symbols. The system further includes a receiver configured to receive the first and subsequent long contention symbols and determine a contention code and a contention channel transmitted with the contention code based on the first and subsequent long contention symbols. Each of the first and subsequent long contention symbols includes a long cyclic prefix and a number of identical contention symbols.

Method and system to providing fast access channel

In an access point operating in a wireless local area network, a method is disclosed for assisting a radio manager to manage a radio environment without location information. By performing radio discovery to receive beacon signals from neighboring access points, an initial configuration of a radio environment is generated based on said received beacon signals. Measurements are received from a client device that performs measurements by a user walking through a desired coverage area while operating the client device and the radio configuration is adjusted based on the received measurements.

Managing a radio environment without location information

Determining the location of a radio tag or client station of a wireless network, and the location of coverage holes by receiving from a plurality of wireless stations of the wireless network path loss information of the path loss of one or more location frames received at the respective wireless stations. The location frames transmitted by the radio tag or client station having a pre-defined frame structure. The radio tags and client stations use a common infrastructure for transmitting a location frame configured for radiolocation by path loss measurement. The common infrastructure includes a pre-defined protocol common for both radio tags and client stations for transmitting information for reception by the plurality of stations of the wireless network for radiolocation. The pre-defined protocol includes using the location frame having the pre-defined frame structure.

Tag location, client location, and coverage hole location in a wireless network

Error bursts are detected and corrected in a communication system using shortened cyclic codes, such as shortened Fire codes. Data is loaded into a first error syndrome register and a second error syndrome register. The data in the registers may be evaluated to determine if the data bits contain a correctable error. Shortened zero bits are shifted into the second error syndrome register. A number of zero bits are shifted into the first error syndrome register to trap an error burst pattern in the data. A determination is made as to the number of zero bits shifted into the second error syndrome register to trap the location of the error burst in the data. Using the number of zero bits shifted into the second error syndrome register and the error burst pattern, the error in the data is located and corrected.

Method and apparatus for using fire decoder to correct burst errors in a real-time communications system

A method, an apparatus, and a carrier medium to determine the location of a wireless station (a client station of a wireless network or a potential rogue access point). The method includes accepting an ideal path loss model and calibrating the ideal model using path loss measurements between access points at known locations. The calibrating determines a calibrated path loss model between the access points. The method further includes determining path losses between the wireless station of unknown location and at least some of the access points. In the case the wireless station is a client station, the determining includes receiving measurements from the wireless station of unknown location measuring the received signal strengths as a result of respective transmissions from at least some of the access points at known respective transmit powers. In the case the wireless station is an potential rogue access point, the determining includes receiving measurements from at least some of the access points measuring the received signal strength at each of the access points resulting from transmission by the potential rogue access point for each of a set of assumed transmit powers for the potential rogue. The method further includes determining the likely location or locations of the wireless station using the measured path loss and the calibrated path loss model.

A technique for improving the image quality of facsimile transmissions by actually recovering data corrupted by channel impairments without retransmission. The technique is adaptable to operate with existing facsimile communications standards and does not require modification of transmitter equipment. A significant increase in image quality results. In many cases, otherwise partially illegible documents can be read by applying the image correction technique of the invention.

Growing community of inventors

Los Gatos, CA, United States of America

Daryl Arnold Kaiser