Cisco Technology, Inc.

Christopher Graham Meil

Brian Donald Hart

Johannes Petrus Kruys

David McClead Theobold

James A Amos

Jyoti Raju

Jason R Crawford

Kevin C H Wong

Edward Frederick Wright

David Sheldon Stephenson

Neal Dante Castagnoli

Robert B O'Hara, Jr

Xiaohong Gong

Raghuram Rangarajan

Hari Narayanan Rangarajan

Philip O′Sullivan

Philip O'Sullivan

Philip O'sullivan

Kevin C Wong

A mesh tree formation system. In particular implementations, a method includes responsive to a selection of a channel potentially bearing a higher priority use, entering a silent state and initiating a channel scan of the selected channel for a period of time. The method also includes, responsive to receipt of an enabling signal, entering a limited transmission state that enables transmission of wireless frames on the selected channel. The method also includes, responsive to termination of the period of time of the channel scan wherein no higher priority use is detected, entering a full transmission state comprising transmission of enabling signals corresponding to the selected channel.

Mesh tree formation in wireless networks

A coordinated channel change system. In particular implementations, a method includes receiving a prepare-to-change message, wherein the prepare-to-change message indicates instructions to prepare to change channels and includes a designated channel, and forwarding the prepare-to-change message to one or more child nodes. The method also includes receiving a ready-to-change message from the one or more child nodes, and transmitting a change-to-channel message to the one or more child nodes, wherein the change-to-channel message indicates instructions to switch to the designated channel. The method also includes receiving an acknowledgement message from the one or more child nodes, and changing to the designated channel.

Coordinated channel change in mesh networks

A wireless access point selection system. In particular implementations, a method includes receiving a notification that identifies a wireless access point that detects radar on an operating channel and identifies the operating channel; updating neighbor lists of one or more neighboring wireless access points to remove the wireless access point from the neighbor list, where the neighbor list comprises neighbor wireless access points, corresponding operating channels, and corresponding enable indications, where each enable indication indicates if a channel availability check is required before performing active scanning; and transmitting the updated neighbor list to the neighboring wireless access points. In one implementation, a system provides a DFS enable indication to wireless clients so they can know whether a channel availability check is required prior to transmitting.

Infrastructure-based enabling indication for dynamic frequency selection in wireless networks

Described in an example embodiment herein is a procedure that comprises sampling one or more channels that are not in use for a short time at certain intervals. In particular embodiments, the interval duration is irregular so as to prevent 'out of step' lock with a radar's pulses. During the sampling period, detection events are stored in terms of start time and duration. If potential radar events are detected, the channels are sampled for a longer, second interval to determine whether the detection events are indicative of radar. The length of the sampling period determines the number of samples needed to get an acceptable detection probability.

Adaptive sampling of radio frequency channels for radar detection

An external primary spectrum user detector (ESUD) is used to take over the role of integral radar detectors, and relieve user devices of the constraints associated with Primary Spectrum User detection. The ESUD can establish a relationship with the user devices by means of a cryptographic signature. The ESUD installation includes assigning it a frequency band to scan for primary spectrum user signals and the type of signals to be detected. Once activated, the ESUD will scan its assigned frequencies and emit to types of messages, 'All Clear' and 'Primary Spectrum User detected.' User devices on the network listen for the ESUD messages. In the absence of messages from the ESUD, the user devices activate their internal primary spectrum user detectors until ESUD messages are received.

System and method for detection of primary spectrum users

A method for radar protection. The method includes recording energy events and calculating differences in recorded energy events to determine pulses. The method further includes sorting intervals between pulses into histogram bins, each bin representing a range of time intervals between two pulses, each pulse indicative of a radar frequency and limiting network traffic on a frequency based on a selected bin count.

Radar protection device for wireless networks

A method for detecting a signal having random characteristics. A plurality of bursts are detected within a predetermined time period. The plurality of bursts are evaluated to determine how many pulses each of the plurality of bursts contains. The signal having random characteristics is present responsive to the ratio of number of bursts containing a first predetermined number of pulses being approximately equal to number of bursts containing a second predetermined number of pulses. For signals such as a Bin-5 Test Signal, the signal is determined to be present responsive to the number of singletons (bursts having one pulse), the number of pairs (bursts having two pulses) and the number of triplets (bursts having three pulses) being approximately equal.

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Akron, OH, United States of America

Christopher Graham Meil