Radar detection and dynamic frequency selection for wireless local area networks
First Claim
1. A method of detecting radar signals in a wireless network device comprising the steps of:
- receiving a plurality of signal pulses as detected events;
eliminating any detected events that correspond to network traffic;
determining whether any non-eliminated events of the individual detected events correspond to radar signals by examining at least one of;
a pulse repetition frequency, a pulse period, or a number of pulses in a pre-defined time period.
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Accused Products
Abstract
A system for detecting and avoiding interference with radar signals in wireless network devices is described. The receiver circuit of the device receives incoming 5 GHz traffic. Such traffic could comprise both WLAN traffic as well as radar signals from radar systems. The incoming packets are treated as an input event, and are screened to be examined as radar pulses. Radar pulses are identified using the length of the detected event. The radar pulses are examined using frequency domain analysis, and the packet train is examined to find gaps between radar pulses. The periodic nature of the packet is determined using frequency domain and time domain analysis to calculate the period of the pulse train. Particular intervals within the pulse train are analyzed using threshold numbers of periodic pulses within the interval and threshold power levels for the pulses. The calculated period information is used to identify the radar source and screen non-radar traffic.
123 Citations
58 Claims
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1. A method of detecting radar signals in a wireless network device comprising the steps of:
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receiving a plurality of signal pulses as detected events;
eliminating any detected events that correspond to network traffic;
determining whether any non-eliminated events of the individual detected events correspond to radar signals by examining at least one of;
a pulse repetition frequency, a pulse period, or a number of pulses in a pre-defined time period. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A device coupled to one or more remote terminals over a wireless network, comprising:
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a receiver circuit for receiving network data traffic as an input signal from the one or more remote terminals;
a media access control circuit coupled to the receiver circuit, and configured to detect an error contained in the network data traffic received by the receiving circuit, and to classify the error based on a pre-defined error type; and
a radar detection circuit coupled to the media access control circuit and configured to receive the input signal if the error contained in the input signal is of a first error type, the radar detection circuit comprising, a first process receiving a plurality of signal pulses as detected events, a second process eliminating any detected events that correspond to network traffic, and a third process determining whether any non-eliminated events of the individual detected events correspond to radar signals by examining at least one of;
a pulse repetition frequency, a pulse period, or a number of pulses in a pre-defined time period. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48)
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49. A method of identifying radar signals in a network device coupled to one or more remote terminals over a wireless network, comprising the steps of:
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receiving an input signal comprising a plurality of pulses as detected events;
determining whether the detected events correspond to expected network traffic;
assigning a time stamp to each event of the detected events that is above a pre-defined power threshold;
determining a first time interval between a first event and second event;
assuming that the first time interval represents the period of the events; and
comparing the first time interval with a second time interval between the second event and a third event to determine whether the first and second time intervals match to within an error factor associated with the time stamp. - View Dependent Claims (50, 51, 52, 53, 54, 55, 56, 57, 58)
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Specification