System and method for discriminating radar transmissions from wireless network transmissions and wireless network having radar-avoidance capability
For use in a wireless network, systems and methods for identifying radar signals and for giving the wireless network a radar-avoidance capability. The system for identifying radar signals includes: (1) a pulse analyzer, associated with a wireless device, configured to make a determination whether a received pulse is a radar pulse and not a wireless network pulse and (2) a pulse reporter configured to generate, if the determination is positive, a report thereof for transmission over the wireless network. Another system gives the wireless network a radar-avoidance capability and includes: (1) a report receiver configured to receive reports via the wireless network from wireless devices thereof and (2) a report analyzer, associated with the report receiver, configured to analyze relationships among the reports to make a determination whether a sequence of radar pulses exists and, if the determination is positive, generate a radar transmission alert.
1. For use in a wireless network, a method of identifying radar signals, comprising:
collecting data at a central aggregation node of said wireless network, said data pertaining to pulses determined by wireless devices of said wireless network to be radar pulses;
discarding duplicate portions of said data for a pulse determined by multiple of said wireless devices to be a suspected radar pulse;
determining, based on remaining data after said discarding, if a radar sequence exists by identifying X successive repetitions of a given time interval between ones of said pulses in said remaining data subject to a maximum of Y missing pulses and within a tolerance of Z microseconds;
determining if an additional time interval exists in said data when determining a radar sequence does not exist based on said given time interval; and
if an additional time interval does not exist, incrementing said given time interval and determining if a radar sequence exists based on said incremented time interval.
2. The method as recited in claim 1 further comprising, if an additional time interval exists, determining if a radar sequence exists based on said additional time interval.
3. The method as recited in claim 1 wherein said data includes timestamps associated with said pulses and said determining if a radar sequence exists employs said timestamps.
4. The method as recited in claim 1 wherein said data is collected into a table at said central aggregation node.
5. An apparatus identifying radar signals in a wireless network, comprising:
a report receiver configured to collect data of suspected radar pulses from wireless devices of said wireless network, said data pertaining to pulses determined by said wireless devices to be radar pulses; and
a report analyzer, associated with said report receiver, configured to discard duplicate portions of said data for a pulse determined by multiple of said wireless devices to be a suspected radar pulse and determine, based on remaining data after said discard, if a radar sequence exists by identifying X successive repetitions of a given time interval between ones of said pulses in said remaining data subject to a maximum of Y missing pulses and within a tolerance of Z microseconds, wherein said report analyzer is further configured to determine if an additional time interval exists in said data when determining a radar sequence does not exist based on said given time interval and if an additional time interval does not exist, increment said given time interval and determine if a radar sequence exists based on said incremented time interval.
6. The apparatus as recited in claim 5 wherein said report analyzer is further configured to generate a radar transmission alert for said wireless devices if said determination is positive.
7. The apparatus as recited in claim 5 wherein said data includes timestamps derived from a common timebase and widths of said radar pulses, wherein said report analyzer analyzes time intervals between ones of said radar pulses and widths of ones of said radar pulses.
8. The apparatus as recited in claim 5 wherein said report analyzer identifies a maximum of N time intervals between ones of said radar pulses.
9. The apparatus as recited in claim 5 wherein said wireless network conforms to IEEE 802.11a and said sequence is associated with a radar operating in a 5 GHz band.
10. The apparatus as recited in claim 5 wherein said report analyzer is further configured to determine, if an additional time interval exists, if a radar sequence exists based on said additional time interval.
11. The apparatus as recited in claim 5 wherein said data includes timestamps associated with said pulses and said report analyzer is configured to determine if a radar sequence exists employing said timestamps.
12. The apparatus as recited in claim 5 wherein said report receiver collects said data into a table.
13. The apparatus as recited in claim 5 wherein said apparatus is a wireless access point of said wireless network.
14. The method as recited in claim 1 wherein X, Y and Z are programmable variables.
15. The apparatus as recited in claim 5 wherein X, Y and Z are programmable variables.
16. The apparatus as recited in claim 8 wherein N is a programmable variable.