Method and apparatus for low-power, long-range networking
First Claim
1. A system comprising:
- a plurality of sensors configured to communicate over a shared wireless medium, wherein;
access to said medium is time-division multiplexed into three cyclically repeating windows;
a first of said windows is reserved for connectionless beacons;
a second of said windows is reserved for connectionless alarm signals;
a third of said windows is an open access window available for bidirectional communications among said plurality of sensors; and
a particular sensor of said plurality of sensors is operable to transmit a packet on said wireless medium, wherein said packet comprises a fore chirp portion, a data portion, and a post-chirp portion.
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Accused Products
Abstract
An endpoint device may be operable to transmit and receive data wirelessly via a medium to which access is time-division multiplexed into a plurality of repeating windows. A first window of the plurality of repeating windows may be time-division multiplexed into a plurality of timeslots utilized for transmitting beacon signals. A second window of the plurality of repeating windows may be time-division multiplexed into a plurality of timeslots utilized for transmitting alarm signals. The endpoint may be assigned one of the first timeslots and, when an alarm condition is present, select one of the second timeslots for transmitting an alarm signal based on the assigned first timeslot, and based on a hash function. The endpoint may then transmit an alarm signal during the second timeslot. The endpoint may be operable to synchronize its local clock by listening to beacons transmitted by other endpoints.
220 Citations
47 Claims
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1. A system comprising:
a plurality of sensors configured to communicate over a shared wireless medium, wherein; access to said medium is time-division multiplexed into three cyclically repeating windows; a first of said windows is reserved for connectionless beacons; a second of said windows is reserved for connectionless alarm signals; a third of said windows is an open access window available for bidirectional communications among said plurality of sensors; and a particular sensor of said plurality of sensors is operable to transmit a packet on said wireless medium, wherein said packet comprises a fore chirp portion, a data portion, and a post-chirp portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A system comprising:
a plurality of sensors configured to communicate over a shared wireless medium, wherein; access to said medium is time-division multiplexed into three cyclically repeating windows; a first of said windows is reserved for connectionless beacons; a second of said windows is reserved for connectionless alarm signals; a third of said windows is an open access window available for bidirectional communications among said plurality of sensors; and said data portion comprises a shift period field which indicates a number of occurrences of said first of said windows between successive adjustments of a clock of said particular sensor of said plurality of sensors. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A system comprising:
a plurality of sensors configured to communicate over a shared wireless medium, wherein; access to said medium is time-division multiplexed into three cyclically repeating windows; a first of said windows is reserved for connectionless beacons; a second of said windows is reserved for connectionless alarm signals; a third of said windows is an open access window available for bidirectional communications among said plurality of sensors; each of said plurality of sensors is operable to operate in a non-alarm mode of operation and an alarm mode of operation; and while operating is said non-alarm mode of operation, a particular sensor of said plurality of sensors is operable to; transmit beacons during one of said first timeslots assigned to said particular sensor; resynchronize a clock of said particular sensor to a network clock; and transmit and receive data during occurrences of said third window. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47)
Specification