Modular wireless mass evacuation notification system
First Claim
1. A method for synchronizing a wireless base unit in a monitoring and mass notification system, comprising:
- a control unit transmitting a system message having a timestamp that includes a control unit transmission time and a cumulative propagation delay time value;
a wireless base unit receiving the system message having the timestamp via wireless links and updating the cumulative propagation delay time value; and
the wireless base unit updating a local time of the wireless base unit based on the new cumulative propagation delay time value.
1 Assignment
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Accused Products
Abstract
Monitoring and mass notification systems, such as fire alarm systems, for use in occupied structures, and more particularly to wireless monitoring and mass notification systems include wireless base units that can be modular in design. This allows horns, mini horns, strobes, and audio messaging modules (e.g., speakers) to be physically plugged into the wireless base unit creating a unit with the appearance of a single physical unit. Preferably standardized plugs are used. In some cases, visual and audio modules (i.e., notification devices) have their own battery pack or external power interface. Each wireless base unit can optionally function as a repeater if it has dual transceivers (master transceiver and slave transceiver).
48 Citations
19 Claims
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1. A method for synchronizing a wireless base unit in a monitoring and mass notification system, comprising:
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a control unit transmitting a system message having a timestamp that includes a control unit transmission time and a cumulative propagation delay time value; a wireless base unit receiving the system message having the timestamp via wireless links and updating the cumulative propagation delay time value; and the wireless base unit updating a local time of the wireless base unit based on the new cumulative propagation delay time value. - View Dependent Claims (2, 3, 9, 18)
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4. A method for synchronizing a wireless base unit in a monitoring and mass notification system, comprising:
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a control unit transmitting a system message having a timestamp that includes a control unit transmission time and a cumulative propagation delay time value; a wireless base unit receiving the system message having the timestamp via wireless links and updating the cumulative propagation delay time value; the wireless base unit calculating a processing time delay value based on a difference between a receipt time and a local time after processing the system message; and the wireless base unit determining a new cumulative propagation delay time value by summing the processing time delay value with the received cumulative propagation delay time value and the control unit transmission time. - View Dependent Claims (5)
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6. A method for synchronizing a wireless base unit in a monitoring and mass notification system, comprising:
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a control unit transmitting a system message having a timestamp that includes a control unit transmission time and a cumulative propagation delay time value; a wireless base unit receiving the system message having the timestamp via wireless links and updating the cumulative propagation delay time value; the control unit sending a time-correcting system beacon having a global system time to the wireless base unit; and the wireless base unit updating a local time to match the global system time prior to the wireless base unit receiving the system message. - View Dependent Claims (7, 8)
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10. A monitoring and mass notification system, comprising:
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a control unit for transmitting a system message having a timestamp that includes a control unit transmission time and a cumulative propagation delay time value; and a wireless base unit receiving the system message having the timestamp via wireless links and updating the cumulative propagation delay time value, wherein the wireless base unit updates a local time of the wireless base unit based on the new cumulative propagation delay time value. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 19)
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Specification