Alarm system for use over satellite broadband
View Patent ↗The present invention allows an alarm monitoring to use satellite broadband services as a data link for communication between an alarms system and a monitoring station, middleware provider, individual user, or other alarm monitor. Standard alarm system protocols are modified to make the communication protocol compatible with the features of satellite broadband. These modifications compensate for the time delay in data transmission inherent in satellite communications, as well as other limitations of satellite communications. In particular, the “handshake” tone, instead of “1400 hz for 100 ms, silence for 100 ms, 2300 hz for 100 ms”, is changed to “DTMF ‘A’ for at least 100 milliseconds”. In a preferred embodiment the receiver transmits the DTMF A tone for 250 milliseconds. In addition, the delay for “wait for the Acknowledge tone” is extended from 1.25 seconds, to 5 seconds. The “acknowledge” tone, instead of “1400 hz for 400 ms”, is changed to “DTMF ‘D’ for at least 100 milliseconds”. In a preferred embodiment, the receiver transmits the DTMF D tone for 250 milliseconds.
1. A system, comprising:
an alarm system operative to:
detect data path characteristics;
retrieve stored data path parameters corresponding to the detected data path characteristics;
compensate for a data path latency by applying the stored data path parameters corresponding to the detected data path characteristics to at least a portion of communications protocols of the alarm system;
generate a handshake tone over a satellite communication link comprising a Dual Tone Multiple Frequency ‘A’ tone for at least 100 milliseconds; and wait for an acknowledge tone for 5 seconds based on the data path latency; and
a monitoring center operative to generate the acknowledge tone comprising a Dual Tone Multiple Frequency ‘D’ for at least 100 milliseconds.
2. The system of claim 1 , wherein the handshake tone comprises the Dual Tone Multiple Frequency ‘A’ tone for 250 milliseconds.
3. The system of claim 1 , wherein the acknowledge tone comprises the Dual Tone Multiple Frequency ‘D’ for 250 milliseconds.
4. The system of claim 1 , wherein sending and receiving the test signal comprises transmitting the test signal over the satellite communication link.
5. The system of claim 1 , wherein the alarm system is operative to retrieve from memory an indication of the data path characteristics.
6. The system of claim 1 , wherein the alarm system is operative to detect a signal from a data path characteristics selection switch.
7. The system of claim 1 , wherein the alarm system is operative to:
measure the data path latency by measuring time between when the test signal is sent and received; and
determine the data path characteristics from the data path latency.
8. A satellite compatible alarm system capable of communicating via a satellite communication link, comprising:
means for detecting data path characteristics;
means for retrieving stored data path parameters corresponding to the detected data path characteristics;
means for determining a data path latency associated with the satellite communication link;
means for compensating for the data path latency by applying the stored data path parameters corresponding to the detected data path characteristics to at least a portion of communications protocols of the alarm system;
means for generating a handshake tone over the satellite communication link comprising a Dual Tone Multiple Frequency ‘A’ tone for at least 100 milliseconds in accordance with the data path latency;
means for waiting for an acknowledge tone for 5 seconds in accordance with the data path latency; and
means for detecting the acknowledge tone comprising a Dual Tone Multiple Frequency ‘D’ for at least 100 milliseconds in accordance with the data path latency.
9. The alarm system of claim 8 , wherein the handshake tone comprises the Dual Tone Multiple Frequency ‘A’ tone for 250 milliseconds.
10. The alarm system of claim 8 , wherein the acknowledge tone comprises the Dual Tone Multiple Frequency ‘D’ for 250 milliseconds.
11. The alarm system of claim 8 , wherein detecting the data path characteristics comprises detecting a signal from a data characteristics selection switch.
12. The alarm system of claim 8 , wherein detecting the data path characteristics comprises retrieving from memory an indication of the data path characteristics.
13. The alarm system of claim 8 , wherein detecting the data path characteristics comprises the steps of:
sending a test signal over a data path;
receiving the sent test signal from the data path;
measuring the data path latency by measuring time between when the test signal is sent and received; and
determining the data path characteristics from the data path latency.
14. The alarm system of claim 8 , further comprising:
means for generating a handshake tone comprising a tone of 1400 hz for 100 ms, silence for 100 ms, and then a tone of 2300 hz for 100 ms;
means for waiting for an acknowledge tone for a period of 1.25 seconds; and
means for receiving an acknowledge tone comprising a 1400 hz tone generated for 400 ms.
15. A method for communicating between an alarm system and a monitoring center via a satellite communication link, the method comprising the steps of:
detecting communication path characteristics, wherein detecting the communication path characteristics comprises:
sending a test signal over a communication path that comprises the satellite communication link;
receiving the test signal sent over the communication path; and
determining latency for the communication path based on timing between the sending step and the receiving step;
retrieving stored communication path parameters corresponding to the detected communication path characteristics; and
compensating for the determined communication path latency by modifying at least one alarm system protocol based on the determined latency, wherein the at least one alarm system protocol is modified by applying the stored communication path parameters to at least a portion of communication protocols of the alarm system protocol, and wherein applying the stored communication path parameters to at least the portion of the communication protocols comprises:
generating a handshake tone comprising a Dual Tone Multiple Frequency ‘A’ tone for at least 100 milliseconds in accordance with the modified at least one alarm system protocol;
waiting for an acknowledge tone for 5 seconds in accordance with the modified at least one alarm system protocol; and
receiving the acknowledge tone comprising a Dual Tone Multiple Frequency ‘D’ for at least 100 milliseconds in accordance with the modified at least one alarm system protocol.
16. The method of claim 15 , wherein the step of generating the handshake tone comprising the Dual Tone Multiple Frequency ‘A’ tone for at least 100 milliseconds comprises the step of generating the Dual Tone Multiple Frequency ‘A’ tone for 250 milliseconds.
17. The method of claim 15 , wherein the step of receiving the acknowledge tone comprising the Dual Tone Multiple Frequency ‘D’ for at least 100 milliseconds comprises the step of receiving the acknowledge tone comprising the Dual Tone Multiple Frequency ‘D’ for 250 milliseconds.
18. A method, for selecting a handshake protocol for an alarm system, comprising the steps of:
by the alarm system, detecting data path characteristics, wherein detecting the data path characteristics comprises:
by the alarm system, sending a test signal on a data path that extends from the alarm system to a station that receives the test signal and resends the test signal back to the alarm system, wherein the station is remote from the alarm system;
by the alarm system, receiving the test signal from the data path after the station receives and resends the test signal;
by the alarm system, determining latency of the data path based on delay between the sending of the test signal by the alarm system and the receiving of the test signal by the alarm system;
by the alarm system, determining whether the data path comprises a satellite data path based on comparing the determined latency to a threshold;
by the alarm system, retrieving stored data path parameters corresponding to the detected communication path characteristics;
if the data path is determined to comprise the satellite data path, then, by the alarm system, selecting a handshake protocol for the satellite data path or else selecting a different handshake protocol; and
by the alarm system, compensating for the latency of the satellite data path by applying the stored data path parameters corresponding to the data path characteristics of the satellite data path to at least a portion of the selected handshake protocol.
19. The method of claim 18 , wherein the station comprises a middleware processing center.
20. The method of claim 18 , wherein the selected handshake protocol establishes a communication parameter that compensates for signal frequency distortion based on signal frequency distortion of the test signal by the data path.
21. The method of claim 18 , wherein the step of applying the data path parameters to the selected handshake protocol for the satellite data path comprises:
generating a handshake tone comprising a first Dual Tone Multiple Frequency tone for at least 100 milliseconds;
waiting for an acknowledge tone for 5 seconds; and
receiving the acknowledge tone comprising a second Dual Tone Multiple Frequency for at least 100 milliseconds.
22. The method of claim 21 , wherein the step of generating the handshake tone comprising the first Dual Tone Multiple Frequency tone for at least 100 milliseconds comprises the step of generating a Dual Tone Multiple Frequency ‘A’ tone for at least 100 milliseconds.
23. The method of claim 21 , wherein the step of receiving the acknowledge tone comprising the second Dual Tone Multiple Frequency for at least 100 milliseconds comprises the step of receiving a Dual Tone Multiple Frequency ‘D’ tone for at least 100 milliseconds.
24. The method of claim 22 , wherein the step of generating the handshake tone comprising the Dual Tone Multiple Frequency ‘A’ tone for at least 100 milliseconds comprises the step of generating the Dual Tone Multiple Frequency ‘A’ tone for 250 milliseconds.