Signal transmission

• US 4,442,426 A
• Filed: 02/04/1981
• Issued: 04/10/1984
• Est. Priority Date: 01/18/1978
• Status: Expired due to Fees

• Current Assignee: Compur-Electronic GmbH
• Original Assignee: Compur-Electronic GmbH
• Inventors: Heuschmann, Herr F., Plank, Herr A.
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US06/231,548
• Time in Patent Office: 1,161 Days
• Field of Search: 340/539, 340/179, 340/182, 340/147 SY, 340/150, 340/345, 340/346, 340/825.06, 340/825.69, 340/825.14, 340/825.72, 340/870.09, 340/870.11 , 340/870.13, 340/870.14, 340/870.16, 455/51, 455/67, 455/78, 455/90, 455/103, 455/115, 455/127, 455/128, 455/53, 455/63, 455/65, 455/101, 455/54, 455/56, 375/23, 375/106-113, 375/121, 371/46, 371/47, 370/84
• US Class Current: 340/539.22
• CPC Class Codes: G08B 21/0297 Robbery alarms, e.g. hold-up alarms, bag snatching alarms
• CPC Class Codes: G08B 21/04 responsive to non-activity, e.g. of elderly persons G08B21/06 takes precedence
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence
• CPC Class Codes: G08B 29/08 Signalling of tampering with the line circuit
• CPC Class Codes: G08B 29/16 Security signalling or alarm systems, e.g. redundant systems
• CPC Class Codes: G08C 15/06 successively, i.e. using time division

Abstract

Plural transmitters, which transmit signals to a common receiver, transmit their signals in a fixed time-staggered pattern. As a result, the individual signals which are transmitted by the respective transmitters do not interfere with one another or influence one another. Between the fixed time-staggered signals, which are sent out, for example, as standard signals to facilitate routinelike monitoring, signals of a higher priority, for example alarm signals, can be transmitted without any time delay. This is particularly suited for use in connection with a personal security and monitoring system, in which the function monitoring of the unit and the wireless connection between several transmitters and a receiving center must constantly be monitored, and signals of a higher priority, namely alarm signals, are transmitted without delay.

Claims

1. A security and monitoring method in a wireless information system which includes receiving means and plural separate transmitting means, comprising the steps of:

transmitting from each of said plural and separate transmitting means to said receiving means a monitoring signal of predetermined duration at a fixed repetition rate, the period of said repetition rate being an integer multiple of a first fixed interval of time;

synchronizing said plural transmitting means to transmit said respective monitoring signals so that any two successive said monitoring signals transmitted by respective said transmitting means are spaced in time by a respective delay interval which is an integer multiple of said first fixed interval of time; and

sending alarm signals separate from said monitoring signals and of predetermined duration to said receiving means, each said alarm signal being transmitted during a respective said delay interval and at a point in time spaced a second fixed interval of time after transmission of a respective said monitoring signal by a respective said transmitting means;

whereby said monitoring and alarm signals are transmitted by said plural transmitting means according to a rigid timing schedule and all said monitoring signals and said alarm signals of each said transmitting means are free of interference with said monitoring signals of other of said transmitting means.

2. The security and monitoring method according to claim 1, wherein said alarm signals of each said transmitting means are separately coded.

3. The security and monitoring method according to claim 2, wherein said coding is a separate 5-tone frequency sequence.

4. The security and monitoring method according to claim 1, wherein said alarm signals are produced during at least two of said delay intervals, and thereafter are produced in place of said monitoring signals at said fixed repetition rate.

5. The security and monitoring method according to claim 1, wherein said alarm signals are produced during at least two of said delay intervals.

6. The security and monitoring method according to claim 1, wherein said monitoring signals occur cyclically.

7. The security and monitoring method according to claim 1, wherein said synchronizing step is accomplished by the step of connecting said transmitting means to a master time-base circuit

8. The security and monitoring method according to claim 7, including the step of halting the sending of said monitoring and alarm signals when said transmitting means is connected to said master time-base circuit means.

9. The security and monitoring method according to claim 1, including the step of sending said alarm signals to said receiving means in place of said monitoring signals and at said fixed repetition rate.

10. A wireless security and monitoring system, comprising:

plural synchronized transmitting means for transmitting radio frequency signals according to a rigid timing schedule, each of said plural signal transmitting means being arranged to transmit in a first mode, said first mode being a monitoring mode wherein each said transmitting means transmits a monitoring signal having a duration which is a first fixed unit of time at a first repetition rate, said first repetition rate having a period which is a second fixed unit of time greater than said first fixed unit of time, each said transmitting means being further arranged to transmit each said monitoring signal at a point in time spaced from each said monitoring signal transmitted by other said transmitting means, each said monitoring signal being spaced from an immediately preceding monitoring signal transmitted by any other said transmitting means by a respective delay interval which is an integer multiple of a third fixed unit of time, so that all said monitoring signals will be free at all times of interference with said monitoring signals of other said transmitting means; and

receiving means arranged for receiving said monitoring signals;

and wherein each of said plural transmitting means is further arranged to transmit in a second mode wherein an alarm signal having a duration which is a fourth fixed unit of time less than said third unit of time is transmitted at a second repetition rate greater than said first repetition rate, each said alarm signal being transmitted during a said delay interval at a point in time spaced a fifth fixed unit of time after transmission of a respective said monitoring signal from a respective said transmitting means so that all said alarm signals will be free at all times of interference with said monitoring signals of other of said transmitting means, said receiving means also receiving said alarm signals. PG,28

11. The wireless security and monitoring system according to claim 10, wherein each of said transmitting means includes presynchronized time-base circuit means for effecting an emitting of said monitoring and alarm signals at said spaced points in time to maintain said interference free relationship between said transmitting means.

12. The wireless security and monitoring system according to claim 11, wherein each of said time-base circuit means in each of said transmitting means includes a presynchronized oscillating quartz and a coded control stage series connected thereto for determining the mode of operation of said transmitting means, said time-base circuit means being arranged for specifying said points in time at which said monitoring signals and said alarm signals are to be transmitted so that said interference free relationship is maintained.

13. The wireless security and monitoring system according to claim 11, wherein said receiving means includes a master time-base circuit means which includes means for synchronizing each of said time-base circuit means in each of said transmitting means.

14. The wireless security and monitoring system according to claim 13, wherein each of said transmitting means includes a plug connection, wherein said receiving means includes a stowage board means with plug-in connection means for connection to said plug connection, said synchronizing means of said master time-base circuit means being arranged for effecting a synchronization of said time-base circuit means in said transmitting means when stowed on said stowage board means.

15. The wireless security and monitoring system according to claim 14, wherein said master time-base circuit means is arranged for synchronizing each said transmitting means to produce said monitoring signals at said points in time spaced from said monitoring signals and alarm signals of other said transmitting means.

16. The wireless security and monitoring system according to claim 10, wherein said transmitting means is further arranged to produce a said alarm signal in each of at least two sequential said delay intervals, said alarm signals being transmitted thereafter only at said first repetition rate and in place of said monitoring signals for the respective one of said transmitting means.