Emergency communication system

• US 3,986,119 A
• Filed: 12/28/1973
• Issued: 10/12/1976
• Est. Priority Date: 12/28/1973
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Valakos, Agis Demetrius, Hemmer, Nicholas Howard Jr.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Bookbinder, Marc E.
• Application Number:
  US05/429,241
• Time in Patent Office: 1,019 Days
• Field of Search: 325/3, 325/5, 325/39, 325/53, 325/54, 325/62, 325/64, 325/31, 325/67, 325/363, 343/178, 179/1 VE, 179/41 A, 340/213.1, 340/213.2, 340/226, 340/311-313, 340/31-33, 340/23, 340/24
• US Class Current: 455/15
• CPC Class Codes: G08B 25/007 Details of data content structure of message packets; data protocols
• CPC Class Codes: G08B 25/016 Personal emergency signalling and security systems emergency non-personal manually actuated alarm activators G08B25/12
• CPC Class Codes: G08G 1/205 Indicating the location of the monitored vehicles as destination, e.g. accidents, stolen, rental

Abstract

An emergency communication system used by stranded motorists to summon help when travelling on toll roads or other limited access highways. The emergency communication system comprises a portable, self-powered, hand-held transceiver set which transmits coded distress signals and directional signals, when activated, and cycles until reception of an answer back signal. The signals or messages from the portable transceiver are transmitted at incrementally increasing power levels to a single or a plurality of roadside relay stations spaced strategically along a limited access highway or toll road. The relay stations retransmit the signals to a terminal station which has means to decode the signals and determine the location of the repeater station nearest to the stranded motorist. The terminal station also has means for displaying the location of the relay station with the information derived from the decoded signal, and means for generating an answer back signal which is transmitted via the roadside relay station to the portable handset.

Claims

1. An improved emergency communication system for summoning help in case of an emergency comprising:

a portable transceiver having power level sequencing circuit means for transmitting a coded message on a first radio link at incrementally increasing power levels and for receiving a first acknowledge signal and a second acknowledge signal, said coded message comprising a squelch code, a transceiver identification code, a distress code and a directional code, said portable transceiver including acknowledge decoder means responsive to said first and said second acknowledge signals such that on receiving said first acknowledge signal, said power sequencing circuitry means is inhibited, thereby, stopping said portable transceiver from stepping into a higher power level, and such that on receiving said second acknowledge signal said portable transceiver is turned off;

a plurality of relay stations positioned along a highway for receiving said coded message on said first radio link and for generating and transmitting said first acknowledge signal on said first radio link, each of said plurality of relay stations including electronic enabling means responsive to said squelch code of said coded message such that a relay station nearest to said portable transceiver is enabled allowing said coded message to be received, and including relay receiving means responsive to said coded message and relay transmission means responsive thereto, thereby causing said portable transceiver to transmit at one of said incrementally increasing power levels, said enabled relay station relaying said distress code, said directional code and said portable transceiver identification code via a second radio link, and generating and transmitting a relay station identification code via said second radio link; and

a terminal station for receiving said distress code, said directional code, said portable transceiver identification code and said relay identification code, said terminal station including display means for displaying said distress code, said directional code, said portable transceiver identification code and said relay identification code, locating means for determining the location of said relay station nearest to said portable transceiver by utilizing said relay identification code, and electronic circuit means for generating and transmitting said second acknowledge signal via said second radio link to said nearest relay station, said nearest relay station retransmitting said second acknowledge signal via said first radio link to said portable transceiver turning said portable transceiver off.

2. The emergency communication system as recited in claim 1 wherein said portable transceiver comprises:

input means for inputting distress and directional information;

storage means operably connected to said input means for receiving and assemblying information for transmission, said information for transmission being said coded message; and

circuit means operably connected to said storage means for controlling automatic transmission of said coded message at predetermined intervals, and enabling said portable transceiver to operate at said incrementally increasing power levels until reception of said first acknowledge signal and for enabling said portable transceiver to operate at a fixed power level until reception of said second acknowledge signal turning said portable transceiver off.

3. The emergency communication system recited in claim 2 wherein said circuit means comprises:

gating means for controlling the transfer of signals generated by an oscillator, with one input of said gating means operably connected to the output of said oscillator and the other input operably connected to a first control signal means activated by said first acknowledge signal;

counting means having a plurality of outputs operably connected to the output of said gating means for generating a plurality of delay signals and for generating variable power sequence control signals; and

system reset memory means operably connected through a second control signal means to said counting means until said system reset memory means is rendered inoperable by a push-to-send switch means.

4. The emergency communication system as recited in claim 2 wherein said circuit means includes a power sequence control circuit means comprising:

a voltage supply means having positive and negative terminals with a first terminal of a first coil connected to said positive terminal of said voltage supply means;

a first capacitor having a first terminal connected to a second terminal of said first coil and a second terminal connected to a first terminal of an output resistor, a second terminal of said output resistor being connected to said negative terminal of said voltage supply means;

a second capacitor having a first terminal connected to an RF driver means and a second terminal connected to a first terminal of a first resistor, a second terminal of said first resistor being connected to said first terminal of said first capacitor;

a pair of switching means, each of said switching means having at least three terminals, a first terminal of each switching means being operably connected through a second coil and a third coil respectfully to gating means for activating said switching means at predetermined intervals, a second terminal of each switching means being connected to said negative terminal of said voltage supply means and a third terminal of each switching means being connected through second and third resistors to said second terminal of said first coil and said first terminal of said first capacitor said pair of switching means controlling the attenuation of the output voltage of said power sequence control circuit across said output resistor by changing the impedance thereof.

5. An emergency communication system having a terminal station with a relay station identification decoder means for receiving and decoding a plurality of identification signals transmitted thereto by respective ones of a plurality of relay stations, said relay station identification signals each being transmitted together with a relayed coded message from a portable transceiver, said relay station identification decoder means providing a plurality of output signals each indicative of reception of a particular relay station identification signal, and said terminal station further including display means and relay selection logic circuit means for receiving said plurality of output signals to determine the location of said portable transceiver, said relay selection logic circuit means comprising:

event buffer means for storing and circulating said plurality of output signals;

a plurality of logic circuits connected to said event buffer means for determining the location of said relay station nearest to said portable transceiver;

control means operably connected to each of said logic circuits for sequentially enabling said logic circuits, one at a time, as said output signals in said event buffer means are circulated, and for generating timing control signals; and

memory means operably connected to said logic circuits for storing location data obtained therefrom;

said display means being responsive to said timing control signals from said control means and said location data from said memory means, thereby, displaying the location of said relay station nearest to said portable transceiver.