US 5,081,667 · Granted 1992-01-14
The Patent That Taught Car Alarms to Talk to Cell Phones
In the early 1990s, someone figured out how to make a car's security system communicate with any brand of cellular phone—even though phones used totally different languages to talk to each other. The patent covers a smart translator box that sits between your phone and your car, switching protocols on the fly so they can actually understand each other.
The plain-English version
What it protects
The claim covers a controller system that bridges cellular phones and vehicle security systems by storing multiple translation tables in memory—each one matched to a different phone's communication protocol. What's protected here is the specific arrangement of: a library of protocols, an initializing system that picks the right one when you plug in a phone, and the hardware-software connections linking everything together. Anyone building a device that automatically detects a phone type and switches translation tables to make that phone work with a car alarm would be stepping on this patent.
Why it matters
This patent arrived at a critical inflection point: cellular phones were exploding in popularity, but every manufacturer used proprietary protocols. A single, rigid car-alarm interface couldn't talk to all of them. By creating an adaptive intermediary with a swappable protocol library, the inventor solved a real integration nightmare for aftermarket car security companies like Clifford Electronics. This approach—detecting the device and loading the right translation rules—became a template for how accessories learn to work across incompatible ecosystems.
Real-world use
Imagine calling your car from a payphone in the 1990s to arm or disarm your alarm; that kind of remote vehicle control relied on systems like this to bridge the gap between your specific phone brand and your car's security hardware.
Original USPTO abstract
An interfacing system for integrating a wide variety of cellular communication systems with most vehicle security systems. The system includes a controller and an interfacing arrangement for matching the cellular telephone to the controller. The interfacing arrangement includes a library, stored in memory, having a plurality of unique translation tables corresponding to the protocols of a plurality of unique cellular communication systems. The interfacing arrangement further includes an initializing capability for selecting an operating protocol for the interfacing system from the library which is compatible with the protocol of the cellular communication system. Hardware and software are included for interfacing the vehicle security to the controller and for interfacing the controller to the vehicle. In a specific embodiment, the selection of cellular telephone type or make is made from the keypad of the cellular telephone.
Patent details
- Publication number
- US 5,081,667
- Filing date
- 1990-03-20
- Grant date
- 1992-01-14
- Assignee
- Clifford Electronics, Inc.
- Inventor(s)
- DRORI; ZE'EV, WOSKOW; ROBERT M.
- CPC class
- B60R25/104
Want to file your own patent?
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