Personal security system with fixed testing transmitters
US5416466A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1994 |
| Grant date | May 16, 1995 |
| Priority date | — |
| Expiry date | Feb 18, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B25/007
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A personal security system includes signaling transmitters and receivers for detecting the transmitted signals. The receivers provide an output representing the received signal strength, which is used in combination with the position of the receiver for locating the point of transmission. All of the transmitters are substantially identical, at least in their transmission characteristics and transmitted signal strength, but include a first portable set of transmitters intended to be carried by subscribers, and a second fixed set of transmitters associated with the receivers. The fixed transmitters are actuated one after another and the receivers are polled to record received signal strength after each transmission from each receiver. The results permit comparisons with expected values, between receivers and over time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.