System of communications between a post and moving bodies
US5821877A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 17, 1992 |
| Grant date | Oct 13, 1998 |
| Priority date | — |
| Expiry date | Jan 17, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08G1/017
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Disclosed is a system of communication between a fixed post and moving bodies that may arrive simultaneously in the radius of action of this post. This system uses an exchange protocol that begins with an initializing signal (INIT) common to the different moving bodies that arrive and continues with the transmission of an identification signal by each moving body, this transmission being done at the end of a duration (T+Nt) related to the value (N) of a part of an intrinsic specific code associated with the moving body, this duration being measured from the initialization signal. Preferably, the moving body transmits the beginning of its specific code, for example the first character of this code, followed by a random word having stipulated characteristics such that the terminal can detect whether several moving bodies have transmitted the same first character simultaneously. The post then asks them to transmit a second character in order to distinguish them from one another. Personalized exchanges could then begin when all the moving bodies have been identified.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.