Device for remote dialog between a station and one or more portable objects

US5359323A · kind A · utility

Assignee

• France Telecom (Centre National d-Etudes des Telecommunications) · FR

Inventor

• Philippe Michel · Hyères, FR

Key dates

• Filing date: Aug 20, 1991
• Grant date: Oct 25, 1994
• Expiry date: Aug 20, 2011

Classification

• Technology area (CPC G): Physics
• CPC primary: G07C9/28
• WIPO field: Control
• WIPO sector: Instruments

Abstract

Inside a range of action defined by a station, the station is able to generate therein an enquiry message followed by a silence zone. The station then selectively analyzes the respective contents of a plurality of disjoint time intervals from this silence zone. In the event of obtaining in one of these time intervals, chosen randomly by a single portable object, a content identified as a specified response message associated with this portable object, the station generates a selection message intended for this portable object, which, on reception of this selection message, generates in its turn an acknowledgement message. There follows provision for a phase of transactional communication between the selected portable object and the station.