Communication system message acknowledgement

US5923662A · kind A · utility

Inventors

• Andrew Stirling · Epsom, GB
• Patrick Heck · Durmersheim, DE
• Andreas Stiegler · Ettlingen, DE

Key dates

• Filing date: Jun 11, 1996
• Grant date: Jul 13, 1999
• Expiry date: Jun 11, 2016

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L2001/0093
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

A local communication system includes a number of stations interconnected for the communication of messages via a serial data channel. A first station transmits a directed type of message to individual ones of the other stations, or transmits a broadcast type of message to all or a subset of the other stations. For a broadcast message, any receiving station unable to accept the message transmits a common negative acknowledgment signal and the first station re-transmits the message up to five times. Each receiving station may be unable to accept a message because its receive buffer is still occupied by a previous message. In such a case generation of the negative acknowledgment signal is suppressed if the message which cannot be accepted is judged identical to the message occupying the receive buffer of the receiving station. In this way, unnecessary communication is avoided, and certainty of communication is increased.