Patent · US Expired

Local area network with message priority

US5353287A · kind A · utility

107Cited by
6References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 25, 1992
Grant dateOct 4, 1994
Priority date
Expiry dateMar 25, 2012

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L12/413
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

A message priority scheme for use in local areas networks (LANS) operating in accordance with carrier sense, multiple access/collision detect (CSMA/CD) bus access protocol. A LAN station having a high priority message to send ignores the carrier sense signal, and thereby obtains immediate bus access. If the high priority message collides with another message already on the bus, both messages are subject to a backoff period. However, the backoff period for a high priority message is guaranteed to be less than that of a low priority message for a certain number of re-transmission attempts. An intermediate priority status is assigned to a message that previously had a high priority status, after a certain number of transmission attempts. The intermediate priority message is deprived of its ability to transmit while ignoring the carrier sense signal, but retains its shorter backoff period.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.