Patent · US Expired

Collision detection method using CRC code

US4573045A · kind A · utility

17Cited by
8References
15Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 24, 1983
Grant dateFeb 25, 1986
Priority date
Expiry dateJan 24, 2003

Classification

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

Abstract

A method for detecting collisions between digital messages transmitted on a common cable communication system is disclosed. A transmitting station computes a cylic redundancy checking (CRC) code for the transmitted message, and stores the value of the code after N bits have been sent. N bits corresponds to the number of bits transmitted during the "collision window" of the particular system. The transmitting station monitors the receive channel and computes a CRC value for N bits of the received message. If the CRC value calculated for the received message does not match the stored CRC value for the transmitted message, a collision is assumed. If no message is received by the transmitting station after the collision window has elapsed, a collision is also assumed.

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