Patent · US Expired

Asynchronous packet switching with common time reference

US6272132A · kind A · utility

48Cited by
9References
76Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 22, 1998
Grant dateAug 7, 2001
Priority date
Expiry dateJul 22, 2018

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L69/28
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

The invention describes a method for transmitting and forwarding packets over a packet switching network. The switches of the network maintain a common time reference, which is obtained either from an external source (such as GPS--Global Positioning System) or is generated and distributed internally. The time intervals are arranged in simple periodicity and complex periodicity (like seconds and minutes of a clock). A packet that arrives to an input port of a switch, is switched to an output port based on specific routing information in the packet header (e.g., IPv4 destination address in the Internet, VCI/VPI labels in ATM). Each switch along a route from a source to a destination forwards packets in periodic time intervals that are predefined using the common time reference. The time interval duration can be longer than the time duration required for transmitting a packet, in which case the exact position of a packet in the time interval is not predetermined.

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