Level Of Fault Tolerance Research Articles

Design of Recovery Strategies for a Fault-Tolerant No. 4 Electronic Switching System

This paper focuses on the design of recovery strategies that have been developed to give the No. 4 Electronic Switching System (ESS) the necessary high level of fault tolerance. Reliability and availability are the key watchwords to operational integrity in the No. 4 ESS. It is the world's largest toll and tandem switching system, capable of handling 616,000 call attempts per hour, and serving up to 100,000 active terminations. With a downtime objective of less than two hours in 40 years, the No. 4 ESS must be designed to be very fault tolerant viewed from the caller's perspective.

Reconfigurable Redundancy Management for Aircraft Flight Control

A highly fault tolerant digital computer system has been configured based on extensive experience with flight proven, redundant digital flight control systems. The feasibility of minimizing hardware complexity is shown while maintaining high levels of fault tolerance. The emerging hardware design combines reconfiguration concepts with conventional hardware redundancy techniques and special operational software to provide dual fail operate performance with a basic triplex system. The design provides high reliability and flight safety, enhances maintainability, and reduces life cycle cost while offering improved performance for future aircraft.

Instruction architecture of an aerospace multiprocessor

This paper describes the architecture, the data forms, and the instruction set of a multiprocessor computer designed to provide the central computational facilities of a long-lifetime orbiting space laboratory. An overview of the system [M73] describes other aspects of the design, including its high level of fault-tolerance, flexible capacity, real time control capability, and process security in the presence of software faults. The present treatment emphasizes the considerations which led to the chosen instruction set, and discusses its design relative to system objectives.