Applications of Modelling and Simulation (Dec 2019)
A GUI Simulator for Analysis of Real-Time Tasks Assignment on Modified Fault-Tolerance Scheme by Means of Active Backup Replication Technology
Abstract
A graphical user interface (GUI) called the task allocation scheme simulator (TASS) for simulation of sensor nodes in wireless sensor networks (WSNs) using the real-time fault-tolerance task assignment scheme (RFTAS) and the modified real-time fault tolerance task assignment scheme (mRFTAS) is developed to carry out the performance evaluation of tasks or resources assignment in networks that are for sensor nodes. This paper focuses on the development of mRFTAS using the technology of backup (active-backup) for simulation of WSNs. Malicious attacks and the risk of sensors node failures are known to create a profoundly negative consequence on WSNs considering real-time events. The RFTAS is developed to address these issues, however, it has the problem of processing time delay. This is attributed to the characteristic of the passive backup copy technique adopted for the RFTAS in which the copies of backups tasks are activated when the copies of the primaries tasks have failed. Delay in the activation of copies of the backups tasks, of the primary tasks in tasks allocation execution processes as a result of a failure of sensor nodes or the primary tasks, will consequently lead to disastrous penalties if the systems under observation are safety-critical, such as aircraft, detecting fire burning in the forest, nuclear power plant, monitoring military battlefield. The mRFTAS is therefore enhanced using the active replication backup technique where both the primary and backup copies of tasks are executed concurrently. The analyses of the RFTAS and mRFTAS are conducted using total execution time of the task and energy consumption. The performance of mRFTAS shows an improvement over RFTAS in terms of minimizing task execution time by 28.65% and a trade-off in energy consumption by -17.32%.
