Expected-reliability analysis for wireless CORBA with imperfect components

Abstract

Reliability analysis has long been an important area of research for wired networks. However, little reliability analysis has been conducted on wireless networks. Wireless networks, such as wireless CORBA, inherit the unique handoff characteristic which leads to different communication structures with various types and numbers of components and links. Therefore, the traditional definition of two-terminal reliability is not applicable any more. We propose a new term, two-terminal expected-reliability, to integrate those different communication structures into one metric, which includes not only the failure parameters but also the service parameters. Nevertheless, the two-terminal expected-reliability is still a monotonically decreasing function of time t. The expected-reliability and the corresponding MTTF are evaluated quantitatively in different communication schemes. To observe the gains in reliability improvement, the reliability importances of imperfect components are also evaluated. The results show that the failure parameters of different components take different effects on the MTTF and on the reliability importance. With different expected working times of a system, the focus of reliability improvement should be transferred to different components. Although our analysis is conducted on wireless CORBA platforms, it is extensible to generic wireless network systems.