Title: User-perceived reliability of shared protection systems with the Erlang type-k repair scheme

Authors: Hirokazu Ozaki, Atsushi Kara, Zixue Cheng

Addresses: Department of Systems and Informatics, Hokkaido Information University, 59-2, Nishi-Nopporo, Ebetsu, Hokkaido 069-8585, Japan. ' The University of Aizu, Tsuruga, Ikki-machi, Aizu-Walamatsu, Fukushima 965-8580, Japan. ' Department of Computer Science and Engineering, The University of Aizu, Tsuruga, Ikki-machi, Aizu-Walamatsu, Fukushima 965-8580, Japan

Abstract: This paper describes the availability and mean time to first failure (MTTFF) of M-for-N shared protection systems (with M + N units) from the viewpoint of an arbitrary one of the N end users. Various forms of M-for-N shared protection are used to improve the reliability of telecommunication network devices such as access node devices, routers, switches, servers, network address translators, etc. In this paper, the time between failures of units and the time for repair are assumed to be an exponential distribution and the Erlang type-k distribution respectively. We consider the Erlang type-k distribution because repair time does not necessarily follow the exponential distribution and the Erlang type-k distribution is more flexible and useful for determining the system parameters such as the mean repair time and the variance based on the reliability objectives. The purpose of this paper is to evaluate the user-perceived reliability of such systems in a quantitative manner.

Keywords: perceived reliability; shared protection systems; Erlang type-k distribution; repair; mean time to first failure; MTTFF; telecommunications networks; access node devices; routers; switches; servers; network address translators; failures; system parameters; reliability objectives.

DOI: 10.1504/IJICT.2011.041925

International Journal of Information and Communication Technology, 2011 Vol.3 No.3, pp.209 - 226

Published online: 15 Aug 2011 *

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