Authors: Mohamed Escheikh; Kamel Barkaoui
Addresses: Syscom Laboratory, ENIT, Tunis El Manar University, Tunis, Tunisia ' Cedric Laboratory, Conservatoire National des Arts et Métiers, Paris, France
Abstract: Cooperative diversity or virtual antenna arrays (VAA) enables transmission range extension and provides robustness enhancements in wireless multi-hop relay networks, when compared with relaying non-cooperative diversity-based schemes. Moreover redundant spare nodes willing to cooperate when used in a virtual multiple input multiple output (VMIMO) scheme allow better dependability and lead to a more efficient transmission that is of particular interest in mobile environment. This talk addresses a model-based probabilistic approach for dependability assessment of a VMIMO link. More precisely, we show how through Markov models, we can evaluate availability and survivability measures of a VMIMO link. We show through extensive numerical computations how instantaneous availability (A(t)) decreases for different failure rates and how the steady state availability (As) behaves with respect to the number of redundant spare nodes. Also we illustrate how node failure rates affect VMIMO link survivability metrics, i.e., excess loss due to failure (ELF) and excess delay due to failure (EDF). Finally we highlight reliability metrics related to VMIMO link [i.e., reliability (R(t)), mean time to failure (MTTF) and mean time to repair (MTTR)] and we show how they behave with respect to node failure and repair rates.
Keywords: virtual multiple input multiple output; VMIMO; dependability evaluation; availability; survivability; reliability; continuous time Markov chains; CTMC; cooperative diversity; virtual antenna arrays; VAA; relaying; network failure; mobility; multi-hop wireless networks.
International Journal of Critical Computer-Based Systems, 2017 Vol.7 No.1, pp.43 - 58
Received: 08 May 2021
Accepted: 12 May 2021
Published online: 08 May 2017 *