On the dependability evaluation of a virtual multiple input multiple output link

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.