Service-level assurance in high-availability multi-unit systems using the M-for-N backup scheme

In this paper, we investigate service-level assurance in high-availability multi-unit systems using the M-for-N backup scheme. M-for-N shared protection (backup) systems with priority control (i.e. prioritized protection switching and prioritized re-housing of repaired units) can be applied to actual telecommunication devices that are subject to service-level agreement (SLA) involving reliability measures. A priority level is assigned to each end user in such a system and the switching and unit re-housing process is subject to the priority. The main contribution of this paper is to give a practical computation method of the user-perceived availability under the priority control. Our case studies for real telecommunication systems reveal the effect of priority control on the user-perceived availability.