ATIS 0100037.2013(R2018)

The impact of failures in modern systems for voice and data transmission (e.g., IP routers or a Radio Network Controller) as well as mobility and wire-line communication networks with hierarchical design increases progressively with the hierarchical level. The Impact Weighted Mean Time Between Failure (IW-MTBF) - a combination of MTBF values for all hierarchical levels of a given network element or network segment weighted for each level by its respective impact on failures - is proposed as a method for evaluating overall reliability of the hierarchical system during the design phase.