  Achieving end-to-end ultra-reliability and resiliency in mission critical
communications is a major challenge for future wireless networks. Dual
connectivity has been proposed by 3GPP as one of the viable solutions to
fulfill the reliability requirements. However, the potential correlation in
failures occurring over different wireless links is commonly neglected in
current network design approaches. In this paper, we investigate the impact of
realistic correlation among different wireless links on end-to-end reliability
for two selected architectures from 3GPP. In ultra-reliable use-cases, we show
that even small values of correlation can increase the end-to-end error rate by
orders of magnitude. This may suggest alternative feasible architecture designs
and paves the way towards serving ultra-reliable communications in 5G networks.

Networking and Internet Architecture