Access to the network is becoming more and more like a utility service – and, at the same time, user behavior is changing, we are storing more and more of our personal data (and applications) in the “cloud”. This model is viable, if the user can be sure that he/she will be able to access the network anytime, anywhere. It brings the focus on the time and space availability, i.e. coverage and availability of the network. However, access networks are highly cost sensitive, hence reliability cannot be achieved by extensive use of redundant resources, just like in the core network domain.

At first, evaluation of the access network reliability is necessary, introducing metrics to capture user perceived network outages, and its probability. Applying traditional reliability metrics is a complicated, as not in independent fixed or mobile network is under evaluation. Current industry trends clearly point towards the convergence of co-existent, overlapping fixed and mobile network, which will be further driven with the advent of 5G networks. Modeling joint reliability of the converged network as a whole is a complex task.

Using appropriate metrics, we will be able to identify the critical points of the access network, and once we are aware of such weak points or bottlenecks, the steps needed to reach the desired reliability may be found. The goal is to develop network design methods to avoid or limit user perceived downtime in the network, without using costly redundant resources.

We are therefore willing to investigate:

  • What survivability requirements are derived from operation of the most relevant network services and applications without user perceived downtime?
  • What metrics describe the reliability and survivability of a converged access network?
  • How can we make the various access networks completely, or to the largest extent survivable, at the expense of zero or very limited redundancy?
  • At what extent are the various access networks not only supplement, but rather substitute each other?

Our related publications are collected under the “Access Network Reliability” keyword.