Reconfiguring Networked Infrastructures by Adding Wireless Communication Capabilities to Selected Nodes

Robustness is an important requirement on many critical networked infrastructures. One of the most important ways to achieve robustness is to keep an appropriate level of redundancy by adding redundant resources for the critical networked infrastructures. Considering wireless with good reconfigurabilities, we add wireless communication capacities to selected nodes of a wired networked system in this paper, where we firstly focus on adding minimum wireless communication capacities to achieve biconnectivity requirements, secondly optimize the wireless capacities installation that maximizes the efficiency of reconfiguration, and thirdly propose an approach of topology reconfiguration with wireless communication to keep system connectivity if there are node failures. To resolve the computational complexity issue in searching for the optimal node combination to add wireless capacities, we propose the concept of the equivalent network that reduces the system topology as a simplified acyclic network. The topology optimization is under a metric of reconfiguration distance which guarantees the maximum of the shortest distances between any one node and that in the set of reconfigurable nodes to be minimal such that the efficiency of topology reconfiguration with node failure is the highest. The performances of the methods presented in the paper are demonstrated through numerical experiments and testing.

I. Introduction

ROBUSTNESS [1] is an important requirement on many critical networked infrastructures such as the information networks for intelligent buildings, industrial control systems, energy management systems, and emergency response systems [2] to tolerate failure. However, many information networks running independently with private protocols may coexist in above systems without interaction. Most wired information network infrastructures are vulnerable to fire, line and device failure and other emergencies [3]. An incident such as a fire or attack usually causes system malfunctions due to failure of network nodes or communication links. When an emergency occurs, reconfiguring the networked infrastructures is often required or desirable to recover system functions at least partially [3] [4].