QUANTUM IMPLEMENTATION OF THE MODIFIED DIJKSTRA'S ROUTING ALGORITHM

Quantum computing can be used to solve certain problems faster than classical computers. One such problem is related to optimal routing in Internet of Things and sensor networks where the number of nodes is very high and multiple constraints (energy efficiency, latency, throughput) must be met. We propose a quantum implementation of the Modified Dijkstra's algorithm for finding the optimal route between a source node and a destination node in a connected graph. This is a particular case of the Travelling Salesman Problem, which is NP hard. Our contribution is two-fold: first of all, we encode both the Available Transfer Rate and the One-Way Delay in the controlled unitary matrices in order to be able to use Quantum Phase Estimation for computing the composite metric of a path. Second, we use an optimized version of the Grover quantum search algorithm to find the path with the minimum composite metric with zero failure rate.