Biblio

Radio is the most important part of any wireless network. Radio Access Network (RAN) has been virtualized and disaggregated into different functions whose location is best defined by the requirements and economics of the use case. This Virtualized RAN (vRAN) architecture separates network functions from the underlying hardware and so 5G can leverage virtualization of the RAN to implement these functions. The easy expandability and manageability of the vRAN support the expansion of the network capacity and deployment of new features and algorithms for streamlining resource usage. In this paper, we try to address the problem of scheduling 5G vRAN with mid-haul network capacity constraints as a combinatorial optimization problem. We transformed it to a Quadratic Unconstrained Binary Optimization (QUBO) problem by using a newly proposed quantum-based algorithm and compared our implementation with existing classical algorithms. This work has demonstrated the advantage of quantum computers in solving a particular optimization problem in the Telecommunication domain and paves the way for solving critical real-world problems using quantum computers faster and better.

Graph partitioning (GP) applications are ubiquitous throughout mathematics, computer science, chemistry, physics, bio-science, machine learning, and complex systems. Post Moore's era supercomputing has provided us an opportunity to explore new approaches for traditional graph algorithms on quantum computing architectures. In this work, we explore graph partitioning using quantum annealing on the D-Wave 2X machine. Motivated by a recently proposed graph-based electronic structure theory applied to quantum molecular dynamics (QMD) simulations, graph partitioning is used for reducing the calculation of the density matrix into smaller subsystems rendering the calculation more computationally efficient. Unconstrained graph partitioning as community clustering based on the modularity metric can be naturally mapped into the Hamiltonian of the quantum annealer. On the other hand, when constraints are imposed for partitioning into equal parts and minimizing the number of cut edges between parts, a quadratic unconstrained binary optimization (QUBO) reformulation is required. This reformulation may employ the graph complement to fit the problem in the Chimera graph of the quantum annealer. Partitioning into 2 parts and k parts concurrently for arbitrary k are demonstrated with benchmark graphs, random graphs, and small material system density matrix based graphs. Results for graph partitioning using quantum and hybrid classical-quantum approaches are shown to be comparable to current "state of the art" methods and sometimes better.