  Problems related to wavelength assignment (WA) in optical communications
networks involve allocating transmission wavelengths for known transmission
paths between nodes that minimize a certain objective function, for example,
the total number of wavelengths. Playing a central role in modern
telecommunications, this problem belongs to NP-complete class for a general
case, so that obtaining optimal solutions for industry relevant cases is
exponentially hard. In this work, we propose and develop a quantum-inspired
algorithm for solving the wavelength assignment problem. We propose an advanced
embedding procedure for this problem into the quadratic unconstrained binary
optimization (QUBO) form having an improvement in the number of iterations with
price-to-pay being a slight increase in the number of variables ("spins"). Then
we compare a quantum-inspired technique for solving the corresponding QUBO form
against classical heuristic and industrial combinatorial solvers. The obtained
numerical results indicate on an advantage of the quantum-inspired approach in
a substantial number of test cases against the industrial combinatorial solver
that works in the standard setting. Our results pave the way to the use of
quantum-inspired algorithms for practical problems in telecommunications and
open a perspective for the further analysis of the employ of quantum computing
devices.
