Design Methodology for Wireless Backhaul/Fronthaul Using Free Space Optics and Fibers

Abstract

The recent increase in data rates for Free space optics (FSO) transmission technology, means they could be used for designing the backhaul/fronthaul for 5G and beyond cellular networks. The flexibility and cost-effectiveness provided by FSO are the primary reasons for the mobile operators to investigate the potential of the technology as a mobile backhaul/fronthaul. Unfortunately, the reliability of FSO links is weather dependent, especially if the link covers considerable distance. Optical fibers, on the other hand, are expensive but more reliable. Hence, optimally designing a hybrid network consisting of both fiber and FSO connections can bring in the cost-effectiveness of FSO as well as the robustness of fibers. In such a design, the more important links are connected using fibers while the links with higher tolerance towards failure are designed using FSO. Therefore, in this paper, we propose a hybrid FSO/fiber backhaul/fronthauling methodology for connecting wireless base stations (BSs) to the network core. We first formulate a mixed integer non-linear program (MINLP) for determining the number of splitter/FSO distribution points required in the network that optimally provide connectivity to the BSs. The MINLP is designed to identify the locations of the splitters/FSO distribution points as well. Thereafter, we solve the MINLP with the help of particle swarm optimisation (PSO) and mixed integer linear programming (MILP) techniques. We also derive a heuristic for solving the MILP. Finally, we propose another method for determining the number of splitters required in a relatively shorter time: K-means cluster based method. The results verify that the hybrid network is cost-effective while conforming to the data rate and reliability requirements of the links. The proposal allows evaluation of a seamless design solution of the hybrid network with practical time-complexity.

Design and performance evaluation of a 350 m free space optical communications link for pico-macrocell backhauling

“…With these, the picocell needs to connect to the macrocell with the most cost-effective and high data rate backhaul technology. The flexibility and the effective cost of deployment and maintenance offered by FSOC technology serve as a motivation for the Researchers to explore the potential of its installation for mobile backhauling [12].…”

Enhancing security and capacity in FSO transmission for next-generation networks using OFDM/OCDMA-based ICSM codes

“…Out of the various options for implementing mobile network fronthaul technologies [3][4][5][6], free-space optic (FSO) communications have emerged as a popular choice, largely attributed to advancements in laser-based transmission methods [7]. FSO belongs to the category of optical wireless communication (OWC), wherein the information signal is conveyed through the atmosphere (channel) from the transmitting end to the receiving end, which is linked by a direct line-of-sight (LOS) link [8,9].…”