Hybrid Radio/Free-Space Optical Design for Next Generation Backhaul Systems

Abstract

The deluge of date rate in today's networks imposes a cost burden on the backhaul network design. Developing cost efficient backhaul solutions becomes an exciting, yet challenging, problem. Traditional technologies for backhaul networks include either radio-frequency backhauls (RF) or optical fibers (OF). While RF is a cost-effective solution as compared to OF, it supports lower data rate requirements. Another promising backhaul solution is the free-space optics (FSO) as it offers both a high data rate and a relatively low cost. FSO, however, is sensitive to nature conditions, e.g., rain, fog, line-of-sight. This paper combines both RF and FSO advantages and proposes a hybrid RF/FSO backhaul solution. It considers the problem of minimizing the cost of the backhaul network by choosing either OF or hybrid RF/FSO backhaul links between the base-stations (BS) so as to satisfy data rate, connectivity, and reliability constraints. It shows that under a specified realistic assumption about the cost of OF and hybrid RF/FSO links, the problem is equivalent to a maximum weight clique problem, which can be solved with moderate complexity. Simulation results show that the proposed solution shows a closeto-optimal performance, especially for practical prices of the hybrid RF/FSO links.Index Terms-Network planning, optical fiber, free-space optic, backhaul network design, cost minimization.

Cost-effective backhaul design using hybrid radio/free-space optical technology

“…To conclude the proof, we show that the weight of the clique is equivalent to the merit function of the optimization problem (12). A complete proof can be found in Appendix D of the arvix version [19].…”

“…Finally, we show that any solution that cannot be reduced to a single cluster is not optimal. The complete proof can be found in Appendix B of the arxiv version [19].…”

“…Proof: The proof can be found in Appendix C of the arxiv version [19]. The following theorem links the solution of problem (12) to the planning graph.…”

Analysis of Optical Attenuation from Measured Visibility Data in Islamabad, Pakistan

“…The advantages of rapid deployment, portability and high data rate make FSOL as a potential alternative to radio frequency links. FSOL have been in use for different nomadic communication application for civil and military [9][10][11][12].…”

Cascaded FSO-VLC Communication System

“…On the other hand, free space optical (FSO) communication system, which is a line-of-sight (LOS) technology, has attracted significant attention as high bandwidth last mile transmission technique. FSO is a reasonable alternative to optical fibers as it requires less initial deployment [1] and can be installed at locations where deployment wired connection is challenging.…”