Design and optimization of fiber optic small-cell backhaul based on an existing fiber-to-the-node residential access network

As the number of wireless users and per-user bandwidth demands continue to increase, both the vendor and carrier communities agree that wireless networks must evolve toward more dense deployments. So-called heterogeneous networks are a commonly proposed evolution, whereby existing macrocellular networks are supplemented with an underlay of small cells. The placement of new small-cell sites is typically determined based on various location-dependent factors such as radio propagation calculations, user densities, and measurements of congestion and demand. The backhaul network, which can account for a significant portion of the total cost of the deployment, is then designed in reaction to the placement of small cells. In contrast, we describe a design method that first considers the locations of existing fibered and powered facilities that might be leveraged to provide inexpensive backhaul. Naturally, such a method is only feasible if the carrier has a legacy local fiber network. This article describes an efficient fiber backhaul strategy for a small-cell network, which leverages facilities associated with an existing FTTN residential access network. Once potential small-cell sites are determined from among all FTTN remote terminals, optimization techniques are used to choose the most efficient subset of sites for maximum coverage, and to design the fiber backhaul architecture.