Small cell backhaul: challenges and prospective solutions

Operators are currently considering the deployment of small cells to complement their macrocellular networks and increase their coverage and capacity. However, in order to roll-out a large number of small cells and allow anytime, anywhere wireless broadband connectivity through wireless technologies, operators must still face the challenge of backhauling the traffic from the small cells to the core network in a cost-effective manner. In this paper, backhaul challenges for small cell base stations (BSs) are discussed, and potential wired and wireless solutions together with their benefits and drawbacks are presented. The use of large scale antennas systems and free-space optics is also discussed. Moreover, a wireless backhaul planning tool targeted at finding the most cost-effective backhaul solution using a mixture of wireless technologies is presented. Simulation results confirm that the optimum backhaul solution is a combination of various options, which can overcome inherent scenario constraints while providing a cost-effective performance.