Joint Access and Backhaul Power Consumption Optimization in Heterogeneous Mobile Broadband Networks

Capacity overprovisioning in mobile networks leads to underutilization of network resources and thus inefficient operation from a power consumption perspective. In addition, as operators constantly evolve their networks to denser heterogeneous layouts, with overlaying macrocellular base stations coexisting with numerous smaller cells, to cope with upcoming increase in peak mobile data traffic, the energy consumption of mobile networks will continue to grow in the next years. In this context, although backhaul connections can be responsible for tremendous power consumption, the corresponding study is usually neglected in most of the recent energy related literature. An approach for fast and low cost connectivity of dense microcellular sites is the deployment of wireless in-band backhaul links via existing macrocellular base stations. In this paper, we consider this wireless in-band backhaul approach, where access and backhaul links share the same frequency spectrum, and examine joint energy efficient resource optimization on both links. We introduce an iterative low-complexity polynomial backhaul-aware heuristic, which directs traffic to the most energy efficient network resources, and compare it against i) an exhaustive search method that provides optimum results, Journal of Green Engineering, Vol. 6 4, 337–368. doi: 10.13052/jge1904-4720.641 c © 2017 River Publishers. All rights reserved. 338 G. Kyriazis and A. Rouskas ii) a previously proposed reference algorithm, and iii) ordinary Full Operational Topology (FOT) network, where no energy aware technique is applied. From the results obtained, we conclude that our heuristic achieves high energy efficiency gains in all scenarios examined, while wireless in-band backhaul method proved a solid choice for this purpose.