Wireless access networks have undergone tremendous improvements to be able to provide high capacity connectivity to an increasing number of mobile users. As a result, and also due to the wide spread request for an (almost) ubiquitous access todata-trafﬁc-demanding services (e.g., video), forecasts indicate that current trafﬁc volumes will increase by 1000 times by2020.
In such a scenario operators are likely to face decreasing revenues in terms of per-unit-of-data consumed, thus highlighting the importance of having cost effective solutions in place while deploying and operating their wireless access networks. In this regard, energy efﬁciency is of great interest due to the fact that power consumption represents a non negligible portion of an operational expenditure (OPEX), a portion that is expected to increase even further if nothing would be done to address this issue.
Mobile operators are facing an exponential trafﬁc growth due to the proliferation of portable devices that require a high-capacity connectivity. This, in turn, leads to a tremendous increase of the energy consumption of wireless access networks.
A promising solution to this problem is the concept of heterogeneous networks, which is based on the dense deployment of low-cost and low-power base stations, in addition to the traditional macro cells.
However, in such a scenario the energy consumed by the backhaul, which aggregates the trafﬁc from each base station towards the metro/core segment, becomes signiﬁcant and may limit the advantages of heterogeneous network deployments.
Results show that backhaul can amount to up to 50% of the power consumption of a wireless access network. On the other hand, hybrid backhaul architectures that combines ﬁber and microwave performs relatively well in scenarios where the wireless network is characterized by a high small-base-stations penetration rate.
On the other hand, recent studies, highlighted that the backhaul has a non negligible impact on the overall power budget of mobile heterogeneous networks. This is mainly due to the fact that in some cases power consumption of backhauling operations at one small base station(BS) might be comparable to the amount of power necessary to operate the BS itself. Therefore, with a potential evolution towards denser heterogeneous wireless network deployments (i.e., where a massive number of small base stations are expected to be used) the power consumption of backhaul might potentially become a serious bottleneck.
Courtesy of Sibel Tombaz [email protected]