The problem of reducing power consumption in backbone networks by adopting sleep modes has been extensively studied in the literature. In contrast to previous work, we forecast power consumption and traffic in two operator networks (France Telecom (FT) and Telefo´nica Investigacio´n y Desarrollo (TID)) for the year 2020, and consider both Single Line Rates (SLRs) and Mixed Line Rates (MLRs) deployments. Given these realistic scenarios, the set of devices in sleep mode is computed autonomously on each network node by a simple power-aware algorithm using only local information as input and requiring no rerouting. Results show that the savings obtained by adopting sleep modes are significant, even if power efficiency (W/Gbps) is increased. Moreover, we show that networks using MLR always consume less energy than SLR-based networks when the power-aware algorithm is applied to the considered scenarios.