Correlation-based energy saving approach for smart fiber wireless networks

Energy saving is an important issue that should be taken into consideration when planning telecommunication networks. In fiber–wireless access networks the potential for energy consumption reduction is higher, when compared to other architectures, as many routes toward the optical section are available for nodes at the wireless section, allowing some optical network units (ONUs) to enter long sleep state. However, in a multiradio and multichannel wireless front end, some nodes might not be able to reach all the ONUs. Thus, integrated energy saving mechanisms should be smart and allow for ONU mode adjustments according to wireless node reachability and traffic distribution across the wireless section. In this paper we propose a correlation-aware approach that allows the optical line terminal to infer which ONUs are reachable by wireless nodes. Then, when the network is under low traffic conditions, the appropriate set of ONUs to enter long sleep can be selected. This approach is able, therefore, to integrate knowledge of a wireless front end to promote long-standing sleep periods at the ONUs while avoiding heavy exchange of network state information.