## 1 Introduction  
Electric energy is currently an essential resource all around the world. With the increase in the use of new technologies in all sectors of human activity, it is easy to predict that the consumption of this type of energy will grow considerably in the near future. For this reason, great research and development efforts have been made, with the aim of improving the generation processes, transport networks and storage systems for this energy. The smart grid networks are the result of the work carried out to obtain improvements in the management, operation and maintenance of the transport infrastructure, as well as in the efficiency with which the energy is used. Their main objective could then be considered as achieving the best use of electrical energy through an improvement in the management and maintenance of the energy sources and the transport infrastructure. At the same time, new services are offered to both supplying companies and consumers. With these objectives in mind, one of the main advances is being made in the improvement of the data networks associated with the electricity transport infrastructures. These data networks are responsible for carrying and delivering all the control, management, maintenance, and security information of the electricity network infrastructure, as well as the applications that allow a better management of the available resources. The data networks are therefore a fundamental part of the smart grid, and so, their reliability, availability, and security have to be guaranteed in all situations, taking into account that they can stop providing correctly their service due to intrinsic (hardware, software, communications protocols, etc.) or extrinsic (weather conditions, malicious agents, terrorist attacks, etc.) failures [1]. The smart grid data communication network is made up of several subnetworks. The different Smart Meters (SM), devices, and other utilities present inside the customers' homes are interconnected by the Home Area Network (HAN). These HANs are in turn interconnected through the Neighborhood Area Network (NAN), and finally, the information can reach the control centers through a Wide Area Network (WAN). To implement all these subnetworks, different technologies can be chosen. Selectable technology standards for HANs can be, among others, IEEE 802.15.4 (Low-Rate Wireless Personal Area Networks (LR-WPAN)) or IEEE 802.11 (Wireless Local Area Networks (WLAN)). For NANs, Power Line Communication (PLC) technologies or standards such as IEEE 802.15.4g or IEEE 802.11s (Wireless Mesh Networks) can be considered. Guaranteeing that the quality of service offered is that required by every application, while maintaining a high efficiency in the use of resources, is one of the most important issues to be taken into account both during the planning process and during the maintenance and operation of the network. It is therefore essential to have deep knowledge of the services that will be provided. These issues are especially important when working with smart grids, given the critical importance of the power grid infrastructure. The offered services belong to very different types, and therefore, their service quality requirements are also different [2]. Generally speaking, most smart grid applications have strong security and reliability requirements. However, their bandwidth needs, as well as their behavior in high packet losses or high latency situations can be very different. Thus, some applications, such as Substation Automation Systems (SAS) or overhead transmission line monitoring, present very strict requirements in terms of latency, but they are not as demanding in terms of bandwidth. On the other hand, demand response management or Advanced Metering Infrastructure (AMI) generally consumes more bandwidth, but can allow greater delays. In the context of WLANs standardized by the IEEE, the proposal for multi-hop mesh networks was published in 2011 as Amendment Number 10 to the 2007 general standard, with the name of IEEE 802.11s [3].