Research Article Planning and Performance Challenges in Power Line Communications Networks for Smart Grids Miguel Seijo, 1 Gregorio López, 1 Javier Matanza, 2 and José Ignacio Moreno 1 1 Telematic Engineering Department, Universidad Carlos III de Madrid, Avenida de la Universidad 30, 28914 Legan´ es, Spain 2 Automatic and Electrical Department, ICAI School of Engineering, Calle Alberto Aguilera 25, 28015 Madrid, Spain Correspondence should be addressed to Gregorio L´ opez; gregorio.lopez@uc3m.es Received 16 October 2015; Revised 24 January 2016; Accepted 11 February 2016 Academic Editor: Jianxin Wang Copyright © 2016 Miguel Seijo et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te Smart Grid represents a revolution especially at distribution and customer levels, bringing monitoring and control capabilities, traditionally available up to the primary substations, down to the secondary substations, and beyond. Machine-to-Machine (M2M) communications networks are key to enable managing the huge number of sensors and actuators distributed all over the low voltage and medium voltage networks. Such M2M communications networks must meet demanding requirements from the technical perspective (e.g., low latency, high availability), since eventually the stability of the grid may rely on them, and from the economic perspective (e.g., low deployment and operational costs), due to the huge volume of devices to be monitored and controlled. Tus, Power Line Communications (PLC) technologies are winning momentum in these scenarios because they represent a great trade- of between both perspectives. However, electrical networks also represent a harsh communications medium, mainly because they are not designed for data communications, but for power transmission. Consequently, although much research has been carried out on this topic recently, PLC networks still present technological problems and challenges. Tis paper highlights some of the most relevant challenges in this area and presents a set of cutting-edge sofware tools which are being developed to overcome them, facilitating the planning, deployment, and operation of this kind of networks. 1. Introduction Te Smart Grid represents a revolution, especially at the distribution and customer domains, due to the following reasons: (i) First, the most radical changes are introduced at the medium voltage (MV) and low voltage (LV) networks, for example, Distributed Generation (DG) based on renewables, Electric Vehicle (EV), or Residential Demand Response (RDR). (ii) Second, the management of the electrical grid has traditionally been focused on the bulk generation and transmission domains, based on the so-called Supervisory Control and Data Acquisition (SCADA) systems, which were deployed down to the primary substations, responsible for transforming high voltage into medium voltage levels. However, the Smart Grid gets deep into the MV and LV networks, with the remarkable increase on the number of devices to be monitored and controlled that such a new approach entails. Tus, Machine-to-Machine (M2M) communications net- works are especially important in the Smart Grid in that they are key to enable efectively managing the aforementioned huge number of sensors and actuators distributed all over the MV and LV networks. As a result, such M2M communi- cations networks must meet demanding requirements from the technical perspective (e.g., low latency, high availability) [1], since eventually the stability of the electrical grid may rely on them, and from the economic perspective (e.g., low deployment and operational costs) [2], due to the huge volume of devices to be monitored and controlled. As a matter of fact, Power Line Communications (PLC) technologies are winning momentum in these scenarios, notably because they represent a great trade-of between both perspectives. First, Narrowband-PLC (NB-PLC) technologies are being widely used—especially in Europe—to enable the com- munication between smart meters and data concentrators Hindawi Publishing Corporation International Journal of Distributed Sensor Networks Volume 2016, Article ID 8924081, 17 pages http://dx.doi.org/10.1155/2016/8924081