## 1 Introduction  
Since the invention of the thermostat by [PERSON] in 1883, mankind dreams of intelligent and automated environments. When applied to buildings, the possible applications of this concept are countless: from the improvement of the safety and the comfort of occupants, to the application of energy efficiency measures, and the care for the disabled and the elderly, just to mention a few [1]. Among these, energy efficiency has become one of the most important aspects in the design and management of both residential and commercial buildings [2], also following the increasing concerns on global warming and on fossil fuels depletion. In particular, when it comes to non-residential sites, such as, public agencies, commercial, and industrial buildings, the concept of energy efficiency has an even greater bearing, by dealing with larger amounts of heterogeneous users, equipment, and facilities. This in fact implies larger opportunities of energy savings, which in the case of public buildings, may be particularly critical, due to the use of public money. The efficient use of energy intensive equipment, such as Heating, Ventilation, and Air Conditioning (HVAC) systems, plays a key role for the development of sustainable energy buildings. It is worth noting that this applies not only to the design stage, i.e., by making use of high performing insulating materials, advanced construction technologies, efficient equipment, or renewable sources [2; 3], but also to the operation stage, i.e., by defining how equipment and energy resources must be operated to ensure an efficient use of energy [4]. The efficient operation of equipment and energy resources, particularly in the case of large buildings, requires the monitoring and control of several parameters, concerning the use of facilities (i.e., the presence of users, the thermo-hygrometric conditions in rooms, etc. ), such as well as the working condition of devices and equipment [5]. In this context, the recent diffusion of Information and Communication Technology (ICT) solutions and, in particular, of the Internet of Things (IoT) paradigm, allowed the development of the smart building concept [6], which is opening the way for improved energy management capabilities, thanks to the use of advanced monitoring and control functions over heterogeneous sensors and devices [7; 8]. Of particular interest is the application of such functionalities in complex systems, such as campuses, where the coordinated monitoring and control of clusters of buildings and dispersed resources is required to implement the optimal management of the whole system. In this kind of applications, distributed and holonic control architectures are suggested by the scientific literature, by following the recent research trends in the monitoring and control of Distributed Energy Resources (DERs) in Smart Grids [9]. In particular, decentralized control architectures inherited by smart and micro-grids management systems [10; 11] have been proposed as viable solution also in smart campus environments, such as suggested in [12; 13]. The application of advanced monitoring and control strategies (and of the related ICT solutions) relies on the availability of proper communication infrastructures. The complexity and the installation costs of proper communication systems represent one of most critical aspects of such application. The installation of wired systems, such as optical fiber in large areas (e.g., where distances are on the order of hundreds of meters) or ethernet networks in small areas (e.g., where distances are below 100 m) may present relevant costs, particularly in old buildings or in complex scenarios, such as that of smart campus, where the distance between buildings may be up to dozen or even hundreds of meters. For this reason, the use of wireless networks are gaining momentum, particularly when large area or hybrid environments are taken into account.