POWER LINE COMMUNICATIONS FOR SMART HOME NETWORKS: MODELING, SIMULATION AND OPTIMIZATION

In recent years, research and development efforts are devoted to the deployment of information and communication technology (ICT) within residential buildings and houses, in order to provide services that will increase the quality of life. Although this trend is originated in the late 60’s as a result of the application of industrial automation to residential buildings and houses, i.e., home automation, nowadays, further services are offered to the final users, i.e., home networking and energy management. In fact, a lot of effort is put on the joint delivery of these services in order to make the home, namely the smart home (SH), an integral part of the future smart grid (SG). The concept of SH can be described as a house equipped with electronic systems and appliances, namely, “smart” appliances, which are able to exchange information by means of a communication network. However, these systems are characterized by a broad variety of communication technologies, standards and protocols, so that they often cannot interconnect, and/or interoperate and in some cases even coexist. In our opinion, coexistence, interconnection and interoperability problems represents the bottleneck to a pervasive deployment of smart appliances and systems within residential buildings and houses. To this respect, the first topic that we consider in this thesis is the definition of the SH network architecture and devices, which allows to obtain convergence among smart appliances. To this aim, a survey of the communication technologies, standards, protocols and also media, which can be used for SH applications, is necessary in order to define a network topology that is able to be scalable, extensible, and rather reliable. Moreover, in order to achieve interconnectivity among “smart” appliances, we define a shared common layer that is able to manage heterogeneous lower layers allowing network convergence. Once defined the SH network architecture and its network devices, we focus on power line communication (PLC) technologies and we implement a network testbed in order to evaluate some of the functionalities of the SH network within real environments. From the analysis of field trial data, we are able to highlight performances and disadvantages of two representative narrow band PLC (NB-PLC) solutions. Furthermore, exploiting the network testbed where broadband PLC (BB-PLC) technology is used to provide an Ethernet backbone for NB-PLC devices, we achieve interconnectivity between heterogeneous devices and we observe a significant improvement of the performances. Although NB-PLC technologies have been conceived for the development of low data rate applications and, in particular, for automatic meter reading (AMR), we focus our attention on the G3-PLC technology, for which we propose enhancements at the medium access control (MAC) sub-layer to allow the implementation of SH applications that could potentially require higher data rate than AMR. The G3-PLC technology has been taken into account since (i) it has been used as baseline technology for the development of popular communication standards for SG applications, and (ii) we have found, from the field trials, that the performance of NB-PLC may be poor in large houses where the signal is strongly attenuated because it spans large distances and crosses different circuit breakers (CBs), e.g., in multi-floor houses. Furthermore, an innovative cross-platform simulator that allows to realistically simulate the G3-PLC technology up to the network layer is presented. The proposed cross-platform consists of two different simulators jointly connected: one for the physical (PHY) layer and one for the data link layer (DLL)/network layer (NL). The PHY layer simulator is implemented in MATLAB, while the DLL/network simulator in OMNeT++. A convergent network architecture that permits the integration of the G3-PLC technology within a switched Ethernet network is also presented with the aim of improving the G3-PLC performance in large scale houses/buildings. The performance of the considered communication technology are presented through extensive numerical results for the in-home application scenario. Finally, the cross-platform simulator is used to evaluate G3-PLC systems for SG applications in the access network scenario. This is fundamental since the interaction of the outside world, i.e., the access network, with the SH is mandatory in order to achieve and exploit the SG concept. Moreover, to improve the performance and coverage of G3-PLC, a simple adaptive tone mapping algorithm together with a routing algorithm are also presented.