Secure Real-Time Monitoring and Management of Smart Distribution Grid Using Shared Cellular Networks
Electricity production and distribution is facing two major changes. First, production is shifting from classical energy sources such as coal and nuclear power toward renewable resources such as solar and wind. Second, consumption in the low voltage grid is expected to grow significantly due to the expected introduction of electrical vehicles. The first step toward more efficient operational capabilities is to introduce an observability of the distribution system and allow for leveraging the flexibility of end connection points with manageable consumption, generation, and storage capabilities. Thanks to advanced measurement devices, management framework, and secure communication infrastructure developed in the FP7 SUNSEED project, the distribution system operator (DSO) now has full observability of the energy flows in the medium/low voltage grid. Furthermore, the prosumers are able to participate pro-actively and coordinate with the DSO and other stakeholders in the grid. The monitoring and management functionalities have strong requirements for communication latency, reliability, and security. This article presents novel solutions and analyses of these aspects for the SUNSEED scenario, where smart grid ICT solutions are pr
Massive M2M access with reliability guarantees in LTE systems
Machine-to-Machine (M2M) communications are one of the major drivers of the cellular network evolution towards 5G systems. One of the key challenges is on how to provide reliability guarantees to each accessing device in a situation in which there is a massive number of almost-simultaneous arrivals from a large set of M2M devices. The existing solutions take a reactive approach in dealing with massive arrivals, such as non-selective barring when a massive arrival event occurs, which implies that the devices cannot get individual reliability guarantees. In this paper we propose a proactive approach, based on a standard operation of the cellular access. The access procedure is divided into two phases, an estimation phase and a serving phase. In the estimation phase the number of arrivals is estimated and this information is used to tune the amount of resources allocated in the serving phase. Our results show that the proactive approach is instrumental in delivering high access reliability to the M2M devices.
Joint estimation and contention-resolution protocol for wireless random access
We propose a contention-based random-access protocol, designed for wireless networks where the number of users is not a priori known. The protocol operates in rounds divided into equal-duration slots, performing at the same time estimation of the number of users and resolution of their transmissions. The users independently access the wireless link on a slot basis with a predefined probability, resulting in a distribution of user transmissions over slots, based on which the estimation and contention resolution are performed. Specifically, the contention resolution is performed using successive interference cancellation which, coupled with the use of the optimized access probabilities, enables throughputs that are substantially higher than the traditional slotted ALOHA-like protocols. The key feature of the proposed protocol is that the round durations are not a priori set and they are terminated when the estimation/contention-resolution performance reach the satisfactory levels.