Tarek AlSkaif

Game theory for energy efficiency in Wireless Sensor Networks

In the area of Wireless Sensor Networks (WSNs), improving energy efficiency and network lifetime is one of the most important and challenging issues. Most of the considered WSNs are formed by nodes with limited resources, in which each node plays dual rule of both sensing the environment and relaying traffic to the sink from other nodes. On the one hand, the nodes need to stay alive as long as possible by achieving energy efficiency. On the other hand, they have to provide the required service. This conflict of interest makes game theory very useful in WSNs. Moreover, nodes usually have to make decisions with limited information about the state of the network. Game theory has been used recently in a remarkable amount of research in this area. In this survey, we review the most recent papers about using game theory in WSNs to achieve a trade-off between maximizing the network lifetime and providing the required service. The paper contains a complete taxonomy of games applied to this specific research problem. It summarizes and compares the different published proposals along with tables and statistical charts showing in which domains game theory has been applied recently. Overall, the paper will give to researchers a clear view of the newest trends in this research area, underlining its main challenges and hopefully fostering discussions and new research directions.

Energy efficiency of MAC protocols in low data rate wireless multimedia sensor networks: A comparative study

Some new application scenarios for Wireless Sensor Networks (WSNs) such as urban resilience, smart house/building, smart agriculture and animal farming, among others, can be enhanced by adding multimedia sensors able to capture and transmit small multimedia samples such as still images or audio files. In these applications, Wireless Multimedia Sensor Networks (WMSNs) usually share two conflicting design goals. On the one hand, the goal of maximizing the network lifetime by saving energy, and on the other, the ability to successfully deliver packets to the sink. In this paper, we investigate the suitability of several WSNs MAC protocols from different categories for low data rate WMSNs by analyzing the effect of some network parameters, such as the sampling rate and the density of multimedia sensors on the energy consumption of nodes. First, we develop a general multi-class traffic model that allows us to integrate different types of sensors with different sampling rates. Then, we model, evaluate and compare the energy consumption of MAC protocols numerically. We illustrate how the MAC protocols put some constraints on network parameters like the sampling rates, the number of nodes, the size of the multimedia sample and the density of multimedia nodes in order to make collisions negligible and avoid long queuing delays. Numerical results show that in asynchronous MAC protocols, the receiver-initiated MAC protocols (RI-MAC and PW-MAC) consume less energy than the sender-initiated ones (B-MAC and X-MAC). B-MAC outperforms X-MAC when the sampling rates of multimedia nodes is very low and the polling periods are short. PW-MAC shows the lowest energy consumption between the selected asynchronous MAC protocols and it can be used in the considered WMSNs with a wider range of sampling rates. Regarding synchronous MAC protocols, results also show that they are only suitable for the considered WMSNs when the data rates are very low. In that situation, TreeMAC is the one that offers the lowest energy consumption in comparison to L-MAC and T-MAC. Finally, we compare the energy consumption of MAC protocols in four selected application scenarios related to Smart Cities and environment monitoring.

A reputation-based centralized energy allocation mechanism for microgrids

The increasing energy prices and the need to provide energy security during emergencies have pushed researchers and companies to find smarter and more sustainable solutions. In this context, microgrids appear to be increasingly popular. In this paper we present an energy sharing framework for microgrids in which houses share their renewable energy, harvested from some kind of on-site renewables, by transmitting it to an Energy Management Center (EMC). In each time period, the EMC collects the renewable energy and stores it in a central storage unit. It also receives power requests from demanding houses and manages distribution. How to achieve a fair and efficient energy allocation is a challenging problem. For this purpose, we propose a reputation-based energy distribution mechanism that allows the EMC to allocate energy to houses when they request it according to their reputation. We apply our mechanism over three different classes of households. Simulation results show that our energy sharing framework improves the utilization of renewable energy and that the proposed energy allocation mechanism achieves fairness. It is also expected to promote energy conscious behavior as houses will receive energy in proportion to their contribution and energy consumption behavior.

Citizens collaboration to minimize power costs in smart grids: A game theoretic approach

Generating the power necessary to run our future cities is one of the major concerns for scientists and policy makers alike. The increasing global energy demands with simultaneously decreasing fossil energy sources will drastically affect future energy prices. Strategies are already being implemented to develop solutions for the generation and efficient usage of energy at different levels. Involving citizens in the efficient planning and usage of power is a key. In this paper, we propose a game theory based power sharing mechanism between end-users in smart grids. We consider that citizens can produce some amount of electric power obtained from on-site renewable sources rather than just purchasing their whole demands from the grid. Simulation results show that consumers can achieve considerable cost savings if they adopt the proposed scheme. It is also noticed that the more the consumers cooperate, the higher the percentage of cost savings is.

A Method for Developing a Game-Enhanced Tool Targeting Consumer Engagement in Demand Response Mechanisms

This work focuses on enhancing consumer engagement in demand response mechanisms through the employment of gamification techniques. Demand response mechanisms are employed by electricity suppliers, other market parties, and transmission and distribution system operators as options for market optimisation, balancing supply and demand, and ensuring system security. Gamification is the use of game design elements in non-game contexts, and the use of game principles in the design of certain systems to enhance engagement with these systems and make the interaction more motivating. The development of flexibility mechanisms at the demand-side is considered a key aspect for an effective energy transition, which requires the active participation and empowerment of consumers in the energy system. However, a significant barrier to realise the full flexibility potential is insufficient consumer engagement and awareness regarding energy usage. Serious games, and gamification, can effectively empower consumers by enhancement of engagement and stimulation of collaboration between them. The goal is to enable a playful interaction between technology, such as smart metering systems, energy management systems and smart appliances, and consumers that will result in higher engagement in demand response. An overview of demand response is provided, and the linkage is made between retail markets, markets at the wholesale level and ancillary services. The role of gamification techniques is discussed based on literature review, focusing on strategies to increase consumer engagement in demand response mechanisms. A user-centred, iterative design method is proposed for the development of a game-enhanced tool in which also collaboration between players can be stimulated, whereas the impact of applying the game-enhanced tool on consumer engagement can be empirically verified.