Union Game-based Wireless Sensor Networks, Energy-efficient Data Transmission Strategies

Wireless sensor network (WSN) is an important technology. It has gained increasing attention from both the research community and actual users. The energy of sensor nodes is limited since they are usually battery-powered. In addition, it could be impossible to recharge the battery, since the nodes may be deployed in an unpractical environment. On the other hand, the WSN should have a lifetime that is long enough to fulfill the application requirements. Therefore, it is important to develop some energy-efficient strategies for WSN. It is known that the energy consumption of transferring 1-byte data is 1000 times as much as processing 1-byte data. It is necessary to develop energy-efficient data transfer strategies of WSN since data transfer affects the energy consumption greatly.Game theory is the study of conflict and cooperation between individual decision makers. The data transfer strategy, which is defined as the proportion of data sent by a node and that forwarded by a node, is a game activity. Coalitional game, which is an important concept of the game theory, is usually used to increase the coalitions'payoff. To reduce the energy consumption, some nodes in a WSN will form a coalition by transferring data coordinately instead of transferring alone.Generally, the main contributions of this thesis can be summarized as follows:We use the coalitional game theory as the backbone of determining the WSNs' energy-efficient data transfer strategies and the Shapley value is used to measure the satisfaction degree of sensor nodes to coalitions.We use the Markov process to model the forming of coalitions and propose the concept of absorption coefficient to measure the coalitional profiles. Then, we find the coalitional profile with the largest absorption coefficient as the reasonable coalitions for all the sensor nodes. Nodes in the reasonable coalitions can get more payoffs compared with the other ones.We determine the coalitions'data transfer strategies based on the idea of Nash equilibrium (NE). We find the approximate NE of strategy profile to guarantee the reachability and balance the energy consumption.