A Cross-Layer Design Framework for Wireless Sensor Networks with Environmental Monitoring Applications

In the past few years, wireless sensor networks (WSNs) are becoming more and more attractive because they can provide services that are not possible or not feasible before. In this paper, we address the design issues of an important type of WSNs, i.e., WSNs that enable environmental monitoring applications. We first provide an overview and analysis for our ongoing research project about a WSN for coastal-area acoustic monitoring. Based on the analysis, we then propose a cross-layer design framework for future WSNs that provide environmental monitoring services. The focus of the framework is the network layer design and the key idea of the framework is to fully understand and exploit both the physical layer characteristics and the requirements of upper layer applications and services. Particularly, for the physical layer characteristics, our framework 1) can enable advanced communication technologies such as cooperative communication and network coding; 2) can utilize the transmission characteristics for identifying/authenticating a sender; and 3) can exploit the communication pattern as a mean of sensing. For the requirements of applications and services, our framework 1) is service-oriented; 2) can enable distributed applications; 3) can utilize the fact that many applications do not have strict delay constraints. To illustrate the advantages of the framework, we also conduct a case study that may be a typical scenario in the near future. We believe that our study in this work can provide a guideline for future WSN design.