Universal Modular Framework for Sensor Networks

Abstract

Research in wireless sensor networks has known a tremendous boost in the last few years [1]. Wireless sensor networks (WSNs) are becoming more and more widespread. Whereas sensor networks were originally used mainly for monitoring purposes, new applications such as process and asset monitoring, disaster intervention and wireless building automation are rapidly emerging. These new and advanced applications impose new challenges and requirements on the design of WSNs. Special devices such as actors [2] are required, which can interact with the environment. Additionally, each application has its own set of specific QoS requirements, such as maximal delay, desired reliability and so on. Also, the sensors can become mobile, thus making communication more and more complex. Considering these facts, it is clear that future sensor networks will know a wider diversity regarding the capabilities of the sensor nodes. Whereas the first sensor networks consisted of a large number of homogeneous nodes, additional computing power or functionality will be required in some. Sensor networks are thus evolving into heterogeneous networks. Even though new applications for sensor networks are being set up frequently, there is currently no protocol framework which is widely applicable. For each layer, an application developer has to determine which protocols are most suited for the purposes of the intended application, and has to go through the complicated process of combining them into an optimized protocol stack. This comes at a great development cost, impeding the growth of sensor networks and hindering the cooperation between different sensor networks. Accordingly, there is currently a large need for a universally applicable framework for sensor networks in which existing protocols can easily be integrated. In this paper, we propose a new universal framework for wireless sensor networks. This framework is a generic one, that can be used by different types of applications. It is designed to allow for easy integration of current protocols and takes into account the heterogeneity of the sensor nodes. Furthermore, energy-efficiency is optimally supported through cross-layer optimization. Finally, in order to support a wide range of applications, advanced functionality such as QoS and mobility can be supported. The remainder of this paper is organized as follows. An overview of related work in the area of sensor network architectures and cross layer communication in wireless networks is given in section 12.2. Section 12.3 gives an insight of how we see WSNs evolving towards heterogeneous networks, and how we tend to cope with this evolution using node classifications. In section 12.4 we discuss the advantages of a modular architecture. Some challenges when designing a modular architecture are given in section 12.5. The universal modular framework itself is discussed in section 12.6. In section 12.7 we go into more detail on how to handle dependencies between modules. Finally, section 12.8 gives some future directions and section 12.9 concludes the paper.