Wireless sensor systems - constraints and opportunities

Summary form only given. The collaboration of countless tiny sensor nodes in a network promises an enormous potential of novel applications. Advances in miniaturization and integration of electronic and mechanical components will enable sensor nodes with a size of a few cubic millimeters in the near future. At the same time, an ongoing price decline will allow the deployment of sensor networks covering thousands of nodes and, as a consequence, replace conventional wired sensors in many areas. Besides application-specific tasks of a node, the entire network requires a conformance to dynamical system requirements. The development focus changes from the single result of a sensor node to the cumulative result of the network. Consequentially, the following requirements for the design and implementation process of sensor networks arise: (i) sensor networks have to be self-organizing, (ii) sensor nodes must perform tasks of network maintenance, (iii) cooperative processing of tasks should lead to more precise results and new application fields, (iv) sensor networks require security mechanisms that are adaptive to environmental conditions, (v) all algorithms and protocols must be optimized with respect to resources, i.e. energy. The key constraint is energy. While many research teams are investigating better means to store, save, or generate electrical energy, progress is still slow. The paper addresses the inherent limitations and arising research opportunities of wireless sensor networks, both in terms of hardware and software issues.