In the recent past, wireless sensor networks have found their way into a wide 
variety of applications and systems with vastly varying requirements and 
characteristics. As a consequence, it is becoming increasingly difficult to 
discuss typical requirements regarding hardware issues and software support. 
This is particularly problematic in a multidisciplinary research area such as 
wireless sensor networks, where close collaboration between users, application 
domain experts, hardware designers, and software developers is needed to 
implement efficient systems. In this paper we discuss the consequences of this 
fact with regard to the design space of wireless sensor networks by 
considering its various dimensions. We justify our view by demonstrating that 
specific existing applications occupy different points in the design space.