Carlos Manuel Rodrigues Machado Autonomic Ubiquitous Computing

4.2 Sensing and acting in a ubiquitous system
Sensing and acting in a ubiquitous system involve some technological, social and economic
requirements to be taken into account, as presented in Table 1. These constrains limit and define
the quality of the context that can be acquired and achieved. Some of the requirements are more
important for mobile devices, others are more relevant for stationary devices when included in a
ubiquitous system, e.g., the power consumption is a requirement that is important for mobile
devices but it is also significant when they are applied in a large quantity, as stationary devices in
an ubiquitous system environment. These requirements must be examined and studied as they
relate to each another. A balance among them must be taken into account because their
implementation can be impracticable in the same device.
Table 2 – Requirements when designing and building sensors and actuators
Requirements when building sensors and actuators
• Design and Usability
• Robustness and Reliability
• Unobtrusiveness
• Social Acceptance and user concern
• Accuracy and Precision
• Openness and impromptu interoperability
• Price and Development Cost
• Energy Consumption
• Start-up Time and Calibration
• Portability, Size and Weight
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