1. Computer Engineering and Networks Technische Informatik und Kommunikationsnetze Jan Beutel, ETH Zurich Wireless Sensor Networks for Extreme Environments

2. Computer Engineering and Networks Technische Informatik und Kommunikationsnetze Exam Questions (Correct answers are BOLD) Which factors influence power savings without sacrificing performance (latency, throughput)? Lower operating voltages Higher battery capacity Exact timing Low-power modes What effects can not be accounted for in a testbed? Long-term performance Real sensor input signals Synthesized sensor input signals Environmental conditions How much data is lost on a sensor node reboot due to power failure? All data contained on the node Only the portion in the registers of the processor All on-chip SRAM data Only the data in the cache All data in Flash and SRAM All on- and off-chip SRAM data

3. Computer Engineering and Networks Technische Informatik und Kommunikationsnetze Exam Questions (Correct answers are BOLD) Hard reasons for online wireless data gathering systems Users process data on the fly Data access is faster System operation can be monitored/controlled Impact of the environmental dynamics on a low-power wireless system Clock drift Measurement accuracy Excessive wear of mechanical components Wireless disconnects Faster discharge/less capacity in batteries Slower discharge/more capacity in batteries