Wireless Sensor Networks

7.2 Sensor Network Programming Challenges 245

transmission bears the maximum power consumption. However,

each radio packet (e.g., 30 bytes) only takes 4 ms to send, while lis-

tening to incoming packets turns the radio receiver on all the time.

The energy that can send one packet only supports the radio receiver

for about 27 ms. Another observation is that there are huge differ-

ences among the power consumption levels in the active mode, the

idle mode, and the suspend mode of the MCU. It is thus worthwhile

from an energy-saving point of view to suspend the MCU and the RF

receiver as long as possible.

7.2 Sensor Network Programming Challenges

Traditional ...