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Internet of Things, Exam– February 7, 2014 Family Name Given Name Student ID Total Available time: 2 hours 1 – Exercise (7 points) The two-hop personal area network (PAN) in the figure is composed of 4 motes and a PAN Coordinator. The PAN works in beacon-enabled mode. Ø Mote 1 and Mote 2 have statistical (non-deterministic) traffic towards the PAN coordinator characterized by the following probability distribution: P(required rate=100 [bit/s])=0.5, : P(required rate=200 [bit/s])=0.25, P(required rate=0 [bit/s])=0.25. Ø Mote 3 and Mote 4 have deterministic traffic towards the PAN coordinator with a required rate of 500 [bit/s]. Assuming that: Ø the active part of the Beacon Interval (BI) is composed of Collision Free Part only Ø The collision free part is divided in two: the first part is dedicated to host the transmissions from Motes 1,2 and 3 towards Mote 4, the second part is used by Mote 4 to deliver its own traffic and the relayed one to the PANC. Ø the motes use b=128 [bit] packets to communicate with the PANC which fit exactly one slot in the CFP Ø the nominal rate is 250 [kb/s] Ø Mote 4 is 10 [m] away from the PANC Find 1. The duration of the single slot, the duration of Beacon Interval (BI), the duration of the CFP and the duration of the inactive part, a consistent slot assignment for the four motes, and the duty cycle 2. The energy consumption in a BI for Mote 4 if the energy required to operate the TX/RX circuitry is Ec=50 [nJ/bit], the energy required to support sufficient transmission output power Etx(d)= k d2 [nJ/bit], being k=1 [nJ/bit/m2], the energy of being idle in a slot is Eidle = 20 [uJ] and the energy for sleeping is Esleep = 5 [nJ]. Assume that the four motes cannot overhear the respective transmissions. 2 – Exercise (7 points) A visual sensor…