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Contact: ambujv@nus.edu.sg, COM3: #02-25
[1] Question 1: What is the typical battery capacity of common devices that you use in your daily life such as wearables (Apple Watch/Fitbit), earphones, laptops, and mobile phones?
[2] Question 2:
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In the figure represnting state transition diagram, which chipset is more suitable for used in Internet of Things applications? Explain your reasoning.
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For the chipset chosen in the question above, assume that the devices are designed to operate at a very low duty-cycle (<0.01%) and you are allowed to reduce the current drawn from only one of the states (idle, receive (RX) or transmit (TX)). Which state would you reduce the current from?
[3] Question 3: Please find specification of following technologies:
| Specification | Bluetooth| ZigBee | WiFi | LoRa | LoRea (Backscatter) | Judo (Backscatter) | |-------|--------|---------|---------|---------| | VDD(V) | 1.8 | 3.0 | 3.3 | 3.3 | 2| 0.12| | Transmit (mA)| 60 | 30 |220| 28 | 0.035| 0.7 | | Receive (mA)| 50 | 25 | 210| 13.8 | N.A | N.A| | Bitrate (Mb/s)| 1.2| 0.25 | 54 | 0.027 | 0.003| 0.1|
- Calculate the energy (in milli-joules (mJ)) require to transmit 1 bit for different technologies listed above.
- For low power IoT devices, should you always select the network technology with the lower transmission energy per bit? Explain your answer
- In addition to energy needed to transmit/receive a bit, what other criteria(s) should you take into account when selecting a network technology for use in a low power Internet of Things?
- What kind of applications would choose to use Bluetooth technology?
- What kind of application would choose to use LoRa technology?
- What kind of application would choose to use Backscatter technology?