Chapter 1 Answers

Answers to Exercises

1. a. Since they belong to the same vertical, they should be similar in terms of their regulatory bodies, and standards. However, since they do not belong to the same use case, they might be quite different in terms of their platforms and processing.
2. d. The traffic generated by people when talking on the phone or receiving data is somewhat different as compared to the IoT traffic. All three choices of a, b, and c are important differences between these two types of traffics.
3. b. A WSN network has nodes that communicate with each other, but might be local and not connected to the Internet.
4. a. The concept of remote device connection existed before the era of modern Internet. The first connected vending machine was invented in 1990. But, the term “IoT” first used by Kevin Ashton, to promote Radio Frequency Identification (RFID) technology.
5. a. An IoT gateway enables many IoT devices with no Internet connectivity to connect to the Internet via the gateway.
6. b. In an IoT network, several IoT devices might play the role of IoT gateways, if they have access to the Internet. For example, in a local area network with mash topology where more than one IoT device is connected to the Internet, all connected devices can be programmed to play the role of the IoT gateway.
7. c. Due to the existence of massive number of IoT devices, it would be beneficial to consider low power consumption as a requirement for IoT. Reducing the power consumption of each device reduces the total energy needed to be produced to power these devices.
8. c. An IoT device can reduce its power consumption by reducing the time that the radio is active. It is clear that when an IoT device goes to sleep and inactivates its radio, the device becomes unreachable. Therefore, the IoT device needs to go to sleep if it does not have anything to perform. Fortunately, in many IoT applications, that is the case.
9. d. The technologies such as Zigbee, BLE, or WiFi are short-range wireless technologies. LPWAN technologies are related to wide area networks and they can provide long range connectivity.
10. c. IIoT stands for Industrial Internet of things. The term XIoT where X can be different letter, has been widely used in IoT related articles and documents.
11. d. It is possible for an IoT device to send the medical data of a patient to the Internet. After the data is analyzed, the information for treatment can be sent to the same IoT device. In fact, the IoT device should have the equipment needed for treatment. For example, an IoT device may send the glucose level of a patient and receive a command that automatically adjusts the insulin pump.
12. b. An IoT device can have one or several sensors such as body temperature, pulse, blood pressure. The connectivity should be wireless due to the patient’s mobility.
13. b.  500×4=2000 zettabytes which is equal to 2 yottabytes.
14. a. smart meter can play the role of an IoT gateway.

Answers to Review Questions

1. Due to the mobility of the bird and the need for a connectivity scheme for providing a good coverage, cellular IoT is preferred. 

2. A sensor (or a collection of sensors) is mounted on the helmet and is connected to a Bluetooth device. The Bluetooth device on the helmet is paired with the Bluetooth device on the smartphone. In this scenario, the smart phone plays the role of an IoT gateway. Once the helmet hits a hard object such as ice, or cement, the smart helmet will send the accident-related data to the smart phone. An app on the smartphone determines the severity of the crash based on the data. If the injury is severe, the location data in addition to the health data will be sent to an emergency contact. The smartphone can also send the data to the cloud, so that more processing and analysis can be performed.

3. Sensors can be embedded in the handle of racket to collect and send data. The data indicates the player’s performance metrics regarding the type of shots (forehand/backhand), its power and effect, and the frequency that the ball is hitting the best spot of the racket during the game. This data can be used for training purposes to improve the performance of the players.

4. To determine the drowsiness of a driver, IoT glasses can determine the eye closure ratio as a sign of driver fatigue. The glasses can send the data related to eye closure ratio to the Internet. If this ratio is smaller than a standard threshold, the driver should be alerted.

5. From each welding spot 15 KB of data is generated per seconds. Since welding operation for each spot takes 10 seconds, 150 KB of data is generated in 10 seconds. There are 500 spots per each equipment. Therefore, 150 × 500 KB= 75 MB of data is generated for each equipment. A factory builds 200 equipment per day. So, the total amount of generated data would be 200 × 75 MB= 15 GB.