Question

A flower nursery has commissioned you to investigate how an Internet of Things (IoT) sensor network can be effectively used to monitor several battery-powered sensors in their greenhouses. The sensors measure temperature, humidity, light intensity and soil moisture, as well as monitoring equipment such as water sprays. The owners want to use an IoT network to transmit and store sensor measurements on a server located in their nursery office. Their specification includes a requirement that the sensors must have very long battery lives; low transmission data rates with a maximum bit-rate of 8 kilobits per day, and sufficient radio range to cover all greenhouses, which can be located up to 1 km away from the nursery office.

Based on what you have learnt in Block 3, Parts 3 and 4, write a short comparison for the nursery owners on the features and technical performance of the following IoT networks: Wi-Fi (IEEE 802.11), LPWAN and ZigBee.

Your comparison, which must NOT be a table, should reflect on the respective data-rates, coverage and battery life performance features of the three technologies and their suitability for this nursery scenario. It should also conclude with your recommendation to the owners for which IoT technology to adopt for their nursery.

The maximum word limit for Question 2(a) is 350 words

Answer 1

IEEE 802.11: WiFi

WiFi uses radio waves (RF) in order to allow two devices to communicate with one another. The technology is most commonly used to connect Internet routers to devices like computers, tablets, and phones. However, it can be used to connect together any two hardware components. WiFi is a local wireless network that runs of the 802.11 standards set forth by the Institute of Electrical and Electronics Engineers (IEEE).

WiFi can utilize both the global 2.4GHz UHF and 5GHz SHF ISM radio bands. The WiFi Alliance certifies some products, allowing them to be labeled as “Wi-Fi Certified.” In order to receive that designation, and product must go through the Alliance’s interoperability certification testing.

Low-power WAN (LPWAN)

Low-power WAN (LPWAN) is a wireless wide area network technology that interconnects low-bandwidth, battery-powered devices with low bit rates over long ranges created for machine-to-machine (M2M) and internet of things (IoT) networks, LPWANs operate at a lower cost with greater power efficiency than traditional mobile networks. They are also able to support a greater number of connected devices over a larger area.

LPWAN technologies include:

1) GreenOFDM from GreenWaves Technologies

2) DASH7 from Haystack Technologies Inc.

3) Symphony Link from Link Labs Inc.

4) ThingPark Wireless from Actility

5) Ultra Narrow Band from various companies including Telensa, Nwave, and Sigfox

6) WAVIoT

ZigBee

ZigBee is an open global standard and is designed specifically to be used in M2M networks. The technology is inexpensive to run and doesn’t require a lot of power, making it an ideal solution for many industrial applications. The technology has a low latency, and a low duty cycle, allowing products to maximize battery life.