Internet of Things Network Study By Masters in Embedded and Cyber-Physical Systems Research Advisor Dan Cregg Team members Ta-Yu Chiu Neha Sadhvi Yidi Fan Ricky Yang Contents 1.Thesis Statement 3 2. Introduction 3 3. Objectives 3 4. Equipment and Devices 3 5. Network Protocols in Study 4 6. Testing Environment 6 7. Number of devices under Test 6 8. Network Layer Frequency 6 9. Physical Layer Frequency 6 10. Test Setup 7 11. Results 8 12. Constraints 13 13. Conclusion 14 14. References 14 15. Acknowledgements 15 16. Contacts 15 1.Thesis Statement As the use of smart embedded devices grows in our daily life, current networking technologies are expected to be strained beyond their original intent. Consumers face unacceptable performance as nodes are increased and network bandwidth is consumed in physically constraining environments. Various network types and use cases, thus, are explored to determine current failure points in common IoT home smart devices. 2. Introduction At the time of this report, there has been an unprecedented uptake in the use of ‘smart’ devices in the home. The introduction of voice recognition platforms such as Google Home and Amazon Alexa has fueled the use of small, inexpensive, connected sensing and control devices. Controls for Heating and Air Conditioning have been popular, as well as various sensors for doors, windows, etc.. Perhaps the most pervasive has been the acceptance of these types of systems for lighting control. Due to the sheer number of nodes available in a home, lighting nodes to be controlled is very large. This research will focus on various types of network technologies with the goal of physically simulating small to large sets of devices to determine acceptable response time. 3. Objectives In order to determine acceptable consumer performance levels and evaluate selected IoT network protocol, we severely tested the 4 well-known wireless network protocols under various real environmental conditions. We also tested these protocols for its scalability by connecting at least 40 devices to the same network to study its performance. To best simulate a typical use case, it is expected that the devices would not all be expected to be at the exact same state (light level for example) and therefore, direct or individual commands were used as required. 4. Equipment and Devices ❏ ESP-32 WiFi / Bluetooth module ❏ Insteon 2457D Plug-in Dimmer Module ❏ Insteon Hub ❏ Insteon Powerline Filter ❏ Philips Dimmable LED bulb ❏ 120VAC-5VDC USB power supplies ❏ STE3000 RF Test Shielded Enclosure ❏ Philips Hue connect LED bulb ❏ Philips Hue Bridge Equipment used for Network Protocol Testing 5. Network Protocols in Study ● Bluetooth : Bluetooth is a wireless technology for wirelessly exchanging data over short distances using ultra-high-frequency radio waves. Technically, Bluetooth operates in the 2400-2483.5 MHz range within the ISM 2.4GHz frequency band [1]. This technology was designed to eradicate the use of chords, cables etc. when the devices are in close proximity to each other. However, Bluetooth was originally designed for continuous, streaming data applications; in other words, it is better to apply this technology in the audio, or video transmitting. Thus, the applications of Bluetooth technology in IoT mostly tend to be like a wireless speaker, files transfer between devices, or wireless headsets. On the other side, BLE (also known as Bluetooth Low Energy) is more widely used in the domain of IoT. Thus, we adopt BLE for our testing. For BLE, it also operates the same frequency band as Bluetooth. The reason why we use BLE is that in most cases, smart home devices are mostly dealing with the very simple messages like just turn on/off of appliances, or discrete messages. All of these operations are very simple for not only users but also devices. For instance, if a user wants to operate his/her air conditioner, he/she just needs to issue a message, like “ON” signal to the device, from his phone, and the device just needed to make sure it can receive the message and turn itself to ON status. Furthermore, BLE remains in sleep mode constantly except for when a connection is initiated [2], which can largely decrease the power consumption if we are compared with classic Bluetooth. ● Insteon : With the advent of the IoT industry, lots of wireless protocols are being used in this field and each one is trying their best to make themselves more attractive in this large and competitive market. Insteon, which is also a very popular wireless protocol for IoT, is started in 2005. With years and years of efforts on improvements and adjustment, Insteon protocol is becoming a very powerful and effective wireless protocol. For its technology, Insteon adopts a dual-band technology in which it uses both powerlines as well as wireless technology which allows the signal to travel further without interruption, resulting in a lower effective data loss [3]. Moreover, the use of a simulcast mesh network allows better scalability to adapt to a future of automated homes. To be more concise, every device can repeat messages across the network, eliminating the bottlenecks that occur when a single device fails in a routed network [3]. Also, because of dual-band technology, the mesh network extends over both wireless and wired Insteon devices, which can dramatically lower the data miss rate. ● Wi-Fi : Wi-Fi is a popular wireless networking technology which could provide high-speed internet and network connections using radio waves. It’s frequently used for the wireless local area networking (WLAN) of devices which is based on the IEEE 802.11 family of standards. [4]Wi- Fi technologies have a broad implementations on devices including desktops, laptops, smartphones and smart home devices. Compatible devices can connect to each other over Wi-Fi through a wireless access point as well as to connected Ethernet devices and may use it to access the Internet. Such an access point has a range of about 20 meters (66 feet) indoors and a greater range outdoors. [5]For instance, the coverage of Wi-Fi can be as small as a single room with walls that block radio waves, or as large as many square kilometres achieved by using multiple overlapping access points. Nevertheless, Wi-Fi is potentially more vulnerable to attack than wired networks because anyone within range of a network with a wireless network interface controller can attempt access. To overcome the problem, Wi-Fi Protected Access (WPA) is established to protect information moving across Wi-Fi networks and includes solutions for personal and enterprise networks. Security features of WPA have included stronger protections and new security practices as the security landscape has changed over time. ● ZigBee : Zigbee is an IEEE 802.15.4-based specification for a suite of high-level communication protocols used to create personal area networks with small, low-power digital radios, such as for home automation, medical device data collection, and other low-power low-bandwidth needs, designed for small scale projects which need wireless connection. Hence, Zigbee is a low-power, low data rate, and close proximity wireless ad hoc network. The technology defined by the Zigbee specification is intended to be simpler and less expensive than other wireless personal area networks (WPANs), such as Bluetooth or more general wireless networking such as Wi-Fi. Applications include wireless light switches, home energy monitors, traffic management systems, and other consumer and industrial equipment that requires short- range low-rate wireless data transfer. 6. Testing Environment ● Open Area Scenario: No obstacle in between the devices; in other words, all devices are placed in the same room along with the controller. ● Common Residential Scenario: To simulate a common house with a wooden wall, we kept all the 40 devices in the same closed room and kept the controller in the different room to test the penetration capacity of the protocols through the walls of the room. ● Concrete Material Scenario: To simulate a scenario where the signal penetrates through the concrete material and measure each protocol’s performance. We kept all of the 40 devices on the second floor and used the controller from the first floor to test the performance of each protocol via the concrete floor material. ● Metal Material Scenario: Server devices at placed inside a metal box to test each protocol under the most extreme conditions. This scenario is not likely to happen in real life, but it is a good measurement to measure each protocol in the worst possible conditions. ● Real Home Environment Scenario: Controller and all the 40 devices are scattered around different places inside the real home to test each protocol’s performance in the presence of all of the above-mentioned materials i.e. wood, concrete, metal and many other materials generally available in the house. 7. Number of devices under Test ● Bluetooth: 40 ● Insteon: 40 ● Wi-Fi: 40 ● Zigbee: 40 8. Network Layer Frequency ● Bluetooth: 2.4 GHz ● Insteon: 915 MHz ● Wifi: 2.4 GHz ● Zigbee: 2.4 GHz 9. Physical Layer Frequency ● Bluetooth: None ● Insteon: 132KHz Powerline ● Wifi: None ● Zigbee: None 10. Test Setup ● Bluetooth: For the Bluetooth devices, there can be various different topology set up that could be used, like point-to-point, broadcast and mesh network topology. For our testing, we selected the point-to-point network topology to best simulate a home use-case. We used 40 ESP32 microcontrollers having a BLE module as clients to receive the data of turning on the onboard LED from the server(controller) which is again an ESP32 module. The server sends the data to turn on the light one by one to each of the 40 devices. For this, in our project, we used C++ programming language for the development work and used Arduino as our Integrated Development Environment (IDE) to write and embed code into each of our 40 devices and one server.