Toward High-speed and Reliable Next-generation IoT

By 2030, it is projected that the number of Internet-of-Things (IoT) devices will reach approximately 30 billion [1]. This exponential growth in IoT device deployment opens up a large array of innovative applications that utilize the power of high-speed edge and cloud connectivity. Notably, these applications include immersive computing, mixed reality experiences, AI-assisted cyber-physical systems like autonomous vehicles, and smart homes. However, alongside the promising prospects of widespread IoT adoption and emerging applications, two critical challenges arise: cross-technology interference and low data rates. Firstly, as many IoT devices operate in unlicensed frequency bands, they share channels with high-power devices, leading to potential interference issues. Particularly, low-power devices may encounter low Signal-to-Interference-plus-Noise Ratio (SINR) due to this strong interference. Secondly, most IoT devices currently have limited data rates, often restricted to a few kilobits per second [4, 61, 79], or even bits per second [25, 125, 156]in certain cases. However, as wireless applications, such as those found in AR/VR devices, evolve, there is a growing demand for higher data rates to support high-speed applications [106, 111, 135]. Addressing these challenges is crucial to unlock the full potential of IoT technologies and enable seamless connectivity in various domains. This dissertation addresses these challenges by focusing on two key aspects: reliability and high data rate in wireless IoT networks. First, We propose designs that enhance SINR by either avoiding strong interference or nullifying it. G-Bee wisely utilizes a narrow 2 MHz empty spectrum known as the guard band of WiFi to avoid interference from adjacent WiFi channels. This deterministic allocation of the guardband ensures reliable ZigBee communication with a high SINR. Second, we introduce a high-speed mmWave backscatter system capable of achieving Megabits per second (Mbps) data rates. This work utilizes the 802.11ad mmWave WiFi control packet as a query signal to embed backscatter datainto the WiFi packet. Leveraging the 55Mbps data rate offered by the 802.11ad control packet, our proposed mmWave backscatter system achieves Mbps data rates, significantly surpassing existing a data rate of sub-6 GHz IoT. mmWave backscatter system can further be explored to reduce the beamforming overhead in current mmWave WiFi networks, demonstrating its potential for next-generation IoT applications that can enhance existing networks while maintaining ultra-low power consumption. Maintaining high-quality mmWave links for applications like augmented and virtual reality is challenging due to the overhead of continuous beamforming, especially in networks with multiple users and high mobility. We address this with a tag-assisted beamforming system. It uses a backscatter tag attached to mmWave devices to ”offload” beamforming, reducing the time and energy overhead on the mmWave radio. We employ a multibeam tag with a unique pulse position and on-off modulation to simultaneously beamform multiple users. A custom prototype with 360-degree antenna coverage demonstrates its ability to maintain reliable connectivity even in diverse environments with multipath and blockages. This dissertation presents innovative solutions to improve the reliability and performanceof IoT networks, paving the way for future high-speed, low-power IoT applications. Prototypes and evaluations using off-the-shelf hardware validate the feasibility and effectiveness of these designs.

Author

• Chae, Yoon

• backscatter
• IoT
• Next-generation IoT
• Wireless networks

Identifier

hdl:1920/14797

OAI identifier oai:identifier

oai:MARS:1920/14797