Abstract:Optical wireless communication (OWC) uses light for wireless data transmission, potentially providing faster and more secure communication than traditional radio-frequency-based techniques like Wi-Fi. However, light's high directionality and its limited penetration ability restrict the signal coverage. To address this limitation, we propose an artificial "optical wireless ether" (OWE) fabric. OWE acts as a reconfigurable electromagnetic (EM) wave-propagating medium, intelligently enhancing the strength of light signals and redirecting their propagation to cover a broader area. Our proposed ether fabric comprises simple optical signal amplification units, called ether amplifiers (EAs), strategically placed in the environment, e.g., on ceilings. The EAs amplify and propagate signals at the analog level and are agnostic to the signal format: Signals propagate wirelessly between the EAs, losing strength due to attenuation during transmission but regaining it as they pass through the EAs. The key challenge in OWE design lies in the fact that, while increasing EA gains can extend signal coverage, it can also create positive feedback loops, resulting in self-interference and amplifier saturation, which distort the signals -- the key challenge in OWE design. This paper presents a systematic theoretical analysis to prevent amplifier saturation while optimizing the performance of OWE in both single-basic-service-set (single-BSS) and multiple-BSS scenarios. Optimization objectives could include signal-to-noise ratio, resource allocation fairness, and mutual interference. Furthermore, we conducted simulations and experiments to corroborate our theories. To our knowledge, ours is the first experimental demonstration of the feasibility of an artificial ether fabric for extending and guiding light propagation, laying a solid groundwork for future development and exploration of OWE.
Abstract:In this article, we introduce LLMind, an innovative AI framework that utilizes large language models (LLMs) as a central orchestrator. The framework integrates LLMs with domain-specific AI modules, enabling IoT devices to collaborate effectively in executing complex tasks. The LLM performs planning and generates control scripts using a reliable and precise language-code transformation approach based on finite state machines (FSMs). The LLM engages in natural conversations with users, employing role-playing techniques to generate contextually appropriate responses. Additionally, users can interact easily with the AI agent via a user-friendly social media platform. The framework also incorporates semantic analysis and response optimization techniques to enhance speed and effectiveness. Ultimately, this framework is designed not only to innovate IoT device control and enrich user experiences but also to foster an intelligent and integrated IoT device ecosystem that evolves and becomes more sophisticated through continuing user and machine interactions.