物聯網是一種透過網路將各種裝置、感測器及設備連接在一起以實現即時數據交換與智慧管理的技術架構。在此系統中，閘道器扮演著關鍵的中介角色，其負責通訊轉換、數據傳輸及安全管理，從而使異質設備間得以協同運作，形成完整的監控與管理系統。物聯網技術的應用範圍涵蓋智慧城市、工業自動化、能源管理等多個領域，其中電力監控系統為具代表性的應用實例之一。本研究採用一款硬體規格較低階，且能耗也較低的物聯網閘道器實作電力設備即時能耗數據收集，搭配適用於物聯網系統且支援發佈-訂閱機制的通訊協定來提升閘道器與能源管理系統之間雙向通訊的即時性，藉以減輕傳統主從式架構常見的連線資源浪費與多餘的訊息開銷以達成輕量化之目的，並且在通訊當中導入傳輸加密協定來改善資料傳輸的安全性。最終，我們在這個基礎之上，將閘道器整合至一個基於終端設備數訂閱制及支援預付費電度儲值的能源管理系統，讓消費者可即時關注能源使用狀態以利控制能源花費支出，幫助使用者達到能源使用效率最佳化。

The Internet of Things is a technology architecture that connects various devices, sensors and equipment through the Internet to achieve real-time data exchange and intelligent management. In this system, the gateway plays a key intermediary role, it is responsible for communication conversion, data transmission and security management, so that heterogeneous devices can work together to form a complete monitoring and management system. The application scope of IoT technology covers smart cities, industrial automation, energy management and other fields. Among them, the power monitoring system is one of the most representative application examples. In this work, we aim to use an IoT gateway with lower hardware specifications and lower energy consumption to collect real-time energy consumption data from terminal devices, and we introduce a communication protocol that supports publish-subscribe mechanism for IoT systems to enhance the real-time bidirectional communication between the gateway and the energy management system. This reduces the waste of connection resources and message overhead in the traditional master-slave architecture to achieve lightweight. Also, we introduce transmission encryption protocols in communications to improve the security of data transmission. Finally, based on this foundation, we integrate the gateway into an energy management system based on terminal device subscription and supporting prepaid electricity credit prepayment, so that consumers can pay attention to their energy usage status in real time to control energy expenditure and help users achieve optimal energy efficiency.

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