This book provides a comprehensive exploration of both fundamental principles and practical engineering techniques. It places a strong emphasis on several key areas, including load balancing for IoT sensor devices through effective network management to ensure robust communication reliability among these sensor devices. It also delves into the intricacies of efficient charging scheduling for sensor devices, using probabilistic approaches and integrated sensing and communication technologies to enhance network optimization. Central to the book's goals is its comprehensive and systematic treatment of practical challenges in IoT network optimization. This focus makes it particularly suitable for readers seeking practical solutions in this area. The book's target audience includes researchers, engineers, graduate students, and IoT industry professionals interested in areas such as reliability improvement, load balancing, charging scheduling, and network management. By providing both theoretical foundations and practical insights, this book serves as a valuable resource for those seeking to navigate the complexities of IoT network optimization.