This two-volume set constitutes the refereed proceedings of the 25th International Conference on Next Generation Wired/Wireless Networking, NEW2AN 2025, and the 18th Conference on Internet of Things and Smart Spaces, ruSMART 2025, held in Abu Dhabi, United Arab Emirates, during November 2025.

The 55 full papers included in the joint proceedings were carefully reviewed and selected from 178 submissions. They address various aspects of next-generation data networks, with special attention to advanced wireless networking and applications. In particular, novel and innovative approaches to performance and effciency analysis of 5G and beyond systems, advanced queuing theory, and machine learning are demonstrated. Additionally, the papers focus on the Internet of Things, optics, signal processing, as well as digital Economy and business aspects.