Rate-adaptive refers to a research area focused on developing algorithms and techniques that enable adaptive and dynamic adjustment of data transmission rates in communication networks. This can help optimize network performance by allowing data rates to be adjusted based on changing network conditions, such as congestion levels, signal strength, and available bandwidth. Rate-adaptive techniques are commonly used in wireless networks, video streaming applications, and other communication systems to ensure efficient and reliable data transmission. Researchers in this area aim to develop innovative strategies for dynamically adjusting data rates to enhance network performance and improve user experience.