A Comprehensive Survey on Congestion Control Mechanisms For 4G LTE Random Access Channels (RACH)

The rapid evolution of mobile communication systems has significantly increased the demand for wireless network resources, driven by the widespread adoption of data-intensive and real-time multimedia applications such as live video streaming, video conferencing, online gaming, and Internet of Things (IoT) services. Fourth-Generation (4G) mobile networks, particularly the Random-Access Channel (RACH), play a critical role in facilitating initial network access and connection establishment for user equipment. However, the growing number of connected devices has led to increased congestion on the RACH, resulting in access delays, reduced network efficiency, and degraded quality of service. This paper presents a comprehensive survey of congestion control mechanisms developed for the 4G Random Access Channel. The survey examines the primary causes of RACH congestion and reviews the various techniques and strategies proposed to mitigate congestion and improve network performance. Furthermore, it analyzes the strengths and limitations of existing congestion control approaches and summarizes key findings from previous studies. The paper also highlights current challenges, identifies research gaps, and provides recommendations for enhancing congestion management in 4G RACH systems. The insights presented in this survey serve as a valuable reference for researchers and practitioners seeking to develop more efficient and scalable random-access solutions for future wireless communication networks.