Long Term Evolution (LTE) emerges as the promising communication technology for data and voice service in Human to Human Communication (H2H). Currently, LTE network also includes Machine to Machine (M2M) communication. Combining the legacy systems and evolving Machine type devices, increases the access rate to a particular base station leading to congestion in Access network. Congestion in Random Access Network (RAN) that occurs during the Random Access Process affects the performance of H2H communication. The objective of the paper is to analyze the existing congestion control techniques and to provide a comprehensive summary on classified poll and event based mechanisms.