Impact of Backoff Algorithm on IoT over Multichannel Slotted Aloha System

The increasing trend of Internet of Things brings new challenges to efficiently manage the resource in the access network. As a prominent solution to serve IoT services, LTE incorporates a small data transmission scheme for this reason. In this scheme, the overall system performance is greatly influenced by its random access procedure. Hence, studying the behavior of backoff during random access procedure is important. This work implements an iterative contending-user estimation model to analyze the performance of the contention-based random access procedure supporting finite-population. For the sake of generality, the system is modeled as a multichannel slotted Aloha. This allows our model to be used in wider specifications, including LTE and WiMAX systems. The behavior and performance of the system supporting multiple load scenarios is studied under different network loads. The simulation result demonstrates the accuracy of our proposed method to predict the normalized throughput, the packet-dropping probability, and the average access delay of each access-class. The performance of different backoff algorithm to resolve the collision in the system is compared and evaluated.