Evaluation and Comparison of Anti-Collision Schemes for Contention Based Uplink Small Data Transmission in IoT Networks

IoT is a promising technology offering a reliable and massive connectivity for low-complexity and low-power devices. Especially for passive IoT network, it is densely deployed and very sensitive to power consumption. However, the uplink capacity becomes the main bottleneck of the entire system. In this article, we introduce two anti-collision schemes for contention based uplink small data transmission including OCC-based DSA, and OCC-based CRDSA based on Orthogonal Cover Code (OCC), Diversity Slotted ALOHA (DSA), and Contention Resolution Diversity Slotted ALOHA (CRDSA). Further, we analyze six anti-collision schemes for contention based uplink small data transmission including Slotted ALOHA (SA), DSA, CRDSA, OCC-based SA, OCC-based DSA, and OCC-based CRDSA. Each of these schemes utilizes different anti-collision techniques, such as replicas, code division, and interference cancellation, leading to varied levels of capacity improvements. Moreover, simulation is used to evaluate and compare the performance of these schemes in different scenarios for driving current and future research activities. This simulation offers insights into packet loss ratio and throughput under both low collision and high collision scenarios. Ultimately, it can be observed that all the anti-collision schemes for contention based uplink transmission including SA, OCC-based SA, DSA, CRDSA, OCC-based DSA and OCC-based CRDSA scheme could demonstrates their benefits in specific application scenarios, and OCC-based SA and OCC-based CRDSA scheme show the best performance under almost all the collision scenarios. In the realm of passive IoT networks, OCC-based SA scheme stands out as an effective solution to enhance uplink capacity while maintaining a balance between technological complexity and low collision performance.