Evaluation of the effectiveness of using early feedback in a two-step random access procedure

In modern wireless network standards, one of the key scenarios is the Internet of Things (IoT). Within this scenario, the Massive Machine-Type Communication (mMTC) scenario is actively used. Massive Machine-Type Communication assumes the operation of a huge number of simple devices (such as temperature, pressure, and light sensors) that rarely transmit small amounts of data. The main requirements for the mMTC scenario are: the ability to process a potentially unlimited number of devices, stable network operation at the required total intensity of message occurrence in the system, and the minimum possible average message transmission delay. In existing networks, various random multiple access procedures are used to meet these requirements: 4-step (4G and 5G networks) and 2-step (5G). The paper provides a brief overview of the 4-step and 2-step procedures and considers the possibility of using early feedback for the 2-step random access procedure.