Access Congestion Control Mechanism Based on Dynamic Allocation of PRACH Resources

Abstract

With the increase of smart terminal devices, the large-capacity access congestion control mechanism has an important application in the Machine Type Machine (MTC) scenario and is one of the key technologies for 5G applications. With the continuous increase of communication services and network traffic, 5G applications are facing the challenge of a large number of terminals and ultra-low latency and reliable communication. This paper conducts an in-depth study on the Random Access (RA) process of Long Term Evolution (LTE) and establishes a model. On this basis, an access congestion control mechanism based on dynamic allocation of Physical Random Access Channel (PRACH) resources is proposed. The DPRACH studied in this paper (for readability, the dynamic allocation-based PRACH access mechanism is referred to as DPRACH) can ensure a higher access success rate and lower access delay for MTC devices under the same load. Under the premise of ensuring that the low-priority access performance does not decrease, the high-priority access delay of DPRACH has been less than 250 ms, and the success rate of DPRACH high-priority access is higher than that of QoS-Dracon (QoS-based adaptive The RAN overload control mechanism referred to as QoS-Dracon) is 20% higher. Compared with the adaptive access overload control mechanism, it solves the high-priority delay sensitive problem well.