Integrated Grant-Free Scheme for URLLC and mMTC

摘要

In this paper, we study a grant-free (GF) scheme to efficiently support the IoT user equipments (UEs). Compared with the existing studies regarding the GF schemes where only one type of the IoT UEs is considered, we develop an integrated GF scheme to support both the ultra-reliable low-latency communications (URLLC) and massive machine type communications (mMTC) UEs. Specifically, the proposed integrated GF scheme provides high reliability and low latency for the URLLC UEs by adopting both the contention-based (CB) and contention-free (CF) transmissions, while also supporting the mMTC UEs by adopting the CB transmission. We evaluate the performance of the proposed integrated GF scheme with the ns-3 simulator. Simulation results show that our integrated GF scheme is able to support the both types of the UEs effectively, and especially, the URLLC UEs can achieve high success rate and low latency compared with other GF schemes.