Methods for Cellular Network's Operation in Unlicensed mmWave Bands

The 5G New Radio (NR) specifications by 3GPP include millimeter wave (mmWave) based operations for high data rates. To further satisfy the ever increasing demand for data rates, 5G NR can also be operated on the unlicensed mmWave bands. In this direction, various channel access schemes that consider Listen Before Talk (LBT) and Listen Before Receive (LBR) have been proposed in the literature. However, a thorough comparison of these schemes for fair coexistence with 60 GHz WiFi, also termed as WiGig, in different scenarios is needed. Hence, in this paper, we compare the performance of a combination of omni-directional and directional channel access schemes with LBTILBR/both in the presence of a realistic mmWave array antenna pattern, 3GPP mmWave Indoor path loss model, and fixed backoff mechanism for collision avoidance. Through extensive simulations, we show that the directional LBT combined with directional LBR and omni-directional LBT schemes perform better than other schemes in terms of sum rate, mean rate, and minimum rate in the system. Moreover, directional LBT performs better in terms of number of channel access and proportional fairness in the system as compared to other channel access schemes.