ctrum. 3GPP LTE began to explore 5 GHz unlicensed band for offloading cellular traffic in Rel-12. The non-standard LTE-U and standard LAA both use LTE technology as the baseline in unlicensed spectrum anchored on a licensed carrier to increase user throughput and system capacity. It must be noted that LTE-U can only be deployed in selected regions due to lack of LBT support whereas LTE-based LAA uses a similar LBT procedure as IEEE 802.11 systems. In addi- tion to LTE-U and LAA, the standalone operation of LTE in the unlicensed spectrum has been considered by some operators. 1 MulteFire Alliance: https://www.multefire.org 5G NR. DOI:https://doi.org/10.1016/B978-0-08-102267-2.00008-7 © 2019 Elsevier Inc. All rights reserved. 846 Chapter 8 The 60 GHz band has yet to attain significant large-scale industry traction although the specification for IEEE 802.11ad2 system was finalized in 2012. The 60 GHz frequency bands have been used for wireless backhaul and indoor and outdoor point-to-point commu- nication. The unlicensed 5 GHz spectrum provides about 500 MHz of usable bandwidth. A large number of Wi-Fi deployments based on the IEEE 802.11 are in 5 GHz band and are mainly used for broadband indoor applications. Cellular operators actively use Wi-Fi to off- load traffic in dense hotspots using unlicensed spectrum; however, due to a high level of inter-cell interference, Wi-Fi-based offloading scenarios are not attractive for outdoor use cases. Multi-antenna transmission and beamforming with large antenna arrays are some of the key features of the new radio systems, which can benefit the NR-unlicensed operation in the sense that transmission power can be reduced due to highly directional antennas. In addi- tion, directional transmission leads to lower inter-user/inter-cell interference, which in turn improves the coexistence conditions. For typical network deployment where the elevation angle of the antenna is manually tilted to one fixed direction, the maximum antenna gain is only achieved in the tilted elevation dire