The present document covers the RF, RRM and co-existence aspects of the work item "Air-to-ground network for NR" [2]: The objectives for the study are the following:

• Study and evaluate adjacent channel co-existence for ATG scenarios.
• Study and specify RF core requirements for ATG network and the ATG UE such that ATG deployment are well supported.
• Study and specify RRM requirement supporting ATG network deployment and ATG UE mobility.

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

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Air-to-ground (ATG) network refers to in-flight connectivity technique, using ground-based cell towers that send signals up to an aircraft's antenna(s) of onboard ATG terminal. As a plane travels into different sections of airspace, the onboard ATG terminal automatically connects to the cell with strongest received signal power, just as a mobile phone does on the ground. In this network, a direct radio link will be established between BS on the ground and CPE type of UE mounted in the aircraft. From the trials and commercial operation [https://inflight.telekom.net/ean/] of adapted LTE ATG solutions, some characteristics are considered for ATG network deployment scenarios.

• Extremely large inter-site distance (ISD) and large coverage range: In order to control the network deployment cost and considering the limited number of flights, large ISD is preferred, e.g., about 100km to 200km. At the same time, when the plane is above the sea, the distance between the plane and the nearest base station could be more than 200km and even up to 300km. Therefore, ATG network should be able to provide up to 300km cell coverage range.
• Utilizing non-disjoint frequency for deploying both ATG and terrestrial networks, i.e. same operating band but ATG network and TN use adjacent carriers: Operators are interested to adopt the same frequency for deploying both ATG and terrestrial networks to save frequency resource cost, while interference between ATG and terrestrial networks becomes non-negligible and should be addressed.
• Much powerful on-board ATG terminal capacity: On-board ATG terminal can be much powerful than normal terrestrial UE, e.g., with higher EIRP via much larger transmission power and/or much larger on-board antenna gain.