The Air interface is a communication link between two stations in mobile or wireless communication. The Air interface involves both the physical and data link layers of the OSI (Open System Interconnection) model. It is commonly known as the Physical layer or radio part. Air interfaces possess the ability to broadcast or multicast. Multiple links can be created in the radio spectrum through multiple access technologies like FDMA (Frequency division multiple access), TDMA (Time division multiple access). In cellular telephone communications, the air interface is defined as the radio-frequency portion of the circuit between the cellular phone set or wireless modem and the active base station. As the subscriber moves from one cell to another, the active base changes periodically and the procedure is called a handoff. 5G NR is the new air interface being developed for 5G. 5G NR is being developed to support a variety of services, devices and deployments which 5G will encompass.