The new radio (NR) is a new study item in the 3GPP radio access network (RAN) working group and will be an enabler for the forthcoming 5G cellular networks. The 5G network focuses on enabling a seamlessly connected society that brings together people along with things, data, applications, transport systems and cities in a smart networked communications environment.
Evolution of LTE and 5G
Many of the applications and use cases envisioned for the 5G are expected to be supported by the evolution of LTE as well. By supporting 5G applications and use cases with the evolution of LTE, these applications and use cases can then be provided within the existing traditionally used sub-6GHz spectrum while still supporting legacy devices in that spectrum and hence ensuring backward compatibility.
Single Framework, Multiple Usage Scenarios
The new radio (NR) specification targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including for enhanced mobile broadband (eMBB), massive machine-type-communications (mMTC) and ultra-reliable and low latency communications (URLLC).
Mixing OFDM Numerologies
NR supports multiple numerologies derived by scaling a basic subcarrier spacing. The numerology used can be selected independently of the frequency band although it is assumed not to use a very low subcarrier spacing at very high carrier frequencies. NR also supports multiplexing different numerologies in TDM and/or FDM manner for both downlink and uplink.
In LTE, primary and secondary synchronization signals, cell-specific reference signals or system information are always transmitted by the base station. This “always-on” behavior may lead to increased interference and inefficient network operation. The introduction of the 5G NR, not constrained by backward compatibility to earlier technologies, can enable flexibility to design an ultra-lean radio access technology.