Besides, all of these parameters can change for different users and services in the same frame [7]. Figure 7.1 shows an example demonstration for single-numerology and multi- numerology communications. The users do not communicate with a base station (BS) with different numerologies in a single-numerology system. Forcing to use only one numerol- ogy does not provide high flexibility to meet several requirements of different users and services [3]. Diversifying the number of parameters increases flexibility [9]. Hence, multi-numerology waveforms enhance flexibility. However, there is a non-orthogonality problem between multiple numerologies because of subcarrier spacing variations [10]. If windowing, filtering, or inter-numerology guard bands is not employed, orthogonality cannot be ensured for multi-numerology OFDM systems [6, 11]. Therefore, there is an important trade-off situation regarding the flexibility and inter-numerology interference (INI) in 5G NR. 5G NR comes with more waveform parameters than the previous generations. Moreover, there are new problem sources such as INI. The importance of controlling mechanisms in medium access control (MAC) layer (e.g. parameter optimization, scheduling, radio resource control, evaluating feedback signals and measurements) increases. Through multi-numerology based 5G systems, waveform studies become directly related with scheduling, resource allocation, and radio access network (RAN) slicing [3, 12-27]. Waveform parametrization and waveform parameter assignment are important topics from this perspective. Details of the relationships for different studies are provided in Sections 7.2 and 7.3. This chapter mainly aims to present a vision on waveform parameter assignment con- sidering the current waveform design in 5G NR. The objective of the chapter is to draw attention to waveform parameter assignment by more efficiently employing the available waveform without designing a new one. At that point, multi-numerology concept plays a crucial role in waveform parametrization