## 6 Conclusions  
Motivated by the new RedCap service proposed for 5G NR systems and new UE-side energy conservation mechanisms that allow for skipping synchronization cycles with the BS, in this paper, we developed a framework for the performance assessment of mean SNR, spectral efficiency, and rate attained at a wireless channel under both macro- and micro-mobilities. To this aim, we explicitly accounted for radio pattern parameters by utilizing a 3 GPP standardized antenna model and characterized antenna misalignment caused by the simultaneous displacement of user and UE in the hands of a user over time.  
Our numerical results indicate that the overall time-dependent trend in the investigated metrics is affected by the interplay between the BS antenna radiation pattern and macro- and micro-mobilities. Specifically, macro-mobility manifests itself in different divergence rates of the time-varying spectral efficiency to its mean value specifying the main trend in the considered metric, while the micro-mobility causes rapid fluctuations at much shorter scales, i.e., 1-3 s after the beam alignment. Quantitatively, the difference between spectral efficiency corresponding to perfectly synchronized UE and BS antennas and time-dependent spectral efficiency in a completely desynchronized system is negligible for small cell coverage and stays within approximately 5-10% for a wide range of system parameters. This implies that, opportunistically, the communications can be performed without perfect synchronization between antennas at a slightly degraded quality. The impact of the BS antenna radiation pattern of the time-dependent spectral efficiency is rather limited, resulting in up to 5% of a difference between \(4\times 4\) and \(15\times 15\) arrays. From the modeling perspective, we would like to note that the use of realistic antenna radiation patterns is critical for accurate analysis.  
To the best of the authors' knowledge, the proposed framework is the first one to allow the explicit evaluation of performance metrics of interest as a function of time. Specifically, it can be utilized in applied studies of 5G/6G mmWave/sub-THz systems when evaluating new algorithms and mechanisms whose performance explicitly depends on time. One of the application areas of the proposed framework is the power efficiency assessment of modern energy conservation mechanisms proposed for 5G NR systems, such as wake-up signal (WuS), Radio Resource Management (RRM) Relaxation, and discontinuous reception (DRX).  
Figure 13: Time-dependent gain as a function of the antenna type.  
**Author Contributions:** Conceptualization and methodology, Y.G.; software, E.G. and V.B.; validation, K.S. and D.O.; formal analysis, D.O.; investigation, E.G. and E.M.; writing--original draft preparation, D.O.; writing--review and editing, V.B. and Y.G.; visualization, D.O. and E.M.; supervision, Y.G. and D.O.; funding acquisition, D.O. and K.S. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This paper has been supported by the Russian Science Foundation, project no. 23-79-10084.  
**Data Availability Statement:** The data presented in this study are available in this article.  
**Conflicts of Interest:** The authors declare no conflicts of interest.