LTENBERGER-1.pdf.Accessed Jan 2021 217. SCF, 5G FAPI: PHY API Specification (2020). https://scf.io/en/documents/222_5G_FAPI_ PHY_API_Specification.php. Accessed Jan 2021 218. F. Kaltenberger et al., OpenAirInterface: democratizing innovation in the 5G era. Comput. Netw. 176 (2020) 219. SCF, 5G nFAPI specifications (2020). https://scf.io/en/documents/225_5G_nFAPI_ specifications.php. Accessed Jan 2021 220. Network simulator-3 (2020). https://www.nsnam.org/. Accessed Feb 2021 221. P. Solis, D4.4 Cognitive MAC Simulation, Evaluation and Optimization. 5G-RANGE Research and Innovation Action (2019). http://5g-range.eu/wp-content/uploads/2018/04/D4. 4_final.pdf.Accessed Dec 2020 222. N. Patriciello, S. Lagen, B. Bojovic, L. Giupponi, An E2E simulator for 5G NR networks, in Elsevier Simulation Modelling Practice and Theory (SIMPAT) (2019) C. Felber, Prototyping wireless systems with NI SDR and open source stacks (2019). https:// www.openairinterface.org/docs/workshop/8_Fall2019Workshop-Beijing/Talks/2019-12-054 FELBER.pdf. Accessed Dec 2020 224. R. Gupta et al., NS-3-based real-time emulation of LTE testbed using LabVIEW platform for software defined networking (SDN) in CROWD Project. Association for Computing Machinery (2015). 225. MathWorks, 5G Development with MATLAB. eBook (2020) 226. Mosaic5G, Enabling Agile 4G/5G Service platforms (2018). https://mosaic5g.io/resources/ mosaic5g.pdf. Accessed Jan 2021 227. 3GPP TR 28.801, Study on management and orchestration of network slicing for next gener- ation network (2018). https://www.3gpp.org/ftp//Specs/archive/28_series/28.801/. Accessed Feb 2021 228. ONF, Broadband Projects (2021). https://opennetworking.org/onf-broadband-projects/ Accessed Feb 2021 229. ONF, CORD Project (2021). https://opennetworking.org/cord/. Accessed Feb 2021 Chapter 2 Information Flows at the Deep Physical Check for updates Layer Level Marco Donald Migliore 2.1 Introduction 5G has introduced many technological advances over previous generations of cellu- lar communication systems. Among these, one