icates via nFAPI.¹1 Despite the possibility of implementing a 5G E2E network via OAI, it faces several limitations. For instance, OAI does not provide systematic documentations for the installation and configuration of OAI software with the various SDR platforms. Moreover, it provides few documentations to clarify the RAN threads 10 FAPI protocol is standardized by the small cell forum in [217]. 11 nFAPI protocol is standardized by small cell forum in [219]. 1 A Comprehensive Study on 5G and software. In addition, unlike NS-3 that supports several RATs, OAI supports only 3GPP technologies for LTE and 5G. 1.5.1.2 Network Simulator-3 (NS-3) NS-3 [220] is a discrete-event network simulator approved by Academia for various RATs such as Wi-Fi, WiMAX, and LTE. It provides several modules that are developed on C++ under the license GNU GPLv2 [220]. LTE/EPC network simulator (LENA) [211] is one of the modules provided on NS-3 to analyze LTE networks. It supports several features including DL&UL schedulers, radio resource management algorithms, intercell interference coordination, mobility management, and SO on [221]. The E2E architecture for LENA project is composed of UEs, eNBs, and EPC that contains the SGW and PGW functions as well as the UP and CP interfaces [221]. NS-3 provides a 5G NR module that has been built on the top of the mm-wave and LENA modules. The NR module provides several features for the PHY and MAC layers including flexible frame structure of several numerologies and mini- slots, dynamic time division duplex (TDD), mm-wave with beam management- related operations, channel coding models, flexible MAC schedulers, and multiple bandwidth parts (BWP) [211, 222]. Furthermore, NS3 provides a NR-U module for the mm-wave bands. Even though NS-3 provides several RAT modules and does not consider con- straints on the PC requirements, the NR module on NS-3 has several limitations. For instance, it provides PHY layer abstraction based on look-up tables, employs LTE upper layers, and operates on EPC and mm-wave ba