## 9 Conclusions  
FWA is an attractive scheme for fixed broadband service delivery to homes with irregular or without wired broadband connection both in urban and rural areas. Furthermore, 5G is envisaged to offer an effective platform for true network convergence in which shared infrastructure, and similar technology will be supporting the emerging networks such as IoT, MBB, and FWA. Moreover, 5G technologies implementation is envisaged to offer a considerable performance enhancement compared with the existing mobile networks. Consequently, FWA is expected to leverage the 5G technological improvements to offer cost-effective and enhanced broadband services that are comparable to that of FTTx-type broadband connections. However, 5G FWA implementation requirements will present some challenges on the transport network with regard to the envisaged massive number of the required cell sites to be supported and the resultant increase in the per-site demands. In this paper, we have presented a comprehensive tutorial on the enabling technologies, requirements, prospects, and challenges of broadband solutions and proffer viable solutions on means of achieving an efficient 5G FWA. Furthermore, we have considered several transport network solutions for FWA deployment and their related requirements for different use cases. Moreover, we have presented a comprehensive discussion on the conventional CPRI based fronthaul and consider a number of viable 5G RAN FSOns that are capable of relaxing the associated stringent requirements along with their related trade-offs. Each option entails relatively different QoS requirements regarding throughput and latency that impose certain constraints on the transport network for different deployment scenarios. A vRAN with open and programmable PTNI concepts has been presented for a flexible and scalable evolution of the 5G-based networks. This is an effort to address the stringent and dynamic nature of various system requirements using SDN-aided Netsli with effective preemption. We have also introduced the idea of adaptable FSOn integration into the vRAN not only to facilitate the adoption of innovative technologies and multiplexing gains but also to offer optimal solutions regarding efficient traffic coordination, load balancing, flexible resources allocation, and sharing. This will help in the appropriate adaptation of the transport resources for on-demand resource provisioning with optimal utilization for the 5G FWA networks.  
Conceptualization, I.A.A., N.J.M., A.N.P., A.L.T. and P.P.M.; methodology, I.A.A., R.K.P. and N.J.M.; software, I.A.A. and N.J.M.; validation, I.A.A., N.J.M., A.N.P. and P.P.M.; formal analysis, I.A.A., R.K.P., N.J.M., A.N.P., A.L.T. and P.P.M.; investigation, I.A.A., R.K.P., N.J.M., A.N.P., A.L.T. and P.P.M.; resources, I.A.A., N.J.M., A.N.P., A.L.T. and P.P.M.; data curation, I.A.A., R.K.P. and N.J.M.; writing--original draft preparation, I.A.A. and N.J.M.; writing--review and editing, I.A.A., N.J.M., A.N.P., A.L.T. and P.P.M.; visualization, I.A.A., R.K.P. and N.J.M.; project administration, I.A.A., N.J.M., A.N.P., A.L.T. and P.P.M.; funding acquisition, N.J.M., A.N.P., A.L.T. and P.P.M. All authors have read and agreed to the published version of the manuscript.  
This work is supported by the European Regional Development Fund (FEDER), and Internationalization Operational Programme (COMPETE 2020) of the Portugal 2020 (P2020) framework, under the projects DSPMetroNet (POCI-01-0145-FEDER-029405) and UIDB/50008/2020-UIDP/50008/2020 (DigCORE). It is also supported by FEDER through COMPETE 2020 of the P2020, under Project LandMark (POCI-01-0145-FEDER-031527), ORCIP (CENTRO-01-0145-FEDER-022141), SOCA (CENTRO-01-0145-FEDER-000010), and RETOT (POCI-01-0145-FEDER-016432).  
The authors declare no conflict of interest.