) (2019), pp. 1-7 156. M. Karimzadeh-Farshbafan, V. Shah-Mansouri, D. Niyato, A dynamic reliability-aware service placement for network function virtualization (NFV). IEEE J. Sel. Areas Commun. 38(2), 318-333 (2020) 157. I. Sarrigiannis et al., VNF lifecycle management in an MEC-enabled 5G IoT architecture. IEEE Internet Things J. 7(5), 4183-4194 (2020) 158. S. Lange et al., A network intelligence architecture for efficient VNF lifecycle management. IEEE Trans. Netw. Ser. Manag. 18(2), 1476-1490 (2021) 159. ETSI, ETSI NFV API Specifications (2021). https://nfvwiki.etsi.org/index.php?title=APIs specifications. Accessed Dec 2021 160. 5GPPP, On Board Procedure to 5G PPP Infrastructure Projects (2020). https://5g-ppp.eu/wp- content/uploads/2020/04/. Accessed Dec 2021 161. 5G PPP, 5G Exchange (5GEx) project (2021). [Online]. Available: https://5g-ppp.eu/5gex/. Accessed Dec 2021 162. 5G PPP, Cloud-Native and Verticals services5G-PPP projects analysis (2019). https://5g-ppp. eu/wp-content/uploads/2019/09/. Accessed Dec 2021 163. L.U. Khan, I. Yaqoob, N.H. Tran, Z. Han, C.S. Hong, Network slicing recent advances, taxonomy, requirements, and open research challenges. IEEE Access 8, 36009-36028 (2020) 164. 3GPP TS 38.300, NR and NG-RAN Overall Desciption (2020). https://www.3gpp.org/ftp// Specs/archive/38_series/38.300/. Accessed Jan 2021 165. S. Ahmadi, 5G NR: Architecture, Technology, Implementation, and Operation of 3GPP New Radio Standards (Academic Press, Cambridge, 2019) 1 A Comprehensive Study on 5G 166. D. Sattar, A. Matrawy, Optimal slice allocation in 5G core networks. IEEE Netw. Lett. 1(2), 48-51 (2019) 167. R. Wen et al., On robustness of network slicing for next-generation mobile networks. IEEE Trans. Commun. 67(1), 430-444 (2019) 168. X. Shen et al., AI-assisted network-slicing based next-generation wireless networks. IEEE Open J. Veh. Technol. 1, 45-66 (2020) 169. 3GPP TS 23.501, System architecture for the 5G system (2020). https://www.3gpp.org/ftp// Specs/archive/23_series/23.501/. Accessed Jan 2021 170. I