ation of NOMA is conditioned on whether D2D-Coop is required by the offloaded macroU. NOMA at the femtoBS tier supports the offloaded users from the macroBS tier, whereas at the D2D tier, NOMA is useful to perform D2D-Coop. It is observed that using the proposed D2D- Coop the performance of offloading in HetNet can be further enhanced and therefore is suitable for the 5G and beyond networks. Furthermore, offloading with NOMA leads to massive connectivity, which is vital for the 5G and beyond networks. References 1. Z. Xiang, W. Yang, Y. Cai, Z. Ding, Y. Song, Y. Zou, NOMA-assisted secure short-packet communications in IoT. IEEE Wirel. Commun. 27(4), 8-15 (2020) 2. X. Liu, B. Lin, M. Zhou, M. Jia, NOMA-based cognitive spectrum access for 5G-enabled internet of things. IEEE Network 35, 290-297 (2021) 3. C.-X. Wang, F. Haider, X. Gao, X.-H. You, Y. Yang, D. Yuan, H.M. Aggoune, H. Haas, S. Fletcher, E. Hepsaydir, Cellular architecture and key technologies for 5G wireless com- munication networks. IEEE Commun. Mag. 52(2), 122-130 (2014) P. Swami and V. Bhatia 4. Z. Wei, J. Yuan, D.W.K. Ng, M. Elkashlan, Z. Ding, A survey of downlink non-orthogonal multiple access for 5G wireless communication networks (2016). Preprint r Xiv: 1609.01856 5. M. Giordani, M. Polese, M. Mezzavilla, S. Rangan, M. Zorzi, Toward 6G networks: use cases and technologies. IEEE Commun. Mag. 58(3), 55-61 (2020) 6. R. Mitra, V. Bhatia, Precoded chebyshev-nlms-based pre-distorter for nonlinear led compensa- tion in noma-vlc. IEEE Trans. Commun. 65(11), 4845-4856 (2017) 7. Y. Saito, Y. Kishiyama, A. Benjebbour, T. Nakamura, A. Li, K. Higuchi, Non-orthogonal multiple access (NOMA) for cellular future radio access, in IEEE Vehicular Technology Conference (VTC Spring) (2013), pp. 1-5 8. Z. Ding, P. Fan, H.V. Poor, Impact of user pairing on 5G nonorthogonal multiple-access downlink transmissions. IEEE Trans. Veh. Technol. 65(8), 6010-6023 (2016) 9. K.S. Gilhousen, I.M. Jacobs, R. Padovani, A.J. Viterbi, L.A. Weaver, C.E. Wheatley, On the capacity of a ce