The growth of connected devices has recently forced the demand of its corresponding spectrum to match their communication system needs. The challenge now is to design network architecture to be more energy-efficient by the quality of services they render. This paper introduces Vandermonde sub-space Frequency Division Multiplexing (VFDM), as a recently proposed technique for spectrum-sharing and as candidate to manage the exchange of messages between devices in a smart platform. We also extend our investigations to the coexistence of a two-tier network system for interference management through spectrum-sharing in a time duplex mode (TDM). After comparing the simulation result of both cases, it is shown that the spectrum efficiency performance of multi-user case is higher than the single user case, and this led to the conclusion of the proposed VFDM technique as an efficient real-time solution for next generation mobile technology.