# A Novel Power-Saving Transmission Scheme for Multiple-Component-Carrier Cellular Systems
## 6 Conclusions  
A novel and efficient power-saving scheme for data transmission in multi-CC cellular systems has been proposed and successfully tested. The proposed scheme is more adaptive and flexible than the conventional scheme with regard to SCC usage, while also maintaining the capacity to satisfy the respective minimum required data rates of all the user sessions and simultaneously manage the fairness indexes for different user types. In terms of limitations, it should be noted that the significant gains of the proposed scheme in terms of power consumption come at the expense of some degradation in fairness indexes for the different types of users whenever the traffic load is significantly increased. However, those degradations are always brief, with the fairness levels for the different types of users being re-established within minutes. It is believed that this novel power-saving scheme is an excellent solution to be employed for use in 4G and future 5G multi-CC cellular systems at the BS side for data transmissions. As such, the present work constitutes a reasonable and feasible means of addressing the problems of rising energy costs and CO\({}_{2}\) emissions associated with cellular systems. In the future, we suggest extending the present system model and scheme to a multi-cell environment. Nevertheless, the detailed design of the spectrum management and the transmission performance may need to be re-evaluated. Furthermore, in addition to providing energy savings/efficiency, another key goal of 5G and future cellular systems will be ensuring spectral efficiency [33]. As such, the question of how these two different objective performance metrics can be efficiently coupled and integrated should be given far greater attention in the coming years [34]. Lastly, it is reasonable to believe, in any event, that continued efforts in this research direction may aid in mitigating the problem of global warming by contributing to the establishment of environmental sustainability. Moreover, by conserving and utilizing energy in a judicious manner, various other types of environmental degradation and resource depletion can be avoided or ameliorated.  
\begin{table}
\begin{tabular}{c c c} \hline \hline \(r_{\textbf{req},k}\), \(k\in\Re^{(1)}/r_{\textbf{req},k}\), \(k\in\Re^{(2)}\) & **The Proposed Scheme** & **The Conventional Scheme** \\ \hline
300 kbps/500 kbps & 29.70 W & 59.71 W \\
500 kbps/1 Mbps & 32.15 W & 59.06 W \\
1 Mbps/2 Mbps & 39.16 W & 58.38 W \\ \hline \hline \end{tabular}
\end{table}
Table 1: The average levels of total power consumption, under the proposed scheme and the conventional scheme, when the minimum required data rates for NRT users and RT users are set at different levels given the traffic pattern indicated in Figure 3.  
**Acknowledgments:** The author would like to express his gratitude for the financial support provided by the Ministry of Science and Technology (MOST) in Taiwan, R.O.C. under the Contracts MOST 104-2221-E-019-053- and MOST 104-2218-E-019-004-.  
**Conflicts of Interest:** The author declares no conflict of interest. The founding sponsor had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.