# Software Defined Networks in Wireless Sensor Architectures
## 6 Conclusions and Future Works  
### Conclusions  
We have shown in this paper a review and a taxonomy of existing Software Defined Networking (SDN) technology. SDN is considered to be one of the most important advances in network technologies due to its revolutionary architecture and the network management that it offers. It also plays an important role in other kinds of technologies, improving its performance, reliability and scalability. Different technologies and their main challenges have been discussed in this paper. They differ in terms of organization but look for the same features: resource allocation and efficient management of the network. In conclusion, decoupling both planes (control and data) provides advantages and solutions for each technology presented in this paper. Next, we resume the primary conclusions for each technology and the solutions to their challenges including the SDN model. SDN has removed the rigidity in the traditional networks decoupling control and data planes. Moreover, SDN has managed the constant changing of functions and improved a unified view within the network. Therefore, SDN provides scalability, flexibility, and centralized control to achieve the best performance in the network. Virtualization is identified as an integrated component of programmable networks where different networks can share the same physical underlying infrastructure. Then, there is a need to achieve an efficient virtualization strategy since it is an open challenge. WSNs have been developed due to the need of executing specific applications. Moreover, WSNs have attracted the research community interest due to its versatility to execute several applications using the same hardware. Environmental monitoring, health monitoring and industrial monitoring are the main applications of WSNs. The main field of WSN applicability is the environmental monitoring among others as earth sensing monitoring, air pollution, fire detection systems, natural disasters detection systems [51], and volcano eruption systems [52]. Therefore, WSNs are very used to monitoring environments due to its versatility and mobility to be deployed everywhere. Regarding the health care field, medical applications [49] are able to detect diseases in an early stage in order to \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Reference** & **Proposal** & **OpenFlow** & **Scalability** & **Data Plane** & **Resource Allocation** \\ \hline
[73] & SoftRAN & X & X & RAN & ✓ \\
[77] & SoftMobile & X & X & RAN & ✓ \\
[78] & SoftCell & X & ✓ & CN & X \\
[79] & SoftAir & ✓ & X & RAN and CN & ✓ \\
[80] & MyNet & X & X & RAN and CN & ✓ \\
[82] & CMaaS & ✓ & X & RAN & ✓ \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Differences between Software Defined Sensor Networks. perform a treatment to the person that is being monitored. Security in WSN [49] is also important to send data across the network in a secure way. The union of WSN and SDN into SDSN has supposed important progress in the field of environmental monitoring topologies. We have described three types of SDN-based solutions in terms of their features: multi-application, energy optimization and task distribution. Regarding multi-application solutions [14], Sensor OpenFlow [13] is a SDN-based solution sensor network that provides multi-application environment on a physical network and also a compatible protocol to support multi-vendor data plane resources. Regarding energy optimization, SDN-WISE [67] is an extension of Sensor OpenFlow that looks for an efficient energy use through cycle of works and data aggregation. The last group belongs to task distribution solutions. We have included in this group a proposal called Smart [69] that offers an optimized energy use through task distribution between data and control planes. Regarding Wireless Cellular Networks, we have described its architecture and the main problems that present this kind of network. Moreover, SDN solutions have been proposed to solve the challenges as resource allocation and scalability.