# Logically-Centralized SDN-Based NDN Strategies for Wireless Mesh Smart-City Networks +
## 5 Conclusions and Future Work  
Smart-city environments incorporate a huge amount of nodes deployed in large areas, highlighting the need for efficient multi-hop NDN communication based on appropriate NDN path selection. To address the latter, in this paper, we have discussed two alternative SDN-based NDN strategies, involving a reactive and a proactive solution, extensively evaluated over a real WMN smart-city testbed. We investigated the potential gains of each approach in terms of end-to-end NDN delay performance, considering several use cases and wireless communication conditions. The real experiments demonstrated that i) a reactive approach is preferable in communication environments with frequent network changes since the real-time centralized management increases the network overhead; ii) a proactive solution (e.g., clustering based) may successfully identify wireless routes with high performance and reliability, considering smart-city deployments with stable network conditions.  
In future work, we plan to  
* develops a hybrid-protocol SDN platform involving mechanisms to distinguish between smart-city regions with stable and unstable network communication conditions, deploying accordingly the appropriate NDN path selection strategy.
* extend the controller's decision-making capabilities: (a) involving additional NDN-related parameters, for example, caching information of the intermediate network nodes and (b) elaborating improvements on both (reactive/proactive) NDN path selection strategies, based on AI/ML algorithms.
* validate the proposed NDN path selection approaches over large-scale WMN, with multiple consumers and producers.
* compare experimentally our SDN-based solutions with non-SDN strategies.  
Conceptualization, S.K. and L.M.; Methodology, S.K., S.S., V.D. and L.M.; Software, S.K., S.S. and V.D.; Validation, S.K. and S.S.; Formal analysis, S.K., S.S. and V.D.; Investigation, S.K. and L.M.; Resources, S.K.; Writing--review & editing, L.M.; Supervision, S.S., L.M. and V.T.; Project administration, L.M. and V.T. All authors have read and agreed to the published version of the manuscript.  
This work received funding from EU's H2020 research and innovation programme through the 9 th open call scheme of the Fed4 FIRE+ project (grant agr. num. 732638). It is also co-funded by Greece and the European Union (European Social Fund-ESF) through the Operational Programme \"Human Resources Development, Education and Lifelong Learning\" in the context of action \"Enhancing Human Resources Research Potential by undertaking a Doctoral Research,\" sub-action 2: \"IKY Scholarship Programme for Ph.D. candidates in Greek Universities\".  
Not applicable.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Strategy** & **Advantages** & **Disadvantages** \\ \hline \multirow{4}{*}{**Reactive NDN path selection based on BATMAN protocol**} & Reliability and fault tolerance & Control management overhead \\ \cline{2-3}  & Adaptation to unstable conditions & Need to implement a reliable channel for the control plane \\ \cline{2-3}  & Rapid detection of network changes (e.g., & High complexity, support of small-scale topologies \\ \cline{2-3}  & Rø