# A Survey on IoT-Edge-Cloud Continuum Systems: Status, Challenges, Use Cases, and Open Issues
## 5 Discussion--Open Issues
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Survey Paper** & **Year** & **Contributions** & **Methodology** & **Limitations—Open Issues** \\ \hline
[87] & 2023 & \
\begin{tabular}{c} Cloud-to-Edge-to-IoT \\ Continuum for SAR \\ applications \\ \end{tabular} & NFV, virtual objects at the edge &
\begin{tabular}{c} Advanced AI approaches and \\ computer vision for additional \\ post-disaster scenarios \\ \end{tabular} \\ \hline
[89] & 2023 & \begin{tabular}{c} Integration of multiple use \\ case scenarios in a common \\ architectural approach \\ \end{tabular} & \
\begin{tabular}{c} Reference architecture based on \\ end-edge, net-edge, cloud-edge \\ \end{tabular} &
\begin{tabular}{c} Construction of a multi-tier \\ EC-IoT architecture with one \\ central cloud and multiple \\ edge-clouds with unified \\ regulation and standards \\ \end{tabular} \\ \hline
[90] & 2021 & \begin{tabular}{c} Task offloading for latency \\ minimization \\ \end{tabular} & \
\begin{tabular}{c} Application characteristics and \\ heterogeneity of the \\ infrastructure \\ \end{tabular} &
\begin{tabular}{c} Evaluation in real world \\ scenarios \\ \end{tabular} \\ \hline
[91] & 2021 & \begin{tabular}{c} AI in edge-cloud-IoT \\ environments \\ \end{tabular} & \
\begin{tabular}{c} Sophon edge framework for ML \\ model training and \\ inference \\ \end{tabular} &
\begin{tabular}{c} Distributed ML for latency \\ reduction and privacy \\ enhancement \\ \end{tabular} \\ \hline
[92] & 2023 & \begin{tabular}{c} Interaction between \\ Cloud-IoT environments \\ \end{tabular} & \
\begin{tabular}{c} Cognitive management of \\ services \\ \end{tabular} &
\begin{tabular}{c} Evaluation in real world \\ scenarios and security \\ mechanisms \\ \end{tabular} \\ \hline
[93] & 2016 & \begin{tabular}{c} Software in edge-cloud-IoT \\ environments \\ \end{tabular} & \
\begin{tabular}{c} Model-based approach to \\ automatically assigning \\ multiple software deployment \\ plans to hundreds of edge \\ gateways \\ \end{tabular} &
\begin{tabular}{c} Performance evaluation in \\ additional scenarios apart from \\ e-Health \\ e-Health \\ \end{tabular} \\ \hline
[94] & 2021 & \begin{tabular}{c} IoT application modules \\ placement \\ \end{tabular} & \
\begin{tabular}{c} Particle swarm optimization to \\ acquire the best application \\ module placement strategy \\ \end{tabular} &
\begin{tabular}{c} Extension in multiple IoT \\ application services \\ \end{tabular} \\ \hline
[96] & 2020 & \begin{tabular}{c} Multi-cluster IoT applications \\ \end{tabular} & \
\begin{tabular}{c} Four-layered architecture \\ \end{tabular} &
\begin{tabular}{c} Extension in additional use case \\ scenarios \\ \end{tabular} \\ \hline
[97] & 2021 & \begin{tabular}{c} Optimum cluster usage \\ \end{tabular} & \
\begin{tabular}{c} Task scheduling problem at the \\ edge \\ \end{tabular} &
\begin{tabular}{c} Performance evaluation in real \\ world scenarios \\ \end{tabular} \\ \hline
[98] & 2022 & \begin{tabular}{c} Model fleet deployment \\ \end{tabular} & \
\begin{tabular}{c} Model-based techniques \\ \end{tabular} &
\begin{tabular}{c} Evaluation in real worlds \\ scenarios \\ \end{tabular} \\ \hline
[99] & 2019 & \begin{tabular}{c} IoT platform based on edge \\ and cloud computing for \\ smart agriculture \\ \end{tabular} & \
\begin{tabular}{c} Three-tier open-source software \\ platform at local, edge and \\ cloud planes. \\ \end{tabular} &
\begin{tabular}{c} Performance evaluation in \\ additional farming scenarios \\ \end{tabular} \\ \hline
[100] & 2021 & \begin{tabular}{c} IoT-Edge-Fog-Cloud \\ architecture for agricultural \\ applications \\ \end{tabular} & \
\begin{tabular}{c} Optimization of energy \\ consumption, CO\({}_{2}\) emission, \\ and network traffic \\ \end{tabular} &
\begin{tabular}{c} Machine learning approaches \\ \end{tabular} \\ \hline
[101] & 2018 & IoT-based manufacturing & Interlayer coordination &
\begin{tabular}{c} Performance evaluation in \\ large-scale orientations \\ \end{tabular} \\ \hline
[102,103] & 2019, \begin{tabular}{c} Smart manufacturing based \\ on a three-layered \\ architecture \\ \end{tabular} & \
\begin{tabular}{c} Edge-fog-cloud cooperation \\ Efficient task offloading \\ \end{tabular} &
\begin{tabular}{c} Performance evaluation in \\ large-scale orientations \\ \end{tabular} \\ \hline
[104] & 2020 & IoT-based manufacturing & \
\begin{tabular}{c} Edge computing with \\ blockchain \\ Task assignment based on \\ particle swarm optimization \\ \end{tabular} &
\begin{tabular}{c} Performance evaluation in \\ large-scale orientations \\ \end{tabular} \\ \hline
[105] & 2020 & \begin{tabular}{c} IEC collaboration in smart \\ cities \\ \end{tabular} & \
\begin{tabular}{c} Distributed deep learning task \\ offloading \\ \end{tabular} &
\begin{tabular}{c} Blockchain-based decentralized \\ offloading scheme \\ Metalearning in offloading \\ decisions \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}