# Enabling Heterogeneous IoT Networks over 5G Networks with Ultra-Dense Deployment--Using MEC/SDN
## 3 IoT/5G System Structure
### Radio Access Network (RAN)  
#### 3.1.1 Heterogeneous IoT Networks  
Heterogeneous IoT networks, e.g., low-power wide-area networks (LPWAN), can be connected to the 5G cellular system via MEC servers, as presented in Figure 2. Each IoT gateway is connected to a MEC server via a fiber-wireless, FiWi, connection. The MEC server, deployed for IoT networks, is referred to as the I-MEC server. The introduction of MEC technology to the edge of the access networks of IoT networks achieves various benefits [16]. MEC servers, connected to IoT gateways, provide computing resources, e.g., processing and storage, to IoT devices; one communication hops away. This reduces the communication latency, increases the system availability and reduces the load on the core networks. Furthermore, the introduction of the I-MEC servers achieves higher efficiency in terms of energy, scalability and reliability. Since I-MEC servers provide computing resources near to end-devices, this reduces the load on the end devices, which reduces the consumed energy. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Ref.**} & \multicolumn{4}{c}{**Key Enabling Technology**} & \multirow{2}{*}{**IoT Network**} & \multirow{2}{*}{**Application**} & \multirow{2}{*}{\
\begin{tabular}{c} **Performance** \\ **Metrics** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Cellular** \\ **Integration** \\ \end{tabular} } \\ \cline{2-3} \cline{5-8}  & **Fog/MEC** & & & & & & **Reliability** \\ \hline
[24] & \(\surd\) & X & \(\surd\) & Any & General & Latency & X \\ \hline
[25] & \(\surd\) & X & X & Any & General & Data analysis & X \\ \hline
[26] & X & \(\surd\) & X & Any & General & Energy & X \\ \hline
[27] & \(\surd\) & X & X & Any &
\begin{tabular}{c} Autonomous \\ vehicles \\ \end{tabular} & Latency & X \\ \hline
[28] & \(\surd\) & X & X & Any &
\begin{tabular}{c} Time-critical \\ apps. \\ \end{tabular} & Latency & X \\ \hline
[29] & \(\surd\) & X & X & Any & Medical & Energy & X \\ \hline
[30] & \(\surd\) & X & X & Any & General & Latency & X \\ \hline
[31] & \(\surd\) & X & \(\surd\) & Any & General & Security & X \\ \hline
[32] & \(\surd\) & X & X & LoRaWAN &
\begin{tabular}{c} Low latency \\ apps \\ \end{tabular} & Energy & X \\ \hline
[33] & \(\surd\) & X & X & Any & General &
\begin{tabular}{c} Spectrum \\ Data \\ management \\ \end{tabular} & X \\ \hline
[34] & \(\surd\) & X & X & LPWAN & General &
\begin{tabular}{c} Resource \\ provisioning \\ \end{tabular} & X \\ \hline
[35] & \(\surd\) & X & X & WAN-IoT & \
\begin{tabular}{c} Time- \\ sensitive \\ \end{tabular} & Resources & X \\ \hline IoT/5G & \(\surd\) & \(\surd\) & \(\surd\) & Any & General &
\begin{tabular}{c} Scalability \\ Energy \\ \end{tabular} & \(\surd\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._Figure 1: System structure of (IoT)/5G. Figure 2: Heterogeneous IoT networks connected to 5G edge servers. MEC servers provide resources for existing and upcoming devices and thus increase the overall system scalability. Furthermore, the edge server can be scaled in terms of resources, e.g., storage and processing, to handle more traffic of new devices. Our main contribution is to integrate the heterogeneous IoT networks with the 5G cellular system, which is achieved efficiently by the proposed MEC-based structure introduced in Figure 2. The introduction of edge computing, i.e., I-MEC, to the access networks of the IoT networks provides an interface to the cellular networks since the I-MEC server is connected to nearby MEC servers of the cellular networks, which makes the IoT data available at the edge of the RAN of cellular networks. For managing the data offloading process, we develop an energy-aware offloading scheme for the proposed MEC-based IoT structure. The proposed offloading scheme is based on our developed energy-aware offloading algorithm for multilevel MEC-based 5G systems, presented in [36].