# Communication Technologies for Smart Grid: A Comprehensive Survey
## 4 Challenges of Smart Grid Communication
### Security  
Cyber security is considered to be one of the biggest challenges to SG deployment as the power grid becomes more and more interconnected. With the number of connected devices increasing, the possibility for cyber attacks against the power grid will increase. Cyber security is essential as every aspect of the SG must be secure [112; 113]. Security measures must cover issues involving communication and automation that affects operation of the power system and the utilities managing them. It must address deliberate attacks as well as inadvertent accidents such as user error and equipment failure [112; 13]. SGs are vulnerable to cyber-attacks due to the integration of communication paths throughout the grid infrastructure. SGs are still evolving, and considering security in a new SG environment is important, but challenging. Undetected cyber-attacks can lead to critical damage affecting thousands or millions of customers and life threatening infrastructure [114; 115]. Securing the data is vital for both end-user and power companies to ensure trust. As more functions and capabilities are implemented to the SG importance of secure and safe communication increase. From distributed energy generation, energy storage, electric vehicles to power station and power grid control systems. Additionally, something possibly as trivial as securing that the reading from the end-user's smart meters are sending correct billing information, or that the utilities companies receive the correct information is essential [116]. As for any other communication systems, security enhancement for SG communication can be achieved at different layer of the protocol by utilizing the techniques from the conventional upper layer cryptography [117; 118; 119; 120; 121] to the physical layer security [122; 123; 124; 125]. Different communication technologies, wired and wireless, interconnects and are required to operate the grid securely. Different authorities are responsible securing different data and security aspects in Smart Grid/smart metering. For the Norwegian case:  
* Norwegian Metrology Service: Measurement accuracy
* Norwegian Directorate for Civil Protection (DSB): Electrical safety
* Norwegian Communications Authority: Communication
* Norwegian Water Resources and Energy directorate: Application, function, and safety of smart meters. \begin{table}
\begin{tabular}{l l l l l l l} \hline \multicolumn{2}{l}{**Wired Communication Technologies**} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} \\ \hline
**Technology** & **Data Rate** & **Coverage** & **Application** & **Advantages** & **Disadvantages** & **Network Type** \\ \hline \multirow{3}{*}{Ethernet} & Up to & Up to & In-home communication, & & Good on short & Coverage & Premise network, \\  & 100 Gbps & 100 m & communication & & distances & limitations & NAN/FAN, WAN \\  & & & SCADA, backbone & Existing & & & \\ \multirow{3}{*}{Broadband PLC} & Up to & Up to & communication in & infrastructure, & Noisy channel & \\  & 300 Mbps & 1500 m & power generation & standardized, & environment, & \\  & & & domain & high reliability & Disturbance & \\  & & & SCADA, backbone & & Existing & \\ Narrowband PLC & 10-500 & Up to & communication in power & infrastructure, & Noisy channel & \\  & & & generation domain & & environment, & \\  & & & generation domain & & Disturbance & \\ \multirow{3}{*}{HomePlug} & 4, 5, 10 & Up to & In-home communication, & Low cost, & Coverage & \\  & Mbps & 200 m & Smart appliances & low energy & & \\  & & & & & Disturbance & \\ \multirow{3}{*}{Fiber optic} & \multirow{3}{*}{Up to & Up to & SCADA, backbone & High bandwidth, & \\  & 100 Gbps & 100 km & communication in power & not susceptible to & \\  & & & generation domain & electromagnetic & \\  & & & & interference & \\ \hline \end{tabular}
\end{table} 
Table 6: Overview of wired communication technologies in SG [20, 34, 57, 72, 74].