# Communication Technologies for Smart Grid: A Comprehensive Survey
## 4 Challenges of Smart Grid Communication
### Security
\begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \multicolumn{5}{c}{**Wireless Communication Technologies**} \\ \hline
**Technology** & **Data Rate** & **Coverage** & **Application** & **Advantages** & **Disadvantages** & **Network Type** \\ \hline WiMAX & 75 Mbps & Up to 50 km & In-home communication & Low cost, & Not widespread, coverage highly low energy & NAN/FAN, WAN line of sight & \\  & & In-home communication, energy monitoring, energy monitoring, energy management, home automation & Mesh capability, mobility, low energy, low cost. & Low data rate, short range, interference & Premise network, NAN/FAN line \\ Z-Wave & 9-40 kbps & Up to 30 m & Wireless mesh network & Mesh capability, mobility, low energy, low cost. & Low data rate, short range, interference & Premise network \\  & & In-come communication, energy appliances, 1.7 Gbps & Up to 100 m & Smart appliances, home automation, SCADA & Good on short distances. & Security & Premise network, NAN/FAN line \\ \multirow{2}{*}{3G} & Up to & & SCADA, & Already existing & Network shared with consumers may result in large coverage & NAN/FAN, WAN line \\  & 42 Mbps & 70 km & & & & \\ \multirow{2}{*}{4G/LTE} & Up to & Up to & SCADA, & Network shared network, high & \\  & 979 Mbps & 16 km & Smart meter reading & security, low cost, & may result in large coverage & NAN/FAN, WAN line  
Section 13 in The personal data act, sets requirements for satisfactory information security [126]. Based on this, the Norwegian Electrotechnical Committee (NEK) emphasizes on the following three aspects in relation to security in SGs: confidentiality, integrity and availability, as well as the following four elements [127]. * Protection against unauthorized access to measurement data on the meter. * Protection against unauthorized retrieval of measurement data. * Protection against tampering or alteration of measurement data. * Ensuring that measurement data is available when needed. Vulnerabilities and threats may also be categorized as consumer threat, naturally occurring threat, individual and organizational threat, impacts on consumer, impacts on availability, financial impacts, and likelihood of attack [128]. NEK recommends that communication in HAN use synchronous encryption AES-128, since the data has fixed length. The end-user have to request the utility company to open up for HAN, and to receive encryption key [129]. In Norway, the Norwegian Data Protection Authority (DPA) has identified several aspects relating to SG and smart metering privacy. Since the smart meters can be linked to an address and home-owner, behavioral information can be traced back to individual person [130]. Earlier SCADA systems were isolated on a separate computer network, but the development towards connecting all devices to the Internet are making the system vulnerable to cyber-attacks [131; 132]. Attacks have been carried out on SCADA networks in the past, some with significant impact to infrastructure and power delivery [133]. Attacks on Smart Grids can occur on all levels, from generation and distribution to home networks, it can be protocol-based attacks, routing attacks, intrusion, malware and denial-of-service attacks (DoS). Successful attacks can lead to grid instability, or in the worst case failure and blackouts [116; 128; 134]. A reliable SG depends on avoiding attacks, or detecting and establishing mitigation measures. Protection should be used within SG for message authentication, integrity, and encryption. Security must also address loss of communication, unauthorized access to network and devices (eavesdropping), network attacks, DoS, Distributed Denial of Service (DDoS), Man-in-the-middle (MITM), and jamming of radio signals [78]. There have been several attacks on power companies in the last years, where some have led to system failure and blackout. In 2006 a nuclear power plant in Alabama, USA failed due to overload on the control system network.