# Future Generation 5G Wireless Networks for Smart Grid: A Comprehensive Review
## 4 Smart Grid and 5G
### Challenges of 5G Based Smart Grid Networks  
Even though 5G networks have great potential to be used as the communication technology in smart grids, these systems have not been fully adopted in practice due to the following challenges. In a conventional grid, due to the predictability of both the end user energy pattern and the generation system (such as thermal and hydro-electric systems), it is much more manageable to schedule the appropriate generation as the demand. The main challenge a smart grid network faces is the unpredictably large number of small generation stations and the fluctuating energy consumption at the end user level. Moreover, the demand side and the supply side of the conventional grid are mutually exclusive. With respect to smart grids, the end user becomes the producer as well. The communication technique involved in smart grids should be able to control up to the end user level. The main challenge in introducing any new technology is standardization. The 5G network is expected to be standardized by 2020. a new technology must have the interoperability and backward compatibility with existing technologies. The existing infrastructure should be affordably utilized, and modifications must be made in order to make it compatible with 5G standards. The fundamental requirement of any wireless network is not only its spectral efficiency but its effectiveness of energy parameters as well. The emergence of the 5G network will lead to a multi-fold increase in the number of connected devices. This will lead to a significant rise in the power consumption by the network. Thus, it is crucial to implement a sustainable network with renewable power sources, optimum utilization of power, and minimum power leakage. Authentication of network devices is crucial in any network and requires a hundreds of milliseconds delay in the existing system. This will become a problem in a 5G network [107], as it assures zero latency. There is a trade-off between the latency and the security with the privacy provided by the network. The threat of cyber-attack is one great challenge that the communication network should take care of. Survival of the power-down circumstances and the black start capability is the main concern for any electric network, because unavailability of electric power for even a short duration of time is intolerable [97; 98; 99; 100]. This requires 5G technical solutions that enable switching between different communication technologies, thereby guaranteeing seamless and real-time delivery of information. Scalability [93] can be defined as the ability of a system to manage the increasing needs in an optimal way. For security concerns, in smart grids with reliable infrastructure (which leads to developing smart grid architecture), Supervisory control and data acquisition (SCADA) provides necessary adaptability. SCADA provides increased security [49; 50; 51] Considering SCADA, the process involves three main units--human machine interface, remote, and master terminal unit [52]. The SCADA system in a smart grid brings more secure communication modules that resolve transmission sources to a greater extent. It also provides many security awareness mechanisms to build secured key management with group communications. It provides secured localization with the necessary authenticity and integrity to a greater extent for secure communication structures. The need for bidirectional transmittance of data transfer proves that SCADA is an important concern for self-healing property. The required entities in a smart grid with SCADA show a way for high reliability [49] wireless networks such as 5G to provide an advanced level between the communication channels. The primary requirement for achieving scalability is proper network planning in order to find and utilize the adequate capacity required to accommodate future requirements [98]. Additionally, the smart grid should be able to operate independently in case of a limited availability in critical situations.