## 3 ICT Sub-Systems of the Smart Grid
### Information Management  
The traffic volume of smart grid systems has grown rapidly because of extended business models and service domains, such as gas, water and facility surveillance [6]. Although it was an offshoot of recent power grid systems, the smart grid is required to meet more requirements and has to attain new features. This is because the volume of the generated and consumed data traffic is extremely high when compared to the traditional power grid network.  
Smart grid needs to use real-time analytic engines that enable the analysis of the power network, determine the current state and condition of the power system, predict what may happen and develop an action plan [24,25]. These engines receive data from the utility and external entities, such as weather services, through an advanced metering infrastructure (AMI). AMI is usually a combination of smart meters, data management modules, communication network modules and applications that are specific  
Figure 2: Major ICT application domains in smart grids and their correlation with the grid levels. SCADA, supervisory control and data acquisition.  
to metering and plays a key role in smart grid technology, enabling the enhancement of energy efficiency. Utilities, regulators and policymakers should focus on the consumer-centric architectures for appliance control, the public architecture on which AMI communication is based and the collaborative architecture for content. However, it is evident that choices made by utilities as part of their smart grid deployment strategy and network architecture, which are guided by the policies dictated by state and federal regulatory authorities, may significantly affect the outcome of the smart grid initiatives.  
* Control and management: This is intended to monitor and manage all of the components of the electric power system. For example, their behaviors and performances can be modified and predicted to avoid or address potential emergencies [16; 18; 19; 20; 33]. In the smart grid system, the HES needs to provide dynamic pricing and end-user device management. Meanwhile, the HES needs to find the optimal configuration parameters of the smart grid system, such as the monitoring pattern, business model, network monitoring and network system configuration [6].
* Neighbor area optimization: This is designed to help customers know the real-time prices of power, enabling them to optimize the power usage accordingly [9; 17; 21; 22]. In addition, consumers then become informed participants and can choose different purchasing patterns based on their needs and the Grid's demand, which can ensure the reliability of the electricity supply [5]. Meanwhile, the communication protocol needs to be optimized to provide stable data delivery services in the resource-constrained environment of the NAN [6].  
To realize a stable smart grid, there is a need for information analysis, management and different architectural directions for the smart grid that compares utility-controlled and consumer-controlled energy networks. For instance, with utility control, the intelligence of devices is derived from a central control point via a private utility network. However, with consumer control, these devices use a control system that is located in the home, business or on the Internet, but is ultimately managed by the needs of the consumer [26]. For both of these extremes, in addition to intermediate possibilities, it is important to consider how choices affect the combined efficiency and demand-response application (_i.e._, energy monitoring), as well as support/limit innovation in supporting a responsive energy future. Many utilities have begun smart grid implementation with AMI.