# State of the Art and Trends Review of _Smart Metering_ in Electricity Grids
## 2 Trends of the _Smart Metering_ Systems
### Smart Metering Applications  
Beyond management and control, the implementation of a _Smart Metering_ system allows several applications that join the metering data together with additional information and other devices from which both utilities and end-users should benefit. Most of them are currently under development and are experiencing a remarkable growth since 2006 [17]. A summary of the main _Smart Metering_ applications is described below.  
* Electricity signal quality: In the traditional power distribution networks, the control devices are solely located in the substations; however, with the progressive introduction of the _SG_, the complexity and number of required controlled assets increase and more detailed, distributed, and frequent control information is required. _SMs\({}^{\prime}\)_ capabilities of real-time voltage measurement and communication between the consumers and network controllers are potential key players in voltage control [18]. Several projects implementing voltage control techniques include _SM_s in their solutions [19].
* _DG_ and _DS_ control: The control and management of _DG_, especially regarding _RES_, is more complicated than conventional sources due to its less predictable behavior and varying availability. These uncertainties hinder _CCs\({}^{\prime}\)_ operations and represent a barrier for distributed resources in general. _SM_s can help in those issues by providing accurate, frequently-updated, and real-time generation and charge/discharge metering data from _DG_ and _DS_, respectively, which may facilitate _CCs\({}^{\prime}\)_ duties and foster _RES\({}^{\prime}\)_ introduction in electricity grids.
* Billing: _Smart Metering_ systems are necessary in billing applications. The _SM_s get the tariff costs in real time, in advance or through pre-programmed tariffs and then the cost of the supplied energy is calculated. In addition, the _SM_s can remotely cut or restore the power supply if needed. The most common billing techniques are pricing depending on the time of use, real-time pricing, and peak consumption-dependent pricing [9].
* _Demand Response_: The dynamic coordination of the power consumption curve of end-users within existing supplying conditions or _Demand Response_ (_DR_) contributes to the efficiency of the system. Additionally, _DR_ provides an opportunity for consumers to play a significant role in the operation of the electric grid by reducing or shifting their electricity usage during peak periods in response to time-based rates or other forms of financial incentives. Such programs can lower the cost of electricity in wholesale markets, and, in turn, lead to lower retail rates [20].
* HAN applications: The role of _Smart Metering_ in the end-user\({}^{\prime}\)s premises is very promising. From metering data consumers can know and control their electricity consumption. Additionally, a wide range of services is emerging, such as consuming profiles, load control, remote switching of home devices, and remote consumption monitoring, among others. For instance, in [21] the data from domestic energy consumption is used together with an algorithm to establish categories of energy consumers, while [22] contains an analysis of generated energy savings after the installation of _SM_s in Korean homes. Nevertheless, some energy managers are expected to play an important role in the progressive deployment of the _triple play_ (confluence of audio, video, and Internet access).  
Anti-fraud techniques:  
Bypassing or disrupting the internal performance of a _SM_ and using methods to avoid electric bill payment are considered as electrical frauds. Several countries are developing anti-fraud techniques through _Smart Metering_ systems. For instance, [PERSON] _et al._ present in [23] a complex system formed by _SMs_, harmonic generators, and filters that detect and warn users who commit fraud.