# State of the Art and Trends Review of _Smart Metering_ in Electricity Grids
## 5 Challenges to be Addressed in the Near Future  
With the exception of China, the pace of installation of _SM_s will reportedly slow in the short term, due in large part to a decline in the rate of meter rollouts in the United States and delayed implementation of large projects planned for Europe and Brazil [46]. Additionally, as stated by CEER, despite the many years of assessing European standards, Europe still faces a difficult situation because of the lack of a common standard for _SM_s and an absence of interoperability. This leads to a lack of economies of scale and innovation in customer services since _Smart Metering_ should act as an enabler of additional services [50]. This situation complicates the penetration of multinational _SM_ suppliers in certain foreign markets due to the imposition of local manufacturing standards that may require significant product modifications [46]. Although most of the countries have followed at least some of the recommendations listed in Table 2, a common approach should be envisaged for defining _SM_s and their functional requirements. According to the European Commission, the most challenging functionality to deliver relates to the frequency of consumption data update and its availability to consumers and third parties on their behalf [51]. Also data protection and security issues must be addressed. Not all technologies offer the same security levels and this needs to be faced. It is advisable to assess a specific framework and personal data protection must remain a central concern in the development of standards. In addition, most of the _Smart Metering_ communication networks use a low/medium bandwidth, which generates high traffic and limits the quantity of data to be transmitted. Then, more modulation/demodulation devices and additional memory for storing the data logs will be required, with a corresponding increase of costs [83]. In addition, high levels of data traffic may lead to an inefficient system. Techniques such as reduction of data retransmissions and the introduction of hierarchy levels (priorities according to the type of data: measure, control, management, alarm, _etc._) can help to improve efficiency in _Smart Metering_ communications. Additionally, communication systems may also face disturbances: wireless communications suffer interference from surrounding emitting devices and also _PLC_ is affected by the inherent noise from the power cable and the devices connected to it. Those issues can be overcome by using more robust protection codes, redesigning emitting devices, and legislating on electromagnetic interferences [84]. At present, government investments have propelled a large proportion of _Smart Metering_ deployments, especially in Europe. Most utilities are reluctant to invest in new systems and technology without a government mandate or incentive, despite the savings resulting from _Smart Metering_ systems [46]. The European Commission has listed the advised next steps in the deployment of _Smart Metering_ systems as follows:  
* Gain the trust and confidence of consumers. An intensive communication effort is required to convince customers about three key aspects: understanding their rights as consumers, the benefits of installing _SM_s, and their participation in demand response programs. * Achieve an innovative energy services market. Synergies with the _ICT_ sector will be fundamental for promoting an innovative energy services market. * Protection of sensitive data. The European Commission and the member states will have to assess the need for specific data privacy and security framework legislation. * Management of data. Utilities and the _ICT_ sector will have to work together and explore the possibilities of data management. * Functions of _SM_s. Technical and commercial interoperability in _Smart Metering_ will enable member states to identify common means of achieving cost efficiencies and ensure fit-for-purpose in their rollout. * Long-term economic assessment of costs and benefits.