I have provided introductions to the electrical and specifically the smart grid earlier on. Today I will briefly introduce the advanced metering infrastructure – its purpose, benefits and issues. Moreover, different approaches to metering and some ongoing security standards and specifications processes and organizations will be referenced.

Purpose of Smart Meters
The reason for smart meters is to enable the operators to improve their infrastructure towards a smarter grid and its six characteristics outlined. A smart meter has several advantages over a traditional mechanical meter. A smart meter does lots more [1], [2] than just providing detailed power consumption data to the operator. Primarily, a smart meter can significantly support the distribution system operator (DSO) to balance the network load and improve reliability.

Thus, a smart meter does not only lower manual reading cost but also enables to more efficiently estimate the load on the generators. It helps to more efficiently integrate distributed energy resources (DER) and helps to monitor the distribution network in order to identify power quality (PQ) issues, misrouted energy flows or fire alerts in case a consumer outage is being detected. Moreover, a meter could be used to push real-time pricing information to the consumer in order to allow appliances in the local network to optimize their power consumption according to the current rates. During an emergency, a meter could allow to disconnect consumers from the power grid. A meter could limit the consumption to a specified amount or could enforce pre-payment for defaulting consumers.

Yet, at time of writing, the effective use cases implemented heavily differ from operator to operator. Whereby all of them support at least remote meter reading. However, a security analysis should take all potential use cases into consideration since it is likely that firmware and hardware is being enhanced to support additional use cases in the near future.

Meter Reading vs. Metering Infrastructure
Typically, literature differs between advanced meter reading (AMR) and the advanced metering infrastructure (AMI) whereby AMR is to be seen as a subset of AMI [3].
AMR provides the metering company with usage data only. AMR does not allow for remote controlled action or advanced collection of power information. Thus, one-way communication from meter to the metering company is sufficient for that approach.
AMI will allow for remote initiated actions and will therefore require a two-way communication protocol. Though the border between the two approaches fades since remote initiated reading will also require for a two-way channel in AMR setups.

North American vs. European Implementations
The US as well as the European countries have developed absolutely independent implementations of the AMI. Nevertheless, the key drivers and business needs are exactly the same. Comparing the two, the preferred communication protocols in either continent are not compatible with each other.
The National Institute of Standards and Technology (NIST) and European Network and Information Security Agency (ENISA) respectively the European Committee for Standardization, the European Committee for Electrotechnical Standardization and the European Telecommunications Standards Institute (CEN/CENELEC/ETSI) mandated by the European Commission drive very similar projects to provide security guidance [4], [5] for smart grid and metering implementations. However, the guidance neither specifically requests for nor does it recommend the use of specific protocols.

[1] G. N. Sorebo and M. C. Echols. Smart Grid Security: An End-to-End View of Security in the New Electrical Grid. CRC Press. 2011 (ISBN 978-1-4398-5587-4)
[2] ENISA. Smart Grid Security: Annex I. General Concepts and Dependencies with ICT. 2012
[3] E.D. Knapp. Industrial Network Protocols, AMI and the Smart Grid. In Industrial Network Security: Securing Critical Infrastructure Networks for Smart Grid, SCADA, and Other Industrial Control Systems. Syngress. 2011 (ISBN 978-1-59749-645-2)
[4] NIST. Security Profile for Advanced Metering Infrastructure. v2.0, Jun. 2010
[5] ENISA. Smart Grid Security: Recommendations for Europe and Member States. Jul. 2012