Communication technology is a crucial component of advanced metering infrastructure (AMI). A robust communication technology, primarily for data transmission between head-end systems and smart meters, is vital for generating real-time alerts as well as transferring the huge quantum of data that a smart meter generates. Although several communication technologies are available such as fibre optics, power line communication (PLC) and radio frequency (RF) mesh, no single technology meets all the requirements and, therefore, utilities often adopt a combination of these technologies across their distribution areas. While fibre optics offers the advantage of high bandwidth availability, PLC operates well on low voltage levels. Often, in order to make an informed decision, utilities conduct pilot projects with different technologies to delve deeper into technology deployment and potential challenges.
Smart grid communication options
Currently, there are multiple communication technology options to choose from, based on the requirements of utilities. There is no single technology that is effective for all kinds of networks. Each technology has its own advantages and disadvantages and, therefore, can be chosen for use on a case-by-case basis. For instance, fibre optic communication has high bandwidth availability, but it has issues related to laying and maintenance of the communication network. Although multiprotocol label switching technology is reliable, it is not cost effective as it requires expensive network equipment. PLC is an effective solution for low voltage levels but it is largely untested in Indian conditions. There are also issues related to bypassing of transformers and transmission frequency in PLC communication. RF canopy is considered to be effective for quick deployment but has reliability issues, which could hamper critical operations. Besides, it also has issues of availability of frequency ranges. Cellular network (2G/3G/4G) proves to be effective only for a low volume of data transfer and there are issues of feasibility and reliability in certain areas. Narrowband internet of things (NB-IoT) is the latest effective solution for low volume data transfer. However, this is yet to be tested on various applications.
Therefore, the best-suited technology solution for utilities is a combination of various technologies depending on the needs and requirements of different pockets in their distribution areas. In terms of RF mesh and cellular network, the operational expenditure of a cellular network is expected to reduce, making it more competitive with RF mesh. Meanwhile, RF mesh topology is more reliable for dense areas as compared to a cellular network. Signal strength variation and technological obsolescence issues are concern areas in a cellular network. Further, RF mesh works on licence-free bands, with a lot of free users, walkie-talkies, etc. In terms of comparison of communication technology between a public and a private network, public carrier networks have proven to have a mixed record regarding survivability. There is a lack of adequate backup power on commercial networks, which results in the public network remaining unavailable until the utilities’ electric service has been restored. Further, congestion severely affects availability of public networks in case of emergencies when availability is most needed. Public networks are also vulnerable to hacking attempts.
A private network, in contrast, offers high availability and security, but it suffers from low life cycle. Globally, RF mesh communication technology is being widely used by utilities. Currently, it is being deployed by the Dubai Electricity and Water Authority, Provincial Electricity Authority, Thailand, Singapore Power, Meralco, Tepco, Pacific Gas and Electric Company, Oncor, Florida Power & Light Company, and United Energy Distribution – Australia. Besides this, with regard to NB-IoT, a pilot project is under way by the Lithuania State Utility to identify whether the technology will be sufficient for equipment control, and maintenance, replacement and updating of software. The roll-out of the technology is expected by the end of 2020.
Challenges and the way forward
One of the biggest challenges for discoms is to keep pace with the constantly evolving technology. With new technological solutions emerging at a rapid pace, older technologies become obsolete fast. Thus, utilities must adopt communication solutions that are scalable and can adapt to different circumstances. Another major challenge is handling the quantum of data transmitted from smart meters. Although this data can provide significant insights to utilities, managing the data can be a problem. To this end, utilities must support advanced communication technologies with sophisticated data management tools in order to efficiently manage and analyse the data. Apart from this, while adopting any communication technology, utilities need to put in place various checks and balances in order to ensure robust cybersecurity.