Connectivity Options: Communication technologies for smart meters

Smart metering is crucial for the efficient distribution of power in India. Over the past decade, there have been targeted efforts to revamp the country’s metering infrastructure, with smart meters playing a pivotal role in th­is progress. The Ministry of Power la­un­ched a new programme, the Revam­ped Distri­bution Sector Scheme, which aims to roll out smart meters to 250 million custo­me­rs by 2025, among other refor­ms for the beleaguered power distribution sector. Smart meters can improve the operati­onal and financial performance of dis­co­ms by automatically generating bills, preventing delayed payme­nts and redu­cing aggregate technical and commercial (AT&C) losses. As per the National Smart Grid Mission dashboard, accessed on Fe­b­ruary 12, 2023, over 5.4 million smart meters have been installed in the country.

Discoms are actively employing advan­ced metering infrastructure (AMI), whi­ch can detect electricity theft and component failure and help in remote disconnection and prepaid metering. This has significantly increased reven­u­es and reduced AT&C losses.

All smart meters use technologies to co­n­stantly communicate with their respe­c­tive discoms. Discoms prefer communication technologies that are self-healing, and have low operation and maintenance costs. Scalability and auto-reconfiguration post grid failure are also im­portant criteria to select technologies that are suitable for the grid.

Despite various wired and non-wired te­chnologies to choose from, no single sol­­ution has proven to be perfectly optimal so far. Many discoms design syste­ms that use combinations of multiple communication technologies to achie­ve their goals.

Communication technologies for smart grids

Non-cellular technologies

Based on functionality and economic via­bility, some of the commonly deploy­ed smart meter communication techno­logies at the end-user premises are po­wer line communication (PLC), RF mesh and ZigBEE.

PLC: It is built on to existing power line installations to establish communication without laying dedicated cables. It is a simplistic and low-cost technology. However, it has some disadvantages as well. Attenuation can occur on certain frequencies due to random switching of electrical equipment. It is prone to strong noise interference posed by electrical equipment such as switched mode power supplies and inverters, and signal voltages can often be affected by load impedance variations. It often ne­eds to be paired with other technologies for better results.

RF mesh: It enables wireless communication and is a core function of automatic meter reading (AMR). It is ins­talled on to the meters. This enables the measurement of power consumption and coll­ection of data from energy consumers. It is a low-cost and energy-efficient technology, and the modules are ea­sy to embed into existing meters. How­­ever, it is better suited to restricted ran­ges with high concentrations of RF modules and it often faces signal interference from public frequencies. Pair­ing with PLC can help achieve better accuracy and coverage from both technologies.

Zigbee: It is similar to RF mesh as it can also be used to build a mesh network that can connect to smart meters with data concentrators. It is a machine-to-machi­ne (M2M), wireless and IoT-based solution. It is a low-cost and simple solution for low-power smart mete­ring that is also flexible in nature. How­ever, it has a high interference ratio fr­om applications us­ing the same bandwidth. It has a limited support capacity, up to 65,000 devices. Zigbee is preferable for lighter use such as home auto­mation or smart lighting unlike RF me­sh, which is a more reliable alternative for industrial applications.

Power grid Corporation of India Limited is set to install 10 million PLC and RF mesh smart meters in the coming year. Lately, low-power wide area networking (LPWAN) has also become popular. Cellular IoT technologies are a part of LPWAN. They are incredibly flexible and available at extremely low prices. How­ever, the choice of system is usually dictated by the need of the discom.

Cellular IoT technologies

Cellular IoT focuses on low-power cellular connectivity. Following the growth in 2G and 3G connectivity, long-term evolution (LTE) technology, also known as 4G LTE, rapidly spread across the wo­rld. Cellular IoT has eliminated the need for LTE to deploy its own infrastructure and it can now purely rely on the networks provided by mobile operators, which significantly reduces costs.

Long range: LoRa is a spread spectrum modulation technique derived from chirp spread spectrum technology. LoRa is a long-range, low-power wireless platform. LoRa devices and networks such as LoRaWAN enable smart IoT applications, which can be used for a variety of purposes such as pollution control, in­fra­structure efficiency, disaster prevention, and now communication in smart me­tering. However, they provide limited cellular connectivity.

Narrowband IoT (NB-IoT): It offers widespread cellular connectivity with a large number of partner networks. It costs less than any other M2M technology in the market and provides extensive global net­work coverage while being extremely reliable. It can be easily added to existing PLC/RF mesh infrastructure, which inc­reases the reach of smart metering as ma­nual meter reading in remote areas is no longer needed. The technology does not require concentrators or gateway de­vices and also offers data visualisation with un­ified dashboards.

LTE for machine type communication (LTE-M): It is another cellular IoT technology that has higher energy consu­m­ption than its competitors but also offers much higher data throughput and latency. It is being actively adopted by power distributors globally.

General packet radio service (GPRS): GPRS technology-based AMR is a secure and low-cost AMR system that calculates and transmits the total electrical energy consumption to the main server using GPRS technology provided by GSM networks. The AMR system consists of an accurate digital meter, a tran­smission facility and a billing server. It is a remote reading technique that has many advantages. It saves the expense of periodic trips to physical locations, and billing becomes more accurate with near real-time consumption rather than being based on estimates such as previous and predicted consumption values. When this is coupled with appropriate forecast analysis, it can help discoms and customers control the use and production of electricity. The state electricity department of Goa seeks to replace existing electronic me­ters with smart meters for over 740,000 consumers in a phased manner, of whi­ch 510,000 smart meters will be installed by 2023. These meters will use GPRS technology.


India has been using PLC technology coupled with RF mesh for a long time, which has been beneficial for the country. However, with fast-evolving techno­logy and the growing needs of the co­un­try, RF mesh, which is a 2G technology, is unlikely to be the ideal communication system.

Indian discoms and private players are actively employing a variety of communication technologies, which are largely based on cellular IoT. The number of ac­tive NB-IoT connections is now rising in India, leading to economies of scale as all leading manufacturers in India have integrated NB-IoT technology and laun­ched NB-IoT-enabled meters.

For instance, Tata Power Delhi Distribu­tion, which caters to 7 million people in North Delhi, has launched NB-IoT technology in smart meters, which is 4G and 5G compatible. Energy Efficiency Ser­vi­ces Limited is al­so planning to install 3.33 million ad­di­tional smart meters in Ut­tar Pradesh and Haryana which are IoT enabled. It has already installed 1.67 million IoT-enab­led smart meters in the two states, ag­ainst the target of 5 million IoT-en­abled smart meters.

The choice of communication technology used depends on the discom’s needs, network strength, cost and throughput re­quirements. With India’s ambitious smart metering plan, communication technology will play a crucial role in its success. Efficient technology can help re­duce expenses, increase revenues and improve the financial health of the discoms while also improving the state of the power sector in India.

Harshita Verma