Technologies developed over the past decade provide the means of information transfer to enable remote control and monitoring. Power companies often use a combination of these technologies to accomplish their goals, such as power line communications (PLC), second- and third-generation (2G, 3G) cellular communications technologies, and mesh network radio technologies.
Also known as broadband-over-power line, PLC uses a very broad spectrum of low-power digital radio signals to rapidly convey a large amount of information, even from multiple sources. This technology rides over the power grid without polluting the air with radio frequency interference. It operates bidirectionally, up and down the power lines, and is used for grid monitoring and control, smart meter communications, and Internet access. The presence of PLC signals on the power lines has no impact on the electrical energy those lines carry.
Another technology used to connect with smart meters is 2G or 3G broadband cellular, used by both smart meters and smart grid hardware.
Mesh network radio technology enables a wide range of household and industrial devices to automatically form a multilinked network. This hardware is very low power—often battery operated with sleep modes to conserve and extend battery life. It works bidirectionally for both reporting and control. All mesh devices pass data to and take commands from the smart meter.