A telecommunications circuit is an electronic circuit that is used to transmit and receive information between two or more points. Over time, these types of circuits have evolved from physical connections like the ones used in an analog phone, to virtual circuits that are established over packet switching networks.
The critical components of a telecommunication circuit include: transmitters, transmission mediums, receivers, amplifiers, filters, multiplexers, demultiplexers, and protocol convertors.
When designing a telecommunications circuit, consider the overall function, thermal management, and electrical noise, as well as the microcontroller and the ability to upgrade the circuit as needed.