What is a characteristic of plain old telephone service (POTS)?

Plain old telephone service (POTS) is based on circuit switching, which is a method of communication where a dedicated communication path or circuit is established between two parties for the duration of the call. This means that once a call is initiated, a fixed connection is maintained between the two telephones, allowing for a constant stream of audio. This is a defining characteristic of traditional landline telephone systems and contrasts with other communication methods, such as packet switching, which is used in modern digital communication systems where data is sent in discrete packets over a shared network.

Circuit switching ensures that the quality of the call remains stable and consistent throughout its duration, as the circuit is reserved solely for that conversation. This fundamental aspect of POTS technology differentiates it from more contemporary systems, which may incorporate digital switching or wireless methods and rely on shared bandwidth, potentially impacting call quality.