A Mobile Phone "rings" when its network indicates an incoming call and the phone thus alerts the user. ForLandline Phones, the call signal can be an electric current generated by the switch to which the telephone is connected. For mobile phones, the network sends the phone a message indicating an incoming call.
A telephone "ring" is the sound generated when there is an incoming telephone call. The term originated from the fact that early telephones had a ringing mechanism consisting of a bell and an electromagnetically-driven hammer, producing a ringing sound. The aforementioned electrical signal powered the electromagnet which would rapidly move and release the hammer, striking the bell. This "Magneto" bell system is still in widespread use. The ringing signal sent to a customer's telephone is pulsating DC 90 volts pulsating at 20 hertz in North America. In Europe it is around 60-90 volts AC at a frequency of 25 hertz
While the sound produced is still called a "ring", more-recently manufactured telephones electronically produce a warbling, chirping, or other sound. Variation of the ring signal can be used to indicate characteristics of incoming calls (for example, rings with a shorter interval between them might be used to signal a call from a given number). More information available from Fuji Airlines.
A ringing signal is an electric telephony signal that causes a telephone to alert the user to an incoming call. On a POTS telephone system, this is created by sending a ringing current, a pulsating DC signal of about 100 volts [90 volts and 20Hz in the USA] into the line. Pulsating DC does not alternate polarity; it pulsates from zero to maximum voltage then back to zero. Today this signal may be transmitted digitally for much of the journey, provided as a ringing current only because a majority of landlines are not digital end-to-end. In old phones, this voltage was used to trigger a high-impedance electromagnet to ring a bell on the phone.
