Why no dial tone in mobile?

Answer 1

Line fault, Instrument fault or Exchange fault. you should always have a wired telephone on a landline so it still works when domestic power is lost. You can check the instrument by substitution. The provider will check the exchange and line. If the fault is past the first box in the house they will not fix it and will probably charge you for the diagnosis.

Answer 2

1. In the beginning on the first telephone exchanges you initiated a call by turning a crank on the side of the phone to tell the operator that you wanted to make a call. When the operator then replied with "Number please?" you told her the number and she connected you through on the switchboard.
2. The first upgrade to the telephone exchange added a subscriber loop current relay. You initiated a call by just picking up the phone (no crank to turn). When the operator then replied with "Number please?" you told her the number and she connected you through on the switchboard.
3. With the introduction of the automatic exchange (which also used the subscriber loop current relay) you initiated a call by just picking up the phone. When you heard the originating register of the exchange send you dial tone (which might be instant to as long as about a minute later depending on how busy the exchange is making calls at that moment) you knew that you could dial the number that you wanted. If the automatic exchange had a problem and could not assign you one of its originating registers within about a minute, it instead connected your phone to a fast busy circuit to inform you that it is overloaded and you need to hang up and wait for a less busy time to try your call. Once the number you dialed is in the originating register, the automatic exchange switches would then connect you through.
4. With the introduction of the mobile phone (cellphone) the phone now has a visual RF signal strength indicator showing how many "bars" you have or if you are currently out of range of any cell tower. This visual indicator replaces the dial tone as the indicator that the telephone exchange switch is ready to accept the number. You initiate a call by dialing a number (which you can also edit because the "originating register" is in your phone, instead of in the automatic exchange) then press the send button. The switch in the nearest cell tower will accept this number and begin the process of having the phone system switches connect you through.

Many people lamented the loss of the familiar female voice saying "Number please?" when the automatic exchange replaced the manual switchboard exchange in their town. She was friendly and was often willing to chat for a short period of time (although the phone company frowned on her wasting too much time this way). Lonely men would often just pick up the phone to hear a friendly female voice and often asked operators out on dates (and were almost always turned down). All of this went away with the introduction of the automatic exchange and dial tone (unless you dialed 0 to be connected to one of the very few operators that remained for handling special types of calls that the automatic equipment could not handle without human assistance).

The change from an audible dial tone to a visual bar graph display on the phone as an indication that the system is ready for you to dial a number is actually a big improvement.

Answer 3

On a mobile phone, you enter the full number and press "send"; there is no need for a dial tone, because the network receives the entire number as a single chunk, rather than digit by digit as with a landline.