In general, the system supports traditional landline, also known as "telephone service" to use all of the information and audio signals through the same cable scheduler component of insulated wire, which represents a telephone line. In spite of that the phone has been designed specifically for communication by voice, the communication system has been modified to include also communication by sending data, such as telex, fax or Internet access. The tool is designed to send signals consist of a bell and a warning e-light or any other means to alert the user of incoming calls, in addition to a set of numbered buttons or a circular disk to enter the phone number for the outgoing calls. It should be noted that preferred to use the cable scheduler; where it is more effective in the prevention of electromagnetic interference and also prevent confusion (signals or unwanted sounds in the dial result of contact between the broadcasting services).
Also composed the phone from the warning device, which is usually a bell, so that they remain the alarm device connected to a phone line as long as it is not used (ie the handset is lifted), in addition to some other parts that are connected to the phone when it is used (ie, when the hook) . These include parts: the transmitter (microphone) and receiver (loudspeaker), as well as some other departments which are used in communication and purification of sound and the opening. When the calling party wants to talk to any other party, it will lift the handset, and then run the Convert button or the handset (which is absolutely in your phone works when you put the headset or the adjournment), which makes the phone in case of use ( hook), this is done by connecting the transmitter (Almsdh) (microphone) and receiver (loudspeaker) and some other audio parts of a phone line. This group of circuits have the resistance is very weak (less than 300 ohms), which causes the DC power (48 volts), which issued from the telephone exchange and known Balsntral (unit established by the telephone company to manage the telephone service in a particular area) to continue to flow through phone line. The central tracking and delivery of the DC Department of digital communication line, in addition to sending a dial tone to indicate readiness for the work of the call. In the modern phones, the calling party by pressing the buttons on the phone in the sequence corresponds to the telephone number of the party that is calling. These relate to the buttons circuit generating tones give rise to multi-frequency binary melody (DTMF) and ends at one of the other circuits in the exchange. The telephone-based disc to rotate the turntable when you connect to the system is working contact pulse, sending electrical pulses compatible with the phone number to the exchange. (Most exchanges are still equipped to be able to deal with the communication system pulse). In the event that the line telephony to the party being contacted is not used or is busy, the central office sends a signal from the ringing intermittent (occurs in general through 100 volts AC); and to alert the party that the connection is made to a call received. If the line telephony to the party being contacted is busy at that time, the central office sends a signal to the party line is busy the caller. In spite of that, in the case of the line is busy Telephony which the connection is made is that the phone provider waiting feature, the central office sends intermittent tone to the party being contacted to alert him to the call received. Associated with bell phone line through the condenser, which is a tool that works to impede the flow of current is constant and only allow the passage of alternating current. Through this way, the phone does not pull any current when the handset is lifted, but the group of circuitry in the central office can send voltage of DC power down the line to create a bell phone to announce incoming calls. When the landline is not used or the headset is placed on the stand, the circuitry in the telephone central tracking the flow of the absence of DC; and then linking it to the handset is lifted through the alarm device electrically connected line. And when he starts one of the parties to connect to this line and is sending a signal ringing, and the party being contacted picked up the phone, the two parties are based by moving the handset of a circuit and double who works in the case on the separation of the alarm device (bell phone) and connect the circuit audio line. This in turn attracts the DC power flow through the line, which confirms that the line-up that the connection is made has been used now. Accordingly, the circuitry in the central stop ring signal, and then becomes both phones are busy, callers to each other through the exchange. And so the parties can talk at that time as long as the headset Altlefonin lifted from the rack. When one of the parties to re-up the phone to a pregnant woman, the DC depends on the flow in this line telephony, which gives a signal to the central disconnect this call. The calls between the parties not participating in the exchange local himself, it is done through the "trunk", a telephone line set up between the exchanges. In modern telephone networks, we find that the fiber optic cable and digital technology are used in such links. The satellite technology can be used to communicate over long distances too. In most phones, there is a body transmitter and receiver (microphone and speakerphone) in the handset, although in the case of some phones that allows several people to speak at the same time, may be placed on these parts in the phone itself or in a separate extension for the phone. It is through the delivery of the transmitter line, the transmitter is working to generate a current of electrically Volatith vary as a result of waves that reach the drum Phone (membrane or disk is wobbling in the handset). The power output is transmitted across the line telephony to exchange local phone and then to the other (through the central or the local telephone network is greater), where this current passes through a receiving device. The diversity of voltage file results in similar movement of the drum in the receiver, which leads to a re-occurrence of sound waves in the transmitter. Lineman's handset is one of the types of phones that are designed to test the phone network can be connected directly to air lines and other infrastructure components.