Telephony is technology associated with interactive communication between two or more physically distant parties via the electronic transmission of speech or other data. Long associated with voice communication, telephony has evolved to also include text messaging, video calling, video conferencing, voicemail, call recording and faxing.
A telephonic exchange historically required the use of traditional fixed-line telephones, handheld devices containing both speakers (transmitters) and receivers that connected to local exchange networks via physical wiring. Telephonic communication increasingly happens using modern computing and cellular technology, thus blurring the line between the fields of telephony and telecommunication. The definition of telephony and its scope have expanded accordingly.
Internet telephony enables users to make calls over Internet Protocol (IP) networks, at much lower cost than over the traditional public switched telephone network (PSTN). Computer applications called softphones behave like legacy telephones but without the need for standalone devices. IP Telephony PBX PBA Doha Qatar software can reside on a variety of computing hosts, including personal computers (PCs), smart desk phones, smart mobile phones and tablets.
How telephony works
How traditional telephony works. Traditional phone systems convert sound waves at one end of a call into electrical signals that travel to their destination via the wires and cables of the PSTN — the circuit-switched telephone network that crisscrosses the globe. The recipient’s phone then converts the transmission back into sound signals, enabling a real-time conversation.
Also known as the plain old telephone service (POTS), the PTSN is operated by international, national, regional and local carriers. Its underlying infrastructure originally featured copper lines but now includes fiber-optic cabling, cellular technology and satellite systems.
How mobile telephony works. Using cellular technology, a mobile phone converts sound into electrical signals that it broadcasts via radio waves to a local cell tower. The cellular network uses radio signaling to forward this information to the recipient’s phone, which, in turn, converts the signals back into sound.
How internet telephony Internet telephony software converts sound waves into data that travels over packet-switched computer networks, enabling voice calls to occur online and independent of the PSTN and cellular systems. Voice over IP (VoIP), a Layer 3 protocol and subset of IP Telephony PBX PBA Doha Qatar, delivers voice and other communication services, such as video conferencing and text messaging, across broadband and private IP networks.
How faxing works. Legacy fax (short for facsimile) technology is similar to traditional voice telephony. Instead of using sound waves as the mechanism for converting data, a fax machine’s sensor encodes a printed document, which it interprets as a two-dimensional, fixed bitmap The machine then converts that graphic into electronic signals. Those signals traverse the telephone network and arrive at the receiving fax machine, which reconverts and decodes the signals, reassembling and printing them to reflect the original document.
IP faxing, also known as fax over IP (FoIP) or virtual faxing, functions much like traditional faxing but via the internet. Software encodes a scanned document and converts it into data that can travel over local or wide area IP networks before being decoded and reconverted on the receiving end.