System description : Telephone service refer to a communication service for the transmission or reception of voice, data, sounds, signals, pictures, writing, or signs of all kinds by wire, fiber, radio, light, or other visual or electromagnetic means, and shall include all telephone lines, facilities, or systems used in the rendition of such service
System Operation flow : Traditional (analog) phone systems work by connecting calls using circuit switching. When one party calls another, the connection made is called a circuit. All of these ‘circuits’ are enabled by the Public Switched Telephone Network (PSTN). When using VoIP, analog voice is converted into packets of data. These data packets travel between callers the same way as any other type of data between two users through the Internet.
System application location : banks, casinos, schools, hotels, airports, hospitals, restaurants, military installations, convenience stores, shopping mall, commercial building and high-rise residential building.