Digital telephone systems use electrical impulses. Voice is compressed and transformed into series of zeros and ones that are known as binary code. The codes are translated back into voice at the receiver’s end. The connection of digital phones is made by category 5 cables or CAT 5. It is the same cable network used for connecting computers networks. These days there are many digital services to choose from and connect to a digital network
Types of digital networks
- ISDN – The integrated services digital network (ISDN) allows the transmission of audio, video and text simultaneously. It is the first digital service that had been offered. From the same phone jack, it allows the operation of multiple digital channels
- ADSL – Asymmetric digital subscriber line (ADSL) is actually broadband over the telephone line. It allows faster data transfer over a copper telephone line. It is best for downloading data
- T1 line – The T1 line gives high-speed connection from one location to another specific location
Other digital services that can be considered include digital service unit (DSU), switched multi megabit data services (SMDS), Asynchronous transfer mode (ATM), etc.
Advantages of digital networks
Digital telephone systems have many advantages of the analog system which slowly is disappearing and being replaced with the digital system. Some of the advantages include
- Programmability – With the digital system, it’s possible to use a variety of applications without the need of changing hardware
- High-speed – The digital system allows high-speed speed operations providing reduced time for any operation
- immunity – Information components are represented by bytes compared to analog that is affected by the level of noise
Voice over IP digital system
Digital telephone systems have revolutionised communication making it faster and with less noise. Recently the trend in business communication is Voice Over Internet Protocol (VoIP). VoIP consists of hardware and software that allows the use of the internet for making telephone calls. With VoIP, there are three different ways of placing a call
- Analog telephone adaptor (ATA) – This allows the connection of a standard phone to the computer. It is and analog -to- digital converter. It converts the traditional analog signal from the telephone to digital data for transmission over the internet
- The IP phones – these are specialised phones similar to traditional phones but do not have the standard RJ-11 phone converter. They have an RJ-45 Ethernet connector. They connect directly a router.
- Computer – to – computer – VoIP allows for a computer to computer calls. The only thing that is necessary for voice communication between two computers is a microphone, a sound card, and a speaker, and most likely a fast internet connection such as cable or DSL modem.
Digital telephone system is now becoming the norm and slowly all service providers are adapting the system. Businesses, in particular, prefer VoIP because it offers the possibility of many application and it is also less expensive than other digital system solutions.