Analog switching vs Digital switching | Difference between Analog switching and Digital switching

This page compares Analog switching vs Digital switching and mentions difference between Analog switching and Digital switching. It covers basics of analog switching vs digital switching including their working operation of the systems in order to derive difference between analog switching and digital switching.

Introduction:  As we know telecommunication system is used to pass information from one terminal to any other terminal selected by the originator. The telecom system composed of four parts viz. end terminals (e.g. telephone or mobile), transmission system, switching system and signaling.

Communication switching system

transmission system,switching system

The figure-1 depicts plain old telephone system components from calling to called terminal. Transmission system can be wired or wireless medium used to transport information in various forms to withstand against various path losses. Transmission link carry both user information (voice, data, message, video) as well as signaling information. Medium of transmission can be guided or unguided. Based on this, typical examples of transmission systems are microwave link, satellite link, fiber optic line, coaxial line, 2-wire transmission line etc.

The switching system offers various services to the subscribers. The switching system is a collection of switching elements arranged and controlled in such a way as to setup a communication path between any two distant points or terminals.

➤Switching system is categorized into manual and automatic.
➤Automatic switching system is divided into electro-mechanical switching and electronic switching types.
➤Strowger (i.e. step by step switching) and crossbar switching falls under electro-mechanical switching.
➤Time division switching, Space division and space-time switching falls under electronic switching.
➤Typical examples of switching systems are telephone exchanges, voice switches, gateways, routers, switches etc.

Based on type of information to be transported such as voice, data or message there are different switching mechanisms such as circuit switching, packet switching and message switching respectively.

Analog Switching

analog switching

• Analog switching refers to switching of analog signals using analog switches.
• The system uses analog signals on line side and trunk side of the switch on both the ends.
• Analog lines and/or trunks are interfaced with digital system with the help of A/D converter and D/A converter as required.
• Hence analog switching system requires A/D and D/A converters in order to process digital signals.

Digital Switching

digital switching

• Digital switching refers to switching of digital signals using digital switches.
• Digital switches can interact with each other via digital trunks while simultaneously supporting analog lines and analog trunks.
• There is no analog lines/trunks in digital switching system. Hence all the communications between digital switches are carried out via digital signaling.

Digital Switching System Modules

The figure depicts various modules of digital switching system. As shown, line modules (LMs) and trunk modules (TMs) are the major building blocks of such system. The other modules include Interface controller (IC), switching fabric, service circuits (SC), central processor, network control processors etc. Here switching fabric means switching matrix which is used to switch lines and trunks under the control of central processor and network controllers.

Analog switching vs Digital switching | Difference between Analog switching and Digital switching

Following table compares analog switching vs digital switching and mentions tabular difference between analog switching and digital switching.

Analog switching Digital switching
Operates on analog signals Operates on digital signals
Requires analog switches for its operation. Requires digital switches for its operation.
It is slow in speed of operation. It is fast in speed of operation.
Performance is good. Performance is best compare to analog switching counterpart.
It does not require memory for its operation. It uses memory to store calling and called party informations.

Conclusion: In order to understand basics of Analog switching vs digital switching i.e. difference between analog switching and digital switching, also refer Analog switch vs Digital switch types >>.

Switching Related Links

Refer following links to know more on various switching systems/elements.
Circuit switching vs Packet switching   Packet switching vs Message switching  Advantages and disadvantages of circuit switching   Advantages and disadvantages of packet switching   Advantages and disadvantages of message switching   Optical Switching   Telephone call message flow   Telephone system tutorial   Transmission vs switching system   EPABX basics   Voice Switch vs Data Switch   Router vs Switch   Networking Gateway

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