Why in the News?
In most modern office environments, internal and external communication is managed through a technology known as EPABX — Electronic Private Automatic Branch Exchange.
About EPABX:
- What is it: It is a system used by offices to manage internal and external phone calls efficiently.
- Internal and External Communication: It enables intercom communication within the organisation and provides access to external telephone lines through a unified network.
- Call Handling Features: EPABX can route, transfer, forward, or hold calls, reducing the need for multiple phone lines and improving overall communication.
- Modern Features: Advanced EPABX systems offer voicemail, call recording, automated attendants, and digital tool integration for business productivity.
How EPABX Works?
- Starting a Call: When the phone is picked up, an off-hook signal goes to the EPABX, which responds with a dial tone.
- Making Internal Calls: Users dial an extension number (like 104), and the EPABX connects them through its internal switching system.
- Making External Calls: To reach outside numbers, users dial an access code (usually 0) followed by the number; EPABX connects via the Public Switched Telephone Network (PSTN).
- Handling Incoming Calls: Calls from outside are routed to the right extension using either a receptionist or an automated system (IVR) in newer setups.
- Switching Logic: The EPABX system works like a railway yard, directing signals along the correct path between the caller and the recipient.
Advancements in EPABX Technology:
- Early Systems: Older EPABX systems used electromechanical switches like crossbars for call routing.
- Digital Transition: Since the 1980s, systems adopted Pulse Code Modulation (PCM) and Time Division Multiplexing (TDM) to digitise and share voice signals over fewer lines.
- VoIP Technology: Modern EPABX uses Voice over IP (VoIP) to transmit calls over the internet, similar to email routing using IP addresses.
| [UPSC 2019] With reference to communication technologies, what is/are the difference / differences between LTE (Long-Term Evolution) and VoLTE (Voice over Long-Term Evolution)?
1. LTE ‘is commonly marketed as 3G and VoLTE is commonly marketed as advanced 3G. 2. LTE is data-only technology and VoLTE is voice-only technology. Select the correct answer using the code given below. Options: (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2* |
