ISDN चे विस्तारीत रूप

The correct answer is Option A (Integrated Service Digital Network).

Key Points:
• ISDN stands for Integrated Services Digital Network.
• It is a set of international communication standards formulated by the ITU-T in the late 1980s for simultaneous digital transmission of voice, video, data, and other network services over traditional copper telephone wires.
• Two primary forms of ISDN:
• 1. BRI (Basic Rate Interface): 2 B-channels (64 Kbps each) + 1 D-channel (16 Kbps), providing an aggregate speed of 128 Kbps.
• 2. PRI (Primary Rate Interface): 23 B-channels in North America/Japan or 30 B-channels in Europe/India + 1 D-channel (providing ~1.5 to 2.0 Mbps).
• The official MPSC final answer key confirms Option 1 (Integrated Service Digital Network).
• Key Takeaway: ISDN stands for Integrated Services Digital Network, transmitting voice and data simultaneously over digital lines.