Tunnel Communication Systems in Indian Railways

Inspections are required every month.

The system's failure must be reported daily in the morning.

Optical power meter, Digital Multimeter, Fibre splicing machine.

<p>It must be reported monthly to the Headquarter in the PCDO.</p> Signup and view all the answers

<p>The reference screenshot serves to show the system in satisfactory working condition.</p> Signup and view all the answers

<p>Tunnels are categorized as less than 500 meters, more than 500 meters to 5Km, and more than 5Km in length.</p> Signup and view all the answers

<p>VHF Simplex and GSM-R/LTE are two types of radio communication systems.</p> Signup and view all the answers

<p>Uninterrupted radio communication ensures safety and coordination between train operators, emergency staff, and control centers.</p> Signup and view all the answers

<p>The frequency band allocated for VHF Simplex communication is 146-163MHz.</p> Signup and view all the answers

<p>LocoTrol communication facilitates coordination between trains and their operators, ensuring safe operations.</p> Signup and view all the answers

<p>TCAS stands for Train Collision Avoidance System, using the frequency band of 405-512 MHz.</p> Signup and view all the answers

<p>The Tunnel Radio System provides communication between emergency staff and headquarters, ensuring prompt response to incidents.</p> Signup and view all the answers

<p>The recommended frequency band for LTE is 700 MHz.</p> Signup and view all the answers

<p>To allow radio signals to leak for extended antenna functionality.</p> Signup and view all the answers

<p>Antennas should be installed at the tunnel site.</p> Signup and view all the answers

<p>A power supply unit with battery backup of 230VAC or -48 VDC is required.</p> Signup and view all the answers

<p>It is required for tunnels longer than 500 meters.</p> Signup and view all the answers

<p>It must function properly in high noise and poor light environments.</p> Signup and view all the answers

<p>Optic Fibre and Copper Cable rings should be provided.</p> Signup and view all the answers

<p>Antennas should be installed on a Tower.</p> Signup and view all the answers

<p>Every 250 meters and at key points like cross passages.</p> Signup and view all the answers

<p>The Master Unit converts signals from RF to light for optical links and is used in tunnels longer than 500 meters.</p> Signup and view all the answers

<p>Optical Remote Units convert Optical Signals to RF Signals and transmit them into Leaky cable for wireless communication.</p> Signup and view all the answers

<p>Off-Air Channelized Repeaters are used to cover less than 500 meters tunnels with high gain repeaters feeding dual radiating cable systems.</p> Signup and view all the answers

<p>Leaky Cables are made from FRLS-0H rated materials, which are flame retardant and low smoke to reduce smoke accumulation during fires.</p> Signup and view all the answers

<p>Communication channels in the tunnel operate independently, simultaneously, and are designed to be failure-free.</p> Signup and view all the answers

<p>The Master Unit may consist of channelized VHF Simplex, GSM-R/LTE, and TCAS/LocoTrol Optical Master Units.</p> Signup and view all the answers

<p>Optical Remote Units are monitored, controlled, and alarmed remotely from the Master Unit over Fibre and via an Ethernet Modem.</p> Signup and view all the answers

<p>Continuous coverage ensures clear audio and reliable system operation, even under harsh environmental conditions.</p> Signup and view all the answers

<p>To avoid noise from affecting conversations.</p> Signup and view all the answers

<p>Once a month.</p> Signup and view all the answers

<p>Every 100 meters in the tunnel.</p> Signup and view all the answers

<p>To connect Tunnel Maintenance Boxes to the Central Tunnel Control Room.</p> Signup and view all the answers

<p>IP based Video Surveillance System.</p> Signup and view all the answers

<p>Input and output voltage &amp; currents, and the specific gravity of each cell.</p> Signup and view all the answers

<p>To identify any damage or breakdown in the antenna system and leaky cable connections.</p> Signup and view all the answers

<p>Connect a Laptop/PC to pinpoint the actual fault for rectification.</p> Signup and view all the answers

<p>They facilitate real-time communication between maintenance personnel to ensure coordination and efficiency during inspections and repairs.</p> Signup and view all the answers

<p>It serves as a benchmark for troubleshooting and verifying system performance during subsequent inspections.</p> Signup and view all the answers

<p>Inspections must include system functionality checks and must occur monthly.</p> Signup and view all the answers

<p>It ensures centralized oversight and accountability, enabling timely interventions and resource allocation for persistent issues.</p> Signup and view all the answers

<p>Daily reporting allows for immediate assessment and response to failures, minimizing downtime and ensuring operational safety.</p> Signup and view all the answers

<p>Tunnels are categorized as less than 500 meters, between 500 meters to 5 kilometers, and more than 5 kilometers in length.</p> Signup and view all the answers

<p>VHF Simplex is crucial for uninterrupted communication between radios during train operation and maintenance in tunnels.</p> Signup and view all the answers

<p>The frequency bands for GSM-R are 876-915 MHz for uplink and 921-960 MHz for downlink.</p> Signup and view all the answers

<p>TETRA systems provide reliable radio communication for operational staff and emergency services within tunnels.</p> Signup and view all the answers

<p>Emergency Telephones provide a direct line for communication during emergencies within the tunnel environment.</p> Signup and view all the answers

<p>Inter-tunnel communication ensures coordinated operations and safety across the railway network during emergencies.</p> Signup and view all the answers

<p>The frequency bands for TCAS range from 405 to 512 MHz.</p> Signup and view all the answers

<p>A Fibre Junction Box facilitates seamless integration and connection of various communication devices within tunnels.</p> Signup and view all the answers

<p>-48 VDC</p> Signup and view all the answers

<p>Every 250 meters.</p> Signup and view all the answers

<p>Fibre Junction Box is necessary.</p> Signup and view all the answers

<p>It allows radio signals to leak into or out of the cable.</p> Signup and view all the answers

<p>Video Surveillance System and PA Systems.</p> Signup and view all the answers

<p>To provide VHF Simplex, LocoTrol, GSM-R/LTE, TCAS, TETRA communications.</p> Signup and view all the answers

<p>At the tunnel site.</p> Signup and view all the answers

<p>They should work properly in high noise and poor light environments.</p> Signup and view all the answers

<p>The Master Unit converts signals from RF to light, facilitating communication over long distances in tunnels by connecting to fibre-fed repeaters.</p> Signup and view all the answers

<p>The Optical Remote Unit converts optical signals back to RF signals and transmits them through leaky cables to ensure coverage in the tunnel.</p> Signup and view all the answers

<p>Leaky Cables must be FRLS-0H rated to minimize smoke accumulation during fires and should be 7/8&quot; in diameter for effective communication.</p> Signup and view all the answers

<p>Off-Air Channelized Repeaters use high-gain technology to cover short tunnels and feed dual radiating cable systems for effective wireless communication.</p> Signup and view all the answers

<p>Optical Remote Units support VHF Simplex, LocoTrol, GSM-R/LTE, TETRA, and TCAS communication systems.</p> Signup and view all the answers

<p>The communication channels operate independently and simultaneously to ensure failure-free communication throughout the tunnel.</p> Signup and view all the answers

<p>Optical Remote Units can be monitored, controlled, and alarmed remotely from the Master Unit using fibre connections and Ethernet modems.</p> Signup and view all the answers

<p>Continuous coverage ensures reliable communication and enhances safety for operations and emergencies occurring in the tunnel environment.</p> Signup and view all the answers

<p>It provides information and warnings to maintenance staff and guides people during abnormal conditions.</p> Signup and view all the answers

<p>It should perform effectively in low light scenarios to avoid any blind spots in tunnel monitoring.</p> Signup and view all the answers

<p>Input and output voltage &amp; currents, as well as the specific gravity of each cell need weekly checks.</p> Signup and view all the answers

<p>It enables direct communication with the Central Tunnel Control Room for rapid reporting and coordination.</p> Signup and view all the answers

<p>The antenna system must be physically checked weekly for any damage or breakdown.</p> Signup and view all the answers

<p>Connect a Laptop/PC to the Master Unit to identify and rectify the specific fault.</p> Signup and view all the answers

<p>They ensure comprehensive audio coverage for effective communication across the entire tunnel length.</p> Signup and view all the answers

<p>All camera feeds must be transferred to the Tunnel Control Center for viewing, recording, and monitoring.</p> Signup and view all the answers