projects completed

Tunnel Communication System

There are 9 nos. of mountain tunnels varying in length from 550 mtr. to 3400 mtr. in the following sections of NF railways in the Lumding -- Silchar Section. The minimum distance of the tunnel from the nearest station is approximately 1 km. In order to provide VHF based voice communications inside the tunnel & from the station master to the engine drivers & guards a leaky feeder system has been installed in the tunnels, with an intelligent repeater system at the tunnel face. Station masters can speak on the VHF radio either a Hand Held radio or base radios from the station or the track to inside the tunnel through Intelligent Repeater based In-Tunnel VHF wireless communication system.


The system provides Seamless voice communication inside the tunnel using Leaky Co-axial cable and allows Communication from inside the tunnel to open space through the repeater.

The Solution components are

  • Intelligent repeater (25W) installed at portal of tunnel.
  • Pre fabricated Room installed for housing the repeater and associated equipment.
  • Leaky coaxial cable with Bi Directional Amplifier as required.
  • Base Radio at the station master room with related infrastructure & Walkie Talkie.

This project was executed through M/s Technocom, Guwahati, & Green Connect Technologies acted as a technical consultant & provided necessary installation & commissioning support. Presently the System is under Warranty & Green Connect Technologies has been providing necessary maintenance services as required.

Project completed

Portal for Real Time Dynamic LED Display Control

Designed Developed and Deployed a Web Portal for Data Entry of Agriculture Produce Market Committee (APMC) Dynamic LED Display Boards. The data entered by the operators at APMC headquarters / offices are automatically displayed on Large LED Walls located at various parts of New Delhi / NCR.

project in pipeline


Considering the safety requirement to take care of any emergency situation inside the Tunnels & confined spaces GCT is working on a Public address system ( WACS) which would be based on wireless. The system can operate on Wifi or any VHF /UHF network

The WACS System consists of two main components

    Central Command & Control Console

The Heart of PA system is the Central Command & Control Console which will act as Main Console. Central Command & Control Console is an control and management unit for audio distribution of public address and call box intercom communication
This Console will be interconnected into a VHF /Wifi system. This Console acts as a command Centre and can select any Public address speaker within the Coverage area & relay voice messages. The console can make announcement either in system wide broadcast mode or to individual PA speaker system/ Node. The Console can page messages for particular sections of the tunnel (i.e. a group of nodes). The console can also receive voice calls from inside the from the Call boxes which is an integrated part of the system.

    Remote Nodes

Remote Nodes are field units equipped with PA Horns/Speakers, Audio Amplifier, Call Boxes for Talkback to the control centre and integrated Radio interfaces. These field units operate on wireless technology & can operate either through Wifi or any VHF /UHF network . Each remote Node has two nos. of PA Horns/Speakers & one Call Box. Each of the speaker would cover around 75 meters and hence each node can cover @ 150 meter in a stretch. In case any distressed person wishes to speak to the Console he can have two way communication through the Call Box associated with the Node.

project in pipeline

VHF/ Microwave /IP based Disaster Management System

A reliable communication network backbone that will be operational on 24*7 basis. in the remote areas is mandatory in areas which do not have any public networks in operation . Also there are large tunnels where communication, control & command is a challenge . GCT is developing a communication network considering the various requirements of communication which would be there in this locations.

It is expected to facilitate effective disaster response by maintaining continuous communication between the Main controller and various subsystems .The network will be used for voice communications and to support incident management systems during all stages of disaster management..

The integrated Disaster management communication system being designed is a scalable control room based system and provides voice communication facility for various applications. It is a ROIP/VOIP based VHF radio communication which is also integrated through the Microwave network created for this application.

Main components of the proposed system are:

Control Room communication unit

  • Dispatcher ( 1+1)
  • Lan network
  • Despatcher server along with Call & Voice logger

Microwave network

Multi site microwave link interconnected with VHF system having the following :

  • Radio over Ip convertors
  • VHF Repeater & Microwave Equipments
  • Interface units

Base units

  • >VHF radios with Audio interface unit for Controller communications