projects completed

Tunnel Communication System

There are 12 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 and Silchar - Agartala Section. The minimum distance of the tunnel from the nearest station is approximately 1 km. The  VHF-based voice communications system is based on leaky Coaxial Cable and intelligent repeater system to provide communication between Radios and Walkie Talkies inside the tunnel & from the nearest station master to the engine drivers & guards and other personnel inside the tunnel. Station masters can speak on the VHF radio, either a Hand-Held radio or base radio 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 using Leaky Co-axial cable and allows Communication between radios inside the tunnel as well as from inside the tunnel to open space through the repeater.

This project was executed through M/s Technocom, Guwahati, & Green Connect Technologies acted as a technical consultant & system designer, and provided necessary technical support for Installation & Commissioning, Site acceptance and Handover.

projects completed

RoIP Based Integrated VHF Communication System

Green Connect Technologies recently completed RoIP based integrated VHF communication requirement of Shyama Prasad Mookerjee Port, Kolkata for the first time in India. RoIP connected VHF stations have been deployed at four (04) locations to cover the entire Hugli River passage and deep-sea for VHF communication to facilitate the Navigation as well enhance the Operation level to optimum. These RoIPs have been connected through a mixed mode of IP backbone --- the WAN/ Leased Line IP network of SPM Port and GSM 3G/4G  network.

Any communication being received by the VHF set at any RoIP site from any ship is transmitted through to all other sites for onwards broadcast and control & command operations.

Radio over IP is a cost-effective way to interconnect VHF radio systems. Radio over Internet Protocol (RoIP) transfers the analog audio signals used by VHF Radio/Repeater Systems, digitally over the LAN (or Internet).

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