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Control and Monitoring System


TVILIGHT (pronounced "Twilight") is an integrated control system to monitor and control street lights over a wide area, from a centralized workstation. A specialized IOT network is utilized to integrate the various components of the system.

TVILIGHT uses IOT equipped sensors that are provisioned along with every street light to continuously monitor and control its operation through an loT equipped control device. These sensors are connected via the internet to a central control station, where access is allowed only to those with proper authorization, due to the critical nature of the system.

Feature List

  • Instantaneous control of system devices and Street Light / Electrical Load (less than 5 seconds latency)

  • LoRA based communication with a range of up to 1000 meters (Line of Sight) for each device / sensor

  • Near Real-time data Telemetry to Cloud with an interval of up to 1 data set / second

  • Internet Gateway device to relay information from multiple sources over the internet

  • Transit Gateway device to relay information between sensor devices / control devices over longer distances (greater than 1000 meters)


TVILIGHT system comprises a variety of devices covering different operational aspects. They are

  1. Direct Powered Street Light Controller

  2. Direct Powered Ambient Sensor

  3. Internet Gateway

  4. Transit Gateway

Each of these devices comes with a built-in battery backup to allow them to operate during power outages, as non-grid applications such as solar powered streetlights, continue operating. It also allows operation when a section of the grid is offline, for maintenance or other purposes.

Networking between Devices

The schematic shown below explains how data transfer is achieved by the TVILIGHT system. The ambient sensor and the control device exchange data with the transit gateway via the LoRa radio.

The transit gateway extends the range of communication of the LoRa radio by acting as a repeater for the Wi-Fi network signal. This range allows the internet gateway to be placed at a longer distance, allowing a single device to provide connectivity to multiple streetlights.

This increase in range also enables operation in remote locations, as the internet gateway has multiple

options for connectivity - 10/100 Ethernet LAN Port and 4G Mobile Network as standard, along with

Add-ons sold separately such as Long-Range Ubiquiti Wi-Fi (250m Line-of-Sight) and Satellite modem.


TVILIGHT is a monitor and control system for streetlights, that uses IOT technology for telemetry via internet. TVILIGHT uses Ambient Sensors to monitor the operating parameters of every streetlight and controllers to alter them. A LoRa radio is provisioned for each streetlight for telemetry.

The data transfer between the control station and the controller and sensor devices is facilitated by devices called gateways. TVILIGHT uses 2 types of gateways — Transit and Internet. Multiple sensors and controllers connect to a single transit gateway, which increases the transmission range of the LoRa radio by acting as a repeater. The data is then sent to an internet gateway for transmission to the control station.


The TVILIGHT system infrastructure can be divided into 3 segments, namely

  • The street light apparatus

  • The telemetry networks

  • The monitor and control system

Street Light Apparatus

Every street light in the system is provided with a sensor and a Lora radio. The sensor has the ability to monitor and control the operation of the street light. The data statistics collected from the sensor are sent to the LoRa radio, which transmits them to the control station via an internet gateway.

Telemetry Network

Telemetry constitutes the transfer of data from the sensor to the LoRa (Long Range) radio and there on to the control station over the internet via the transit gateway. LoRa radio is a long range, low power wireless transmission platform and is the basis for the IOT technology. IOT is used to collect and transmit data over the internet continuously, without any need for human intervention.

Every data transmission from a sensor occurs with a time interval of 15 seconds by default, but it is adjustable up to 1 second. This transmission delay preserves the battery life of the sensor, allowing it to last for a period of 2 years. And coupled with the use of the LoRa radio, it allows for operation without any need for an additional power source.

Monitor and Control System

The incoming data from the sensors are fed to the control system, which employs a state machine based embedded software. The software allows for the monitoring of operational parameters and the ability to control operations when required. It also offers an array of communication protocols, whose selection is dependent on the mode of operation.

Software Architecture

Network Security

TVILIGHT utilizes public-private encryption keys for relaying the data from the internet gateway to the control system. In addition to this, all devices in the system comprise of an RTC unit and an external AES 256-bit encryption hardware as standard. The inclusion of timestamp on the data payload during encryption helps in tracking down malicious nodes / devices.

A proprietary Authentication Agent software in the system helps to prevent unauthorized access, through any of the devices used or the internet gateway. Hence new devices or operators, to be added to the system, need to undergo provisioning by this software to be provided with the authentication to access the system.

Data Security across Embedded Devices

To prevent unauthorized access with malicious intent to the TVILIGHT system or server, any data from the devices in the system is encrypted before transmission. This is done by utilizing asymmetric encryption methods, and other types of packet encryption based on the operational mode and the type of monitoring device used.

Software Modules for IOT

The software modules required for TVILIGHT's complete cloud infrastructure is mentioned below

  • Telemetry of data from the system devices, along with Data Abstraction and ETD of the data

  • Authentication, Provision, and Management for every device in the system

  • Provision for Dashboard view and Live Analytics, for Real-time monitoring and control.

  • Log generation and parsing for quick tracing and debugging of any issues.

  • OTA upgrades for the devices and the software, including specific control of the device / software to be upgraded.

  • Configuration, Debugging and Decommissioning of system devices as the situation demands.

  • Establishment of an Admin account for operator onboarding and a Ticket based support system for technical support.

  • RPA for reducing human intervention in software modules

***Only OTA update module and it's RPA based implementation is explained below. For further information on RPA implementations on other modules, contact Sales Team***

Server Deployment

TVILIGHT includes a server system to integrate and store the large amount of data accumulated by the system. The server allows for authorization-based data retrieval for analysis. It is also used for OTA upgrades from SVC repositories to the various system devices, allowing for precise control over the updates and the devices that are upgraded, by using just a commit id.

OTA Device Updates using Robotic Process Automation (RPA)

TVILIGHT's software architecture permits selective OTA updates on target devices directly from SVC repositories by just using a commit id. This Robotic Process Automation (RPA) makes deploying and testing of nightly builds, release candidates and intermittent patch fixes on any number of provisioned devices a lot easier thereby reducing human intervention for OTA updates by over 95%.


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