The wave adoption of wireless over wire-line is a global phenomenon and the Oil & Gas industry is no exception. This paper presents a multi-tiered secure hardened Wireless Remote Terminal Unit (WRTU) for SCADA systems. The WRTU is based on ARM Coter-M4 Processor supported by GSM & Satellite modems, GPS, WiFi and Ethernet. WRTU can be interfaced to an array of standard industrial sensors, and actuators. WRTU has data acquisition, monitoring, and control capabilities. WRTU is an inexpensive device, using Commercial-
of-The-Shelf (COTS) modules. WRTU is an easy to deploy (using existing public available infrastructure) device and 'single device that does it all'. WRTU connects to the Control and Monitoring Centre (CMC) via GSM or Satellite modem. The CMC monitors and controls all peripherals of the WRTU, maintains a log of alerts, sensors information, set critical limits and provides geo-location of all WRTUs via its GIS portal. TheCMC has a database to maintain all operational centric data, for report generation, historical analysis and forecasting. A multitiered cybersecurity framework has been designed to protect entire communication infrastructure. Cybersecurity is critically important for national security in todays connected world. Cybersecurity is of critical importance as most national security agencies want the introduction of cybersecurity into all new SCADA systems used in critical infrastructure.