FCS BR18 Chateau Impney Ofcom Systems Team Monitoring Solutions Baldock Radio Station Royston Road Baldock Herts Paul Jarvis
Contents Introduction to the Technical Systems Team Overview Transmitter location using Time Difference of Arrival Cost Effective Monitoring Monitoring using a drone 2
Ofcom s Technical Systems Team The Systems Team are known as the Enablers as they provide innovative solutions to any technical problem that needs resolving for Spectrum Engineering Services. In some cases. Our services extend to other groups within Ofcom. The team has a wide range of skills and expertise utilising appropriate technologies in RF design, electronics, computing and software together with the design and build of the finished solution. The team works in a collaborative way with our colleagues to ensure the solution matches requirements. Monitoring can produce huge data sets and the team also has expertise in processing, analysis and visualisation techniques. Monitoring The majority of Ofcom smonitoring resources are spread across the country and accessed remotely. The systems team manages these resources and is developing a standardised control interface. Results are stored on a server and the data, reports and in some cases special analysis can be made available to our collogues as part of ongoing work. Maintenance The team also has responsibility for maintain the monitoring facilities, antennas and on site resources. 3
Case Study RMS Controller Radio Monitoring System Most commercial monitoring equipment manufacturers have their own bespoke remote control system and a monitoring station such as Baldock, has many different types of equipment. It made both economic and practical sense to develop a standard management and control system. Using industry standard off the shelf hardware we have designed and built a controller that supports our requirements for both fixed and mobile control of equipment. It uses ethernet and mobile broadband technology, has built in GPS and enables secure connection to our remote resources. A server based program running at Baldock orchestrates the monitoring setting the monitoring parameters and retrieving the results. 4
RF Sensors geo-location (Time Difference of Arrival)
What is a RF sensor? Small computer controlled radio receiver 20MHz to 6GHz (size of A4 ream of paper) Compact installation low power consumption Automatic setup (location & timing taken from GPS) ~ 15k per site (including local controller)
Typical RF Sensor site Local Controller (Mounted inside) Discone antenna 50-500 MHz Discone Antenna 700-3000 MHz GPS Bullet LAN + 15v RF Sensor 3G/4G / DSL Communications
The TDOA process Select sensors, configure frequency, span, samples + press GO! Can include trigger parameters Send parameters to selected sensors Grab block of spectrum data on each sensor Transfer data from sensors to TDOA server Determine distinctive event contained in spectrum data Calculate correlation for each sensor pair (it s only maths!!!) Overlay results on map
The TDOA result
Sensor Geometry 3 sensors needed for a location More than 5 sensors don t add much merit Sensor geometry is key for best geolocation results