Since 2014 we have seen the NFL (National Football League) in America use player tracking devices to deliver information to coaches and fans about every move a player is making on the field. The technology was first introduced into State of Origin broadcasts last year and it has evolved even further this year. With over three million viewers on Wednesday night, some new to the game, it was another opportunity to pack even more information into the modern broadcast.

Even watching a contest such as the State of Origin game, I can’t help but be the nerd. I want to know more about the technology behind all of this information.

Most viewers would be familiar with the small bulge between the should blades of players which is the actual device used for this tracking. Many people erroneously say this is the GPS (Global Positioning System) tracking device used by players. They are half correct. It is the tracking device – but it is not using GPS. We are familiar with GPS with satellite navigation systems that have been available for civilian use since the 1980s but the twenty-four medium Earth orbit (MEO) satellites sit at 20,200km above the earth and a device needs to see at least three satellites to calculate its position.

For navigating your car to an address, the typical accuracy to within ten metres is quite sufficient. Tracking a player in a stadium environment would reduce the accuracy even further rendering the data of little use. Keep in mind that a normal GPS device is a receiver – not a transmitter. The reason a GPS device can be small and have good battery life is that it is only receiving information transmitted from a satellite. It doesn’t need to transmit that data to a satellite 20,200km away!

Enter various companies that provide player tracking technology. They install approximately twenty sensors around a stadium to provide accurate tracking information to within fifteen centimetres. The RFID (Radio Frequency Identification) tracking devices in the jersey of players establishes two-way communication with the sensors around the ground.

With so many sensors in close proximity, the RFID devices can be accurately tracked by recording the differences in time it takes for a signal to travel from multiple sensors. The sample rate needs to be high – at 37.1km/h, Josh Addo-Carr is moving at 10.3 meters per second!

The devices typically sample the position of players one hundred times per second but some systems are capable of ten times that sample rate. In addition to the tracking with ground-mounted sensors, the devices themselves measure heart rates and G forces experienced by players.

Unlike the distance problem of transmitting data to satellites, the close proximity of the sensors results in all of this data being able to be transmitted from each player to the sensors in real-time. Hence we can see the information about each player as it is happening.

For coaches, decisions can be made during a game based on this real data. Decisions can also be made by administrators during contract negotiations based on this information. The NFL has just made the decision to deliver all player data from every team to all teams which will result in some interesting contract negotiations based on even more player metrics.

In the bigger picture, this is all part of the Internet of Things. Predictions are that we will see one trillion devices of this nature connected to the Internet by the year 2025. 

I can hardly wait to see some devices I could use in a retail environment. Imagine a staff review that showed some retail metrics. Reaction time from when a customer entered the store to when a staff member acknowledged the client. Speed of movement to serve a client. I can hardly wait to see what we will be monitoring next.