This is a guest post by Ciaran Connell, CEO, DecaWave, an Irish fabless semiconductor company which develops ICs for indoor location and communication based on its UWB wireless technology platform.
Sports training has evolved quite a bit since backyard pick-up games. Today’s professional and college teams use a wide variety of technology to track exactly what players are doing on the field and to analyze their performance.
Much of this technology for training is based on video cameras, which record what happens on the field and let coaches play it back in great detail from a variety of angles. But a new kind of technology is enabling this information to be gathered with even more precision. That technology is called Real-Time Location Systems (RTLS), also called indoor location positioning technology. This new technology area is in the process of revolutionizing location-based smartphone apps, and is poised to revolutionize a number of niche markets, including sports training.
Real-Time Location Systems generally consist of beacons (also called “locators”) and tags. The beacons are at fixed locations around a site, and work together to track the locations of the tags as they move around the site. The system is engineered such that the entire site is within the range of enough beacons that the beacons will be able to track the tag locations effectively.
In a sports setting, the tags can be worn by players or attached to balls or other equipment. The tags can be used to evaluate plays and positioning and to keep tabs on equipment to make sure, for example, they stay in the weight room.
Think about all the questions that coaches and players discuss after a practice or a game. How close was my hand to blocking the ball? How fast was I running up the field? Which player jumped the highest on defense? Which players’ throws are barely on target and which have room to spare?
All these questions and more can be answered if precise location technologies are used to track players and balls moving on the field. The challenge in this new and growing area is how to achieve the necessary accuracy, indoors and outdoors, while keeping the tracking devices small and unobtrusive.
Anyone who has used smartphone GPS systems while walking around has seen that the “blue dot” is often several meters off from where the person really is. The truth is, when drivers use GPS, the GPS-based positioning is also often off by several meters, but the GPS software adjusts your location by assuming that you’re on the nearby road. When you’re walking across a field or in a stadium, the GPS discrepancies are more apparent.
Moving indoors, the location positioning accuracy becomes even worse. Many solutions are coming to market, one mall at a time or one airport at a time, but many of these systems are only accurate to within five-to-ten meters. This is accurate enough to know that you’re standing in the mall in front of the coffee shop and not in front of the baby clothes store, but on a ball field a few meters of inaccuracy makes the whole endeavor useless.
Consider, for example, the Bluetooth Low Energy (BLE) technology. The –goal here is to install a bunch of inexpensive and simple BLE beacons around your site, and receive alerts when mobile users enter or leave the proximity of those beacons. Unfortunately, programmers creating BLE-based applications are finding out that the technology is sometimes very inaccurate, and can take up to 20 seconds to register a device’s proximity. Inaccuracies and time delays defeat the purpose of the technology in a sports training application.
There are a number of solutions currently on the market that overcome these challenges using sophisticated wireless technologies. Some are based on the common wireless protocol Bluetooth, and some are based on a more sophisticated Very Low Frequency (VLF) phase difference technology. But many of these systems require that the tags worn by players remain within line of sight of the locator devices around the edges of the field. In an active game with two full teams on the field, there are likely to be a lot of people or equipment between the tag and the locator.
Moreover, if the technology is used in a real game, the system must account for thousands of fans in attendance, most of which have smartphones and other mobile devices that are emitting wireless signals, including 3G, Bluetooth and Wi-Fi. In such a setting, the relatively “clean” wireless environment of a practice session has become one of the most “messy” wireless environments imaginable.
The implementation of Ultra-Wideband (UWB) radio has created new opportunities for tracking locations of tags very accurately even when there are obstructions and radio interference. Additionally, it can work well even with tens or hundreds of tags all emitting signals.
Several companies are already bringing UWB technology to market for sports training. UWB radio is designed to deliver more accurate location and distance measurements in the presence of interference. When narrowband radio signals (including most wireless systems on the market today) go through or around obstructions, they are received at the other end multiple times, and effectively cancel each other out. UWB signals transmit much shorter and sharper pulses, and remain distinct even where there are obstructions and multiple paths of transmission. In addition, UWB systems measure location based on the refractive index of the signals, and not based on the signal strength, which is more affected by people’s bodies and other interference. Most other radio-based location systems on the market are based on received signal strength measurements.
In sum, as players, coaches and trainers elevate their requirements, indoor location technology must be able to keep up with the accuracy and speed requirements of a sports game, the radio environment of a sports stadium, and the inherent interference of other players and equipment.