**3.1 Validity of UWB technology**

*Innovations in Ultra-WideBand Technologies*

in sport.

**Table 1.**

**Table 2.**

Indoor positioning wireless technologies are classified into infrared, radiofrequency (Radio frequency identification (RFID), Wi-Fi, Bluetooth and ultrawide band [UWB]), and ultrasound systems [13]. Among different types of wireless indoor positioning systems, UWB is a promising technology for indoor positioning and tracking [13] and also for outdoor venues where there is no possibility of the surrounding infrastructure interfering in the results [3, 13, 14]. Therefore, the aim of this review was to make an update about UWB technology

International Federation of Amateur Football (FIFA) organized an event in which EPTS of those manufacturers that wish an official assessment of its devices´ security may be evaluated under standards and common conditions. All of these providers´ devices evaluated positively are certified with International Match Standard (IMS) license and published in the FIFA's website [15]. In addition, FIFA offer a second certificate under the name "FIFA Quality" certificate, in which manufacturers show the accuracy of their devices against a *Gold Standard* registration system. **Tables 1** and **2** show those manufacturers that provide UWB

**Manufacturer Brand Test Institute** REALTRACK SYSTEMS SL WIMU PRO Victoria University STATSports Group LTD APEX POD Sports Labs Ltd. Catapult Sports VECTOR Sports Labs Ltd.

Based on a recently published systematic review about the validity and reliability of LPS technology [9], and additional one added due to its recently publication [16], it may be summarized that three studies used UWB technology with 6 antennae around the field and, in general, 18 Hz [10, 17–19], and one used UWB technology with 8 anchors and 33 Hz [16]. All of them belong to three different manufacturer:

**Manufacturer Brand Test Institute Certification** 

Catapult Sports VECTOR (LPS) Victoria University 05-FEB-20

REALTRACK SYSTEMS SL WIMU PRO Victoria University 29-NOV-19

**period**

23-JAN-22

23-JAN-22

Realtrack Systems [10, 17, 18], KINEXON [20], and Ubisense [19].

**2. Safe and accuracy certificates of UWB in team sports**

technology-based devices with IMS or "FIFA Quality" certificates.

**94**

**3. UWB in scientific articles**

*UWB manufacturers with FIFA quality certificate.*

*UWB manufacturers with IMS certificate.*

**FIFA Quality certificate**

Realtrack Sytems´ UWB (WIMU PRO™, RealTrack Systems, Almeria, Spain) was tested in indoor context to assess its validity, revealing 5.2 cm (0.97%) and 5.8 cm (94%) of mean absolute error (MAE) of all estimations in x- and y- position, respectively [17] (**Table 3**). The same system, in outdoor field showed a MAE of 9.57 cm in x-axis positioning and 7.15 cm in y-axis positioning [18] (**Table 3**). A third study assess the validity of an UWB during linear, circular and zig-zag drills in soccer training in walking and running intensities [10]. The authors showed a bias (%) of 0.55 to 5.85% for determining distance covered, and, moreover, a bias between −0.56 and 0.67 for determining mean velocity [10]. Additionally, this system has been compared with an GNSS revealing lower MAE than satellitebased system (**Table 3**). Athlete tracking technology is continually improving due to developments in microprocessors, data processing, and software [21]. Hence, Realtrack System have provide a new modified UWB with height antennae and 33 Hz, which has been recently compared against a real-measure [16]. The authors showed that the mean difference (MD) was less than 4 cm and in 95% of the cases was between 1 cm and 7 cm. the magnitude of the differences was expressed as 0.28% with real measures as the reference. %CV was less than 1% in all cases (**Table 3**). Despite the fact that Realtrack System (Almería, Spain) has published most of the article, an alternative brand of UWB (Ubisens Series 7000 compact tag) was also tested for its accuracy [19]. The authors also showed sufficient accuracy to test positions of players independently of the length of the recorded runs (**Table 5**). Summarizing, all manufacturers that provide UWB technology have showed acceptable accuracy levels for monitoring the position of players in team sports settings (**Tables 3–5**).
