Methods
Among the different telecommunication positioning systems (i.e. outdoor and indoor) are utilized in the process of determining the spatial position of people, equipment, and other objects (Alarifi et al., 2016). As has been mentioned (Chapter 1), FIFA divided EPTS into three main groups: GPS/GNSS, VID and LPS. Due to the mentioned limitation and narrow possibilities of the VID, this update focuses on the possibilities of real-time feedback of radio-frequency technologies (GPS/GNSS and LPS).
Data Sending from Device to a Laptop
Given the limitations of the technologies, the first decades of the last century heralded a revolution in wired communication (Salayma et al., 2017). It was not long before the wireless sensor networking (WSN) revolution changed course to a technology that suited human mobility by devising technology that can be wearable or even implanted in the human body (Salayma et al., 2017). This technology is characterized by miniature, lightweight, ultra-low power, intelligent monitoring devices, which are low-cost, tiny, and include heterogeneous sensor nodes that form a special type of WSN (Jovanov et al., 2005; Salayma et al., 2017). A number of these devices can be integrated into a Wireless Body Area Network (WBAN), a new enabling technology for health and sport monitoring (Jovanov et al., 2005). Specifically, a WBAN comprises sensors that capture information and send it to a central base station through wireless communication (Salayma et al., 2017). WBAN sensor devices are supposed to provide real-time feedback. Until a few years ago, real-time feedback had been mainly applied in the medical field. However, health care and entertainment fields such as sport picked up the idea and today WBAN is applied in team sport training and competitions (Salayma et al., 2017). Specifically, team sport is facing a rapid growth due to the interest of providing players with rapid feedback to optimize players’ performance and team sport training.
There are several reasons behind the motivation of wireless communities to standardize their technologies.
Standardization allows interoperability, which enables wide use of the products since manufacturers depend on common fixed specifications in developing their products (Salayma et al., 2017). In addition, customers need not depend on a certain vendor. This saves the costs for both the vendors and customers (Cavallari, Martelli, Rosini, Buratti, & Verdone, 2014). It is worth mentioning that WBAN often follows a star topology and due to the body nature, the majority – if not all – the WBAN challenges are related to the reliability of the channel access mechanisms. In this regard, this section presents the main technologies that are proposed to serve WBAN and focuses on the MAC techniques adopted by these technologies to support WBAN (Salayma et al., 2017). In the WBAN communication standard (Table 8.1), the IEEE 802.15 Task Group 6 has proposed sports applications (Salayma et al., 2017). It aims to support an array of applications with a range of requirements such as data rates and channel bandwidths. Thus, the standard offers three bandwidths defined in three different physical layers:
Narrow Band (NB), Human Body Communication (HBC) and ultra-wide band (UWB) (Figure 8.1) (Cavallari et al., 2014).
Table 8.1 WBAN communication standards and technologies (Adapted from Arbia (2018))
Standard Standardization Topology No. of nodes Frequency Data rate Tx power
consumption Tx range Stronghol
Wi-Fi p2p, p2mp 2.007 2.4/5 GHz up to 600 Mbps Transmit
power:
18 dBm
⁓180 mA
300 m High data
Bluetooth Standard Piconet, Scatter net
7 2,4 GHz 3 Mbps Transmit
power:
+8.5 dBm
⁓40mA
30 m Interopera cable replacem
Bluetooth 4.0 (BLE)
Standard Star Undefined 2.4 GHz 1 Mbps Transmit
power:
< 11 dBm
<10 mA
⁓ 50 m Low cost, to run fo on stand coin-cel batteries 802.15.4
802.15.4J
Standard Standard
P2P, Star, Cluster Tree, Mesh
+65.000 868/915 Mz 2.4 GHz
40 Kbps 250 Kbps
Transmit power:
0 dBm 17.4 mA
100 m Long batte low cos
802.15.6 Standard Star (One hop, two- hop extendable)
255 2.4 GHz
800 MHz 900 MHz 400 MHz
75.9 Kbps (narrowband) up to 15.6 Mbps
Transmit Power:
-10 dBm 2.4 mA
< 100 m Low cost, reliabili ultra-low and sho Wireles commun in or aro human b
802.11 ah Standard Single hop 8,191 Sub – 1
GHz
150 Kbps Up to 78 Mbps
– 100–
1000 m
Ultra-low long ran coverag Ward compati with802
Ant Standard Point-to-
point, star, tree, mesh
65533 per shared channel (8 shared channels)
2.4 GHz Broadcast/Ack - 200 Hz × 8 bytes × 8 bits
= 12.8 kbit/s Burst - 20 kbit/s Advanced Burst - 60kbit/s
ANT transmit power level for the beacons.
30 meters at 0 dBm
Ultra-low wireless technolo supports differen of low d network topolog such as peer, sta mesh.
Z-Wave Proprietary Mesh 232 devices
per network
2.4 GHz and 900 MHz (slightly varies per country)
100kbit/s High 10–100
meters Cross- compati among d branded systems
Standard Standardization Topology No. of nodes Frequency Data rate Tx power consumption
Tx range Stronghol
ZigBee Standard Mesh star - 65536 2.4 GHz
(+ sub- GHz for ZigBee PRO)
250 kbit/s (at 2.4 GHz)
Medium 10–100
meters
Low rate, complex cost. It c of a microco and a multich two-way on one p silicon image
Figure 8.1 UWB technology installation for real-time feedback.
Data Acquisition and Visualization
The aforementioned devices, integrate positioning sensors (i.e. GPS/GNSS or LPS) and MEMS (e.g.
accelerometer, gyroscopes) (Bastida Castillo et al., 2018; Leser; Schleindlhuber; Lyons; Baca, 2014). Additionally, heart rate monitors as well as other devices are available to measure load and physical-physiological parameters (FIFA, 2015). So, all together they measure four kinds of variables: (1) physiological, (2) kinematic, (3) neuromuscular and, (4) tactical. Specifically, the recorded data can be physiological, kinematical, and neuromuscular, or about positioning (i.e. tactics and velocity) on the x axis and data recorded by LPS on the y axis, and in latitude and longitude for GPS/GNSS. Once the data is recorded, the following steps are sending and calculation, but these differ among manufacturers. In this respect, there are three kinds of process: (1) the data is sent and calculated on the laptop, (2) the data is calculated in the device and sent to the laptop, and (3) hybrid systems, which combine both. As was mentioned, data are sent through a WBAN to a laptop, tablet or mobile. If the data are processed in the device, they are visualized in the software directly; if not, the data are processed before the visualization. However, some manufacturers only allow the analysis once the session has finished.
Finally, beyond the used system, when the session or competition has finished the data can be kept in a program in the internet’s space (Cloud) or in an HDD (Figure 8.2).
image
Figure 8.2 Possibilities within the device (left), possibilities when it reaches the PC (right).
Physiological, kinematical and neuromuscular data are shown as numerical data. However, currently, the possibilities to show positional data have grown. The idea of a Geographical Information System (GIS) was picked up for team sports in order to see data in a software application (Bastida-Castillo et al., 2019). GIS was proposed as the reference system (Bastida-Castillo et al., 2019), which does not require any instrument other than a device with software included. The reference system to compare the results was projected in the software using the GIS mapping application. GIS allows representation of positional data such as cold maps, or collective tactical variables based on geometrical primitives (i.e. point, lines or polygons) (Rico-González et al., 2019), with centimetre accuracy.