Analysis of information sources in references of the Wikipedia article "Tracking system" in English language version.
{{cite journal}}: Cite journal requires |journal= (help)Imagine a world where children all wear wristbands about the size of a Zippo lighter'-not as the newest fashion statement, but instead for security. These wristbands can transmit a signal with an effective range of over two football fields, narrowing down each child's position to within thirty feet. Furthermore, the system can track the children over a two square mile area surrounding their school. If a child walks off their path or does not make it to school on time, the centralized system automatically sends an e-mail or text message to the child's parents. ... In addition, cars near the children's school are fitted with the same technology, and if a vehicle drives near a child, a voice prompt will alert the driver ... While this scenario may seem fitting for the newest science fiction motion picture, the scene is reality in Yokohama City, Japan