Optical sensors; Wireless transmitters; Wireless receiving apparatus; Computer networks; Computer hardware; Computer apparatus for use with computer networks; Computer programs relating to computer networks; Computer apparatus for use in local area networks; Computer software applications (downloadable); Computer software for authorising access to data bases; Telecommunications apparatus; Telecommunications equipment; Computer programs for use in telecommunications; Programs (recorded); Ethernet adapters; Amplifiers; Computer networking apparatus; Computer software; Global positioning system (GPS) apparatus