Guided and Unguided Media All types of communications

Guided and Unguided Media • All types of communications need some kind of medium. • The information is encoded in a signal that is carried through a medium. – Quality depends on the characteristics of the medium. • Two main groups of transmission media, namely the guided medium and the wireless medium. UTM, 23 May 2012 1

Guided and Unguided Media • For the guided medium, there is a physical path (such as a cable) for electromagnetic wave propagation. • For the wireless medium, the electromagnetic wave is transmitted through air, water, or vacuum (space). • A wireless medium is also called an unguided medium. UTM, 23 May 2012 2

Wireless Network Features • Wireless networks are treated as having more vulnerabilities than wired networks because of their – – shared nature naturally broadcasted states unclear perimeters invisible access UTM, 23 May 2012 3

What other “Wireless”? • 4 G Wireless Networks – In telecommunications, 4 G is the fourth generation of cell phone mobile communications standards. It is a successor of the third generation (3 G) standards. – 4 G system provides mobile ultra-broadband Internet access, for example to laptops with USB wireless modems, to smartphones, & to other mobile devices. – Conceivable applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, 3 D television. UTM, 23 May 2012 4