16-03-2011, 04:23 PM
ch7_1_v1.ppt (Size: 1.84 MB / Downloads: 90)
Transmission Media
GUIDED MEDIA
Guided media, which are those that provide a conduit from one device to another, include twisted-pair cable, coaxial cable, and fiber-optic cable.
UNGUIDED MEDIA: WIRELESS
Unguided media transport electromagnetic waves without using a physical conductor. This type of communication is often referred to as wireless communication.
Wireless Channels
Are subject to a lot more errors than guided media channels.
Interference is one cause for errors, can be circumvented with high SNR.
The higher the SNR the less capacity is available for transmission due to the broadcast nature of the channel.
Channel also subject to fading and no coverage holes.