Telecommunications & The Internet Basic Telecom Model

Transmission Speed

• BPS, bits-per-second, the amount of information that can be transmitted through a channel
• BAUD - a binary event, a signal change from positive to negative or vice versa.

Speed II

• At higher speeds a single signal change can transmit more than one bit at a time, so the bit rate will generally be higher that the baud rate.
• Transmission capacity is a function of the frequency, higher frequency means higher capacity

More Speed

• Bandwidth = range of frequencies that a channel can support (difference between highest and lowest frequency).
• Greater range means greater bandwidth.
• Greater bandwidth means greater transmission capacity.

Faster Yet

• Bandwidth is like pipe diameter.
• Larger diameter pipes can transmit more water in a given period of time.
• Personal Communication Services, PCSs, have a greater bandwidth than fiber optics.

Communications Processors

• Front End
• Processor

• CPU

• Controller

• Computer

• C
• h
• a
• n
• n
• e
• l

• Multiplexer

• PC

• PC

• PC

• T

• T

• T

• T

• Concentrator

• Channel

Network Topology

• Star Network
• Bus Network
• Ring Network

• C

• C

• C

• C

• C

• C

• C

• C

• C

• C

• C

• C

• P

• P

• P

Networks

• Local Area Network, LAN
• Wide Area Network, WAN
• Value Added Network, VAN