1. Telecommunications and Networks Chapter 8

2. Types of Signals Analog – a continuous waveform that passes through a communications medium Digital signal is a discrete waveform. It transmits data coded into two discrete states: 1-bits and 0-bits.

3. Modem Translate a computer’s digital signals into analog form for transmission over ordinary telephone lines, or it translate analog signals back into digital form for reception by a computer

4. Transmission media Twisted wire Coaxial cable Fiber optics Terrestrial microwave Satellite Wireless transmission

5. Transmission speed Bit per seconds – total amount of information that can be transmitted through any telecommunications channel 56 Kilo bit per second for current modem

6. Bandwidth The difference between the highest and lowest frequencies that can be accommodated on a single channel The greater the range of frequencies, the greater the bandwidth and the greater the channel’s transmission capacity

7. LAN Local Area Network Encompasses a limited distance, usually one building or several buildings in close proximity Used to connect PCs in an office to shared printers and other resources

8. Servers May be powerful PCs with large hard-disk capacity, workstations, midrange computer, or mainframe Some specialized computers are used for network connections

9. Gateway Generally a communication processor that can connect dissimilar networks by translating from one set of protocols to another. The network gateway connects the LAN to public networks, such as the internet

10. Router Is used to route packets of data through several connected LANs or a wide area network

11. WAN Wide area network Span broad geographical distances, ranging from several miles to entire continents

12. DSL Digital Subscriber line Operate over existing copper telephone lines to carry voice, data, and video, but they have higher transmission capacities

13. Cable modems Modems designed to operate over cable TV lines Provide high speed access to the Web or corporate intranets of up to 4 megabits per second

14. T1 line A dedicated telephone connection comprising 24 channels that can support a data transmission rate of 1.544 megabit per second Are used for high-capacity internet connections

15. TCP/IP Transmission Control Protocol / Internet Protocol Developed by US department of Defense in 1972 Become Internet standard OSI (Open Systems Interconnect) is another transmission model

16. Management Issues New Way of life Managing the changes Planning for connectivity, bandwidth, and reliability Security and privacy