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Telecommunication
– Transfer of meaningful information from sender to
receiver over cable or wireless media
– Includes all of the hardware and software necessary
for its transmission and reception
Telephony
– Limited to transmission of sound over wire or wireless
– Assumes temporarily dedicated point-to-point
connection rather than broadcast connection
Network
– Series of points or nodes interconnected by
communication paths
Switching Exchange
Connection points or network nodes
Backbone
Large transmission line that interconnects smaller lines
Benefit of Telecom Networks
• Powerful, flexible collaboration
• Cost-effective sharing of equipment
• Software management
• Freedom to choose the right tool
• Flexible use of computing power
• Secure management of sensitive information
• Easy, effective worldwide communication
Classified by Spatial Distance

WAN
Wide Area Network

• More than 50 km, private/public, kbps to Mbps
Classified by Spatial Distance

LAN
Local Area Network

• Less than 5 km, private, Mbps to Gbps
Classified by Spatial Distance

MAN
Metropolitan Area Network

• 5 to 50 km, private/public, kbps to Mbps
Classified by Ownership

Public Network
Owned by a common carrier
Classified by Ownership

Private Network
Built for exclusive use by a single organization
Classified by Ownership

Virtual Private Network
Encrypted tunnels through a shared private or public network
Classification by switching technology

Circuit Switching
Connection-oriented networks, ideal for real-time
applications, guaranteed quality of service
Classification by switching technology

Message Switching
Store-and-forward system
Classification by switching technology

Packet Switching
Shared facilities, used for data communications
Classification by switching technology

Cell Switching
Fast processing of fixed length cells


Distributed Computing
Client/server set-up


Centralized Computing
Thin-client architecture
1837: Samuel Morse invents the telegraph
1858: Transoceanic telegraph cable is laid
1876: Alexander Graham Bell invents the telephone
1885: AT&T is incorporated
1888: Hertz discovers the electromagnetic wave
1895: Marconi begins experimenting with wireless telegraph
Telegraph
The patterns consisted of dots(short beeps) and dashes (long beeps) corresponding to the Morse code

Information rate varied between 5-10 words per minute
Telephone
In the earliest magnet-telephone, speaker's voice was converted into electrical energy patterns that were sent over wires. At the receiving end, these energy patterns were converted back to sound waves

Information rate was limited only by the rate of human speech
History of Radio
Built in U.S. in 1906

Human voice was encoded, superimposed onto electromagnetic waves, transmitted to receivers, which decoded the information and converted to speech by speakers

WWII was the stimulus to wireless communications
History of Computer
1st computer: Mark I, developed by Aiken between 1939-1944
AT&T has dominated the telecom market since 1885
Four-wire trunk-side access available only to AT&T, while others had two-wire line-side access
U.S. Justice Department filed an antitrust lawsuit against AT&T in early 1974
Outcome was a restructuring agreement, which led to the divestiture of AT&T, effective January 1, 1984
Outcomes of Divestiture of AT&T
Formation of seven Regional Bell Operating Companies (RBOC) same as Baby Bells

Equal access

Local Access and Transport Area (LATA) - Predetermined area used to govern who would care calls in what area
7 Original RBOC's
US West
PAC Bell
Southwestern Bell
Ameritech
BellSouth
Bell Atlantic
Nynex
1969: ARPANET funded by teh DARPA commitment to standard communication protocol
1978: Unix-to-Unix copy program
1981: Development of CSNET and BITNET
1982: Term Internet coined
1986: Establishment of NSFNET
1989: CSNET and BITNET merge to form CREN
1990: WWW becomes part of the Internet
Scalability
The ability to increase the power and/or number of users without major redesigns
RAID
Redundant Array of Independent Disks
UPS
Uninterruptible Power Supply
Data Communications
Digital transmission of information
Voice Communications
Telephone Communications
Video Communications
Cable TV or video conferencing
What is a Standard?
Standards are documented agreements containing technical specifications or other precise criteria to be used consistently as rules, guidelines, or definitions of characteristics, to ensure that materials, products, processes, and services are fitted for their purpose.
Purpose of Technical Standards
Compatability
Portability
Interoperability
ISO
International Standards Organization

(Intl)
ITU
International Telecommunications Union

(Intl)
IEEE
Institute of Electrical and Electronics Engineers

(Intl)
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