Telecommunications and its History - BZU PAGES: Find Presentations, Reports, Student's Assignments and Daily Discussion; Bahauddin Zakariya University Multan

**Waqas Ahmed** · #1 23-09-2008, 11:16 PM

Telecommunications and its History

What is Telecommunications?

To be able to communicate at a long distance.
A long distance communication via a combination of information sharing networks all tied together.

Some of the Factors involved

Format of Information
Transmission Speed
Transmission Medium
Transmission Distance
Modulation technique
Error Control

Telecommunication Networks include

Public Switched Telephone Network
Data Communication Network
- Internet.
Wireless Networks
Radio
Television
Fiber

1996 Telecommunications Reform Act 1996

Intended to eliminate the distinction between local and long distance companies, cellular, cable, broadcast and on-line service providers

History of Telecommunication and
Data Networks

1830's Gauss and Weber develop a small scale telegraph system (tele=distant, graph=writing) in Gottingen
1840 Samuel Morse patents the practical telegraph
1844 Morse sets up 40-mile telegraph line between Washington, DC, and Baltimore
1876 Alexander Graham Bell and Thomas A. Watson demonstrate and patent the telephone (tele=distant, phone=voice). Elisha Grey submitted independent invention disclosure on same day as Bell's patent submission, but lost out
1878 Bell forms the Bell Telephone Company and establishes 1st switching office in New Haven
1878 Thomas Watson applies for first telephone ringer patent
1881 John Carty, a Bell engineer, invents the two-wire local loop
1887 Heinrich Hertz produces the first man-made radio waves
1887 Charles Vernon Boys describes concept of guiding light through glass fibers
1890 Telephone network consists of Switching Offices + wires to customers (balanced, insulated, twisted pairs) + long-distance connections between switching offices

1892 Almon B. Strowger, undertaker, patents (1889) and installs the first automatic circuit switch (his motivation was that his competitor ran the switchboard)
1896 Guglielmo Marconi develops the first wireless telegraph system
1926 First public crossbar switch exchange opened in Sweden
1927 First commercial radio telephone service operated between Britain and the US
1939 Pulse code modulation (PCM) invented, which later became the basis for digitized voice transmission
1940's First practical crossbar exchanges become popular in the US
1946 First car-based mobile telephone set up in St. Louis,
1946 The L1-carrier system installed to support 1800 telephone circuits using frequency division multiplexing over 3 pairs of coax cables
1948 Claude Shannon publishes two benchmark papers on Information Theory, containing the basis for data compression (source encoding) and error detection and correction (channel encoding)
1950 TD-2, the first terrestrial microwave telecommunication system, installed to support 2400 telephone circuits

1956 First transatlantic telephone cable laid
1950's Late in the decade, several "push-to-talk" mobile systems established in big cities for CB-radio, taxis, police, etc.
1950's Late in the decade, the first paging access control equipment (PACE) paging systems established
1950's Late in the decade, AT&T introduced a 300-bps modem (Bell 103) and 1200-bps modem (Bell 202) using frequency-shift keying (FSK) modulation
1960's Early in the decade, the Improved Mobile Telephone System (IMTS) developed with simultaneous transmit & receive, more channels, and greater power

1960's Early in the decade, AT&T introduced a 2400-bps modem (Bell 201)using 4-phase phase-shift keying (PSK) modulation
1962 The first communication satellite, Telstar, launched into orbit
1962 Semiconductor injection laser invented
1963 The American Standard Code for Information Interchange (ASCII) developed for encoding alpha-numeric and control characters into 7-bit binary strings

1964 The International Telecommunications Satellite Consortium (INTELSAT) established, and in 1965 launches the Early Bird geostationary satellite
1964 The International telephone numbering plan defined in ITU-T's recommendation E.163 which has governed the country codes, area codes, and local numbering system
1968 The CCITT (Now ITU-T) standards organization publishes first "Group 1" standards for facsimile machines
1968 DARPANET assigned the work of developing ARPANET to BBN (Bolt, Beranak, and Newman) which became basis of Modern Internet
1960's Late in the decade, modems appear at 4800 bps using 8-phase PSK and at 9600 bps using quadrature amplitude modulation (QAM)
1970 First low-loss optical fiber announced having an attenuation of 20 dB/km
1970's Packet switching emerges as an efficient means of data communications, with the X.25 standard emerging late in the decade
1976 Ethernet invented by Robert Metcalf, leading to 1-Mbps to 10-Mbps Ethernet local area networks (LANs) based on the IEEE 802.3 standard
1977 The Advanced Mobile Phone System (AMPS), invented by Bell Labs, first installed in the US with geographic regions divided into "cells" (i.e., cellular telephone)
1978 The L5E-carrier system installed to support 132,000 telephone using frequency division multiplexing over 10 pairs of coax cables
1983 January 1, TCP/IP selected as the official protocol for the ARPANET, leading to rapid growth
1984 January 1, AT&T broken up into: a) AT&T Long Lines, b) 23 Bell Operating Companies (BOCs), which were economically driven to group into the 7 regional BOCs

1984 World's telephone companies, led by the CCITT standards organization, agree to build fully digital, circuit-switched telephone system, known as Integrated Services Digital Network (ISDN) for voice and non-voice data communications
1985 BellCore, the RBOCs research arm, begins work on the standard for the Synchronous Optical Network (SONET)
1986 Optical fiber attenuation achieves a loss of 0.154 dB/km, close to the 0.13 dB/km silica limit
1980's In the middle of the decade, 565-Mbps optical fiber systems are common in the public switched network

1989 CCITT publishes SONET standards G.707, G.708, G.709
1989 A source book lists approximately 10,000 data communication products, in about 1000 categories, from about 2000 companies
1980's Late in the decade, Local Area Networks (LANs) emerge as an effective way to transfer data between a group of local computers
1980's Late in the decade, AT&T replaces all its analog multiplexing with digital multiplexing. MCI followed in the early 1990's
1990 Motorola files FCC application for permission to launch 77 (revised down to 66) low earth orbit communication satellites, known as the Iridium System (element 77 is Iridium)
1992 Bell Labs demonstrated 5-Gbps transmission of optical solutions over 15,000 km, and 10-Gbps over 11,000 km
1992 One-millionth host connected to the Internet, with the size now approximately doubling every year
1993 Internet Protocol version 4 (IPv4) established for reliable transmission over the internet in conjunction with the Transport Control Protocol (TCP)

1993 Asymmetric Digital Subscriber Lines (ADSL) standardized using the discrete multitone technique to allow greater services to be provided over the plain old telephone service (POTS)
1994-5 FCC licenses the Personal Communication Services (PCS) spectrum (1.7 to 2.3 GHz) for $7.7B
1996 1000BASE-T standardization begins for 1 Gbps Ethernet, expected to be available in 1999
1997 75% of elementary schools and 90% of secondary schools in US have Internet access. 25% and 30% of elementary and secondary classrooms, respectively, have Internet access

1998 Sprint Corp announces it will offer an advanced packet-switching network to simultaneously send voice, data, and video down a single phone line
1998 Ericsson, IBM, Intel, Nokia, and Toshiba announce they will join to develop Bluetooth for wireless data exchange between handheld computers or cellular phones and stationary computers
1990's Late in the decade, 56-kbps modems are available for high-speed communication over standard telephone lines
1990's Late in the decade, Virtual Private Networks (VPNs) become available

1990's Late in the decade, the very-high-performance Backbone Network Service (vBNS) implements connectivity for the next-generation Internet using IP-over-ATM running on a SONET 622.08-Mbps infrastructure
1990's Late in the decade, desktop video-teleconferencing (VTC) begins to mature
1990's Late in the decade, cable modems that exploit cable television connectivity begin to mature