Telephone communication The Nature and Development of Science and Technology Topic : The important issues of science and technology.

Telephone Telephone communicationcommunication

The Nature and Development of The Nature and Development of Science and TechnologyScience and Technology

Topic : Topic : The important issues of science and The important issues of science and technologytechnology

Before the development of telephonesBefore the development of telephones

I. I. How did ancient people How did ancient people communicate with each communicate with each other?other?

Before the development of telephonesBefore the development of telephones

Ancient communication methods:Ancient communication methods:

• Signal fire (fire and smoke)Signal fire (fire and smoke)

• Letters by doveLetters by dove

• Drum beatingDrum beating

More recent methods:More recent methods:

• The feasibility of communication by telegraphThe feasibility of communication by telegraph

Igniting signal fireIgniting signal fire

In 1200BC, Homer had stated about using signal fire to communicate in the book《 Iliad 》

Letters by doveLetters by dove

From 700 BC to AD 300, the Greeks used doves to transmit information in the Olympic Game

Drum beatingDrum beating

Telegraphic communicationTelegraphic communication

Morse proved the feasibility of telegraphic communication

II. II. Invention of telephonesInvention of telephones

Invention of telephonesInvention of telephones

The history of telephone The history of telephone communication developmentcommunication development

1.1. Timeline of telephone inventionTimeline of telephone invention

2.2. How was telephone inventedHow was telephone invented ？？3.3. How does telephone operateHow does telephone operate ？？4.4. Types of telephonesTypes of telephones

5.5. What are the functions of the telephonesWhat are the functions of the telephones ？？

1. Timeline of telephone invention1. Timeline of telephone invention• 18441844- Morse proved the feasibility of telegraphic communication- Morse proved the feasibility of telegraphic communication• 18651865- Physician - Physician Maxwell mathematically predicts the Maxwell mathematically predicts the propagation of electromagnetic waves through air in the propagation of electromagnetic waves through air in the spacespace • 18751875- The principle of using telephone for information - The principle of using telephone for information transmission proposed by A.G. Bell was verified by transmission proposed by A.G. Bell was verified by experimentexperiment• 18761876- A.G.Bell invented telephones- A.G.Bell invented telephones• 18761876- T.A. Edison invented- T.A. Edison invented the electric motor and the phonograph the electric motor and the phonograph• 18881888- - H. Hertz investigated the principles and application of radio H. Hertz investigated the principles and application of radio waveswaves• 19021902- - First conversation by long distance underground cableFirst conversation by long distance underground cable • 19351935- - First around-the-world telephone conversation by wire and First around-the-world telephone conversation by wire and radioradio • 19461946- - Mobile telephone service was placed into commercial useMobile telephone service was placed into commercial use Source: http://cd1.edb.hkedcity.net/cd/science/science_and_technology/Compulsory/Part2_Eng/ref4_1t.docSource: http://cd1.edb.hkedcity.net/cd/science/science_and_technology/Compulsory/Part2_Eng/ref4_1t.doc

2. How was telephones invented2. How was telephones invented ？？In addition to discover the feasibility of telegraph, Morse also invented the Morse Code - a very conventional communication method. Since the telegraphic era, this method already existed. As it has the advantages of simple, low cost and high efficiency, it is still on an important position in the advanced communication technology nowadays.

2. How was telephones invented2. How was telephones invented ？？

Maxwell mathematically dMaxwell mathematically deduced that electromagnetieduced that electromagnetic waves propagate in the aic waves propagate in the air . r . The equations about electrThe equations about electromagnetic waves proposed omagnetic waves proposed by him is still applied wideby him is still applied widely nowadaysly nowadays

Bell became known to the world since his invention of telephone. He dedicated his whole life as an enthusiastic educationalist and inventor. After Bell has invented telephone successfully, he continued on other experiments and investigated on several inventions included the Photophone (the predecessor of disk records) and the hydrofoil 。

2. How was telephones invented2. How was telephones invented ？？

Bell produced the prototype of the telephone in the figure above in 1875. Bell produced the prototype of the telephone in the figure above in 1875. The set-up was equipped by an electric wire, an arm-shaped magnet and a The set-up was equipped by an electric wire, an arm-shaped magnet and a tight held thin diaphragm to compose a sound vibration diaphragm to tight held thin diaphragm to compose a sound vibration diaphragm to induce the arm-shaped magnet to vibrates. Displacement of the magnet induce the arm-shaped magnet to vibrates. Displacement of the magnet induced fluctuating electric current to the coil and this electrical signal can induced fluctuating electric current to the coil and this electrical signal can be transformed as sound by the same installment in another end.be transformed as sound by the same installment in another end.

The telephone produced by Bell

3. How does telephone operate3. How does telephone operate ？？

4. Types of telephones4. Types of telephones

• 2-pieces telephone2-pieces telephone

• Indoor wireless phoneIndoor wireless phone

• Cellular phoneCellular phone （（ mobile phonemobile phone ））

5.5.What are the functions of the What are the functions of the telephonestelephones ？？

• Radio wave technology is applied in wired telephones Radio wave technology is applied in wired telephones and cellular (mobile) phonesand cellular (mobile) phones

• In addition to general telephone services, the new In addition to general telephone services, the new generation mobile phone even provide wireless web generation mobile phone even provide wireless web accessing service for users to send and receive e-accessing service for users to send and receive e-mails and browsing the Internet through the phonesmails and browsing the Internet through the phones

• Micro-video camera is installed in video phones for Micro-video camera is installed in video phones for sound and video information transmission sound and video information transmission simultaneously.simultaneously.

Modern 3G mobile phone Modern 3G mobile phone technologytechnology

• The third generation (3G) mobile phone The third generation (3G) mobile phone system has combined high-speed mobile system has combined high-speed mobile connection and Internet Protocol (IP) servicesconnection and Internet Protocol (IP) services

Causes of the rapid development of Causes of the rapid development of mobile phonesmobile phones

• Social needsSocial needs- Pursuing for bettermentPursuing for betterment

- Communicate with distant peopleCommunicate with distant people

• Military investmentMilitary investment- Governments develop for military Governments develop for military

purposespurposes

- Military contestMilitary contest

The influences of 3G mobile The influences of 3G mobile phones to the usersphones to the users

• Services of communication, Services of communication, information, media and information, media and entertainment, etc. can be entertainment, etc. can be enjoyed through a single enjoyed through a single terminal. All of the terminal. All of the communication services communication services combined into one body.combined into one body.

III. Modern telephone technologyIII. Modern telephone technology

Assisting tools of communication Assisting tools of communication development:development:

• InternetInternet

• Optic fiberOptic fiber

• Wireless transmissionWireless transmission

• Satellite signalSatellite signal

Assisting tools of communication Assisting tools of communication developmentdevelopment::

Internet

Assisting tools of communication Assisting tools of communication developmentdevelopment::

Optic fibers

http://www.info.gov.hk/digital21/eng/images/strategy2001/Fibre2.jpg

Assisting tools of communication Assisting tools of communication developmentdevelopment::

Wireless transmission

Assisting tools of communication Assisting tools of communication developmentdevelopment::

Satellite signal

Modern telephone technologyModern telephone technology

• Modern third generation mobile phone Modern third generation mobile phone technology (3G)technology (3G)

• Blue-tooth technologyBlue-tooth technology

• Global Positioning System (GPS)Global Positioning System (GPS)

Techniques Functions

AMPS Advanced Mobile Phone Service -Analogue voice service--No data positioning capability

2G CDMA Code Division Multiple Access

-Digital voice service-- 9.6kbps - 14.4kbps- CDMA 、 TDMA 和 PDC 均只提供單向數據傳輸- 更強來電功能，例如來電識別號碼- 不能提供永遠在線的數據連接

  TDMA Time Division Multiple Access

  GSM Global System for Mobile Communications

  PDC Personal digital cellular

3G W-CDMA Wide-band Code Division Multiple Access

-超卓話音質素- 最高可達每秒 2M 位元，永遠在線的數據連接- 寬頻數據服務，例如視訊及多媒體- Higher efficiency roaming service- Multimedia data, positioning capability, connection to Internet, always connected

  CDMA-2000 Transition standard according to that of CDMA－ 95

  TD-SCDMA Time-division synchronous code-division multiple-access

1G

TECHNOLOGY FEATURES

AMPS Advanced Mobile Phone Service -Analog voice service- No data service

2G CDMA Code Division Multiple Access

- Digital voice service- 9.6K to 14.4K bit/sec.- CDMA, TDMA and PDC offer one-way data transmissions only- Enhanced calling features like caller ID- No always-on data connection

  TDMA Time Division Multiple Access

  GSM Global System for Mobile Communications

  PDC Personal digital cellular

3G W-CDMA Wide-band Code Division Multiple Access

- Superior voice quality- Up to 2M bit/sec. always-on data- Broadband data services like video and multimedia- Enhanced roaming

  CDMA-2000 Based on the Interim Standard-95 CDMA standard

  TD-SCDMA Time-division synchronous code-division multiple-access

1G

3G Mobile phone

Simulation of video-phone

http://foma.nttdocomo.co.jp/english/index.html

Blue-tooth technologyBlue-tooth technology

Source ： Corega Technology Ltd.

Blue-tooth technologyBlue-tooth technology

• A wireless radio wave communication A wireless radio wave communication

technology without affected by technology without affected by

electromagnetic waveelectromagnetic wave

• Information transmission is not restricted by Information transmission is not restricted by

geographic environment, communication geographic environment, communication

system or networksystem or network

Global Positioning System(GPS)Global Positioning System(GPS)

• Information supplied by artificial satellitesInformation supplied by artificial satellites• GPS comprises of 3 parts: control, satellite and GPS comprises of 3 parts: control, satellite and

receptor partsreceptor parts• Control part: traces the satellite’s position and Control part: traces the satellite’s position and

transmit orderstransmit orders• Satellite part: emits navigating signals to the Satellite part: emits navigating signals to the

earth continuallyearth continually• Receptor part: as user’s receptor Receptor part: as user’s receptor

SPACE SEGMENTSPACE SEGMENT

CONTROL SEGMENTCONTROL SEGMENT USER SEGMENTUSER SEGMENT