Telefon

Dari Wikipedia bahasa Melayu

Telefon
Telefon
Dail telefon nada-sentuh (touch-tone)
Dail telefon nada-sentuh (touch-tone)

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Telefon berasal daripada (bahasa Greek: tele = jauh dan phone = suara) adalah alat telekomunikasi yang digunakan bagi memancar dan menerima bunyi (kebiasaanya suara dan percakapan) pada jarak jauh tanpa terikat, secara bebas. Kebanyakan telefon beroperasi melalui pemancaran isyarat eletrik melalui jaringan telefon rumit yang membenarkan sebarang pengguna telefon untuk berhubung dengan hampir kesemua yang lain. Terdapat telefon awam yang mana mengutip sedikit bayaran, menurut tempoh penggunaan, bagi kegunaan orang awam yang tidak memiliki telefon.

Jadual isi kandungan

[Sunting] Pengenalan

Terdapat empat prinsip utama di mana pengguna yang menggunakan penerima telefon boleh disambungkan kepada jaringan telefon: "talian darat" tradisi telefon kekal, di mana sambungan wayar fizikal khusus digunakan bagi menyambungkan sesuatu lokasi; wireless dan telefon radio, yang menggunakan samaada isyarat radio analog atau digital; telefon satelit, yang menggunakan satelit komunikasi; dan telefon suara melalui protokol internet (VOIP), yang menggunakan perhubungan capaian Internet Jalur Lebar.

Antara pengguna akhir, pemancar antara jaringan boleh dilakukan melalui kabel gentian optik, titik ke titik microwave atau relay satelit.

Sehingga kini, sebuah "telefon" merujuk kepada telefon talian tetap. telefon tanpa wayar atau wayarles dan juga telefon bimbit adalah satu perkara yang biasa wujud di mana-mana sahaja di seluruh dunia. Telefon bimbit pula dijangkakan bakal menggantikan penggunaan talian tetap. tidak seperti telefon bimbit, telefon tanpa wayar masih digelar sebagai talian tetap kerana ia hanya boleh digunakan pada jarak yang pendek di dalam suatu kawasan seperti rumah yang dihubungkan dengan telefon talian tetap.

Identiti pencipta telefon elektrik masih lagi menjadi tanda tanya dan kontroversi. Antonio Meucci, Philip Reis, dan Alexander Graham Bell, semuanya telah diiktiraf sebagai penciptanya.


[Sunting] Sejarah

Sejarah awal sebuah telefon adalah sedikit mengelirukan apabila banyak tuntutan dan tuntutan balik berlaku, di mana ia tidak diperjelaskan oleh pihak yang sepatutnya mengikut lunas undang-undang supaya dapat menyelesaikan pertikaian individu yang menuntuk hak paten masing-masing. ia adlah amat penting bagi semua pihak mengetahui bahawa tiada sesuatu pihak sahaja yang menjadi "pencipta telefon". Telefon moden sekarang ini adlah hasil sumbangan dan hasil kerja banyak pihak, yang sepatutnya diberikan pengiktirafan selayaknya.

[Sunting] Pembangunan Awal

Berikut adalah huraian secara ringkas sejarah penciptaan telefon:

  • 1849 Antonio Meucci mendemonstrasi suatu peranti yang kemudian dipanggil telefon kepada orang ramai di Havana.
  • 1854 Charles Bourseul menerbitkan suatu penerangan mengenai make-break transmiter telefon dan penerima tetapi tidak membuat sebarang instrumen kerja.
  • 1854 Meucci mendemonstrasi telefon elektrik di New York.
  • 1860 Johann Philipp Reis
  • 1860 Meucci dijangka (ketika itu) mendemonstrasi telefon tersebut di Staten Island.
  • 1861 Reis berjaya memindahkan suara secara elektikal dengan jarak melebihi 340 kaki. Untuk lebih lanjut, lihat Telefon ciptaan Reis.
  • 1871 Meeucci memfailkan satu paten caveat.
  • 1872 Elisha Gray menubuhkan Western Electric Manufactering Company.
  • July 1873 Thomas Alva Edison menemukan rintangan yang berbeza pada grain karbon oleh kerana tekanannya tetapi terpaksa menangguhkan penyelidikannya.
  • 1874 Gray mendemonstrasi telfon trnsmiter cecairnya di Gereja Highland Park Presbyterian.
  • 2 June 1875 Alexander Graham Bell orang pertama memindahkan suaranya melalui telefon.
  • 1 July 1875 Bell pertama kali menggunakan telefon berkebolehan dwi-arah (Kedua-dua, transmiter atau penghantar dan penerima isyarat merupakan instrumen membran yang serupa).
  • 14 February 1876 Bell memfailkan telefon tersebut sebagai paten pertama beliau.
    • Dua jam kemudian, Grayy memfailkan paten caveatnya.
  • 30 January 1877 Bell mempatenkan telefon dengan transmiter-penerima elektrodinamik.

[Sunting] Telefoni Digital

Digital Telefoni telah mula diterima pengguna setelah sistem litar analog telah digantikan dengan litar digital. Teknologi transmisi digital yang telah jauh berkembang telah menjadikan ia tidak mustahil untuk membawa pelbagai litar digital dalam satu medium transmisi(dikenali sebagai multiplex). Ketika penghujung instrumen kekal analog, isyarat-isyarat analog yang sampai ke titik agregat (Serving Area Interface (SAI) atau Central Office (CO) kemudian ditukarkan ke isyarat digital.


Digital telephony emerged when end-to-end analog circuits were replaced by islands of digital circuits. Advances in digital transmission technology made it possible to carry multiple digital circuits on a single transmission medium (known as multiplexing). While the end instrument remained analog, the analog signals reaching the aggregation point (Serving Area Interface (SAI) or the Central Office (CO) ) were converted to digital signals. Digital Loop Carriers (DLC) carried multiple analog telephone lines to the CO after converting them to digital signals, initially on copper wire pairs and later on optical fiber. COs were interconnected by SONET carriers.

[Sunting] Wireless phone systems

While the term "wireless" means radio and can refer to any telephone that uses radio waves it is primarily used for cell phones. In the United States wireless companies tend to used the term wireless to refer to a wide range of services while the cell phone itself is called a mobile phone, mobile, cell phone or simply cell with the trend now moving towards mobile.

The changes in terminology is partially due to providers using different terms in marketing to differentiate newer digital services from older analog systems and services of one company from another.

[Sunting] Cordless telephone

Cordless handset
Cordless handset

Cordless telephones, first invented by Teri Pall in 1965, consist of a base unit that connects to the land-line system and also communicates with remote handsets by low power radio. This permits use of the handset from any location within range of the base. Because of the power required to transmit to the handset, the base station is powered with an electronic power supply. Thus, cordless phones typically do not function during power outages. Initially, cordless phones used the 1.7 MHz frequency range to communicate between base and handset. Because of quality and range problems, these units were soon superseded by systems that used frequency modulation (FM) at higher frequency ranges (49 MHz, 900 MHz, 2.4 GHz, and 5.8 GHz). The 2.4 GHz cordless phones can interfere with certain wireless LAN protocols (802.11b/g) due to the usage of the same frequencies. On the 2.4 GHz band, several "channels" are utilized in an attempt to guard against degradation in the quality of the voice signal due to crowding. The range of modern cordless phones is normally on the order of a few hundred meters.

[Sunting] Telefon selular

Modern mobile phone systems are cell-structured. Radio is used to communicate between a handset and nearby cell sites.

When a handset gets too far from a cell site, a computer system commands the handset and a closer cell site to take up the communications on a different channel without interrupting the call.

Radio frequencies are a limited, shared resource. The higher frequencies used by cell phones have advantages over short distances. Connection distance is somewhat predictable and can be contolled by adjusting the power level. By only using enough power to connect to the "nearest" cell site phones using one cell site will cause almost no interference with phones using the same frequencies on another cell site. The higher frequencies also work well with various forms of multiplexing which allows more than one phone to connect to the same tower with the same set of frequencies.

[Sunting] Cordless/mobile phone

There are phones that work as a cordless phone when near their corresponding base station (and sometimes other base stations) and work as a wireless phone when in other locations but for a variety of reasons did not become popular.

Some kinds of cordless phones work like cellular phones but only within a small private network covering a building or group of buildings. These kinds of systems using VoIP are poplular in hospitals and factories where the same wireless network can be used for both data and voice.

[Sunting] VoIP Telephony

A WiFi-based VoIP phone
A WiFi-based VoIP phone

Also known as Internet telephony or Voice over IP (VoIP), digital telephony is a disruptive technology that is rapidly replacing traditional telephone networks. In Japan and Korea up to 10% of subscribers, as of January 2005, have switch from analog to digital telephone service. A recent Newsweek article suggested that Internet telephony may be "the next big thing." [1]

Digital telephones use a broadband Internet connection to transmit conversations as data packets. In addition to replacing the PSTN, digital telephony is also competing with mobile phone networks by offering free or lower cost connections via WiFi hotspots. As mentioned above VoIP is also used on private wireless networks which may or may not have a connection to the outside telephone network.

[Sunting] Telephone equipment research labs

Bell Labs is a noted telephone equipment research laboratory, amongst its other research fields.

[Sunting] Telephone operating companies

In some countries, many telephone operating companies (commonly abbreviated to telco) are in competition to provide telephone services. Some of them include those in the following list. However, the list only includes providers of copper wires from the exchange to the user, not those who only supply "Voice over IP" or only transport voice signals between exchanges. See also: List of telephone operating companies

[Sunting] Trivia

  • The modern handset came into existence when a Swedish lineman tied a microphone and earphone to a stick so he could keep a hand free.
  • The folding portable phone was an intentional copy of the fictional futuristic communicators (which in use actually more closely resembled walkie-talkies, Nextel-style) used in the television show Star Trek.

[Sunting] Lihat juga

Carilah telephone dalam Wiktionary, kamus yang bebas.

[Sunting] Telephone equipment

  • 431A
  • 610
  • Answering machine
  • Cordless telephone
  • Modem
  • Payphone
  • Pen register
  • Photophone
  • Telautograph
  • Telecommunications Device for the Deaf (TDD or TTY)
  • Telegraph
  • Switchboard
  • Telex
  • Teletype
  • Electronic Switching System

[Sunting] Telephone equipment manufacturers

Several manufacturers build telephones of all kinds. Some of these are:

  • Alcatel
  • Avaya
  • Conair (makers of Southwestern Bell Freedom Phone)
  • Ericsson
  • Huawei
  • Kyocera
  • Lucent
  • Marconi
  • Mitel
  • Motorola
  • Nokia
  • Nortel
  • palmOne / Handspring
  • Samsung
  • Siemens AG
  • Sony Ericsson
  • Unical Enterprises (makers of Northwestern Bell Phones)
  • US Electronics (makers of BellSouth Products)

[Sunting] Telephone technology

  • Asymmetric Digital Subscriber Line (ADSL)
  • AIOD leads
  • ANAC
  • ANI
  • Assistive technology
  • Automatic redial
  • Call capture
  • Call forwarding
  • Call waiting
  • Caller ID
  • Computer telephony integration (CTI)
  • Customer premises equipment (CPE)
  • Dial tone
  • Digital subscriber line (DSL)
  • Direct dial
  • Direct distance dialing
  • Dual tone multi frequency (DTMF)
  • Interactive Voice Response (IVR)
  • Last Call Return (*69)
  • Telephone feature code (* code)
  • Party line
  • Plain old telephone service (POTS)
  • Ringing signal
  • Videotex
  • Voice over Internet Protocol (VOIP)

[Sunting] Telephone system, organization, and structure

  • Area code
  • Office code
  • Basic exchange telecommunications radio service
  • Bell System
  • Call center
  • Competitive local exchange carrier (CLEC)
  • Foreign exchange service
  • Incumbent local exchange company (ILEC)
  • Key system
  • Local exchange company (LEC)
  • Public Switched Telephone Network (PSTN)
  • Regional Bell operating company (RBOC)
  • Post office
  • Private line
  • Private branch exchange (PBX)
  • Station set

[Sunting] Telephone hacking and exploitation

  • Blue box
  • Bomb threat
  • Crank (or prank) call
  • Demon dialing
  • (Phone) phreaking
  • Speed dialer
  • Telephone fraud
  • War dialing

[Sunting] US-specific terminology

  • Competitive local exchange carrier (CLEC)
  • Federal Standard 1037C
  • Interexchange carrier (IXC)
  • List of telephony terms
  • Local access and transport area (LATA)
  • Local exchange carrier (LEC)
  • Modification of Final Judgment
  • Federal Regulations - Part 68
  • Regional Bell operating company (RBOC)
  • US telephony

[Sunting] Telephone terminology

  • Call originator
  • Call waiting
  • Called party
  • Caller
  • Calling party
  • Circuit busy
  • COCOT
  • Deaf
  • Emergency telephone number
  • End instrument
  • Fax
  • Help desk
  • Hook
  • Hook Flash
  • Hunt Group
  • Infrastructure
  • Interactive voice response (IVR)
  • Line
  • Local loop
  • Long-distance operator
  • Operator assistance
  • Person-to-person
  • Red telephone, Red telephone box,
  • Ringer equivalency number (REN)
  • Ringing signal
  • Rural radio service
  • Smartphone
  • Station-to-station
  • Telemarketing
  • Telephone booth
  • Telephone call
  • Telephone card
  • Telephone directory
  • Telephone exchange
  • Telephone tapping
  • Telephone User Interface (TUI)
  • Telephony Application Programming Interface (TAPI)
  • Trap and trace
  • TWX
  • Vertical service code
  • Voicemail
  • Western Union
  • Wide Area Telephone Service (WATS)
  • WATS line
  • Wireless network
  • Wi-Fi
  • Zenith number

[Sunting] Telephone Standards

[Sunting] Wired Standards

  • RJ-11
  • BS_6312

[Sunting] Wireless Standards

There are many standards for common carrier wireless telephony, often with incompatible standards used in the same nation:

  • First generation - Analog
    • marine and mobile radio telephony
    • AMPS
      • CDPD
    • NMT
  • Satellite systems- digital
    • Inmarsat
    • Iridium (satellite)
  • Second generation (2G) - Digital
    • CDMA IS-95A
    • GSM, (different frequencies for different continents: see GSM article)
    • iDEN
    • TDMA IS-136
  • 2.5G
    • CDMA IS-95B
    • GPRS
    • EDGE
    • PDC-P
  • Third generation (3G)
    • CDMA 2000
    • UMTS, also called W-CDMA
    • TD-SCDMA

[Sunting] References

  • Huurdeman, Anton A. (2003). The Worldwide History of Telecommunications, IEEE Press and J. Wiley & Sons, 2003. ISBN 0471205052


[Sunting] Patents

  • US174465 -- Telegraph -- A. G. Bellem:Telephone