6. 6
ខាងច្រកាមគឺោ ឧទាហរណ
៍ ច្សវាកមមសដលសផអកច្លើ Telecommunication
• Banking, automatic teller machines, telebanking
• Aviation, booking of ticket
• Sales, whole sale and order handling
• Credit card payments
• Material purchasing by industry
• Government operation, such as taxation
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៥. ជំនាន់ Mobile Communication
- 1st Generation (16Mobiles): Analog (Frequency) ច្របើបានអេិងិជនេិច
- 2nd Generation (26Mobiles): Digital speed: 13kbps as fax
- 3rd Generation (36Mobiles): Digital speed: 2Mbps as internet(video call)
- 4th Generation (46Mobiles): Digital(code:0,1,1,0,…) speed: 10Mbps as
video call
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៥.១ . 1st Generation(1980):
- 1895 : telegraph (បញ្ជូ នោសញ្ញ
ា ច្រេ)
- 1946 :telephone in car (USA)
- 1970 :1st analog cellular system AMPS(Advance Mobile Phone
System: use in Chicago)
- 1980 :HCMTS(High Capacity Mobile Telephone System: use in
Tokyo)
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៥.១ . 1st Generation(1980):
- 1981 :NMT(Nordic Mobile Telephone: used in Nordic
country(NMT450, NMT900))
- 1985 :TACS(Total Access Communication System: used in UK)
- 1985 :Radio Com2000 used in France
- 1986 : C450 used in Germany
- 1985-1990 : Generalization of analog cellular system
- 1986-1990 : Develop European Digital System
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៥.២ . 2nd Generation(1992) :data speed 13Kbps, voice
- GSM(Global System for Mobile Communication): GSM900900MHz),
GSM1800(1800MHz) , GSM1900(1900MHz)
- IS-95A(Interim Standard – 95A) or call CDMA(Code Division Multiple
Access)
GSM1800 changed to DCS 1800(Digital Cellular System)
GSM1900 changed to PCS 1900(Personal Communication System):
japan
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៥.៣ . 2. 5nd Generation:
- GPRS : General Packet Radio Service(data speed : 115Kbps)
- CDMA (rev B rare use) :( data speed : 64Kbps)
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៥.៤ . 3rd Generation: data speed : 2Mbps(voice and data: video call)
- EDGE, UMTS, CDMA 2000
- UMTS(Universal Mobile Telecommunication System) or
- WCDMA(Wide Code Division Multiple Access)
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៥.៥ . 3.5th Generation: data speed from 2Mbps to 5Mbps(voice and
data: video call)
- HSPA : High Speed Packet Access(HSDPA and HSUPA)
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៥.៦ . 4th Generation: speed 1Gbps(video call)
- LTE: Long Term Evolution
- WiMAX (Wireless Interoperability for Microwave Access)
