pengantar teknologi informasi -...
TRANSCRIPT
Sebelumnya
Standard
Protocol
Layer
OSI LAYER TCP/IP
Application (7) 5. Application
Presentation (6)
Session (5)
Transport (4) 4. Transport
Network (3) 3. Internet
Data link (2) 2. Data link
Physical (1) 1. Physical
1. Layer Fisik: sinyal
Masalah pe-sinyal-an:
Sinyal digital
Sinyal analog
VOLTAGE LEVEL
1 CLOCK CYCLE
1. Layer Fisik
Masalah pe-sinyal-an:
Komputer memahami digital (biner)
Media ‘hanya’ menghantarkan sinyal analog
Komputer A Komputer B Modem Modem
Sistem Perteleponan
Sinyal digital
Sinyal digital
Sinyal analog Sinyal analog
1. Modulasi
Sinyal dikirimkan dalam perubahan modus
Jenis modulasi:
AM : amplitude
FM : frequency
PM : phase
CM : complex
AM
FM
PM
Carrier
1. Modem
Modulator: ubah sinyal digital ke analog
Demodulator: ubah sinyal analog ke digital
(biasa) digunakan menghubungkan komputer melalui line telepon (analog)
Modem komputer PC
1. Modem
Modem:
Modulator - Demodulator
Modem komputer PC:
External
Internal
PCMCIA
Port: serial / com, usb, …
Standard: ITU-T
1. Komunikasi
Komunikasi: mengirim data dari sumber ke tujuan.
Transmiter: alat untuk mengirim Receiver: alat untuk menerima
DestinationSource
PC 1
transmitter receiver
Destination receiver transmitter Source
PC 2
1. Arah Transmisi
Simplex
Contoh: siaran radio
Duplex:
Half duplex
Full duplex
Pc-1 Pc-2
iBook
tra
nsm
it
recv
Re
ce
ive
Pc-1 Pc-2
RX
TX
TX
RX
Duplex: full-duplex
simplex
Pc-1 Pc-2
TX
RX
TX
RXmedia
Half duplex
2. Media Transmisi
Jenis media
Kabel, wire, guided
Nirkabel, wireless, unguided
Karakteristik
Topologi
Jarak
Kabel
Twisted Pair
Shielded twisted pair (stp)
Unshielded twisted pair (utp)
Coaxial cable
Optical fiber
Hubungan 2 komputer
Hubungkan 2 komputer:
serial-to-serial: terminal, null modem
network card, UTP cable
Network card, coaxial cable
PC-1PC-2
Berbeda: hubungan komputer dengan external device
(printer, keyboard, …)
Hubungan 2 komputer
Hubungkan 2 komputer melalui PSTN
PC-1 PC-2Modem
Modem
USBCOM
Telephone
PSTN
Public Service
Telephone
Network
Telephone
Hubungan 2 komputer
Hubungkan komputer ke ISP
Internet Service Provider
PC-1Modem
COM
Telephone
PSTN
Public Service
Telephone
Network
T1: 32 lines
Rack modem Router
Internet
Twisted Pair
Jenis:
STP
UTP
Speed autosensing
RJ-45
Jack RJ-45
Connector
4 pairs (8 lembar)
No metal shielding
Fiber Optic
Serat lensa
Light
Source
(LED or
Laser)
Light
Source
(LED or
Laser)
Cladding
Core
Light
Ray
Reflection at Core/Cladding Boundary
Service band
service band = pita layanan
Setiap service band dibagi dalam beberapa chanel
Bandwidth: lebar pita
Makin lebar pita, makin cepat sinyal
Broadband: wide bandwidth
Narowband: small bandwidth
Channel 4
Channel 3
Channel 5
Channel 2
Channel 1
Service
Band
0 Hz
Frequency
Spectrum
(0 Hz
to infinity)
Radio Modem
Frekuensi radio: 30 – 300 MHz
Max data rate: 100 Kbps
Jarak tergantung amplifier
Radio amatir
waveLAN
Standard: 802.11
Unlicensed frequency: 2,4 GHz dan 5,8 GHz industrial, scientific and medical devices (ISM)
Hubungan antar gedung, maks: 5 km; amplifier->60km
Digunakan oleh: warnet, sekolah, isp
Wired Equivalent Privacy (WEP)
WiFi
Wireless Local Area Network based on IEEE 802.11 specification 802.11b: 11 mbps; 2.4 GHz
802.11g: 50 mbps ; 2.4 GHz
802.11a: 50 mbps; 5 GHz
connecting mobile data devices and Wi-Fi access points to wired network
Wireless Protected Access
hotspot
Satellite
Point-to-Point
Uplink Broadcast
Downlink
Earth Station A
Earth Station B
Geosynchronous
Satellite