Pengantar Teknologi Informasi

Jaringan (Layer Fisik)

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

Layer Fisik

1. Sinyal digital dan analog

Contoh alat: modem

2. Media transmisi

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

UTP, banyak komputer

1 hub: beberapa komputer

jumlah port di hub

Jaringan UTP

Hubungan antar hub

Twisted Pair

Jenis:

STP

UTP

Speed autosensing

RJ-45

Jack RJ-45

Connector

4 pairs (8 lembar)

No metal shielding

UTP

Coaxial

cabel TV (CATV)

LAN

Fiber Optic

Serat lensa

Light

Source

(LED or

Laser)

Light

Source

(LED or

Laser)

Cladding

Core

Light

Ray

Reflection at Core/Cladding Boundary

Wireless

Radio modem

waveLAN

Access Point

WiFi

VSAT

PAN: bluetooth, IrDA

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)

Access Point

Penghubung dari wireless ke LAN

Access Point

UTP RJ-45Port

SwitchOr Hub Server

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

Bluetooth

connecting between mobile data devices

PAN: personal area network

Frekuensi: 2.4 GHz

IrDA

Infrared Data Association

Satellite

Point-to-Point

Uplink Broadcast

Downlink

Earth Station A

Earth Station B

Geosynchronous

Satellite

Topology

Star

Bus

Ring Bus

Switch, hub, repeater

Jarak

LAN: jarak dekat, area terbatas

WAN: jarak jauh, melalui area publik