10-20pengantar-20jaringan-20komputer-20dan-20kom-20dat-131115111613-phpapp02.pdf

PENGANTAR JARINGAN
KOMPUTER DAN
KOMUNIKASI DATA
PENGANTAR TEKNOLOGI INFORMASI

Telecommunications Systems
 Data Communication : High speed data exchange between computers
and/or other electronic devices via cable or wireless.
(BussinesDictionary.com)
 Telecommunications can be defined as communication of data and
information by electronic means such as telephone, radio, television, and
computer, usually over some distance
 Computer communications : a process in which one computer
transfers data, information and instructions to another computer
 Telecommunications system is a collection of compatible hardware
and software arranged to communicate data, information and instructions
from one location to another
 Telecommunications systems can transmit text, graphic images, voice,
and video information through communications channel
Overview

Contoh sistem telekomunikasi
Overview
Telecommunications Systems(cont.)

Model telekomunikasi
Overview

 A sending device that initiates an instruction to transmit data,
information, or instructions. It can be a computer system, a terminal, a
cellular telephone, a WebTV, a GPS receiver, an Internet-enabled PDA,
or another device that originates the message.
 A communications device that connects the communications channel to
a sending device.
 A communications channel or transmission media on which the data,
instructions, or information travel.
 A communications device that connects the communications channel to
a receiving device.
 A receiving device that accepts the transmission of data, information, or
instructions.
 A communications software that controls and manages the activities
and functions of the communications network.
 The telecommunications model consists of the following:
Overview

Telecommunications System Components
1.
Communications
Devices
 Devices that handle
the movement of data
in a computer network
include:
 modem
 Router
 Hub
 Network interface
cards
 Multiplexer
 Front-end
processor
 Host computer

 MODEM (Modulation/Demodulation)
 Connects a communications channel to a sending or receiving device
 Computers process data as digital signals.
 Data, instructions, and information travel along a communication
channel in either analog or digital form
 Modem converts analog to digital signals and digital to analog signals
 Converting signal from digital to analog is called modulation
 converting signal from analog to digital is called demodulation
1.
Communications
Devices
Telecommunications System Components(cont.)

1.
Communications
Devices
1. Dial-up modem
• usually is in the form of an adapter card
that you insert in an expansion slot on a
computer's motherboard
• One end of a standard telephone cord
attaches to a port on the modem card
and the other end plugs into a telephone
outlet
2. Cable modem
• a digital modem that sends and
receives digital data over the cable
television (CATV) network
• A cable modem usually is an external
device, in which one end of a cable
connects to a CATV wall outlet and
the other end plugs in a port in the
system unit

3. wireless modem
• allows access to the Internet
wirelessly from a notebook
computer, a PDA, a smart phone,
or other mobile device
• Wireless modems, which have an
external or built-in antenna,
typically use the same waves used
by cellular telephones
1.
Communications
Devices

 DEVICES CONNECTING NETWORKS
 Network bridging provides
an easy way to connect 2
or more network to become
a single big network without
using router in order to
share file, printer or
Internet connection.
 Please note that all
computers in different
network that needs to be
bridged must sit in same
logical IP network.
1. bridge
1.
Communications
Devices

2. gateway
 a communications processor that
connects networks that use
different protocols by providing
the translation from one set of
protocols to another
3. router
 an intelligent bridge for large
networks
 connect multiple networks and
routs communications traffic to
the appropriate network using
the fastest available path
 many routers are protected by a
built-in firewall
1.
Communications
Devices

4. front-end processor
 a small computer dedicated to communications management and is
attached to the main, or host, computer in a large computer system
 The front-end processor is largely responsible for collecting and
processing input and output to and from terminals and grouping
characters into complete messages for submission to the CPU of
the host computer
5. network card/network interface card (NIC)
 is an adapter card, that enables the
computer or device that does not have
built-in networking capability to access a
network
1.
Communications
Devices

6. repeater
 a device that accepts a signal from a transmission medium,
amplifies it, and retransmits it over the medium
 As a signal travels over a long distance, the signal undergoes a
reduction in strength, an occurrence called attenuation
7. hub or switch
 a device that provides a central point for cables in a network
 receives data from many directions and then forwards it to one or
more destinations
1.
Communications
Devices

2.
Communications
Channels
 Communications Channels
 communications path between
two devices.
 composed of one or more
transmission media
 The amount of signals that can
travel over a communications
channel sometimes is called the
Bandwidth
 Baseband transmission media
can transmit only one signal at a
time
 broadband media can transmit
multiple signals simultaneously

 Transmission media are one of two types:
 physical or
 wireless
 Physical transmission media use wire, cable, and other tangible
materials to send communications signal
 Wireless transmission media send communications signals through
the air or space using radio, microwave, and infrared signals
 Physical transmission media used in communications include
 twisted-pair cable,
 coaxial cable, and
 fiber-optic cable
 These cables typically are used within building or underground between
buildings
2.
Communications
Channels

1. twisted-pair wire cable
 consists of one or more twisted-pair wires bundled together
 The wires are twisted together to reduce noise, which is an electrical
disturbance that can degrade communications
 shielded twisted-pair (STP) cable, has a metal wrapper around each
twisted-pair wire, which further reduces noise
 Cables that do not have this shielding are called unshielded twisted-
pair (UTP)
 Physical Transmission Media
2.
Communications
Channels

2. coaxial cable
 consists of a single copper wire
surrounded by at least three
layers:
• an insulating material,
• a woven or braided metal, and
• a plastic outer coating
3. fiber-optic cable
 consists of dozens or hundreds of thin strands
of glass or plastic that use light to transmit
signals
 Each strand, called an optical fiber
 advantage include (1) capability of carrying
significantly more signals; (2) faster data
transmission; (3) less susceptible to noise from
other devices; (4) better security for signals
during transmission; and (5) smaller size
2.
Communications
Channels

The speeds of various physical communications
media when they are used in LANs
2.
Communications
Channels

 Wireless Transmission Media
Wireless transmission media used in communications include
 broadcast radio,
 cellular radio,
 microwaves,
 communications satellites, and
 infrared
1. Broadcast radio
 a wireless transmission
medium that distributes radio
signals through the air over
long distances
 Bluetooth, Wi-Fi, UWB, and
WiMAX communications
technologies use broadcast
radio signals
2.
Communications
Channels

2. Celular radio
 a form of broadcast radio that is used widely for mobile
communications, specifically wireless modems and cell phones
 Several categories of cellular transmissions exist, defining the
development of cellular networks:
• 1G (first generation) transmitted analog data
• 2G (second generation) transmit digital data at speeds from
9.6 kbps to 19.2 kbps
• 3G (third generation) transmit digital data at speeds from 114
kbps to 2.4 Mbps
• 4G (fourth generation) transmit digital data at speeds up to 15
Mbps
 3G technology allows users quickly to display multimedia and
graphics, browse the Web, watch television or a video, have a
video conference, and transfer data on a cellular device
2.
Communications
Channels

2.
Communications
Channels

3. microwafe
 high-frequency radio waves that are sent
through the atmosphere and space
 Microwaves provide a high-speed signal
transmission, and can transmit data at
rates up to 4,500 times faster than a dial-
up modem
 Microwaves are limited to line-of-sight transmission, which means
that microwaves must be transmitted in a straight line with no
obstructions between microwave antennas
 To avoid possible obstructions, such as buildings or mountains,
microwave stations often sit on the tops of buildings, towers, or
mountains
 Microwave signals can carry thousands of channels at the same
time.
2.
Communications
Channels

4. communications satellite
 basically a microwave station
placed in outer space
 The satellite receives the signal
from the earth, amplifies the
relatively weak signal, and then
rebroadcasts it at a different
frequency to any number of earth-
based stations
 Transmission from an earth-based station to a satellite is an uplink
 Transmission from a satellite to an earth-based station is a downlink
 The advantage of satellite communications is the ability to receive
and broadcast over larger geographic regions
2.
Communications
Channels

5. infrared
 a wireless transmission media that
sends signals using infrared light waves
 Infrared transmission requires a line-of-
sight transmission and short distances
-- under a few hundred yards
 Infrared transmission can be used to
connect various devices and
computers.
 For example, infrared transmission has been used to allow handheld
computers to transmit data and information to larger computers within
the same room
 This means of transmission can be used to establish a wireless
network with the advantage that devices can be moved, removed,
and installed without expensive wiring and network connections
2.
Communications
Channels

3.
Comm.
Soft.,
standards,
Protocol
 Communications software
 consists of programs that
 help users establish a connection to another computer or network;
 manage the transmission of data, instructions, and information;
 provide an interface for users to communicate with one another
 A set of rules and procedures governing transmission between
components in a network is called a protocol
 The principal functions of protocol in a network include:
 identifying each device in the communication path
 securing the attention of the other device
 verifying correct receipt of the transmitted message
 determining that a message requires retransmission if it is
incomplete or has errors
 performing recovery when errors occur

 Ethernet
 a network standard that specifies no central computer or device on the
network (nodes) should control when data can be transmitted
 each node attempts to transmit data when it determines the network is
available to receive communications
 If two computers on an Ethernet network attempt to send data at the
same time, a collision will occur, and the computers must attempt to
send their messages again
 Ethernet is the popular communications protocol often used with local
area networks (LAN) because it is relatively inexpensive and easy to
install and maintain
 A more recent Ethernet standard, called Fast Ethernet , 10-Gigabit
Ethernet
3.
Comm.
Soft.,
standards,
Protocol

 Token Ring
 another popular network standard for LANs.
 Token ring is based on ring topology (although it can use a star topology)
 Some token ring networks connect up to 72 devices
 The data transfer rate on a token ring network can range from 4 Mbps to
1 Gbps
 Transmission Control Protocol/Internet Protocol (TCP/IP)
 a network standard that defines how messages (data) are routed from
one end of a network to the other, ensuring the data arrives correctly
 TCP/IP has been adopted as a network standard for Internet
communications.
 TCP provides transport functions, ensuring, among other things, that the
amount of data received is the same as the amount transmitted
 IP provides the addressing and routing mechanism that acts as
postmaster
3.
Comm.
Soft.,
standards,
Protocol

TCP/IP’s four-layer reference model:
 Application layer serves as the
window for users and application
processes to access network
services
 Transport layer handles end-to-
end packet transportation
 Internet layer formats the data into packets, adds a header containing
the packet sequence and the address of the receiving device, and
specifies the services required from the network.
 Network interface layer places data packets on the network for
transmission
3.
Comm.
Soft.,
standards,
Protocol

The TCP/IP suite of applications includes five protocols:
 Simple Mail Transfer Protocol (SMTP): It is TCP/IP s own
�
messaging system for e-mail.
 File Transfer Protocol (FTP): It allows files containing text,
programs, graphics, numerical data, and so on to be downloaded
off or uploaded onto a network.
 Telnet Protocol: It provides terminal emulation that allows a
personal computer or workstation to act as a terminal, or access
device, for a server.
 Hypertext Transfer Protocol (HTTP): It allows Web browsers
and servers to send and receive Web pages.
 Simple Network Management Protocol (SNMP): It allows the
management of networked nodes to be managed from a single
point.
3.
Comm.
Soft.,
standards,
Protocol

 802.11 (Wi-Fi)
 developed by IEEE, is a series of
network standards that specifies how
two wireless devices communicate over
the air with each other
 The 802.11 standard often is called the
wireless Ethernet standard because it
uses techniques similar to the Ethernet
standard to specify how physically to
configure a wireless network
 The term Wi-Fi (wireless fidelity) identifies any network based on the
802.11 series of standards
 Windows Vista and Windows Mobile include support for Wi-Fi. Most of
today's computers and many personal mobile devices are Wi-Fi
enabled.
3.
Comm.
Soft.,
standards,
Protocol

 Bluetooth
 a network standard that defines how two Bluetooth devices use short-
range radio waves to transmit data
 The data transfers between devices at a rate of up to 3 Mbps
 To communicate with each other, Bluetooth devices often must be
within about 10 meters but can be extended to 100 meters with
additional equipment. Windows Vista has built-in Bluetooth support.
 UWB
 stands for ultra-wideband, is a network standard that specifies how two
UWB devices use short-range radio waves to communicate at high
speeds with each other
 At distances of 10 meters (about 33 feet), the data transfer rate is 110
Mbps. At closer distances, such as 2 meters (about 6.5 feet), the
transfer rate is at least 480 Mbps
 Because of its high transfer rates, UWB is best suited for transmission of
large files such as video, graphics, and audio.
3.
Comm.
Soft.,
standards,
Protocol

 IrDA
 a standard for transmitting data wirelessly to each other via infrared light
waves
 he devices transfer data at rates from 115 Kbps to 4 Mbps between their
IrDA ports
 Infrared requires a line-of-sight transmission, which means that the
sending device and the receiving device must be in line with each other
so that nothing obstructs the path of the infrared light wave
 RFID
 a standard that defines how a network uses radio signals to communicate
with a tag placed in or attached to an object, an animal, or a person
 An active RFID tag contains a battery that runs the chip's circuitry and
broadcasts a signal to the RFID reader
 A passive RFID tag does not contain a battery , can be small enough to
be embedded in skin
3.
Comm.
Soft.,
standards,
Protocol

RFID toll collection
3.
Comm.
Soft.,
standards,
Protocol

 WiMAX (Worldwide Interoperability for Microwave Access)
 also known as 802.16, is a newer network standard developed by IEEE
that specifies how wireless devices communicate over the air in a wide
area
 Using the WiMAX standard, computers or devices with the appropriate
WiMAX wireless capability communicate via radio waves with other
computers or devices via a WiMAX tower.
 Fixed wireless WiMAX has data transfer rates up to 40 Mbps, while
mobile wireless WiMAX has data transfer rates up to 15 Mbps.
 WAP (Wireless Application Protocol )
 standard that specifies how some mobile devices can display the
content of Internet services such as the Web, e-mail and chat rooms
 On WAP-enabled devices, data transfer rates range from 9.6 to 153
Kbps depending on the type of service
3.
Comm.
Soft.,
standards,
Protocol

Data Transmission
 Signal Type: Analog or Digital
Signal
Type

 Transmission Modes: Asynchronous and Synchronous
 Asynchronous transmission transmits one byte at a time over a line at
random intervals, each byte framed by controls -- a start bit for marking the
beginning of the byte, a stop bit for marking the end of the byte, and a parity
bit for error checking. Asynchronous transmission is relatively slow and used
for low-speed transmission.
 Synchronous transmission transmits groups of bytes simultaneously at
regular intervals, with the beginning and ending of a block of bytes determined
by the timing circuitry of the sending device and receiving devices. it provides
much higher speeds and greater accuracy than asynchronous transmission
Data Transmission(cont.)
Transmission
Modes

 Transmission Direction
Simplex transmission sends data in one
direction only. One example of simplex
transmission is television broadcasting.
Half-duplex transmission allows data
transmission in either direction, but only
one way at a time. Many fax machines,
credit card verification systems and
automatic teller machines use half-duplex
transmission.
Full-duplex transmission, data can flow in
both directions at the same time. A regular
telephone line, for example, supports full-
duplex transmission, allowing both parties
to talk at same time.
Multiplex transmission, several different
types of signals can be carried at once
through the same line.
Data Transmission(cont.)
Transmission
Direction

Networks
1.
Network
Topologies
 A network is a collection of
computers and devices connected
by telecommunications channels
that allows users to facilitate
communications, and to share
data, information, software, and
hardware with other users.
 A network topology is a
description of the possible
physical connections within a
network
 Network Topologies
 In a network topology, a component is called a node, which refers to any
device connected to a network, including the server, computers,
telephones, and other devices
 Three commonly used network topologies are bus, ring, and star.

1. Bus network
 consists of a single central cable, to
which all the network nodes are attached
 The bus is the physical cable that
connects the computers and other
devices.
 when a sending device transmits data,
address of the receiving device is
included with the transmission so that the
data is routed to the appropriate
receiving device
 only one node can transfer items at one
time
 If one node in the network fails, none of
the other nodes in the network is affected
Networks(cont.)
1.
Network
Topologies

2. Ring network
 links all nodes together in a circular
chain
 Data messages travel in only one
direction from device to device
around the entire ring
 The node examines any data that
passes by to see if it is the
addressee; if not, the data is passed
on to the next node in the ring
 If a node on a ring network fails, all
nodes before the failed node are
unaffected, but those after the failed
nodes cannot function
Networks(cont.)
1.
Network
Topologies

Networks(cont.)
3. Star network
 all of the computers and
devices (nodes) on the network
connect to a central device,
thus forming a star
 Two types of devices that
provide a common central
connection point for nodes on
the network are a hub and a
switch
 Star networks are fairly easy to
install and maintain
 if one node fails, only that node
is affected
 if the hub computer fails, the
entire network fails
1.
Network
Topologies

2.
LAN,
MAN,
and
WAN
Networks(cont)
 LAN, MAN, and WAN
Usually, networks are classified ad a local area network, metropolitan area
network, or wide area network
1. local area network (LAN)
 a network that connects computers in a limited geographical
area, such as a school computer laboratory, department, or
closely positioned group of buildings
 A local area
network can be
a ring, bus, or
star network.
 A wireless LAN
(WLAN) is a
LAN that uses
no physical
wires.

Networks(cont.)
2. Metropolitan area network (MAN)
 Metropolitan area network (MAN) connects LANs in city or town
 it connects local area networks in a metropolitan area
 A MAN usually is managed by a consortium of users or by a single
network provider who sells the service to the users
3. wide area network (WAN)
 a network that covers a large geographical area using a
communications channel that usually combines many different
types of transmission media
 A WAN can be one large network or can consist of two or more
LANs connected together
 The Internet is the world's largest WAN
2.
LAN,
MAN,
and
WAN

2.
LAN,
MAN,
and
WAN
Networks(cont.)

3.
Network
Architectures
Networks(cont.)
The design of computers, devices, and media in a network, sometimes
called the network architecture
 Network Architectures
1. client/server network
 a network in which one or more computers
are designated as a server(s) and other
computers on the network, called clients, can
request services from the server, such as
providing database access or queuing print
jobs
 A server, also called host computer, controls
access to the hardware and software on the
network and provides a centralized storage
area for programs, data, and information
 The other computers (clients) on the network
rely on the servers for these resources, such
as files, devices, processing power, and
storage

Networks(cont.)
2. peer-to-peer network
 a simple, inexpensive
network
 All computers in a peer-to-
peer network have equal
status; no one computer is
in control
 Each computer, called a
peer, in the network can
share the hardware, data, or
programs located on any
other computer in the
network
 Each computer stores files
on its own storage devices
3.
Network
Architectures

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