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8/3/2019 Networking of Computer (Concept)
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CONCEPT OF NETWORING INTRODUCTION OF NETWORKING
TYPES OF NETWORK
NETWORK MEDIA
NETWORKING DEVICES
NETWORK TOPOLOGIES OSI MODEL & NETWORK PROTOCOLS
WIRELESS TRASMISSION
WIDE AREA NETWORK
IEEE AND NETWORKING STANDARD
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INTRODUCTION OF NETWORKINGA computer network is an interconnection between or morecomputer by witch we can share information & Data to another
Computer System.
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INTRODUCTION OF NETWORKINGA network is any collection of independent computers thatcommunicate with one another over a shared network medium. Acomputer network is a collection of two or more connectedcomputers. When these computers are joined in a network, peoplecan share files and peripherals such as modems, printers, tape backup
drives, or CD-ROM drives. When networks at multiple locations areconnected using services available from phone companies, peoplecan send e-mail, share links to the global Internet, or conduct videoconferences in real time with other remote users. When a network
becomes open sourced it can be managed properly with onlinecollaboration software. As companies rely on applications like
electronic mail and database management for core businessoperations, computer networking becomes increasingly moreimportant.
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TYPES OF NETWORKThere are about eight types of networking which are usedworldwide these days, both in house and commercially.
LAN (Local Area Network)
WAN (Wide Area Network)
MAN (Metropolitan Area Network)
PAN (Personal Area Network)
WLAN (Wireless Local Area Network)
SAN (Storage/Server/Small Area Network)
CAN (Campus/Controller/Cluster Area Network)
DAN(Desktop Area Network)
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LANA local area network (LAN) is a computer network thatinterconnects computers in a limited area such as a home,school, computer laboratory, or office building. The definingcharacteristics of LANs, in contrast to wide area networks
(WANs), include their usually higher data-transfer rates,smaller geographic area, and lack of a need for leasedtelecommunication lines.
ARCNET, Token Ring and other technology standards have
been used in the past, but Ethernet over twisted pair cabling,and Wi-Fi are the two most common technologies currentlyused to build LANs.
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WANA wide area network (WAN) is a telecommunicationnetwork that covers a broad area (i.e., any network
that links across metropolitan, regional, or national
boundaries). Business and government entities utilize WANs to relay
data among employees, clients, buyers, and suppliers from variousgeographical locations. In essence this mode of telecommunicationallows a business to effectively carry out its daily function regardlessof location.
This is in contrast with personal area networks (PANs), local areanetworks (LANs), campus area networks (CANs), or metropolitanarea networks (MANs) which are usually limited to a room, building,campus or specific metropolitan area (e.g., a city) respectively.
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MANA Metro Ethernet is a computer network that covers a
metropolitan area and that is based on the Ethernet standard.
It is commonly used as a metropolitan access network to connect
subscribers and businesses to a larger service network or the Internet. Businesses
can also use Metro Ethernet to connect branch offices to their Intranet.
Ethernet has been a well known technology for decades. An Ethernet interface is
much less expensive than a SONET/SDH or PDH interface of the same and width.
Ethernet also supports high bandwidths with fine granularity, which is not available
with traditional SDH connections. Another distinct advantage of an Ethernet-based
access network is that it can be easily connected to the customer network, due tothe prevalent use of Ethernet in corporate and, more recently, residential networks.
Therefore, bringing Ethernet in to the Metropolitan Area Network (MAN)
introduces a lot of advantages to both the service provider and the customer.
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WLAN, SAN, CAN, DANWLAN: A wireless local area network (WLAN) links two or more devicesusing some wireless distribution method (Radio), and usually providing a
connection through an access point to the wider internet.
SAN: A storage area network (SAN) is a dedicated network that provides
access to consolidated, block level data storage. SANs are primarily used to
make storage devices, such as disk arrays, tape libraries, and opticaljukeboxes, accessible to servers so that the devices appear like locally
attached devices to the operating system.
CAN: ControllerArea Network (CAN or CAN-bus) is a vehicle bus
standard designed to allow microcontrollers and devices to communicate
with each other within a vehicle without a host computer.DAN: The Desk Area Network (DAN) is a multimedia workstation based
around an ATM interconnect (as shown in the above diagram). All
communication between peripherals and even between the CPU and its
main memory is achieved by sending ATM cells through a switch fabric.
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EXAMPLES OF DATA NETWORK
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TWO TYPE OF NETWORK ENVIRONMENT
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NETWORK MEDIANetwork media (sometimes referred to as networked media) refers to media mainlyused in computer networks such as the Internet.
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TWISTED PAIR CABLINGTwisted pair cabling is a type of wiring in which two wires are twisted togetherfor the purposes of canceling out electromagnetic interference (EMI) from external
sources; for instance, electromagnetic radiation from unshielded twisted pair (UTP)
cables, and crosstalk between neighboring pairs. It was invented by Alexander
Graham Bell.
Shielded Twisted Pair (STP)
Is more common in high-speed networks. The biggest difference you will see in the
UTP and STP is that the STP use's metallic shield wrapping to protect the wire from
interference.
Unshielded twisted pair (UTP):
UTP cable is also the most common cable used in computer networking. Modern
Ethernet, the most common data networking standard, utilizes UTP cables. Twisted
pair cabling is often used in data networks for short and medium length connections
because of its relatively lower costs compared to optical fiber and coaxial cable.
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CATEGORY OF UTP
CATEGORY USED FOR SPEED PAIR WIRES
CAT 1 Voice Process 1 MBPS 2 Pair 4 Wires
CAT 2 Computer Networking 4 MBPS 4 Pair 8 Wires
CAT 3 Computer Networking 10 MBPS 4 Pair 8 Wires
CAT 4 Computer Networking 16 MBPS 4 Pair 8 WiresCAT 5 Computer Networking 100 MBPS 4 Pair 8 Wires
CAT 6 Computer Networking 1000 MBPS 4 Pair 8 Wires
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UTP COLOR CODES
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MEASURING BANDWIDTH
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NETWORK DEVICES
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Computer network devices also known as communication devicesand they constitute a data communication network. Computernetworking devices are also called network equipment.
Common basic networking devices & Icon:
Hubs
Switches Router
Bridge
Repeaters
Modems
MSAU
CSU/DSU
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HUB & SWITCH DEVICE
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HUB: The central connecting device in a computernetwork is known as a hub. There are two types of a hubi.e. active hub and passive hub. Every computer is directlyconnected with the hub. When data packets arrives at hub,it broadcast them to all the LAN cards in a network and thedestined recipient picks them and all other computersdiscard the data packets. Hub has five, eight, sixteen andmore ports and one port is known as uplink port, which isused to connect with the next hub. Works on OSI layer 1.
SWITCH: Like the router, a switch is an intelligent devicethat maps the IP address with the MAC address of the LANcard. Unlike the hubs, a switch does not broadcast the data
to all the computers, it sends the data packets only to thedestined computer. works on OSI layer 2.
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ROUTER & BRIDGE DEVICE
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ROUTER: Router is a network communication device
that is used to connect logically and physicallydifferent networks. Works on OSI layer 3.
BRIDGE: A bridge is a network communicationdevice that is used to connect one segment of thenetwork with another that uses the same protocol.
It operates at the Data link layer of the OSI layersmodel.
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REPEATER & MODEM DEVICE
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REPEATER: A repeater is a communication device
that retransmits the weak signals with greater power.It receives the signals over the wireless,
optical transmission and network cable mediums suchas copper wire, UTP/STP and fiber optic cables and
regenerates the analog or digital signals.
MODEM: A modem is a communication device that isused to provide the connectivity with the
internet. Modem works in two ways i.e. modulationand demodulation. It coverts the digital data into theanalog and analog to digital
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MSAU & CSU/DSU DEVICE
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MSAU:A Multi Station Access Unit (MSAU) is a hub orconcentrator that connects a group of computers ("nodes" innetwork terminology) to a token ring local area network. Forexample, eight computers might be connected to an MSAU inone office and that MSAU would be connected to an MSAU inanother office that served eight other computers. In turn thatMSAU could be connected to another MSAU.
CSU / DSU: CSU/DSU stands for Channel service unit andData Service unit. CSU/DSU is a pair of the communicationdevices that converts the LAN data frames into the size of WANdata frames. CSU terminates the link at the customerspremises. It connects the terminal with the digital line. DSUperforms the actual transmission and receives the signals.
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BASEBAND & BROADBAND
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BasebandIn a baseband transmission, the entire bandwidth of
the cable is consumed by a single signal. In broadband transmission,signals are sent on multiple frequencies, allowing multiple signals to
be sent simultaneously.
Baseband refers to a message signal that is transmitted and broadbandrefers to send the message to every one who is having a receiver.
Broadband
The term broadbandrefers to a telecommunications signal or deviceof greater bandwidth, in some sense, than another standard or usualsignal or device (and the broader the band, the greater the capacityfor traffic). Different criteria for "broad" have been applied indifferent contexts and at different times.
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NETWORK INTERFACE CARD
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A network interface card (NIC) is a printed circuit boardthat provides network communication capabilities to and
from a personal computer. Also called a LAN adapter.
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NETWORK TOPOLOGIES
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The way in which the connections are made among all the computers iscalled the topology of the network.
Network topology specifically refers to the physical layout of the network,specially the location of the computers and how the cable is run between
them.
The most common topologies are
Bus
StarRing
Mesh
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BUS TOPOLOGIES
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The bus topology is the simplest and most common. It is often usedwhen a network installation is small, simple, or temporary. It is a
Passive topology. This means that computers on the bus only listen
for data being sent, they are not responsible for moving the data
from one computer to the next. In an active topology network, thecomputers regenerate signals and are responsible for moving the data
through the network. On a bus network, all the computer are
connected to a single cable. When one computer sends a signal using
the cable, all the computers on the network receive the information,
but only one (Addressee) accepts it. The rest disregard the message.
Computer
Computer
Computer Computer
Computer Computer
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BUS TOPOLOGIES
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ADVANTAGE: The bus is simple, reliable in very smallnetwork, and easy to use. The bus requires the least amount
of cable to connect the computers together and is therefore
less expensive than other cabling arrangements. Failure of
one node does not affect the rest of network. DISADVANTAGE: Heavy network traffic can slow a bus
considerably. A break in the cable or lake of proper
termination can bring the network down. It is difficult to
troubleshoot a bus.
Computer
Computer
Computer Computer
Computer Computer
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STAR TOPOLOGIES
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In a star topology, each device has a dedicated point to pointlink only to central controller, usually called ahub/server/host. Each computer on a star networkcommunicates with a central hub that resends the message
appropriate computer(s). The hub can be active or passive. Anactive hub regenerate the electrical signal and sends it to all thecomputers connected to it. This type of hub is often called amultiport repeater. Active hub require electrical power to run.A passive hub, such as wiring panels, merely acts as a
connection point and does not amplify or regenerate the signal.Passive hubs do not require electrical power to run.
Hub
Computer
Computer
ComputerComputer
Server
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STAR TOPOLOGIES
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ADVANTAGE: It is easy to modify and add new computers to astar network. During adding/deleting a node network can
function normally. When the capacity of the central hub is
exceeded, it can be replaced with one that has a larger number of
ports to plug lines into. Provide for centralised monitoring andmanagement of the network. Single computer failure do not
necessarily bring down the whole star network.
DISADVANTAGE: If the central hub fails, the whole network
fails to operate. It cost more to cable a star network. Require
dedicated server and NOS
Hub
Computer
Computer
ComputerComputer
Server
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RING TOPOLOGIES
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In a ring topology, each computer is connected directly to the next computer inline, forming a circle of cable. It uses token to pass the information from one
computer to another. Every computer is connected to the next compute in the
ring, and each retransmit what it receives from the previous computer. The
message flow around the ring in one direction. Ring is an active topology. There is
no termination because there is no end to the ring.
Token passing a method of sending data in a ring topology. A small packet, called
the token passed around the ring to each computer in tern. If a computer has
information to send, it modifies the token, adds address information and the data
and sends it down the ring. The information travels around the ring until it either
reaches its destination or returns to the sender. A token can circle a ring 200meters in diameter at about 10,000 times a second.
Computer
Computer
Computer
Computer
Computer
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RING TOPOLOGIES
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ADVANTAGE: All the computers have equal access to thenetwork. Even with many users, network performance is
even. Allows error checking, and acknowledgement.
DISADVANTAGE: Failure of one computer can affect thewhole network. It is difficult to troubleshoot the ring
network. Adding or removing computers disturbs the
network.
Computer
Computer
Computer
Computer
Computer
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MESH TOPOLOGIES
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In a mesh topology, every devices has a dedicated point to point linkto every other device. A fully connected mesh network therefore hasn(n-1)/2 physical channels to link n devices. To accommodate thatmany links, every device on the network must have n-1 input/outputports.
The type of network topology in which some of the nodes of thenetwork are connected to more than one other node in the networkwith a point-to-point linkthis makes it possible to take advantage
of some of the redundancy that is provided by a physical fullyconnected mesh topology without the expense and complexityrequired for a connection between every node in the network.
Computer
Computer Computer
ComputerComputer
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MESH TOPOLOGIES
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ADVANTAGE: Because of the dedicated link, no trafficbetween computers. Failure of one node computer not affect
rest of the network. Because of the dedicated link privacy
and security are guaranteed. Point to point links make fault
identification and fault isolation easy.
DISADVANTAGE: Due to the amount of cabling and
number of input output ports, it is expensive. Large space is
require to run the cables. Large space is require to run thecables.
Computer
Computer Computer
ComputerComputer
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OSI MODEL
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To address the problem of networks increasingin size and in number, the International
Organization for Standardization (ISO)
researched many network schemes and
recognized that there was a need to create a
network model that would help networkbuilders implement networks that could
communicate and work together and therefore,
released the OSI reference model in 1984.ISO - International Organization for Standardization
OSI - Open System InterconnectionIOS - Internetwork Operating System
The ISO created the OSI to make the IOS more
efficient. The ISO acronym is correct as shown. To
avoid confusion, some people say International
Standard Organization.
7 Application
6 Presentation
5 Session
4 Transport
3 Network
2 Data Link1 Physical
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Layer 7 - The Application LayerThis layer deal withnetworking applications.
Examples:
Email Web browsers
PDU - User Data
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7 Application
6 Presentation
5 Session
4 Transport
3 Network
2 Data Link1 Physical
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Layer 6 - The Presentation LayerThis layer is responsible forpresenting the data in the
required format which may
include:
Encryption Compression
PDU - Formatted Data
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7 Application
6 Presentation
5 Session
4 Transport
3 Network
2 Data Link
1 Physical
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Layer 5 - The Session LayerThis layer establishes,manages, and terminates
sessions between two
communicating hosts.Example:
Client Software( Used for logging in)
PDU - Formatted Data
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7 Application
6 Presentation
5 Session
4 Transport
3 Network
2 Data Link
1 Physical
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Layer 4 - The Transport LayerThis layer breaks up the datafrom the sending host and
then reassembles it in the
receiver.
It also is used to insure
reliable data transport across
the network.
PDU - Segments
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7 Application
6 Presentation
5 Session
4 Transport
3 Network
2 Data Link
1 Physical
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Layer 3 - The Network LayerSometimes referred to as theCisco Layer.
Makes Best Path
Determination decisionsbased on logical addresses
(usually IP addresses).
PDU - Packets
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7 Application
6 Presentation
5 Session
4 Transport
3 Network
2 Data Link
1 Physical
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Layer 2 - The Data Link LayerThis layer provides reliabletransit of data across a
physical link.
Makes decisions based onphysical addresses (usually
MAC addresses).
PDU - Frames
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7 Application
6 Presentation
5 Session
4 Transport
3 Network
2 Data Link
1 Physical
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Layer 1 - The Physical LayerThis is the physical media
through which the data,represented as electronic
signals, is sent from the
source host to the destination
host.
Examples:
CAT5 (what we have)
Coaxial (like cable TV) Fiber optic
PDU - Bits
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7 Application
6 Presentation
5 Session
4 Transport
3 Network
2 Data Link
1 Physical
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IP ADDRESING
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An Internet Protocol address (IP address) is a numerical label assigned to eachdevice (e.g., computer, printer) participating in a computer network that uses
the Internet Protocol for communication.
When the packet arrives at a router connected to the destination network, the
router uses the IP address to locate the particular computer connected to that
network.
Accordingly, IP address has two Versions .
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IPv.4 & CLASSES
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As early as 1992, the Internet Engineering Task Force (IETF) identified twospecific concerns: Exhaustion of the remaining, unassigned IPv4 network
addresses and the increase in the size of Internet routing tables.
Internet Protocol version 6 (IPv6) is a version of the Internet Protocol (IP)intended to succeed Internet Protocol version 4 (IPv4), which currently directs
almost all Internet traffic, but it is unable to fulfill the demand for IP addresses.
IPv6 allows up to 2128 addresses, a massive increase from the 232 (about 4.3
billion) addresses that IPv4 supports, and includes several other improvements.
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NETWORK AND HOST DIVISIONEach complete 32-bit IP address is broken down into a network part and a host part.
A bit or bit sequence at the start of each address determines the class of the address.
There are 5 IP address classes.
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ADDRESS CLASS PERFIXESTo accommodate different size networks and aid in classifyingthese networks, IP addresses are divided into groups called
classes. This is classful addressing.
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NETWORK & BROADCOST ADDRESS
NETWORK BROADCOSTKAMLESHPRAJAPATI
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PUBLIC & PRIVATE IP ADDRESESS
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Public IP Addresses must be obtained from an Internet service provider (ISP) or aregistry at some expense.
Unique addresses are required for each device on a network.
No two machines that connect to a public network can have the same IP address
because public IP addresses are global and standardized. All machines connected to
the Internet agree to conform to the system.
Private IP Addresses are another solution
to the problem of the impending
exhaustion of public IP addresses. As
mentioned, public networks require
hosts to have unique IP addresses.However, private networks that are not
connected to the Internet may use any
host addresses, as long as each host
within the private network is unique.
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WIRELESS TRANSMISSION
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Wireless signals are electromagnetic waves that can travelthrough the vacuum of outer space or
through a medium such as air. No physical copper-based or
fiber optic medium is necessary for
wireless signals, which makes utilizing wireless signals a very
versatile way to build a network. Wireless
transmissions can cover large distances by using high-frequency signals. Each signal uses a different
frequency measured in hertz so that they remain unique from
and another.
Wireless technologies have been around for many years. Satellite TV AM/FM radio, cellular
phones,remote-control devices, radar, alarm systems, weather radios, cordless phones, and retail
scanners are
integrated into everyday life. Today, wireless technologies are a fundamental part of business and
personal life.
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WIRELESS TRANSMISSION
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Wireless Data CommunicationsThe radio spectrum is the part of the electromagnetic spectrum used to transmit voice, video,
and data. It uses frequencies from 3 kilohertz (kHz) to 300 gigahertz (GHz). This section
considers only the part of the radio spectrum that supports wireless data transmission.
Infrared (IR) - Very high data rates and lower cost, but very short distance.
a Narrowband - Low data rates and medium cost. Requires a license and covers a limiteddistance.
Spread spectrum - Medium cost and high data rates, Limited to campus coverage. Cisco
Aironet products are spread spectrum.
Broadband personal communications service (PCS) - Low data rates medium cost, and
citywide coverage. Sprint is an exception; Sprint PCS provides nation wide and international
coverage.Circuit and packet data (cellular data and cellular Digital Packet [ICDPDI])- Low
data rates, high packet fees, and national coverage.
Satellite - Variable data rates depending on type of service, high cost, and nationwide or world
wide coverage.
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WIRELESS TRANSMISSION
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Wireless SignalsWhen a signal is transmitted in a data format, you must consider the following three parameters:
How fast - What data rate can be achieved?
How far- How far can wireless LAN (WLAN) units be placed apart and still get the maximum
data rate?
How many - How many users can exist without slowing the data rate?
Type of modulation used - More complex modulation techniques provide greater
throughput.
DistanceThe Faster signals transmitted, the weaker the signal becomes.
Noise- Electronics noise and barriers negatively after RF.
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WIRELESS TRANSMISSION
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Wireless Modulation
The most common methods of modulation are as follows:-
Amplitude modulation (AM) - Modulates the height of the carrier wave
Frequency modulation (FM) - Modulates the frequency of the wave
Phase modulation (PM) - Modulates the polarity (phase) of the wave
Modulation is the process by which the amplitude,
frequency or phase of an RF of light wave is altered
to transmit data. The characteristics of the carrier
wave instantaneously are varied by another
modulating waveform, Modulation blends a datasignal (text, voice. and so on) into a cannier for
transmission over a network.
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WIRELESS TRANSMISSION
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Wireless Radio Frequency BandsMost radio frequencies are licensed by government agencies, such as the federal Communications
Commission (FCC) in the United States. To broadcast over these frequencies, you need to have a
license and to pay a fee.
Unlicensed frequency bands are easier to implement and cost less over time because they do not
require licenses, Three unlicensed bands exist, as illustrated.
900 megahertz (MHz) - The 900-MHz band carries cordless and cellular phones.
2.4 gigahertz (GHz) - The 802.1lg and 802.11b standard, the most widely deployed wireless
standard, operates in the 2.4-GHz unlicensed radio band, delivering a maximum date rate of
11Mbps.
5 GHz - Recently, the FCC opened up the 5-GHz band for unlicensed use by high-speed data
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WIRELESS TRANSMISSION
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Wireless MediaWhen the computer was first introduced to the world, it was affordable by only large
Corporations governments, and universities. From the first building-sized devices with minimal
computing power to those that fit in the palm of a person's hand, huge leaps in technology have
occurred. The same is true on the connectivity side of the industry
Wireless Devices and TopologiesA wireless network can consist of as few as two devices, two nodes with wireless NICs' The nodes
can be desktop workstations or notebook computers. Equipped with wireless NICs' an ad hoc
network can be established that equates to a peer to wire Network. Both devices act as servers
and clients in this environment, and although it does provide connectivity, security is at a
minimum along with throughput. Another problem with this type of network is compatibility
oftentimes' NICs from different manufacturers do not interoperate.
External USB Wireless NIC
Internal Wireless NIC
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WIDE AREA NETWORK
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A wide area network (WAN) is a
telecommunication network that covers
a broad area (i.e., any network that
links across metropolitan, regional, or
national boundaries). Business andgovernment entities utilize WANs to
relay data among employees, clients,
buyers, and suppliers from various
geographical locations. In essence thismode of telecommunication allows a
business to effectively carry out its daily
function regardless of location
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IEEE AND NETWORKING STANDARDSThe Institute of ElectricalEngineering (IEEE) Developed a
Series of Networking Standards
to ensure that networking
technology developed by
respective manufactures are
capability.
IEEE 802 refers to a family of
IEEE standards dealing with local
area networks and metropolitan
area networks.