Networking and Mobile Technology
CHAPTER 12
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Chapter Objectives
 Define the meaning of a network.
 Explain the difference between wired and wireless
networks.
 Explain Ethernet.
 Explain Wi-Fi.
 Describe the use of LAN’s.
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Networking
What is a network?
 A network consists of two or more computers
that are linked in order to share resources,
exchange files, or allow electronic
communications. The computers on a network
may be linked through cables, telephone lines,
radio waves, satellites, or infrared light beams.
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Local Area Networks
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A Local Area Network also known as LAN is a network that is confined
to a relatively small area. It is generally limited to a geographic area
such as a business, school, or building. The LAN consists of
computers that can be classified as servers or workstations.
Servers can house network files and also run continuously to provide
"services" to the other computers on the network. Services provided
can include printing and faxing, software hosting, file storage and
sharing, messaging, data storage/retrieval and security.
Workstations were traditionally considered a desktop or laptop
computer that interacts with the network and servers of the LAN.
Netbooks, tablet computers, and the touch screen devices can also
be considered a workstation attached to the network.
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Wide Area Networks
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Wide Area Networks also known as a WAN, connect networks
in larger geographic areas. Dedicated cabling or satellite
uplinks may be used to connect this type of global network.
Using a WAN, network users in the United States can
communicate with users across the globe in a matter of
seconds, without paying enormous phone bills. A WAN is
complex due to the size of the network. It uses network
components such as multiplexers, bridges, and routers to
connect local and metropolitan networks to global
communications networks like the Internet. In general use a
WAN will not appear to be much different than a LAN to the
general public.
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Wired Networks
What is a Wired Network
 Wired networks can be defined as a network that
uses cables to connect network devices. Before
wireless networking became available, wired
networks were the standard network connection.
Telephone, Cable television, and Ethernet
connections are examples that are still in use
today. Much of the Internet infrastructure is also a
wired network.
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Wired Networks
Advantages of a wired network:
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Fast
Secure
Simple to configure
Cables have high bandwidth and shielding for little
interference
Disadvantages of a wired network:
Cables mean limited mobility
Cables are unsightly
Tangled and collect dust
Running cables through walls is tricky
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Ethernet

Most wired networks use Ethernet. Ethernet is a
standard that simultaneously broadcasts data packets
to all network devices over a standard Ethernet cable. A
packet is accepted only by the device to which it is
addressed Ethernet is defined by IEEE 802.3 and was
first introduced with a speed of 10Mbps.

Ethernet has continued to thrive since its inception in
1980 and is the standard by which almost all
companies’ public and private use to connect their LAN.
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Ethernet
Ethernet Standard
IEEE
Speed
10BaseT Ethernet
802.3
10 Mbps
Fast Ethernet
802.3u
100 Mbps
Gigabit Ethernet
802.3z
1000 Mbps
10 Gigabit Ethernet
802.3ae
10 Gbps
40/100 Gigabit Ethernet
802.3ba
40 or 100 Gbps
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Ethernet Advantages
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Readily available: A consumer can purchase Ethernet based cables, routers and
other equipment at their local electronics store or even stores like Wal-Mart and
Home Depot.
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Easy to setup and maintain: A computer novice can purchase the equipment he or
she needs and set up an Ethernet LAN very easy.
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Low price: Ethernet is a standard not a proprietary technology. This means that may
manufactures can produce products that feature Ethernet technology. The wide
array of vendors keeps the price low.
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Flexibility: The many standards associated with Ethernet mean that a network can
be tailored for small and large businesses all the while using the familiar Ethernet
cables and equipment.
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Wi-Fi compatible: Ethernet is compatible with wireless Wi-Fi networks. This
compatibility means a network user can mix wired and wireless devices on a single
network.
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Ethernet Setup
What do I need to create an Ethernet network?

Setting up an Ethernet network is easy. To create a simple network
you will need the following which can be purchased at any electronics
store or even at online retailers:
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Two or more Ethernet-ready computers
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Ethernet router
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Ethernet cables for each computer
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Cable or DSL modem for connecting to the Internet.
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Ethernet Setup
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Ethernet Setup
Is my computer Ethernet ready?
.Obviously if you are setting up an Ethernet network the computers that you
are going to use need to be Ethernet ready….meaning that they have a port to
plug in an Ethernet cable. The good news is almost all desktops and laptop
computers come with an Ethernet port built in. To be sure look for a port on
the computer that looks similar to a standard phone jack but is a little larger.
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Ethernet Setup
Ethernet Router
.An Ethernet router is a network device that ships data from one network to
another. Most routers also contain ports or switches to connect other devices
to the router. An Ethernet router with extra ports built in is especially useful
because you can connect and share your Internet connection with all
computers on the network. When you purchase a router you should factor in
price, available ports and speed.
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Ethernet Setup
When you purchase a router you should factor in price, available ports and
speed.
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Price: The good news is that Ethernet routers are very inexpensive. At the
time of the writing of this book, name brand routers were available for less
than Fifty dollars.
Ports: How many ports you will need on the router really depends on how
many devices you want to connect to the router. It is suggested that you
purchase a router with at least four ports.
Speed: A few pages back we saw that Ethernet speeds range from 10 Mbps
to 100 Gbps. In general 10 Mbps is fast enough for most home computer
networks. If you like to play games or do video conferencing than the higher
speed routers are advisable. One thing to think about when considering
speed is whether or not all your computers can handle the faster speeds. For
example if you have a Gigabit router but your computers have a 10/100 Mbps
Ethernet installed…you will not get Gigabit speeds. The router will slow the
data down to the speed of the receiving Ethernet port.
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Ethernet Setup
What kind of Ethernet cables do I need?
 Ethernet cable with RJ45 connector
 All wired network devices in an Ethernet
network are connected with cables that have a
standard RJ45 connector. When you purchase
cables look for the industry standard Category
5 or Category 6 designation.
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Ethernet Setup
Power off all equipment.
 Plug in an Ethernet cable from the router to each
network computer. Make sure you hear a ‘click; as
you plug the ends of the cable into each port.
 Plug in an Ethernet cable between the router and
your modem or Internet device.
 Power on all equipment.
 Configure each computer. This step may not be
needed as most computers auto sense the
presence of a network connection.
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Ethernet Setup
Configure the router. This is step is usually
included in the instructions with the router but in
general you can access the router setup by typing
the following in your web browser:
http://192.168.1.1 or http://192.168.1.100.
 From within setup you can set the network security
features.
 A reboot of all computers may be needed but that
is not usually the case.
 Have fun enjoying your new Ethernet Network!
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Wireless Network
What is a Wireless Network?
 We have seen that a wired network is a great
choice for many home and business users, but
what if a building has limitations where you cannot
run cables? The solution is a wireless network.
We can define a wireless network as a network
that transports data from one device to another
without the use of cables. The wireless network
transmits data as radio frequency signals to a
transceiver that has a built in antenna to capture
the data
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Typical Wireless Router
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Wireless Network
Advantages of a wireless network include:
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Mobility: With a laptop computer or mobile device, access can be
available throughout a home, business, school, mall, etc. More and
more businesses are also offering free Wi-Fi access.
Fast setup: If your computer has a wireless adapter, locating a
wireless network can be as simple as clicking "Connect to a Network"
or you will connect automatically to networks within range.
Cost: Setting up a wireless network can be much more cost effective
than buying and installing cables.
Expandability: Adding new computers to a wireless network is as easy
as turning the computer on (as long as you do not exceed the
maximum number of devices).
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Wireless Network
Disadvantages of wireless networks:
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Security: Then biggest disadvantage to a wireless network. If your
network isn’t secure any one can gain access.
Interference: Because wireless networks use radio signals and
similar techniques for transmission, they are susceptible to
interference from lights and electronic devices.
Inconsistent connections: Because of the interference caused by
electrical devices and/or items blocking the path of transmission,
wireless connections are not nearly as stable as those through a
dedicated cable.
Speed: The transmission speed of wireless networks is good
however; faster options are available via cables. If you are also
moving large amounts of data around a network, a cabled connection
will enable that work to proceed much faster.
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Wi-Fi Network
What is a Wi-Fi Network?
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The term Wi-Fi refers to a set of wireless networking technologies
defined by IEEE 802.11. Wi-Fi is compatible with Ethernet and can
be easily integrated with a wired network. A Wi-Fi device transmits
and receives data as radio waves over the wireless network.
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Wi-Fi wireless was once much slower than a wired solution, but as
you can see from the chart below… speeds have greatly improved.
The key to picking a Wi-Fi device is the IEEE lettering. When you
purchase wireless devices the package will say if they are compatible
with b,g or n. It is recommended to use n compatible products as
they offer the greatest speed and range,
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Wi-Fi Network
Wi-Fi Comparison
IEEE
Frequency
Speed
Range
Comments
802.11b
2.4 GHz
5 Mbps
100-300 feet
Original Wi-Fi
802.11a
5 Ghz
27 Mbps
25 – 75 feet
Stand alone
802.11g
2.4 Ghz
27 Mbps
100-150 feet
Faster than b
802.11n
2.4/5 Ghz
144 Mpbs
100-150 feet
Faster than b or g
802.11y
3.6-3.7 Ghz
27 Mbps
3 Miles
Commercial use
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Wi-Fi Network
What do I need to create a Wi-Fi network?

Setting up a wireless network is easy. To create a simple network you
will need the following which can be purchased at any electronics
store or even at online retailers:

Two or more wireless-ready computers or devices

Wireless router
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One Ethernet cable to run between router and one computer
.
Cable or DSL modem for connecting to the Internet
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Wi-Fi Network
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Wi-Fi Network
How do I set up a Wi-Fi network?
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Setting up a wireless network is very easy. You can follow the general guidelines
below and also read the instructions that are packaged with your wireless devices.
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Set up the wireless router by placing it in a central location to the devices you want to connect to
the network.
Connect router to one computer by use of an Ethernet cable to aid in setup.
Access the router setup by using the computer you connected to the router in step 4. Type
http://192.161.1.1 or http://192.168.1.100 in your browser to connect to the router.
Set a new password for the router. This prevents unauthorized access.
Enter a SSID for the new network. The SSID is a Service Set Identifier that is basically the name
of your new network. SSIDs help keep track of overlapping wireless networks.
Activate router specific security such as WEP, WPA or PSK.
Set up any wireless devices.
Connect the wireless router to your cable or DSL modem for Internet access.
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Wi-Fi Network
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LAN Usage
Local Area Network Usage
As we have seen in the previous pages, setting up a wired or wireless LAN is really not that difficult. LAN’s
have become an integral part of computing at home, school and at work.
LAN advantages:
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Enable people to work together: Using special software several people can work on a single document
at the same time, communicate via email and instant messaging, play games, and join online
meetings.
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Sharing of software reduces cost: Software designed to be installed using a site-user license for all
the people on the network are cheaper than buying standalone copies of the software.
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Sharing data can increase productivity: Transferring data between standalone computers is time
consuming…the ability to transfer files between networked computers is much easier and faster.
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Sharing hardware also reduces costs: Setting up a networked printer instead of a printer installed on
one computer just makes sense. All network users can access this printer and in turn reduce
hardware costs.
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LAN Usage
LAN disadvantages:
There aren’t many disadvantages to a LAN but there are a few:
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Network down: If the network goes down for any reason all users on
the network are affected and productivity is lost
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Virus propagation: If a virus gets into a stand alone computer it’s a
problem….if that virus gets out to a LAN and into all the networked
computers…that’s a bigger problem.
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Unauthorized Access: When a computer is networked it is connected
to other resources on the network. If unauthorized access occurs it
can happen across all of the network computers.
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END OF CHAPTER TWELVE
End of chapter
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