2. 2
Intro
Networks are categorized according to how
many locations they span.
A network confined to a single location is
known as a LAN.
Networks that span multiple geographic
locations are known as WANs.
There is also another category, called a
MAN, which is used to classify networks
that fall somewhere between LANs and
WANs.
3. 3
LANs
A LAN is confined to a single
geographic location, such as a single
building, office, or school.
LANs are created with networking
media that are very fast but that can
cover a limited distance.
5. 5
WANs
A WAN is a network that spans multiple
geographic locations. WANs are generally
slower than LANs and are considerably
more expensive to run.
WANs are all about data throughput, and
the more need, the more you spend. WANs
connect LANs together to create an
internetwork.
When Does a LAN Become a WAN?
Technically, a LAN never becomes a WAN. Avoid
the temptation to refer to the entire
internetwork as a WAN because WANs and LANs
employ some very different technologies.
7. 7
MANs
A MAN is confined to a certain geographic
area such as a university campus or a city.
No formal guidelines dictate the differences
between a MAN and a WAN; technically, a
MAN is a WAN.
Perhaps for this reason, the term MAN is
used less frequently than WAN. If any
distinction exists, it's that a MAN is smaller
than a WAN. A MAN is almost always bigger
than a LAN and usually smaller than or
equal to a WAN.
8. 8
Wireless Topologies
The widespread interest in networks without
wires and the push toward obtaining "anywhere,
anytime" Internet access has encouraged rapid
growth in wireless networking.
Several wireless standards fall under the IEEE-
802.11 banner each with its own speeds, radio
frequencies, and transmission ranges.
The 802.11 wireless standards use two main
types of network topologies: the
infrastructure, or managed, wireless
topology and the ad-hoc, or unmanaged,
wireless topology.
9. 9
Infrastructure Wireless Topology
is commonly used to extend a wired
LAN to include wireless devices.
Wireless devices communicate with
the wired LAN through a base station
known as an access point (AP) or
Wireless Access Point (WAP).
In infrastructure wireless networks,
several access points may provide
wireless coverage for a large area.
11. 11
Ad-Hoc Wireless Networking
In a wireless ad-hoc topology, devices communicate
directly between themselves without using an access
point.
This peer-to-peer network design is commonly used
to connect a small number of computers or wireless
devices.
For example, an ad-hoc wireless network may be set
up temporarily between laptops in a boardroom or to
connect to systems in a home instead of a wired
solution. The ad-hoc wireless design provides a quick
method to share files and resources between a small
number of systems.
14. 14
Infrared Wireless Networking
Infrared wireless networking uses
infrared beams to send data
transmissions between devices.
Infrared wireless networking offers
higher transmission rates reaching
10Mbps to 16Mbps.
The infrared light beams cannot
penetrate objects; therefore, the
signal is disrupted when something
blocks the light.
15. 15
IrDA Features
Infrared devices use less power and a
decreased drain on batteries.
Is a secure medium. Infrared signals are
typically a direct line implementation in a
short range and so do not travel far outside
the immediate connection.
Has no radio frequency interference issues
or signal conflicts.
Replaces cables for many devices such as
keyboards, mice, and other peripherals.
Transmissions travel over short distances.
16. 16
Bluetooth
Bluetooth is a wireless standard used for many purposes,
including connecting peripheral devices to a system.
Bluetooth uses a low-cost, short-range radio link to
create a link to replace many of the cords that used to
connect devices.
Bluetooth is an easily configured technology. When
Bluetooth-enabled devices are within 10 or so meters of
each other, they can establish a connection.
Bluetooth establishes the link using an RF-based link and
therefore does not require a direct line-of-sight
connection. The Bluetooth Standard defines a short RF
link capable of voice or data transmission up to a
maximum capacity of 720Kb/s.
