This is short note of artificial intelligence

1. Art
List of topics

2. Wireless Networks and WAN Technologies
Wireless network
A wireless network is any type of computer network that uses wireless data connections for
connecting network nodes.
Wireless network is a network set up by using radio signal frequency to communicate among
computers and other network devices. Sometimes it’s also referred to as Wi-Fi network or
WLAN.
Wireless networking is a method by which homes, telecommunications networks and enterprise
(business) installations avoid the costly process of introducing cables into a building, or as a
connection between various equipment locations.
Wireless telecommunications networks are generally implemented and administered using radio
communication. This implementation takes place at the physical level (layer) of the OSI model
network structure.
This network is getting popular nowadays due to easy to setup feature and no cabling involved.
You can connect computers anywhere in your home without the need for wires.
Examples of wireless networks include cell phone networks, Wi-Fi local networks and terrestrial
microwave networks.

3. Wireless Network Types
Wireless networks use different technologies depending on the distance to achieve, the number of
devices to connect, and the amount of information to transmit. The technologies include:-
 Wireless personal-area networks (WPAN): Interconnects devices in a short span, generally
within a person’s reach. Have a short range (up to 20–30 feet/7–10meters), commonly use the
802.15 family of specifications to connect two or a few devices with low power consumption.
Bluetooth is an example of WPAN protocol.

4.  Wireless local-area networks (WLAN): Links two or more devices using a wireless distribution
method, providing a connection through access points to the wider Internet. Consume more
power but extend the connection to about 300 feet (100 meters).
 Wireless metropolitan-area network (WMAN): Extend the range to a larger geographic area,
such as a city or suburb. Connects several wireless LANs. Applications vary from point-to-
point or point-to-multipoint links to multiuser coverage. WMANs typically use licensed
frequencies (a fee has to be paid for permission to use the frequency), although implementations
in the ISM (industrial, scientific and medical) bands can also be found. WiMAX(Worldwide
Interoperability for Microwave Access) is an example of WMAN protocol (most WiMAX
implementations use licensed bands).
 Wireless wide-area network (WWAN): Provide connectivity over a wide geographical area.
Covers large areas such as neighboring towns and cities. Usually, WWANs are networks used
for mobile phone and data service and are operated by carriers. WWANs typically use licensed
frequencies.
 Wireless local-area networks (WLAN): Links two or more devices using a wireless distribution
method, providing a connection through access points to the wider Internet. Consume more
power but extend the connection to about 300 feet (100 meters).
 Wireless metropolitan-area network (WMAN): Extend the range to a larger geographic area,
such as a city or suburb. Connects several wireless LANs. Applications vary from point-to-
point or point-to-multipoint links to multiuser coverage. WMANs typically use licensed
frequencies (a fee has to be paid for permission to use the frequency), although implementations
in the ISM (industrial, scientific and medical) bands can also be found. WiMAX(Worldwide
Interoperability for Microwave Access) is an example of WMAN protocol (most WiMAX
implementations use licensed bands).
 Wireless wide-area network (WWAN): Provide connectivity over a wide geographical area.
Covers large areas such as neighboring towns and cities. Usually, WWANs are networks used
for mobile phone and data service and are operated by carriers. WWANs typically use licensed
frequencies.

5. Wireless Network Logical Topologies
Wireless networks have different topologies, just as wired networks do. However, wireless
networks use only two logical topologies:
Star: - the star topology, used by Wi-Fi/IEEE 802.11–based products in the infrastructure mode,
resembles the topology used by 10BASE-T and faster versions of Ethernet that use a switch (or hub).
The access point takes the place of the switch because stations connect via the access point, rather
than directly with each other. This method is much more expensive per unit but permits
performance
in excess of 10BASE-T Ethernet speeds and has the added bonus of being easier to manage.
Point-to-point: - Bluetooth products (as well as Wi-Fi products in the ad hoc mode) use the point- to
point topology. These devices connect directly with each other and require no access point or other
hub-like device to communicate with each other, although shared Internet access does require that
all
computers connect to a common wireless gateway. The point-to-point topology is much less
expensive per unit than a star topology. It is, however, best suited for temporary data sharing with
another device (Bluetooth) and is currently much slower than 100BASE-TX networks.

6. Advantages:-
 There is no need to carry out any personal digital representative.
 The comfort of connection between networks has supported and improved with the devices in
coming generation technologies.
 Wireless networks are low cost and easy to establish.
 You can use internet in several computers, laptops even mobiles in which wireless routers are
used.
 It can be used on multiple devices through a single connection at the same time.
 Its major and most important advantage is that you don’t need to mix up in wires.
 You can move anywhere because you don’t have to worry about wires to plug and unplug etc.
 In many hotels and restaurants, they facilitate you internet access that you can be connected at
all time.
Disadvantages:-
 security risk because wireless networks are created to have radio frequencies in them so
signals are transmitted within the range so if someone uses antenna etc. then willingly or
unwillingly your data can be intercepted.