20-07-2013, 12:40 PM
Security in Wireless Networks and Devices
Wireless Networks .ppt (Size: 600 KB / Downloads: 39)
introduction
Wireless technology is a new technology that started in the early 1970s.
The rapid technological developments of the last twenty years have seen wireless technology as one of the fastest developing technologies of the communication industry.
Because of its ability and potential to make us perform tasks while on the go and bring communication in areas where it would be impossible with the traditional wired communication, wireless technology has been embraced by millions.
It is based on wireless networking technology that includes WLAN, Wireless WAN, Web and an industry of wireless communication devices.
Cellular Wireless Communication Network Infrastructure
The wireless infrastructure, because of distance problems, is in most parts supported and complemented by other wired and other communication technologies such as satellite, infrared, microwave, and radio.
In its simplest form, wireless technology is based on a concept of a cell. That is why wireless communication is sometimes referred to as cellular communication.
Limited and Fixed Wireless Communication Networks
This is a limited area wireless, known mainly as cordless wireless, that is commonly found in homes and offices.
Cordless telephones were developed for the purpose of providing users with mobility.
Cordless has been popular in homes with a single base station that provides voice and data support to enable in-house and a small perimeter around the house or office communication.
However, in office, this can be extended, if there is a need, especially in a big busy office, to multiple BSs connected to a single public branch exchange (PBX) of a local land telephone provider.
WLAN (Wi-Fi) Technology
WLAN technology falls in three types based on the type of transmission used by the LAN:
Infrared (IR) LANs are LANs in which cells are formed by areas, without obstructing objects between network elements, that the network is in. This is necessitated by the fact that infrared light does not go through objects.
Spread spectrum LANs use spread spectrum transmission technology. If the transmission band is kept within a certain frequency range then no FCC licensing is required. This means they can be used in a relatively larger area than a single room.
Narrowband microwave LANS operate at microwave frequencies, which means that they operate in large areas and, therefore, require FCC licensing.
Standards for Wireless Networks
While protocols spell out the “how to” framework for the two or more communicating devices, standards govern the physical, electrical, and procedural characteristics of the communicating entities.
There has been a rapid development of wireless standards – so rapid that some people have called the many standards – a children alphabet. We discuss two: IEEE 802.11 and Bluetooth.