- Wifi has emerged as a very popular technology.
- This
technology has enabled the electronic devices to exchange information between
them and to share the internet connection without using any cables or wires.
- It is a wireless technology.
- This technology works with the help of the
radio waves.
- The Wifi is defined as a WLAN (wireless local area network)
product by the wifi alliance that is based on the standards defined by IEEE
(802.11 standards).
- Most of the WLANs are based upon these standards only and
so this technology has been named as wifi which is the synonymous with the term
WLAN.
- The wifi-certified trademark might be used by only those wifi products
which have the complete certification for the wifi alliance
inter-operability.
- A number of devices now use wifi such as the PCs, smart
phones, video game consoles, digital cameras, digital audio players, tablet
computers and so on.
- All these devices can connect to the network and access
internet by means of a wireless network access point.
- Such an access point is
more commonly known as a ‘hotspot’.
- The range of an access point is up to 20 m.
- But it has a much greater range outside.
- An access point can be installed in a single
room or in an area of many square miles.
- This can be achieved by using a number of overlapping access points.
- However, the security of the wifi is less compared to the wired connections for example
Internet.
- This is so because a physical
connection is not required by an intruder.
- The web pages using SSL have security but the intruders can easily
access the non-encrypted files on the internet.
- It is because of this, that the
various encryption technologies have been adopted by the wifi.
- The earlier WEP
encryption was weak and so was easy to break.
- Later, came the higher quality
protocols such as the WPA2 and WPA.
- The WPS or the wifi protected set up was
an optional feature that was added in the year of 2007.
- This option a very
serious flaw which is that it allowed the recovery of the password of the
router by an attacker.
- The certification and the test plan has been updated by
the wifi alliance for ensuring that there is resistance against attacks in
all the devices that have been newly certified.
- For connecting to a wifi LAN, a wireless network interface controller has to be incorporated in to the
computer system.
- This combination of the interface controller and the computer is
often called as the station.
- The same radio frequency communication channel is
shared by all the stations.
- Also, all the stations receive any transmission on
this channel.
- Also, the user is not informed of the fact that the data was
delivered to the recipient and so is termed as the ‘best–effort delivery
mechanism’.
- For transmitting the data packets, a carrier wave is used.
- These
data packets are commonly known as the ‘Ethernet frames’.
- Each station
regularly tunes in to the radio frequency channel for picking up the
transmissions that are available.
- A
device that is wifi enabled can connect to the network if it lies in the range
of the wireless network.
- One condition is that the network should have been
configured for permitting such a connection.
- For providing coverage in a large
area multiple hotspots are required.
- For example, wireless mesh networks in London.
- Through wifi, services can be provided in independent businesses, private
homes, public spaces, high street chains and so on.
- These hotspots have been
set up either commercially or free of charge.
- Free hotspots are provided at
hotels, restaurants and airports.
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