MAIN FEATURES: WI-FI TECHNOLOGY:-ADVANTAGES AND DISADVANTAGES:

MAIN FEATURES:

WI-FI TECHNOLOGY:-
o Wi-Fi networks operate in the unlicensed 2.4 and 5 GHz radio bands, with an 11 Mbps (802.11b) or 54 Mbps 9802.11a) or 100Mbps (802.11g) data rate or with products that contain both bands (dual band), so they can provide real-world performance similar to the basic 10BaseT wired Ethernet networks used in many offices.
o Modulation used in 802.11 has historically been phase-shift keying (PSK). The modulation method selected for 802.11b is known as complementary code keying or CCK, which makes possible high data speed and is less susceptible to multipath-propagation interference.
o It's powerful.
o Wi-Fi networks use radio technologies called IEEE 802.11b, IEEE 802.11b and IEEE 802.11g to provide reliable, fast wireless connectivity.
o A Wi-Fi network can be used to connect computers to each other, to the Internet, and to wired networks (which use IEEE 802.3 or Ethernet)

ADVANTAGES:

WI-FI TECHNOLOGY:-

Wi-Fi is cheap and fast. It's cheap, compared to 3G. It's already here and its nearterm rollout appears more widespread than 3G will be.
its standards based (IEEE 802.11b); therefore, consumers are not tied to proprietary technology. Since Wi-Fi is not based on proprietary technology, it ideally should allow many companies to enter the market and competitively hasten its evolution. Also, the standard has been improved. IEEE 802.11g, which operates at 100 Mbps.
vendors are backing Wi-Fi. Intel is one of the biggest proponents of Wi-Fi. It has recently unveiled a notebook chip called Banias that is to be the heart of a mobile brand called "Centrino." This chip is designed specifically for wireless computers to enable a longer battery life and to meet the heat/thermal requirements of the notebook and handheld markets. Other major players eager to step into the market include, a joint venture of AT&T, IBM, Intel (again), and others.

DISADVANTAGES:

WI-FI TECHNOLOGY:-
o Wi-Fi transmissions can be ruined by Bluetooth transmissions, since Bluetooth hops faster than Wi-Fi.
o It consumes lot of power so it cant be used efficiently for mobile devices.
o It’s expensive.
o It’s not very secure.
o Opponents of the technology argue correctly that Internet service can be affected by the user's proximity to the access point, the number of people using it, the speed of the server, interference from cordless phones and microwaves, and the user's surroundings (i.e., radio signals are not high powered and cannot travel through metal, water, or other dense materials). All of these factors can cloud Wi-Fi's wireless allure somewhat.
o You might be wondering where 3G fits into the Wi-Fi picture. Ultimately, the two may complement each other. Wi-Fi and 3G also may not even vie for the same pool of users.
o In theory, business travelers could use Wi-Fi to access the Internet when they are stationary, e.g., waiting for a flight in an airport, and 3G when they are in motion, e.g., commuting home from work on the train. However, this scenario must overcome some hurdles before it is realized. Currently, devices cannot alternate between Wi-Fi and 3G service, and it is uncertain when this issue will be addressed.