About WIFI

Short for wireless fidelity and is meant to be used generically when referring of any type of 802.11 network, whether 802.11b, 802.11a, dual-band, etc. The term is promulgated by the Wi-Fi Alliance. Formerly, the term "Wi-Fi" was used only in place of the 2.4GHz 802.11b standard, in the same way that "Ethernet" is used in place of IEEE 802.3. The Alliance expanded the generic use of the term in an attempt to stop confusion about wireless LAN interoperability.

Wireless data networks (Wide Area Networks and Local Area Networks) based on the IEEE 802.11 or “WiFi” standard are perhaps the most promising wireless technology. Given its popularity in developed nations, it is reasonable to consider the use of WiFi in developing countries as well. The forces driving the standardization and proliferation of WiFi in the developed world could also stimulate the communications market dynamic in the developing world. These features include: its ease of set-up, use, and maintenance; its relatively high bandwidth; and, most importantly, its relatively low cost for both users and providers.

Standard WiFi connectivity (IEEE 802.11b) provides up to 11Mb/sec data rates, and operates in a band near 2.4Ghz that is generally unlicensed in Europe and the Americas. Newer versions of WiFi provide 22Mb/sec in this band, and versions that operate at higher frequencies provide up to 54Mb/sec. Tests in rural settings show that a standard WiFi card (such as commonly used with laptop PCs) can provide good connectivity up to a ½ kilometer radius given line-of-sight. With the addition of antennas and repeaters, it is possible to achieve point-to-point connectivity at distances of up to 20 kilometers. WiFi access points (devices commonly used to provide a WiFi network) currently retail for $120, and WiFi cards retail for under $60. WiFi technology opens up new possibilities for rural connectivity in developing countries. However, the successful implementation of this technology and the choice of usage model should be guided by an intimate knowledge of rural communities and their information- and communication-related needs. Our vision is that, provided a conducive regulatory environment, local entrepreneurs within developing countries will leverage WiFi-based technology to: (a) solve the chicken-and-the-egg problem of the simultaneous need for both a market and an infrastructure; and (b) create a widespread wireless infrastructure that grows seamlessly with the rural communications market, ultimately scaling up to universal broadband connectivity.

Specifications

Max speed - 11 MBPS

Max encryption - 128 bit WEP

Discrete channels - 3

Max range @ full throughput - 30ft

Natively compatible - 802.11b,802.11g

Potential user - Entry level and home networks

ADVANTAGES OF WIFI

• Uses an unlicensed part of the radio spectrum.This means less regularly controls in many countries.
• Frees network devices from cables,allows for a more dynamic network to be grown
• Many reliable and bug-free Wi-Fi products on the market.
• Competition amongst vendors has lowered prices considerably since their inception.
• While connected on a Wi-Fi network,it is possible to move about without breaking the internet connection.
• Modern Access points and Client Cards have excellent in-built security and encryption.

DISADVANTAGES OF WIFI

· The 802.11b and 802.11g flavours of Wi-Fi use the 2.4GHz spectrum which is crowded with other devices such as Bluetooth, microwave ovens, cordless phones(900MHz or 5.8GHz ), video sender devices among many others. This may cause degradation in performance. Other devices which use microwave frequencies such as certain types of cell phones , can also cause degradation in performance.

· Power consumption is fairly high compared to other standards, making battery life and heat a concern.

· Users do not always configure it properly. In addition, Wi-Fi commonly uses Wired Equivalent Privacy (WEP) protocol for protection, which has been shown to be easily breakable even when properly configured. Newer wireless solutions are slowly providing support for the superior Wi-Fi Protected Access (WPA) protocol, though many systems still employ WEP.

· Wi-Fi networks have limited range. A typical Wi-Fi home router using 802.11b might have a range of 150 ft(46 m) indoors and 300 ft (92 m) outdoors. But about 10 US$ and an hour of building will give you an antenna that can go much further.

DAKNET NETWORK ARCHITECTURE

The main parts of daknet architecture are:

• Mobile access point
• Hub
• Kiosk

MOBILE ACCESS POINT

Daknet offers data to be transmitted over short point-to-point links. It combines physical and wireless data transport to enable high bandwidth intranet and internet connectivity among kiosks (public computers) and between kiosks and hubs(places with reliable Internet connection) .Data is transported by means of mobile access point, which automatically and wirelessly collects and delivers data from/to each kiosk on the network. Low cost WIFI radio transceivers automatically transfer the data stored in the MAP at high bandwidth for each point-to-point connection.