Abstract :
Wi-Fi is a Wireless technology that
uses the radio frequency to transmit data through air. With the rise of
Wireless Fidelity (Wi-Fi) , technology comes the rise of the hotspot -public
access Wireless Local Area Networks (WLANs) that allow anyone with a Wi-Fi
capable notebook or PDA to connect to the Internet or a corporate intranet in
airports, hotels, coffee shops, or even campgrounds and fast food restaurants.
Wi-Fi hotspots are expected to have an important role in
future provisioning of “anywhere, anytime” connectivity. They are quickly being
deployed at locations that tend to attract nomadic users, such as cafes,
airports, hotels, and conference centers
This paper contributes an alternative billing architecture
using virtual prepaid tokens (VPTs) and experimentally evaluates its performance. Users
buy VPTs at the point and time of access, using a third-party online payment
server. Therefore, such an account is more flexible than is a conventional pay-per-use
account, which can be used only to purchase access from a specific provider or
set of providers.
Unlike physical prepaid tokens, VPTs
allow a user to order and obtain Internet access from a provider in less than
15 s, even if the user has no previous or subsequent relationship with that provider or that
provider’s aggregator. Simultaneous support for captive-portal and 802.1x
authentication allows hotspots to provide recent Wi-Fi security improvements to
those clients whose configuration supports them, without disrupting legacy clients.
Improvements include mutual authentication between client and hotspot and
link-layer packet encryption and authentication with dynamic per-session keys.
Wi-Fi Security Techniques
• Service Set Identifier (SSID)
• Wired Equivalent Privacy (WEP)
• 802.1X Access Control
• Wireless Protected Access (WPA)
• IEEE 802.11i
Service Set Identifier (SSID)
• SSID is used to identify an 802.11
network
• It can be pre-configured or
advertised in beacon broadcast
• It is transmitted in clear text
• Provide very little security
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