A comparison of wi-fi and wimax with case studies - Florida State ...
A comparison of wi-fi and wimax with case studies - Florida State ...
A comparison of wi-fi and wimax with case studies - Florida State ...
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WiFly used Wi-Fi to cover 60% <strong>of</strong> the city including all metropolitan areas. It takes 4200<br />
APs to do it. If it is replaced by WiMax, it <strong>wi</strong>ll not take that much. And for FSU campus, if<br />
WiMax is applied, just one or two base stations are enough to cover the whole campus. However,<br />
two towers are not enough to take care <strong>of</strong> the daily usage. Moreover, it is always dif<strong>fi</strong>cult to<br />
receive a signal from the outside in a concrete building. Therefore it needs a bridge or a gateway<br />
to direct a signal into a building. Wi-Fi may have low coverage, but it can be <strong>fi</strong>xed by using<br />
more APs in a hotspot. The advantage is that it can not only extend the coverage but also reduce<br />
the flow rate for each AP.<br />
To build a city-<strong>wi</strong>de <strong>wi</strong>reless network is going to be a trend <strong>and</strong> it is feasible, but if a<br />
network only uses Wi-Fi or WiMax, it would suffer cost, coverage, signal <strong>and</strong> mobility issues.<br />
The best way would be for them to be used in combination <strong>wi</strong>th each other. So far there is no<br />
single technology can feed all different needs. In local area Wi-Fi has strong capability <strong>and</strong><br />
WiMax is designed as the extension <strong>of</strong> ADSL or cable. The combination <strong>of</strong> these two st<strong>and</strong>ards<br />
can form a most ef<strong>fi</strong>cient <strong>wi</strong>reless network. Therefore the future <strong>of</strong> the <strong>wi</strong>reless technologies<br />
should be created <strong>wi</strong>th the cooperation <strong>and</strong> integration <strong>of</strong> these technologies.<br />
There is a new st<strong>and</strong>ard IEEE 802.11u is based on this idea. It tries to make Wi-Fi interwork<br />
<strong>wi</strong>th other different types <strong>of</strong> networks. [154] The IEEE 802.11u allows devices to interwork <strong>wi</strong>th<br />
external networks. For this purpose, interworking refers to MAC layer enhancements. It allows<br />
the higher layer functionality to provide the overall end to end solution. Instead <strong>of</strong> telling it what<br />
to do, the IEEE 802.11u only helps upper layers to establish an end to end connection <strong>wi</strong>th<br />
external networks. It provides a “virtual point <strong>of</strong> presence” for many different networks via a<br />
single AP. IEEE 802.11u assists the advertising <strong>and</strong> connection to remote service beyond the DS<br />
<strong>and</strong> provides information to the STA about the external network prior to association. In fact, the<br />
IEEE 802.11u is an amendment to the IEEE 802.11 st<strong>and</strong>ard. The <strong>fi</strong>nal approval <strong>of</strong> IEEE<br />
802.11u is expected to be September 2009. [154] the Figure 6-1 shows the possible<br />
implementation <strong>of</strong> the future network.<br />
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