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Unit 10: Wireless MAN Technologies
Self-Assessment Notes
Fill in the blanks:
1. The term Wi-Fi is a contraction of “wireless fidelity” and commonly used to refer to .........
..............................
2. Wi-Fi networks operate in the unlicensed ....................................... bands, with an 11 Mbps or
54 Mbps data rate, respectively.
3. A ....................................... can break into a Wi-Fi network using readily available materials
and software.
4. ....................................... modulation means that the transmitter will automatically shift to a
more robust, though less efficient, modulation technique in those adverse conditions.
5. The ....................................... radio link uses a direct sequence spread spectrum technique
called complementary coded keying (CCK).
6. The 802.11a and g systems use .......................................
7. The idea of a ....................................... network is that messages can be relayed through a
number of access points to a central network control station
8. ....................................... is the idea of selling an Internet access service using wireless LAN
technology and a shared Internet connection in a public location designated a hot spot.
9. To use the ....................................... option, devices must first send a traffic profile describing
bandwidth, latency, and jitter requirements.
10.2 IEEE 802.16: Broadband Wireless MAN Standard (WiMAX)
Satisfying the growing demand for BWA in underserved markets has been a continuing
challenge for service providers, due to the absence of a truly global standard. A standard that
would enable companies to build systems that will effectively reach underserved business and
residential markets in a manner that supports infrastructure build outs comparable to cable, DSL,
and fiber. For years, the wildly successful 802.11x or WiFi wireless LAN technology has been
used in BWA applications along with a host of proprietary based solutions. When the WLAN
technology was examined closely, it was evident that the overall design and feature set available
was not well suited for outdoor BWA applications. It could be done, it is being done, but with
limited capacity in terms of bandwidth and subscribers, range and a host of other issues made it
clear this approach while a great fit for indoor WLAN was a poor fit for outdoor BWA.
This analysis and review was conducted by the IEEE and it was decided that a new, more complex
and fully developed standard would be required to address both the physical layer environment
(outdoor versus indoor RF transmissions) and the Quality of Service (QoS) needs demanded by
the BWA and last mile access market. The IEEE conducted a multi-year effort to develop this
new standard, culminating in final approval of the 802.16a Air- Interface Specification in January
2003. This standard has since received broad industry support from leading equipment makers.
Many WiMAX company members are active in both the IEEE 802.16 standards development and
the IEEE 802.11 efforts for Wireless LAN, and envision the combination of 802.16a and 802.11
creating a complete wireless solution for delivering high speed Internet access to businesses,
homes, and WiFi hot spots. The 802.16a standard delivers carrierclass performance in terms of
robustness and QoS and has been designed from the ground up to deliver a suite of services over
a scalable, long range, high capacity “last mile” wireless communications for carriers and service
providers around the world.
In BWA, applications include residential broadband access – DSL-level service for SOHO and
small businesses, T1/E1 level service for enterprise, all supporting not just data but voice and
video as well, wireless backhaul for hotspots and cellular tower backhaul service to name a few.
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