1. Wireless MAN Neil Tang 10/03/2008
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2. Outline Basic Architecture Physical Properties MAC Protocol
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3. WMAN Basic Architecture: Point-to-Multipoint (PMP) mode and mesh mode
MAC Protocol: TDMA/FDMA(OFDMA)
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4. Basic Architecture
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5. Physical Properties
Encoding & Modulation: OFDM (Orthogonal Frequency Division Multiplexing).
Spectrum: 2-11GHz (Licensed, non-LOS), 11-66GHz (Free, LOS).
Maximum Data Rate: 131Mbps.
Transmission Range: 30 miles. Several miles in practice.
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6. MAC Protocol
Control sub-frames are partitioned into slots of fixed duration (control slots). Data sub-frames consist of a fixed number of data mini-slots.
The control slot is accessed in a contention-based fashion.
A WiMAX-based mesh network can employ up to 16 multiple non-overlapping channels for data transmission.
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7. MAC Protocol Centralized scheduling using the MSH-CSCH message.
Distributed scheduling using the MSH-DSCH message.
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8. MAC Protocol
Collision-Free Scheduling
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9. MAC Protocol
A general framework for link scheduling: In the first phase, the links are labeled, and in the second phase, the links are scheduled one by one based on their labels.
The scheduling problem is equivalent to the problem of finding a valid node coloring in the contention graph.
The hidden and exposed terminal problems are resolved.
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