Siemens IEEE802.11 - Manual (Page 41)

, © Siemens, 2002
Summary: MAC Protocol Features
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Distributed Coordination Function (DCF) provides efficient
medium sharing
– Use Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)
– MAC uses the PHY layer Clear Channel Assessment (CCA) function for
CSMA/CA
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Robust for interference
– CSMA/CA + ACK for unicast frames, with MAC level recovery
– CSMA/CA for broadcast frames
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Virtual carrier sense function provided to protect against hidden nodes
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Includes fragmentation to cope with different PHY characteristics
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Point Coordination Function (PCF) option for time bounded data
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Frame formats to support multiple configurations and roaming