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- Point_coordination_function abstract "Point coordination function (PCF) is a Media Access Control (MAC) technique used in IEEE 802.11 based WLANs. It resides in a point coordinator also known as Access Point (AP), to coordinate the communication within the network. The AP waits for PIFS duration rather than DIFS duration to grasp the channel. PIFS is less than DIFS duration and hence the point coordinator always has the priority to access the channel.The PCF is located directly above the Distributed Coordination Function (DCF), in the IEEE 802.11 MAC Architecture.Channel access in PCF mode is centralized and hence the point coordinator sends CF-Poll frame to the PCF capable station to permit it to transmit a frame. In case the polled station does not have any frames to send, then it must transmit null frame.Due to the priority of PCF over DCF, stations that only use DCF might not gain access to the medium. To prevent this, a repetition interval has been designed to cover both (Contention free)PCF & (Contention Based)DCF traffic. The repetition interval which is repeated continuously, starts with a special control frame called Beacon Frame. When stations hear the beacon frame, they start their network allocation vector for the duration of the contention free period of the repetition period. Since most APs have logical bus topologies (they are shared circuits) only one message can be processed at one time (it is a contention based system), and thus a media access control technique is required.Wireless networks may suffer from a hidden node problem where some regular nodes (which communicate only with the AP) cannot see other nodes on the extreme edge of the geographical radius of the network because the wireless signal attenuates before it can reach that far. Thus having an AP in the middle allows the distance to be halved, allowing all nodes to see the AP, and consequentially, halving the maximum distance between two nodes on the extreme edges of a circle-star topology.PCF seems to be implemented only in very few hardware devices as it is not part of the Wi-Fi Alliance's interoperability standard.".
- Point_coordination_function wikiPageExternalLink 1548381.
- Point_coordination_function wikiPageID "1695464".
- Point_coordination_function wikiPageLength "2883".
- Point_coordination_function wikiPageOutDegree "16".
- Point_coordination_function wikiPageRevisionID "704164687".
- Point_coordination_function wikiPageWikiLink Category:IEEE_802.11.
- Point_coordination_function wikiPageWikiLink Category:Media_access_control.
- Point_coordination_function wikiPageWikiLink Contention_(telecommunications).
- Point_coordination_function wikiPageWikiLink Contention_free_pollable.
- Point_coordination_function wikiPageWikiLink DCF_Interframe_Space.
- Point_coordination_function wikiPageWikiLink Distributed_coordination_function.
- Point_coordination_function wikiPageWikiLink Hidden_node_problem.
- Point_coordination_function wikiPageWikiLink IEEE_802.11e-2005.
- Point_coordination_function wikiPageWikiLink Media_access_control.
- Point_coordination_function wikiPageWikiLink Network_allocation_vector.
- Point_coordination_function wikiPageWikiLink PCF_Interframe_Space.
- Point_coordination_function wikiPageWikiLink Wi-Fi_Alliance.
- Point_coordination_function wikiPageWikiLink Wireless_LAN.
- Point_coordination_function wikiPageWikiLink Wireless_access_point.
- Point_coordination_function wikiPageWikiLinkText "Point coordination function".
- Point_coordination_function wikiPageWikiLinkText "point coordination function".
- Point_coordination_function wikiPageUsesTemplate Template:Channel_access_methods.
- Point_coordination_function wikiPageUsesTemplate Template:Compu-network-stub.
- Point_coordination_function wikiPageUsesTemplate Template:Reflist.
- Point_coordination_function subject Category:IEEE_802.11.
- Point_coordination_function subject Category:Media_access_control.
- Point_coordination_function hypernym Technique.
- Point_coordination_function type TopicalConcept.
- Point_coordination_function type Method.
- Point_coordination_function type Protocol.
- Point_coordination_function type Redirect.
- Point_coordination_function comment "Point coordination function (PCF) is a Media Access Control (MAC) technique used in IEEE 802.11 based WLANs. It resides in a point coordinator also known as Access Point (AP), to coordinate the communication within the network. The AP waits for PIFS duration rather than DIFS duration to grasp the channel.".
- Point_coordination_function label "Point coordination function".
- Point_coordination_function sameAs Q1469951.
- Point_coordination_function sameAs Point_Coordination_Function.
- Point_coordination_function sameAs Point_Coordinated_Function.
- Point_coordination_function sameAs Point_Coordination_Function.
- Point_coordination_function sameAs Point_Coordination_Function.
- Point_coordination_function sameAs m.05p1w3.
- Point_coordination_function sameAs Q1469951.
- Point_coordination_function wasDerivedFrom Point_coordination_function?oldid=704164687.
- Point_coordination_function isPrimaryTopicOf Point_coordination_function.