WLAN - Revision history

141.20.21.143: /* Introduction */

2005-02-10T13:34:46Z

Introduction

← Older revision		Revision as of 13:34, 10 February 2005
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	The standard family concerns the physical and data link layers as defined by the ''Open Systems Interconnection'' (OSI) Reference Model. <br>		The standard family concerns the physical and data link layers as defined by the ''Open Systems Interconnection'' (OSI) Reference Model. <br>
	It describes how to use ''radio frequencies'' (RF: typically in the microwave spectrum around 2.4 / 5 G-Hz, so called [[ISM bands]])		It describes how to use ''radio frequencies'' (RF: typically in the microwave spectrum around 2.4 / 5 G-Hz, so called [[ISM bands]])
	as transmission medium to build a local area network.		as transmission medium to build a local area network. It also includes an infra-red technique for data-transmission.
			This means we have two spread-spectrum methods for radio frequencies and one method for infra-red.

	The Range depends on the used antennas ([[omnidirectional]] vs. high gain [[fixed point]]): 50m up to 8km.		The Range depends on the used antennas ([[omnidirectional]] vs. high gain [[fixed point]]): 50m up to 8km.

Jirka: /* Introduction */

2004-12-02T10:07:04Z

Introduction

← Older revision		Revision as of 10:07, 2 December 2004
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	== Introduction ==		== Introduction ==

	The Wireless Local Area Network standard evolved in 1997 in form of the 802.11 Protocol. <br>		The Wireless Local Area Network standard evolved in 1997 in form of the IEEE 802.11 Protocol. <br>
	The standard family concerns the physical and data link layers as defined by the ''Open Systems Interconnection'' (OSI) Reference Model. <br>		The standard family concerns the physical and data link layers as defined by the ''Open Systems Interconnection'' (OSI) Reference Model. <br>
	It describes how to use ''radio frequencies'' (RF: typically in the microwave spectrum around 2.4 / 5 G-Hz, so called [[ISM bands]])		It describes how to use ''radio frequencies'' (RF: typically in the microwave spectrum around 2.4 / 5 G-Hz, so called [[ISM bands]])

Jirka: /* Provided Functionality */

2004-12-02T09:57:44Z

Provided Functionality

← Older revision		Revision as of 09:57, 2 December 2004
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	to realize everything went correctly.<br>		to realize everything went correctly.<br>
	This also means that the sending station has to do the error recovery part. <br>		This also means that the sending station has to do the error recovery part. <br>
	Access is coordinated through ''Distributed Coordination Function'' ([[CSMA/CA\|DCF]]) that checks whether the radio link is clear before sending.<br>		Access is coordinated through ''Distributed Coordination Function'' ([[CSMA/CA\|DCF; see CSMA/CA]]) that checks whether the radio link is clear before sending.<br>
	Short Ready To Send / Clear To Send (RTS/CTS) frames and a random backoff time might be used to reserve aether for the process of transmission.		Short Ready To Send / Clear To Send (RTS/CTS) frames and a random backoff time might be used to reserve aether for the process of transmission.

Jirka: /* Provided Functionality */

2004-12-02T09:56:29Z

Provided Functionality

← Older revision		Revision as of 09:56, 2 December 2004
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	to realize everything went correctly.<br>		to realize everything went correctly.<br>
	This also means that the sending station has to do the error recovery part. <br>		This also means that the sending station has to do the error recovery part. <br>
	Access is coordinated through ''Distributed Coordination Function'' (DCF) that checks whether the radio link is clear before sending.<br>		Access is coordinated through ''Distributed Coordination Function'' ([[CSMA/CA\|DCF]]) that checks whether the radio link is clear before sending.<br>
	Short Ready To Send / Clear To Send (RTS/CTS) frames and a random backoff time might be used to reserve aether for the process of transmission.		Short Ready To Send / Clear To Send (RTS/CTS) frames and a random backoff time might be used to reserve aether for the process of transmission.

Jirka: /* Provided Functionality */

2004-12-01T22:24:06Z

Provided Functionality

← Older revision		Revision as of 22:24, 1 December 2004
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	to realize everything went correctly.<br>		to realize everything went correctly.<br>
	This also means that the sending station has to do the error recovery part. <br>		This also means that the sending station has to do the error recovery part. <br>
	Access is coordinated through ''Distributed Coordination Function'' (DCF) that checks whether the radio link is clear before sending.		Access is coordinated through ''Distributed Coordination Function'' (DCF) that checks whether the radio link is clear before sending.<br>
	Short Ready To Send / Clear To Send (RTS/CTS) frames and a random backoff time might be used to reserve aether for the process of transmission.		Short Ready To Send / Clear To Send (RTS/CTS) frames and a random backoff time might be used to reserve aether for the process of transmission.

212.144.26.4: /* Provided Functionality */

2004-12-01T21:33:39Z

Provided Functionality

← Older revision		Revision as of 21:33, 1 December 2004
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	After each transmission sender expects to get acknowledge from receiver(''[[positive acknoledment]]''),		After each transmission sender expects to get acknowledge from receiver(''[[positive acknoledment]]''),
	to realize everything went correctly.<br>		to realize everything went correctly.<br>
	This ~~means~~ also that the sending station has to do the error recovery part. <br>		This also means that the sending station has to do the error recovery part. <br>
	Access is coordinated through ''Distributed Coordination Function'' (DCF) that checks whether the radio link is clear before sending.		Access is coordinated through ''Distributed Coordination Function'' (DCF) that checks whether the radio link is clear before sending.
	Short Ready To Send / Clear To Send (RTS/CTS) frames and a random backoff time might be used to reserve aether for the process of transmission.		Short Ready To Send / Clear To Send (RTS/CTS) frames and a random backoff time might be used to reserve aether for the process of transmission.

212.144.26.4: /* Provided Functionality */

2004-12-01T21:32:38Z

Provided Functionality

← Older revision		Revision as of 21:32, 1 December 2004
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	(Frame Control)(Duration ID)(Addr. 1)(Addr. 2)(Addr.3)(Sequence Control)(Addr. 4) (Frame Body)(FCS)		(Frame Control)(Duration ID)(Addr. 1)(Addr. 2)(Addr.3)(Sequence Control)(Addr. 4) (Frame Body)(FCS)

	After each transmission sender expects to get acknowledge from receiver, ~~to realize everything went correctly.~~		After each transmission sender expects to get acknowledge from receiver(''[[positive acknoledment]]''),
			to realize everything went correctly.<br>
			This means also that the sending station has to do the error recovery part. <br>
	Access is coordinated through ''Distributed Coordination Function'' (DCF) that checks whether the radio link is clear before sending.		Access is coordinated through ''Distributed Coordination Function'' (DCF) that checks whether the radio link is clear before sending.
	Short Ready To Send / Clear To Send (RTS/CTS) frames and a random backoff time might be used to reserve aether for the process of transmission.		Short Ready To Send / Clear To Send (RTS/CTS) frames and a random backoff time might be used to reserve aether for the process of transmission.

Jirka: /* Nomenclature */

2004-12-01T18:42:10Z

Nomenclature

← Older revision		Revision as of 18:42, 1 December 2004
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	== Nomenclature ==		== Nomenclature ==

			<div style="float:right; margin-left:5px;"> [[Image:802_11_nomen.png\|Nomenclature]] </div>

	''WLAN''s consist of at least one ''[[basic service set]]'' (BSS).		''WLAN''s consist of at least one ''[[basic service set]]'' (BSS).
	This might be only two or more computational devices with wireless network interfaces (''stations'') or		This might be only two or more computational devices with wireless network interfaces (''stations'') or
	a group of stations communicating through an ''[[access point]]'' (AP),		a group of stations communicating through an ''access point'' (AP),
	which can act additionally as a router to another network.		which can act additionally as a router to another network.

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	Usually the APs work as a bridge between the wireless network and a (not necessarily wired) backbone.		Usually the APs work as a bridge between the wireless network and a (not necessarily wired) backbone.

	The logical mechanism, that forwards the frames to their destination is called ''[[distribution system]]''.		The logical mechanism, that forwards the frames to their destination is called ''distribution system''.

	== Provided Functionality ==		== Provided Functionality ==

Jirka: /* Nomenclature */

2004-12-01T18:33:05Z

Nomenclature

← Older revision		Revision as of 18:33, 1 December 2004
Line 21:		Line 21:
	Usually the APs work as a bridge between the wireless network and a (not necessarily wired) backbone.		Usually the APs work as a bridge between the wireless network and a (not necessarily wired) backbone.

	The logical mechanism, that forwards the frames to their destination is called ''distribution system''.		The logical mechanism, that forwards the frames to their destination is called ''[[distribution system]]''.

	== Provided Functionality ==		== Provided Functionality ==

Jirka: /* Introduction */

2004-11-29T21:12:02Z

Introduction

← Older revision		Revision as of 21:12, 29 November 2004
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	== Introduction ==		== Introduction ==

	The Wireless Local Area Network standard evolved in 1997 in form of the		The Wireless Local Area Network standard evolved in 1997 in form of the 802.11 Protocol. <br>
		⚫	The standard family concerns the physical and data link layers as defined by the ''Open Systems Interconnection'' (OSI) Reference Model. <br>
	802.11 Protocol.
⚫	The standard family concerns the physical and data link layers as defined by the ''Open Systems Interconnection'' (OSI) Reference Model.
	It describes how to use ''radio frequencies'' (RF: typically in the microwave spectrum around 2.4 / 5 G-Hz, so called [[ISM bands]])		It describes how to use ''radio frequencies'' (RF: typically in the microwave spectrum around 2.4 / 5 G-Hz, so called [[ISM bands]])
	as transmission medium to build a local area network.		as transmission medium to build a local area network.