Channel access method - Revision history

Kvng: grammar

2025-04-07T21:57:26Z

grammar

Kku: link data communication

2025-03-09T23:36:07Z

link data communication

← Previous revision		Revision as of 23:36, 9 March 2025
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	One form is [[direct-sequence CDMA]] (DS-CDMA), based on [[direct-sequence spread spectrum]] (DSSS), used for example in [[3G]] cell phone systems. Each information bit (or each symbol) is represented by a long code sequence of several pulses, called chips. The sequence is the spreading code, and each message signal (for example each phone call) uses a different spreading code.		One form is [[direct-sequence CDMA]] (DS-CDMA), based on [[direct-sequence spread spectrum]] (DSSS), used for example in [[3G]] cell phone systems. Each information bit (or each symbol) is represented by a long code sequence of several pulses, called chips. The sequence is the spreading code, and each message signal (for example each phone call) uses a different spreading code.

	Another form is [[frequency-hopping CDMA]] (FH-CDMA), based on [[frequency-hopping spread spectrum]] (FHSS), where the channel frequency is changed rapidly according to a sequence that constitutes the spreading code. As an example, the [[Bluetooth]] communication system is based on a combination of frequency-hopping and either CSMA/CA statistical time-division multiplexing communication (for data communication applications) or TDMA (for audio transmission). All nodes belonging to the same user (to the same [[piconet]]) use the same frequency hopping sequence synchronously, meaning that they send on the same frequency channel, but CDMA/CA or TDMA is used to avoid collisions within the virtual personal area network (VPAN). Frequency-hopping is used by Bluetooth to reduce the cross-talk and collision probability between nodes in different VPANs.		Another form is [[frequency-hopping CDMA]] (FH-CDMA), based on [[frequency-hopping spread spectrum]] (FHSS), where the channel frequency is changed rapidly according to a sequence that constitutes the spreading code. As an example, the [[Bluetooth]] communication system is based on a combination of frequency-hopping and either CSMA/CA statistical time-division multiplexing communication (for [[data communication]] applications) or TDMA (for audio transmission). All nodes belonging to the same user (to the same [[piconet]]) use the same frequency hopping sequence synchronously, meaning that they send on the same frequency channel, but CDMA/CA or TDMA is used to avoid collisions within the virtual personal area network (VPAN). Frequency-hopping is used by Bluetooth to reduce the cross-talk and collision probability between nodes in different VPANs.

	Other techniques include OFDMA and [[multi-carrier code-division multiple access]] (MC-CDMA).		Other techniques include OFDMA and [[multi-carrier code-division multiple access]] (MC-CDMA).

Citation bot: Add: isbn, series. | Use this bot. Report bugs. | Suggested by Dominic3203 | Category:Channel access methods | #UCB_Category 16/22

2025-02-10T08:43:27Z

Add: isbn, series. | Use this bot. Report bugs. | Suggested by Dominic3203 | Category:Channel access methods | #UCB_Category 16/22

← Previous revision		Revision as of 08:43, 10 February 2025
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	==Fundamental schemes==		==Fundamental schemes==
	Several ways of categorizing multiple-access schemes and protocols have been used in the literature. For example, Daniel Minoli (2009)<ref>{{cite book\|author=Daniel Minoli\|title=Satellite Systems Engineering in an IPv6 Environment\|url=https://books.google.com/books?id=4yJi1UQDPp8C&pg=PA136\|access-date=1 June 2012\|date=3 February 2009\|publisher=CRC Press\|isbn=978-1-4200-7868-8\|pages=136–}}</ref> identifies five principal types of multiple-access schemes: [[FDMA]], [[Time-division multiple access\|TDMA]], [[CDMA]], [[Space-division multiple access\|SDMA]], and [[random access]]. [[Raphael Rom\|R. Rom]] and [[Moshe Sidi\|M. Sidi]] (1990)<ref>{{cite book \|last1=Rom \|first1=Raphael \|last2=Sidi \|first2=Moshe \|title=Multiple Access Protocols \|date=1990 \|publisher=Springer-Verlag/University of Michigan \|doi=10.1007/978-1-4612-3402-9}}</ref> categorize the protocols into ''Conflict-free access protocols'', ''Aloha protocols'', and ''Carrier Sensing protocols''.		Several ways of categorizing multiple-access schemes and protocols have been used in the literature. For example, Daniel Minoli (2009)<ref>{{cite book\|author=Daniel Minoli\|title=Satellite Systems Engineering in an IPv6 Environment\|url=https://books.google.com/books?id=4yJi1UQDPp8C&pg=PA136\|access-date=1 June 2012\|date=3 February 2009\|publisher=CRC Press\|isbn=978-1-4200-7868-8\|pages=136–}}</ref> identifies five principal types of multiple-access schemes: [[FDMA]], [[Time-division multiple access\|TDMA]], [[CDMA]], [[Space-division multiple access\|SDMA]], and [[random access]]. [[Raphael Rom\|R. Rom]] and [[Moshe Sidi\|M. Sidi]] (1990)<ref>{{cite book \|last1=Rom \|first1=Raphael \|last2=Sidi \|first2=Moshe \|title=Multiple Access Protocols \|series=Telecommunication Networks and Computer Systems \|date=1990 \|publisher=Springer-Verlag/University of Michigan \|doi=10.1007/978-1-4612-3402-9\|isbn=978-1-4612-7997-6 }}</ref> categorize the protocols into ''Conflict-free access protocols'', ''Aloha protocols'', and ''Carrier Sensing protocols''.

	The Telecommunications Handbook (Terplan and Morreale, 2000)<ref>{{cite book\|author=Kornel Terplan\|title=The Telecommunications Handbook\|url=https://books.google.com/books?id=_lLZLE6-SRsC&pg=PT266\|access-date=1 June 2012\|year=2000\|publisher=CRC Press\|isbn=978-0-8493-3137-4\|pages=266–}}</ref> identifies the following MAC categories:		The Telecommunications Handbook (Terplan and Morreale, 2000)<ref>{{cite book\|author=Kornel Terplan\|title=The Telecommunications Handbook\|url=https://books.google.com/books?id=_lLZLE6-SRsC&pg=PT266\|access-date=1 June 2012\|year=2000\|publisher=CRC Press\|isbn=978-0-8493-3137-4\|pages=266–}}</ref> identifies the following MAC categories:

Kvng: avoid unnec redirect

2024-10-31T16:52:59Z

avoid unnec redirect

← Previous revision		Revision as of 16:52, 31 October 2024
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	{{Use American English\|date = March 2019}}		{{Use American English\|date = March 2019}}

	In [[~~telecommunication~~]]s and [[computer networks]], a '''channel access method''' or '''multiple access method''' allows more than two [[terminal (telecommunication)\|terminal]]s connected to the same [[transmission medium]] to transmit over it and to share its capacity.<ref name="Miao">{{cite book \|author1=Guowang Miao \|author2=Jens Zander \|author3=Ki Won Sung \|author4=Ben Slimane \|title=Fundamentals of Mobile Data Networks \|publisher=Cambridge University Press \|isbn=978-1107143210 \|date=2016}}</ref> Examples of shared physical media are [[wireless network]]s, [[bus network]]s, [[ring network]]s and [[point-to-point link]]s operating in [[half-duplex]] mode.		In [[telecommunications]] and [[computer networks]], a '''channel access method''' or '''multiple access method''' allows more than two [[terminal (telecommunication)\|terminal]]s connected to the same [[transmission medium]] to transmit over it and to share its capacity.<ref name="Miao">{{cite book \|author1=Guowang Miao \|author2=Jens Zander \|author3=Ki Won Sung \|author4=Ben Slimane \|title=Fundamentals of Mobile Data Networks \|publisher=Cambridge University Press \|isbn=978-1107143210 \|date=2016}}</ref> Examples of shared physical media are [[wireless network]]s, [[bus network]]s, [[ring network]]s and [[point-to-point link]]s operating in [[half-duplex]] mode.

	A channel access method is based on [[multiplexing]], which allows several [[data stream]]s or signals to share the same [[communication channel]] or transmission medium. In this context, multiplexing is provided by the [[physical layer]].		A channel access method is based on [[multiplexing]], which allows several [[data stream]]s or signals to share the same [[communication channel]] or transmission medium. In this context, multiplexing is provided by the [[physical layer]].

Kvng: std acro def

2024-10-21T17:46:23Z

std acro def

← Previous revision		Revision as of 17:46, 21 October 2024
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	In [[telecommunication]]s and [[computer networks]], a '''channel access method''' or '''multiple access method''' allows more than two [[terminal (telecommunication)\|terminal]]s connected to the same [[transmission medium]] to transmit over it and to share its capacity.<ref name="Miao">{{cite book \|author1=Guowang Miao \|author2=Jens Zander \|author3=Ki Won Sung \|author4=Ben Slimane \|title=Fundamentals of Mobile Data Networks \|publisher=Cambridge University Press \|isbn=978-1107143210 \|date=2016}}</ref> Examples of shared physical media are [[wireless network]]s, [[bus network]]s, [[ring network]]s and [[point-to-point link]]s operating in [[half-duplex]] mode.		In [[telecommunication]]s and [[computer networks]], a '''channel access method''' or '''multiple access method''' allows more than two [[terminal (telecommunication)\|terminal]]s connected to the same [[transmission medium]] to transmit over it and to share its capacity.<ref name="Miao">{{cite book \|author1=Guowang Miao \|author2=Jens Zander \|author3=Ki Won Sung \|author4=Ben Slimane \|title=Fundamentals of Mobile Data Networks \|publisher=Cambridge University Press \|isbn=978-1107143210 \|date=2016}}</ref> Examples of shared physical media are [[wireless network]]s, [[bus network]]s, [[ring network]]s and [[point-to-point link]]s operating in [[half-duplex]] mode.

	A channel access method is based on [[multiplexing]], ~~that~~ allows several [[data stream]]s or signals to share the same [[communication channel]] or transmission medium. In this context, multiplexing is provided by the [[physical layer]].		A channel access method is based on [[multiplexing]], which allows several [[data stream]]s or signals to share the same [[communication channel]] or transmission medium. In this context, multiplexing is provided by the [[physical layer]].

	A channel access method may also be a part of the multiple access protocol and control mechanism, also known as [[medium access control]] (MAC). Medium access control deals with issues such as addressing, assigning multiplex channels to different users and avoiding collisions. Media access control is a sub-layer in the [[data link layer]] of the [[OSI model]] and a component of the [[link layer]] of the [[TCP/IP model]].		A channel access method may also be a part of the multiple access protocol and control mechanism, also known as [[medium access control]] (MAC). Medium access control deals with issues such as addressing, assigning multiplex channels to different users and avoiding collisions. Media access control is a sub-layer in the [[data link layer]] of the [[OSI model]] and a component of the [[link layer]] of the [[TCP/IP model]].
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	One form is [[direct-sequence CDMA]] (DS-CDMA), based on [[direct-sequence spread spectrum]] (DSSS), used for example in [[3G]] cell phone systems. Each information bit (or each symbol) is represented by a long code sequence of several pulses, called chips. The sequence is the spreading code, and each message signal (for example each phone call) uses a different spreading code.		One form is [[direct-sequence CDMA]] (DS-CDMA), based on [[direct-sequence spread spectrum]] (DSSS), used for example in [[3G]] cell phone systems. Each information bit (or each symbol) is represented by a long code sequence of several pulses, called chips. The sequence is the spreading code, and each message signal (for example each phone call) uses a different spreading code.

	Another form is [[frequency-hopping CDMA]] (FH-CDMA), based on [[frequency-hopping spread spectrum]] (FHSS), where the channel frequency is changed rapidly according to a sequence that constitutes the spreading code. As an example, the [[Bluetooth]] communication system is based on a combination of frequency-hopping and either CSMA/CA statistical time-division multiplexing communication (for data communication applications) or TDMA (for audio transmission). All nodes belonging to the same user (to the same [[piconet]]) use the same frequency hopping sequence synchronously, meaning that they send on the same frequency channel, but CDMA/CA or TDMA is used to avoid collisions within the ~~VPAN~~ ~~(Virtual~~ ~~Personal~~ ~~Area~~ ~~Network~~). Frequency-hopping is used by Bluetooth to reduce the cross-talk and collision probability between nodes in different VPANs.		Another form is [[frequency-hopping CDMA]] (FH-CDMA), based on [[frequency-hopping spread spectrum]] (FHSS), where the channel frequency is changed rapidly according to a sequence that constitutes the spreading code. As an example, the [[Bluetooth]] communication system is based on a combination of frequency-hopping and either CSMA/CA statistical time-division multiplexing communication (for data communication applications) or TDMA (for audio transmission). All nodes belonging to the same user (to the same [[piconet]]) use the same frequency hopping sequence synchronously, meaning that they send on the same frequency channel, but CDMA/CA or TDMA is used to avoid collisions within the virtual personal area network (VPAN). Frequency-hopping is used by Bluetooth to reduce the cross-talk and collision probability between nodes in different VPANs.

	Other techniques include OFDMA and [[multi-carrier code-division multiple access]] (MC-CDMA).		Other techniques include OFDMA and [[multi-carrier code-division multiple access]] (MC-CDMA).

75.155.132.5: /* Code-division multiple access and spread spectrum multiple access */ Acronym for VPAN as per https://www.bluetooth.com/specifications/specs/personal-area-networking-profile-1-0/

2024-10-15T04:26:39Z

Code-division multiple access and spread spectrum multiple access: Acronym for VPAN as per https://www.bluetooth.com/specifications/specs/personal-area-networking-profile-1-0/

← Previous revision		Revision as of 04:26, 15 October 2024
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	One form is [[direct-sequence CDMA]] (DS-CDMA), based on [[direct-sequence spread spectrum]] (DSSS), used for example in [[3G]] cell phone systems. Each information bit (or each symbol) is represented by a long code sequence of several pulses, called chips. The sequence is the spreading code, and each message signal (for example each phone call) uses a different spreading code.		One form is [[direct-sequence CDMA]] (DS-CDMA), based on [[direct-sequence spread spectrum]] (DSSS), used for example in [[3G]] cell phone systems. Each information bit (or each symbol) is represented by a long code sequence of several pulses, called chips. The sequence is the spreading code, and each message signal (for example each phone call) uses a different spreading code.

	Another form is [[frequency-hopping CDMA]] (FH-CDMA), based on [[frequency-hopping spread spectrum]] (FHSS), where the channel frequency is changed rapidly according to a sequence that constitutes the spreading code. As an example, the [[Bluetooth]] communication system is based on a combination of frequency-hopping and either CSMA/CA statistical time-division multiplexing communication (for data communication applications) or TDMA (for audio transmission). All nodes belonging to the same user (to the same [[piconet]]) use the same frequency hopping sequence synchronously, meaning that they send on the same frequency channel, but CDMA/CA or TDMA is used to avoid collisions within the VPAN. Frequency-hopping is used by Bluetooth to reduce the cross-talk and collision probability between nodes in different VPANs.		Another form is [[frequency-hopping CDMA]] (FH-CDMA), based on [[frequency-hopping spread spectrum]] (FHSS), where the channel frequency is changed rapidly according to a sequence that constitutes the spreading code. As an example, the [[Bluetooth]] communication system is based on a combination of frequency-hopping and either CSMA/CA statistical time-division multiplexing communication (for data communication applications) or TDMA (for audio transmission). All nodes belonging to the same user (to the same [[piconet]]) use the same frequency hopping sequence synchronously, meaning that they send on the same frequency channel, but CDMA/CA or TDMA is used to avoid collisions within the VPAN (Virtual Personal Area Network). Frequency-hopping is used by Bluetooth to reduce the cross-talk and collision probability between nodes in different VPANs.

	Other techniques include OFDMA and [[multi-carrier code-division multiple access]] (MC-CDMA).		Other techniques include OFDMA and [[multi-carrier code-division multiple access]] (MC-CDMA).

75.155.132.5: /* Fundamental schemes */ Added links for Raphael_Rom and TDMA

2024-10-15T04:15:48Z

Fundamental schemes: Added links for Raphael_Rom and TDMA

← Previous revision		Revision as of 04:15, 15 October 2024
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	==Fundamental schemes==		==Fundamental schemes==
	Several ways of categorizing multiple-access schemes and protocols have been used in the literature. For example, Daniel Minoli (2009)<ref>{{cite book\|author=Daniel Minoli\|title=Satellite Systems Engineering in an IPv6 Environment\|url=https://books.google.com/books?id=4yJi1UQDPp8C&pg=PA136\|access-date=1 June 2012\|date=3 February 2009\|publisher=CRC Press\|isbn=978-1-4200-7868-8\|pages=136–}}</ref> identifies five principal types of multiple-access schemes: [[FDMA]], TDMA, [[CDMA]], [[Space-division multiple access\|SDMA]], and [[random access]]. R. Rom and [[Moshe Sidi\|M. Sidi]] (1990)<ref>{{cite book \|last1=Rom \|first1=Raphael \|last2=Sidi \|first2=Moshe \|title=Multiple Access Protocols \|date=1990 \|publisher=Springer-Verlag/University of Michigan \|doi=10.1007/978-1-4612-3402-9}}</ref> categorize the protocols into ''Conflict-free access protocols'', ''Aloha protocols'', and ''Carrier Sensing protocols''.		Several ways of categorizing multiple-access schemes and protocols have been used in the literature. For example, Daniel Minoli (2009)<ref>{{cite book\|author=Daniel Minoli\|title=Satellite Systems Engineering in an IPv6 Environment\|url=https://books.google.com/books?id=4yJi1UQDPp8C&pg=PA136\|access-date=1 June 2012\|date=3 February 2009\|publisher=CRC Press\|isbn=978-1-4200-7868-8\|pages=136–}}</ref> identifies five principal types of multiple-access schemes: [[FDMA]], [[Time-division multiple access\|TDMA]], [[CDMA]], [[Space-division multiple access\|SDMA]], and [[random access]]. [[Raphael Rom\|R. Rom]] and [[Moshe Sidi\|M. Sidi]] (1990)<ref>{{cite book \|last1=Rom \|first1=Raphael \|last2=Sidi \|first2=Moshe \|title=Multiple Access Protocols \|date=1990 \|publisher=Springer-Verlag/University of Michigan \|doi=10.1007/978-1-4612-3402-9}}</ref> categorize the protocols into ''Conflict-free access protocols'', ''Aloha protocols'', and ''Carrier Sensing protocols''.

	The Telecommunications Handbook (Terplan and Morreale, 2000)<ref>{{cite book\|author=Kornel Terplan\|title=The Telecommunications Handbook\|url=https://books.google.com/books?id=_lLZLE6-SRsC&pg=PT266\|access-date=1 June 2012\|year=2000\|publisher=CRC Press\|isbn=978-0-8493-3137-4\|pages=266–}}</ref> identifies the following MAC categories:		The Telecommunications Handbook (Terplan and Morreale, 2000)<ref>{{cite book\|author=Kornel Terplan\|title=The Telecommunications Handbook\|url=https://books.google.com/books?id=_lLZLE6-SRsC&pg=PT266\|access-date=1 June 2012\|year=2000\|publisher=CRC Press\|isbn=978-0-8493-3137-4\|pages=266–}}</ref> identifies the following MAC categories:

Kvng: avoid unnec redirect

2024-09-06T16:54:25Z

avoid unnec redirect

← Previous revision		Revision as of 16:54, 6 September 2024
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	The [[time-division multiple access]] (TDMA) channel access scheme is based on the [[time-division multiplexing]] (TDM) scheme. TDMA provides different time slots to different transmitters in a cyclically repetitive frame structure. For example, node 1 may use time slot 1, node 2 time slot 2, etc. until the last transmitter when it starts over. An advanced form is dynamic TDMA (DTDMA), where an assignment of transmitters to time slots varies on each frame.		The [[time-division multiple access]] (TDMA) channel access scheme is based on the [[time-division multiplexing]] (TDM) scheme. TDMA provides different time slots to different transmitters in a cyclically repetitive frame structure. For example, node 1 may use time slot 1, node 2 time slot 2, etc. until the last transmitter when it starts over. An advanced form is dynamic TDMA (DTDMA), where an assignment of transmitters to time slots varies on each frame.

	[[Multi-frequency time-division multiple access]] (MF-TDMA) combines time and frequency multiple access. As an example, [[2G]] cellular systems are based on a combination of TDMA and FDMA. Each frequency channel is divided into eight time slots, of which seven are used for seven phone calls, and one for [[~~signalling~~ (telecommunications)\|signaling]] data.		[[Multi-frequency time-division multiple access]] (MF-TDMA) combines time and frequency multiple access. As an example, [[2G]] cellular systems are based on a combination of TDMA and FDMA. Each frequency channel is divided into eight time slots, of which seven are used for seven phone calls, and one for [[signaling (telecommunications)\|signaling]] data.

	[[Statistical time-division multiplexing]] multiple access is typically also based on time-domain multiplexing, but not in a cyclically repetitive frame structure. Due to its random character, it can be categorized as [[statistical multiplexing]] methods and capable of [[dynamic bandwidth allocation]]. This requires a [[media access control]] (MAC) protocol, i.e. a principle for the nodes to take turns on the channel and to avoid collisions. Common examples are [[CSMA/CD]], used in [[Ethernet]] bus networks and hub networks, and [[CSMA/CA]], used in wireless networks such as [[IEEE 802.11]].		[[Statistical time-division multiplexing]] multiple access is typically also based on time-domain multiplexing, but not in a cyclically repetitive frame structure. Due to its random character, it can be categorized as [[statistical multiplexing]] methods and capable of [[dynamic bandwidth allocation]]. This requires a [[media access control]] (MAC) protocol, i.e. a principle for the nodes to take turns on the channel and to avoid collisions. Common examples are [[CSMA/CD]], used in [[Ethernet]] bus networks and hub networks, and [[CSMA/CA]], used in wireless networks such as [[IEEE 802.11]].

Kvng: unpiped links using script

2024-09-04T04:27:19Z

unpiped links using script

← Previous revision		Revision as of 04:27, 4 September 2024
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	===Frequency-division multiple access===		===Frequency-division multiple access===
	The [[frequency-division multiple access]] (FDMA) channel-access scheme is the most standard analog system, based on the [[frequency-division multiplexing]] (FDM) scheme, which provides different frequency bands to different data streams. In the FDMA case, the frequency bands are allocated to different nodes or devices. An example of FDMA systems were the first-generation [[1G]] cell-phone systems, where each phone call was assigned to a specific uplink frequency channel, and another downlink frequency channel. Each message signal (each phone call) is [[~~modulation\|~~modulated]] on a specific [[carrier frequency]].		The [[frequency-division multiple access]] (FDMA) channel-access scheme is the most standard analog system, based on the [[frequency-division multiplexing]] (FDM) scheme, which provides different frequency bands to different data streams. In the FDMA case, the frequency bands are allocated to different nodes or devices. An example of FDMA systems were the first-generation [[1G]] cell-phone systems, where each phone call was assigned to a specific uplink frequency channel, and another downlink frequency channel. Each message signal (each phone call) is [[modulated]] on a specific [[carrier frequency]].

	A related technique is wavelength division multiple access (WDMA), based on [[wavelength-division multiplexing]] (WDM), where different data streams get different colors in fiber-optical communications. In the WDMA case, different network nodes in a bus or hub network get a different color.<ref>{{Cite web\|url=https://www.abcofnetworks.com/2019/02/Multiple-Access-Techniques-in-communication-FDMA-TDMA-CDMA.html\|title=Multiple Access Techniques in communication: FDMA, TDMA, CDMA\|last=Sadique\|first=Abubaker\|archive-url=https://web.archive.org/web/20191009145423/https://www.abcofnetworks.com/2019/02/Multiple-Access-Techniques-in-communication-FDMA-TDMA-CDMA.html\|archive-date=2019-10-09}}</ref>		A related technique is wavelength division multiple access (WDMA), based on [[wavelength-division multiplexing]] (WDM), where different data streams get different colors in fiber-optical communications. In the WDMA case, different network nodes in a bus or hub network get a different color.<ref>{{Cite web\|url=https://www.abcofnetworks.com/2019/02/Multiple-Access-Techniques-in-communication-FDMA-TDMA-CDMA.html\|title=Multiple Access Techniques in communication: FDMA, TDMA, CDMA\|last=Sadique\|first=Abubaker\|archive-url=https://web.archive.org/web/20191009145423/https://www.abcofnetworks.com/2019/02/Multiple-Access-Techniques-in-communication-FDMA-TDMA-CDMA.html\|archive-date=2019-10-09}}</ref>
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	===Satellite communications===		===Satellite communications===
	In [[satellite communications]], multiple access is the capability of a [[communications satellite]] to function as a portion of a communications link between more than one pair of ground-based terminals concurrently. Three types of multiple access presently used with communications satellites are [[~~code-division multiple access\|~~code-division]], [[frequency-division multiple access\|frequency-division]], and [[time-division multiple access\|time-division]] multiple access.		In [[satellite communications]], multiple access is the capability of a [[communications satellite]] to function as a portion of a communications link between more than one pair of ground-based terminals concurrently. Three types of multiple access presently used with communications satellites are [[code-division]], [[frequency-division multiple access\|frequency-division]], and [[time-division multiple access\|time-division]] multiple access.

	=== Cellular networks ===		=== Cellular networks ===

Adig-pt: Link to Moshe Sidi's Wiki article (uncontroversial COI edit)

2024-07-16T05:26:22Z

Link to Moshe Sidi's Wiki article (uncontroversial COI edit)

← Previous revision		Revision as of 05:26, 16 July 2024
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	==Fundamental schemes==		==Fundamental schemes==
	Several ways of categorizing multiple-access schemes and protocols have been used in the literature. For example, Daniel Minoli (2009)<ref>{{cite book\|author=Daniel Minoli\|title=Satellite Systems Engineering in an IPv6 Environment\|url=https://books.google.com/books?id=4yJi1UQDPp8C&pg=PA136\|access-date=1 June 2012\|date=3 February 2009\|publisher=CRC Press\|isbn=978-1-4200-7868-8\|pages=136–}}</ref> identifies five principal types of multiple-access schemes: [[FDMA]], TDMA, [[CDMA]], [[Space-division multiple access\|SDMA]], and [[random access]]. R. Rom and M. Sidi (1990)<ref>{{cite book \|last1=Rom \|first1=Raphael \|last2=Sidi \|first2=Moshe \|title=Multiple Access Protocols \|date=1990 \|publisher=Springer-Verlag/University of Michigan \|doi=10.1007/978-1-4612-3402-9}}</ref> categorize the protocols into ''Conflict-free access protocols'', ''Aloha protocols'', and ''Carrier Sensing protocols''.		Several ways of categorizing multiple-access schemes and protocols have been used in the literature. For example, Daniel Minoli (2009)<ref>{{cite book\|author=Daniel Minoli\|title=Satellite Systems Engineering in an IPv6 Environment\|url=https://books.google.com/books?id=4yJi1UQDPp8C&pg=PA136\|access-date=1 June 2012\|date=3 February 2009\|publisher=CRC Press\|isbn=978-1-4200-7868-8\|pages=136–}}</ref> identifies five principal types of multiple-access schemes: [[FDMA]], TDMA, [[CDMA]], [[Space-division multiple access\|SDMA]], and [[random access]]. R. Rom and [[Moshe Sidi\|M. Sidi]] (1990)<ref>{{cite book \|last1=Rom \|first1=Raphael \|last2=Sidi \|first2=Moshe \|title=Multiple Access Protocols \|date=1990 \|publisher=Springer-Verlag/University of Michigan \|doi=10.1007/978-1-4612-3402-9}}</ref> categorize the protocols into ''Conflict-free access protocols'', ''Aloha protocols'', and ''Carrier Sensing protocols''.

	The Telecommunications Handbook (Terplan and Morreale, 2000)<ref>{{cite book\|author=Kornel Terplan\|title=The Telecommunications Handbook\|url=https://books.google.com/books?id=_lLZLE6-SRsC&pg=PT266\|access-date=1 June 2012\|year=2000\|publisher=CRC Press\|isbn=978-0-8493-3137-4\|pages=266–}}</ref> identifies the following MAC categories:		The Telecommunications Handbook (Terplan and Morreale, 2000)<ref>{{cite book\|author=Kornel Terplan\|title=The Telecommunications Handbook\|url=https://books.google.com/books?id=_lLZLE6-SRsC&pg=PT266\|access-date=1 June 2012\|year=2000\|publisher=CRC Press\|isbn=978-0-8493-3137-4\|pages=266–}}</ref> identifies the following MAC categories:

← Previous revision		Revision as of 21:57, 7 April 2025
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	===Frequency-division multiple access===		===Frequency-division multiple access===
	The [[frequency-division multiple access]] (FDMA) channel-access scheme is the most standard analog system, based on the [[frequency-division multiplexing]] (FDM) scheme, which provides different frequency bands to different data streams. In the FDMA case, the frequency bands are allocated to different nodes or devices. An example of FDMA systems ~~were~~ the first-generation [[1G]] cell-phone systems, where each phone call was assigned to a specific uplink frequency channel, and another downlink frequency channel. Each message signal (each phone call) is [[modulated]] on a specific [[carrier frequency]].		The [[frequency-division multiple access]] (FDMA) channel-access scheme is the most standard analog system, based on the [[frequency-division multiplexing]] (FDM) scheme, which provides different frequency bands to different data streams. In the FDMA case, the frequency bands are allocated to different nodes or devices. An example of FDMA systems was the first-generation [[1G]] cell-phone systems, where each phone call was assigned to a specific uplink frequency channel and another downlink frequency channel. Each message signal (each phone call) is [[modulated]] on a specific [[carrier frequency]].

	A related technique is wavelength division multiple access (WDMA), based on [[wavelength-division multiplexing]] (WDM), where different data streams get different colors in fiber-optical communications. In the WDMA case, different network nodes in a bus or hub network get a different color.<ref>{{Cite web\|url=https://www.abcofnetworks.com/2019/02/Multiple-Access-Techniques-in-communication-FDMA-TDMA-CDMA.html\|title=Multiple Access Techniques in communication: FDMA, TDMA, CDMA\|last=Sadique\|first=Abubaker\|archive-url=https://web.archive.org/web/20191009145423/https://www.abcofnetworks.com/2019/02/Multiple-Access-Techniques-in-communication-FDMA-TDMA-CDMA.html\|archive-date=2019-10-09}}</ref>		A related technique is wavelength division multiple access (WDMA), based on [[wavelength-division multiplexing]] (WDM), where different data streams get different colors in fiber-optical communications. In the WDMA case, different network nodes in a bus or hub network get a different color.<ref>{{Cite web\|url=https://www.abcofnetworks.com/2019/02/Multiple-Access-Techniques-in-communication-FDMA-TDMA-CDMA.html\|title=Multiple Access Techniques in communication: FDMA, TDMA, CDMA\|last=Sadique\|first=Abubaker\|archive-url=https://web.archive.org/web/20191009145423/https://www.abcofnetworks.com/2019/02/Multiple-Access-Techniques-in-communication-FDMA-TDMA-CDMA.html\|archive-date=2019-10-09}}</ref>
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	===Time-division multiple access===		===Time-division multiple access===
	The [[time-division multiple access]] (TDMA) channel access scheme is based on the [[time-division multiplexing]] (TDM) scheme. TDMA provides different time slots to different transmitters in a cyclically repetitive frame structure. For example, node 1 may use time slot 1, node 2 time slot 2, etc. until the last transmitter when it starts over. An advanced form is dynamic TDMA (DTDMA), where an assignment of transmitters to time slots varies on each frame.		The [[time-division multiple access]] (TDMA) channel access scheme is based on the [[time-division multiplexing]] (TDM) scheme. TDMA provides different time slots to different transmitters in a cyclically repetitive frame structure. For example, node 1 may use time slot 1, node 2 time slot 2, etc., until the last transmitter when it starts over. An advanced form is dynamic TDMA (DTDMA), where an assignment of transmitters to time slots varies on each frame.

	[[Multi-frequency time-division multiple access]] (MF-TDMA) combines time and frequency multiple access. As an example, [[2G]] cellular systems are based on a combination of TDMA and FDMA. Each frequency channel is divided into eight time slots, of which seven are used for seven phone calls, and one for [[signaling (telecommunications)\|signaling]] data.		[[Multi-frequency time-division multiple access]] (MF-TDMA) combines time and frequency multiple access. As an example, [[2G]] cellular systems are based on a combination of TDMA and FDMA. Each frequency channel is divided into eight time slots, of which seven are used for seven phone calls and one for [[signaling (telecommunications)\|signaling]] data.

	[[Statistical time-division multiplexing]] multiple access is typically also based on time-domain multiplexing, but not in a cyclically repetitive frame structure. Due to its random character, it can be categorized as [[statistical multiplexing]] methods and capable of [[dynamic bandwidth allocation]]. This requires a [[media access control]] (MAC) protocol, i.e. a principle for the nodes to take turns on the channel and to avoid collisions. Common examples are [[CSMA/CD]], used in [[Ethernet]] bus networks and hub networks, and [[CSMA/CA]], used in wireless networks such as [[IEEE 802.11]].		[[Statistical time-division multiplexing]] multiple access is typically also based on time-domain multiplexing, but not in a cyclically repetitive frame structure. Due to its random character, it can be categorized as [[statistical multiplexing]] methods and capable of [[dynamic bandwidth allocation]]. This requires a [[media access control]] (MAC) protocol, i.e., a principle for the nodes to take turns on the channel and to avoid collisions. Common examples are [[CSMA/CD]], used in [[Ethernet]] bus networks and hub networks, and [[CSMA/CA]], used in wireless networks such as [[IEEE 802.11]].

	===Code-division multiple access and spread spectrum multiple access===		===Code-division multiple access and spread spectrum multiple access===
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	===Packet mode methods===		===Packet mode methods===
	Packet mode channel access methods select a single network transmitter for the duration of a packet transmission. Some methods are more suited to wired communication while others are more suited to wireless.<ref name=Miao/>		Packet mode channel access methods select a single network transmitter for the duration of a packet transmission. Some methods are more suited to wired communication, while others are more suited to wireless.<ref name=Miao/>

	Common statistical time-division multiplexing multiple access protocols for wired multi-drop networks include:		Common statistical time-division multiplexing multiple access protocols for wired multi-drop networks include: