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WO1998004058A1 - Reseau optique - Google Patents

Reseau optique Download PDF

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Publication number
WO1998004058A1
WO1998004058A1 PCT/SE1997/001267 SE9701267W WO9804058A1 WO 1998004058 A1 WO1998004058 A1 WO 1998004058A1 SE 9701267 W SE9701267 W SE 9701267W WO 9804058 A1 WO9804058 A1 WO 9804058A1
Authority
WO
WIPO (PCT)
Prior art keywords
fibre
node
hub node
hub
satellite
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/SE1997/001267
Other languages
English (en)
Inventor
Magnus ÖBERG
Bengt Johansson
Lars Erik Egnell
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Priority to AU37129/97A priority Critical patent/AU3712997A/en
Priority to EP97933954A priority patent/EP0908029A1/fr
Priority to BR9710364A priority patent/BR9710364A/pt
Priority to JP10506859A priority patent/JP2000515697A/ja
Publication of WO1998004058A1 publication Critical patent/WO1998004058A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0241—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0278—WDM optical network architectures
    • H04J14/0283—WDM ring architectures
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0287—Protection in WDM systems
    • H04J14/0293—Optical channel protection
    • H04J14/0295—Shared protection at the optical channel (1:1, n:m)
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0287—Protection in WDM systems
    • H04J14/0297—Optical equipment protection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0062—Network aspects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0062—Network aspects
    • H04Q2011/0079—Operation or maintenance aspects
    • H04Q2011/0081—Fault tolerance; Redundancy; Recovery; Reconfigurability
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0062—Network aspects
    • H04Q2011/009—Topology aspects
    • H04Q2011/0092—Ring

Definitions

  • This invention relates to an optical hub network device, and particularly for a wavelength routed optical network in a hubbed configuration.
  • Optical systems, circuits and fibre networks have become more and more important for data communication and telecommunication systems.
  • Optical fibres have large transmission capacity without electromagnetic interference and ground loop problems.
  • Optical multichannel systems have an increasing demand, and will probably change network design strategies during the coming years.
  • multichannel techniques By using multichannel techniques, increased transmission capacity and flexibility can be realised on existing fibre cables without increasing modulation speed or adding more complex control functions.
  • one of the nodes in the system is a central node, called the hub node, and the rest of the nodes are satellite nodes.
  • Each satellite node is able to communicate with any other satellite node but only via the hub node.
  • a bus architecture can be used for communication networks of this kind.
  • the bus is formed as a ring with the two end nodes connected to the hub.
  • the different satellite nodes in the system are allotted to individual wavelength channels thereby to provide the star features of the network.
  • Several satellite nodes may then share the same fibre where each fibre can bear up to N wavelength channels.
  • Each satellite node always transmits and listen towards both end nodes.
  • the bus carrying normal satellite to hub traffic towards one end node. In case of fibre failure the traffic is re-routed, by the hub, to the other end node and the traffic is, in this way, restored. In this way, each satellite node in the network can be reached in two separate ways from the hub node with just one optical fibre cable comprising two fibres, so if a fibre break occurs in one direction, the traffic can be re-routed to the other direction.
  • the hub node can receive the incoming signals from certain satellite nodes from one direction and transmit the outgoing signals in the same direction as the incoming signals.
  • Another object of the invention is to provide a method and a device for connecting many satellite nodes and a hub node in an optical logical star network connected in a ring and having as few critical components, i.e. inclined to failure, as possible.
  • Another object of the invention is to provide a method and a device for making a transmitting and receiving traffic between the hub and each of the nodes even if a cable failure has occurred in an optical network.
  • cable failure can be a double, a single fibre break or a damage on one or both of the fibres where still some part of the light flowing through the damaged part, still using the same set of wavelength for both upstream and downstream communications.
  • Yet another object of the invention is to provide a method and a device for keeping a traffic going in an optical telecommunication network comprising a hub node and a plurality of satellite nodes even when a component of the network is damaged.
  • Still another object of the invention is to provide a method and a device for an optical telecommunication network normally having a network interruption only at the hub node.
  • satellite nodes are connected to the fibres by passive multiplexers and demultiplexers, for instance comprising fibre couplers. All kinds of switching in the net is provided in the hub means.
  • the theoretical minimum number of wavelength channels could be used, i.e. only one wavelength channel per satellite node connected to the network. No optical switches are used on the fibre ring, they are provided only in the hub node. The satellite nodes could then have an extremely simple design without any required intelligence.
  • the cable protection could be handled by the hub node.
  • At least one spare hub node for back-up could be installed at any occasion with no modifications on the already installed hardware.
  • FIG 1 shows schematically a first embodiment of a communication network according to the invention
  • FIG 2A-2E show schematically different traffic propagations for different kinds of failure of the network
  • FIG 3 shows schematically a second embodiment of a communication network according to the invention.
  • the communication network comprises one central node, called hub node H, and a number of satellite nodes A, B, C... All the nodes are connected by a two fibre ring, having the fibres F 1 and F2, with counter-propagating traffic on the two fibres.
  • the fibres are preferably singlemode fibres.
  • Logically the network is a star network since every satellite node has a unique designated wavelength channel on which it transmits and receives. Each satellite node is able to communicate directly only with the hub node H. Thus traffic between two satellite nodes, such as A and B, always has to go via the hub node H.
  • the hub node transmits and receives on each wavelength channel belonging to each satellite node A, B, C... connected to the network.
  • each fibre has a number of N wavelength channels in a network having a number of N satellite nodes.
  • the channels in the hub node could then, via the electrical interfaces on its transmitters Tx' and receivers Rx', in a manner known per se also be connected to other communication networks either of the same design as the one described herein or of some other design known in the art.
  • each satellite node A, B, C... is connected to the fibres by passive multiplexers and demultiplexers in order to avoid switching components. Switching elements need to be controlled individually and are also inclined to failure.
  • each satellite node comprises an access point 1 having a transmitter and a receiver (not shown), two l-by-2 fibre couplers 2 and 3, two passive multiplexers 4 and 5, and two passive demultiplexers 6 and 7.
  • the function of the fibre coupler 3 is to distribute the transmitter signal from the transmitter in the access point 1 to the two multiplexers 4 and 5.
  • the function of the fibre coupler 2 is to bring together the received signals from the two demultiplexers 6 and 7 to the receiver in the access point 1.
  • the transmitter and the received signals lie within the same wavelength channel for each station.
  • the multiplexers 4 and 5 couple the transmitter signal onto the bus fibres FI and F2.
  • the demultiplexers tap the desired wavelength channel for the satellite node in question out from the bus fibres to the receiver in the work station 1.
  • the multiplexers may consist of simple fibre couplers 4' and 5'.
  • the demultiplexers may be replaced by fibre couplers 6' and 7' and a bandpass filter 8 adapted to the wavelength channel for the station in question.
  • the hub node means (H) is provided with a fibre break of the fibres FI and F2 and transmitting and receiving means 9, 10, 13 and 11, 12, 14 connected to each end of the fibres FI and F2.
  • the hub node H comprises one light transmitter Tx', such as a wavelength stabilised modulated laser, and one optical receiver per satellite node connected to the network.
  • Each fibre has a deconnection in the hub node.
  • a demultiplexer 10 and a multiplexer 1 1 are connected to each end of fibre FI .
  • a demultiplexer 9 and a multiplexer 12 are connected to fibre F2.
  • An individual switching unit 13 including a PIN diode and a 2-by-2 optical cross-bar switch is connected to each light transmitter Tx' and the two demultiplexers 9 and 10.
  • the function of the 2-by-2 cross-bar switches on the receiver side is to choose which of the two demultiplexers 9 or 10 the receiver in question should listen to, i.e. from which fibre end its belonging satellite node signal should be provided.
  • the switching unit could of course be replaced by some other switching device having the same function, but cross-bar switch structure with the PIN diode provides a cheap application.
  • One of the demultiplexers, 9 in FIG 1, is the one in operation when there is no fibre break in the fibre ring.
  • the PIN diode automatically listens to the other demultiplexer 10 on the same wavelength channel, and provides a change-over for providing signal information from the demultiplexer 10 when there is an incoming signal information only on the demultiplexer 10.
  • the two demultiplexers are connected to the cross-bar switches in the switching units 13 so that a certain switch and thereby a certain receiver/PIN-diode pair always listen to the same wavelength channel, no matter the position of the switch.
  • the satellite nodes always transmits the transmitter signals on both fibres FI and F2 but in different directions, as apparent from FIG 1.
  • the satellite receivers are coupled to listen in both directions even if the same channel never will come simultaneously on the both fibres FI and F2.
  • an optical l-by-2 space switch 14 is connected between the transmitter, only indicated by the reference Tx', and the two multiplexers 11 and 12 for transmitting either on the fibre FI or on the fibre F2.
  • Transmitter/receiver-pairs in the hub node operating on the same wavelength channel and thereby handling the bi-directional communication with a certain satellite node always transmit to and listen from the same direction.
  • the receiver switch 13 for a certain channel changes from a first position, below called left, to a second, below called right, the transmitter switch 14 for the same wavelength channel should do the same.
  • each transmitter switch unit 14 is controlled by the position of the corresponding receiver switch 13.
  • the hub node will lose the incoming signals from at least certain channels either on the receivers or on the PIN diodes.
  • the action from the hub node will then be to reconfigure the transmitter and the receiver switches according to the following two rules.
  • Each satellite node will receive one channel from the hub node and transmit the same (or other) wavelength channel in both directions through its multiplexers 4 and 5 (4' and 5').
  • the signal propagation of the different channels of the satellite nodes A, B, C... has been illustrated by the same node reference but in small letters. Only those signals multiplexed onto the clockwise propagating bus fibre will reach the proper receiver in the hub node, whereas those multiplexed on the other fibre will reach the corresponding monitor PIN diode in the switching unit 13 in the hub node.
  • the same information from the same satellite nodes could be provided twice in the propagation direction on the fibres FI and F2 when it reaches the hub node on its right side. However, this will not cause any problems since the hub node is adjusted to receive only information signals coming from the left side.
  • FIG 2B illustrating that a double cable break has occurred between the satellite nodes C and D.
  • the hub node H loses the incoming channels of the satellite nodes A, B and C.
  • the action of the hub node is to change the receiver switches for those channels from bar to cross state and the transmitter switches of the same channels from the left to the right position.
  • Full communication is restored, which according to FIG 2B means that the hub node communicates with nodes E and D on the left incoming and outgoing bus fibres as before and with the satellite nodes A, B and C on the right bus fibres, as illustrated by the node references in small letters. (Even without a cable break, this could of course be the normal way of operating the network.)
  • the hub node looses the incoming channels a, b, and c.
  • the action of the hub node will be the same as for the double cable break, as illustrated in FIG 2C.
  • a spare hub node SH could be placed anywhere along the bus fibre ring and is shown inserted between the satellite nodes D and E.
  • This spare hub SH is illustrated as a simple kind of hub node having the same kind of connection to the two fibres FI and F2 as the satellite nodes A, B, C..., i.e. the fibre chain should not be broken by the spare hub node SH, only by the hub node H.
  • the spare hub node SH has as many transmitters and receivers as there are satellite transceivers (normally equal to the number of satellite nodes) connected to the fibre ring. However, it has only one multiplexer 17 and one demultiplexer 18, each connected to both fibres FI and F2 by fibre couplers 4" and 5" in the same way as for each satellite node.
  • the transmitters Tx" in the spare hub node SH are off.
  • the spare hub node is then totally transparent and does not affect the traffic passing on the network except for some power losses caused by the fibre couplers 4", 5", 6" and 7".
  • Optical amplifiers could of course be installed anywhere in the network (not shown).
  • the spare hub node SH is activated as soon as a failure of the hub node H occurs.
  • the signals from the transmitters Tx" are sent out in both directions through the fibre couplers 4" and 5".
  • the receivers Rx" listen simultaneously on both bus fibres F I and F2. If no other failure in the network has occurred at the same time as the failure of the hub node H, which should be rare, all satellite nodes have full communication with the spare hub node SH.
  • the signals from the satellite nodes arrives to the spare hub node SH either from the left or from the right. All signals from the spare hub node SH are sent out in both directions.
  • Some of those sent to the right are received by the satellite nodes and the rest are received from the signals sent out to the left.
  • the signals are prevented from circulation all around the fibre ring due to the design of the ordinary hub node H including a fibre break.
  • each satellite node uses the same wavelength channel for both its transmitted and received traffic it is within the scope of invention to have separate wavelength channels for both without changing the network. It is then possible to change the network so that only one fibre for both transmitted and received traffic is used.
  • using the same fibre for both downstream and upstream traffic implies that implemented optical amplifiers need to operate in both directions. This is rather cumbersome, and therefore an application of this kind will be used only in very rare occasions.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Optical Communication System (AREA)
  • Small-Scale Networks (AREA)

Abstract

L'invention concerne un réseau de communications optiques acheminées sur des longueurs d'onde, dans une configuration à noeuds centraux. Le réseau comprend un noeud central (H) et un certain nombre de noeuds satellites (A, B, C...), reliés à deux fibres optiques (F1, F2) dans une architecture optique en anneau. Chaque noeud satellite travaille dans un canal à longueur d'onde propre. Les noeuds satellites (A, B, C...) sont reliés aux fibres (F1, F2) par des multiplexeurs et démultiplexeurs passifs (4' à 7'), tous les types de commutation du réseau étant montés dans le noeuds central (H).
PCT/SE1997/001267 1996-07-18 1997-07-11 Reseau optique Ceased WO1998004058A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
AU37129/97A AU3712997A (en) 1996-07-18 1997-07-11 Optical network
EP97933954A EP0908029A1 (fr) 1996-07-18 1997-07-11 Reseau optique
BR9710364A BR9710364A (pt) 1996-07-18 1997-07-11 Rede de comunica-Æo Äptica encaminhada por comprimento de onda
JP10506859A JP2000515697A (ja) 1996-07-18 1997-07-11 光ネットワーク

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9602806A SE507415C2 (sv) 1996-07-18 1996-07-18 Våglängdsmultiplexerat optiskt nätverk med navnod
SE9602806-3 1996-07-18

Publications (1)

Publication Number Publication Date
WO1998004058A1 true WO1998004058A1 (fr) 1998-01-29

Family

ID=20403420

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1997/001267 Ceased WO1998004058A1 (fr) 1996-07-18 1997-07-11 Reseau optique

Country Status (8)

Country Link
EP (1) EP0908029A1 (fr)
JP (1) JP2000515697A (fr)
CN (1) CN1135752C (fr)
AU (1) AU3712997A (fr)
BR (1) BR9710364A (fr)
SE (1) SE507415C2 (fr)
TW (1) TW387169B (fr)
WO (1) WO1998004058A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2751496A1 (fr) * 1996-07-19 1998-01-23 Nec Corp Systeme de reseau optique a structure simple, capable d'effectuer une communication
WO1999066665A1 (fr) * 1998-06-19 1999-12-23 Ciena Corporation Systeme d'emission en anneau a multiplexage par repartition a longueur d'ondes (mrl) avec deux concentrateurs
WO2002073856A1 (fr) * 2001-03-09 2002-09-19 Lumentis Ab Reseau en anneau wdm flexible
US6456407B1 (en) 1998-02-13 2002-09-24 Nokia Networks Oy Optical telecommunications networks
US6868234B1 (en) 1998-02-13 2005-03-15 Nokia Corporation Optical telecommunications network
WO2018050093A1 (fr) * 2016-09-14 2018-03-22 Huawei Technologies Co., Ltd. Procédé et appareil permettant une utilisation de réseau efficace à l'aide de super-canaux

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1804407B1 (fr) * 2005-12-28 2009-02-11 Alcatel Lucent Noeud d'accès pour réseau de transmission optique en anneau
CN102540986A (zh) * 2010-12-15 2012-07-04 广州星辰热能科技有限公司 一种中央热水远程控制管理系统
CN103414510B (zh) * 2013-08-12 2016-04-13 浙江宇视科技有限公司 一种epon网络保护装置和方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5000531A (en) * 1989-05-22 1991-03-19 Harris Corporation Passive bypass for fiber optic ring network
US5442623A (en) * 1992-08-17 1995-08-15 Bell Communications Research, Inc. Passive protected self healing ring network

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5000531A (en) * 1989-05-22 1991-03-19 Harris Corporation Passive bypass for fiber optic ring network
US5442623A (en) * 1992-08-17 1995-08-15 Bell Communications Research, Inc. Passive protected self healing ring network

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2751496A1 (fr) * 1996-07-19 1998-01-23 Nec Corp Systeme de reseau optique a structure simple, capable d'effectuer une communication
US6456407B1 (en) 1998-02-13 2002-09-24 Nokia Networks Oy Optical telecommunications networks
US6868234B1 (en) 1998-02-13 2005-03-15 Nokia Corporation Optical telecommunications network
WO1999066665A1 (fr) * 1998-06-19 1999-12-23 Ciena Corporation Systeme d'emission en anneau a multiplexage par repartition a longueur d'ondes (mrl) avec deux concentrateurs
US6426815B1 (en) 1998-06-19 2002-07-30 Ciena Corporation WDM ring transmission system having two hubs
WO2002073856A1 (fr) * 2001-03-09 2002-09-19 Lumentis Ab Reseau en anneau wdm flexible
WO2018050093A1 (fr) * 2016-09-14 2018-03-22 Huawei Technologies Co., Ltd. Procédé et appareil permettant une utilisation de réseau efficace à l'aide de super-canaux
US9941992B2 (en) 2016-09-14 2018-04-10 Futurewei Technologies, Inc. Method and apparatus for efficient network utilization using superchannels
CN109690985A (zh) * 2016-09-14 2019-04-26 华为技术有限公司 使用超信道实现高效网络利用的方法和装置
CN109690985B (zh) * 2016-09-14 2020-10-23 华为技术有限公司 使用超信道实现高效网络利用的方法和装置

Also Published As

Publication number Publication date
SE507415C2 (sv) 1998-05-25
SE9602806D0 (sv) 1996-07-18
EP0908029A1 (fr) 1999-04-14
CN1135752C (zh) 2004-01-21
CN1231087A (zh) 1999-10-06
JP2000515697A (ja) 2000-11-21
AU3712997A (en) 1998-02-10
SE9602806L (sv) 1998-01-19
BR9710364A (pt) 1999-08-17
TW387169B (en) 2000-04-11

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