WO2000022765A1 - Optical unidirectional ring network - Google Patents

Optical unidirectional ring network Download PDF

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Publication number
WO2000022765A1
WO2000022765A1 PCT/DE1999/003303 DE9903303W WO0022765A1 WO 2000022765 A1 WO2000022765 A1 WO 2000022765A1 DE 9903303 W DE9903303 W DE 9903303W WO 0022765 A1 WO0022765 A1 WO 0022765A1
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WO
WIPO (PCT)
Prior art keywords
optical
ring network
coupling device
transmission
data signals
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Application number
PCT/DE1999/003303
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German (de)
French (fr)
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WO2000022765B1 (en
Inventor
Wilhelm-Martin Plotz
Michael Lehdorfer
Kuno Zhuber-Okrog
Martin Schreiblehner
Original Assignee
Siemens Aktiengesellschaft
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Application filed by Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Priority to JP2000576569A priority Critical patent/JP2002527990A/en
Priority to EP99900055A priority patent/EP1121777A1/en
Publication of WO2000022765A1 publication Critical patent/WO2000022765A1/en
Publication of WO2000022765B1 publication Critical patent/WO2000022765B1/en

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Classifications

    • 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
    • H04J14/0201—Add-and-drop multiplexing
    • H04J14/0202—Arrangements therefor
    • H04J14/0204—Broadcast and select arrangements, e.g. with an optical splitter at the input before adding or dropping
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0201—Add-and-drop multiplexing
    • H04J14/0202—Arrangements therefor
    • H04J14/021—Reconfigurable arrangements, e.g. reconfigurable optical add/drop multiplexers [ROADM] or tunable optical add/drop multiplexers [TOADM]
    • 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
    • H04J14/0289—Optical multiplex section protection
    • H04J14/0291—Shared protection at the optical multiplex section (1:1, n:m)

Definitions

  • the invention relates to an optical unidirectional ring ⁇ network according to the preamble of claim 1.
  • Ring networks are known for the transmission of large amounts of data, in which data are transmitted unidirectionally or — usually via two fibers — bidirectionally between different network nodes / terminals.
  • the branching and insertion of data should take place on the optical level and it should be possible to reconfigure easily.
  • the ring network including the network nodes should also be implemented as cost-effectively as possible.
  • Such a ring network is specified in claim 1.
  • a unidirectional ring network is particularly cost-effective since only one fiber is required for transmission and that Network nodes can be easily formed.
  • the fixed assignment of a specific transmission channel or a wavelength, which is used only once in the ring network, to a network node provides a clear assignment of transmission channels and thus the transmitted data signals to the network nodes. Since each network node receives the data signals from all other network nodes, it is possible to establish any connection to other network nodes by selecting an appropriate reception filter. If a switchable or tunable receive filter is selected, any connection between all network nodes can be made. Multiple filters also enable simultaneous connection to multiple network nodes.
  • a second ring can be provided for equivalent circuits, in which the data transmission takes place in the opposite direction.
  • FIG. 1 shows a unidirectional ring network
  • FIG. 2 shows a first exemplary embodiment of a network node
  • FIG. 3 shows a preferred exemplary embodiment of this network node
  • Figure 4 shows a unidirectional ring network with a replacement transmission ring.
  • FIG. 1 shows a unidirectional ring network with a plurality of network nodes NA, NB, NC, ..., NN.
  • the transmission between any network node takes place in wavelength multiplex operation over an optical fiber 1 in several transmission channels.
  • channel ⁇ A to ⁇ N which have a predetermined wavelength distance from each other.
  • the direction of transmission is indicated by arrows.
  • the network node NA is shown in FIG. 2 as a basic circuit diagram.
  • Network nodes are used to implement different connections, which are always made via transmission channels.
  • Data signals to be decoupled in the network node are referred to as “drops” to be branched off, and the data signals to be sent out as “to be inserted” (add).
  • add There is also talk of branching off, switching through or inserting channels, in the narrower sense meaning the signals transmitted in these channels.
  • Reference symbols with the same indices are used for the transmission channels and the associated data signals.
  • a data signal ⁇ A is transmitted in the associated transmission channel ⁇ B.
  • the network node which is reduced to the essential functions of an add-drop module, contains the series connection of an amplifier 4, a decoupling device 5 and a coupling device 6.
  • At input 2 there is a wavelength multiplex signal of all data signals ⁇ A received via transmission channels ⁇ A - ⁇ N - ⁇ N on.
  • a single signal can be transmitted in each transmission channel (transmission band) or several individual signals in wavelength division multiplex operation or of course also in time division multiplex operation.
  • the received signals are initially amplified and then arrive at the decoupling device 5.
  • a 1: 2 coupler (branching device)
  • All data signals / transmission channels are first divided into two signal paths. All transmission signals / transmission channels to be switched are switched through via a signal path except for the transmission channel ⁇ A assigned to this network node;
  • the transmission channel ⁇ be diverted dr0p will lected by here as a wavelength switch decoupling se ⁇ .
  • the wavelength crossover is shown schematically here as a coupler 51 with a fixed, switchable or tunable bandpass filter 52 and a bandstop filter 53.
  • the channel ⁇ D R0P is the only one in the passband of the bandpass filter 52. It is routed, for example, participants device via a drop-output 7 to a part ⁇ .
  • a corresponding data signal ⁇ A , ADD present at the add input 8 is inserted into the assigned transmission channel in the coupling device 6 designed as a coupler.
  • the bandstop 53 located in the first signal path is provided, which is tuned to the corresponding wavelength.
  • the transmission of this signal can also be interrupted in the previous network node MN, but this is associated with additional configuration effort if additional network nodes are added.
  • a wavelength multiplex signal is output, which contains the signals of all transmission channels ⁇ A / A D D and ⁇ B to ⁇ N.
  • each network node can receive the corresponding transmit signal of every other network node, i. H. a corresponding connection can be established. This makes it easy to change the configuration.
  • FIG. 3 shows a particularly advantageous variant of a network node. It is a tunable band pass 54 is provided, and as a coupling device 61, 62 a provided with a grating 62 coupler 61.
  • the ker of the Verstär ⁇ 4 coming wavelength division multiplexed signal includes the data signal ⁇ A, which has already passed through the entire ring network (loop return signal). This is reflected by the grating 62, which acts as a bandstop, and destroyed in an optical sump 63 (a suitable termination of an optical fiber).
  • the first opposite to the transmission ⁇ direction of the ring network in the coupler injected signal ⁇ A, ADD is also reflected by the grating, thereby further sent in the direction of transmission.
  • Different structures are known for the coupling 61 provided with the grating. Either the grating is arranged in the coupling area (FIG. 3) or two coupling areas are realized between which separate grating are provided for each fiber.
  • connections with several channels between the individual network nodes can also be realized.
  • the add-drop modules shown in FIGS. 2 and 3 can be connected in series or adapted accordingly.
  • the use of wider filters also enables several adjacent channels to be coupled in and out.
  • FIG. 4 shows an expanded ring network in which the optical fiber 1 has been supplemented by an optical fiber 1P provided for protection purposes.
  • the data signals - only the protection data signal ⁇ AP is shown - are first transmitted via the undisturbed part of the ring network and then fed into the protection optical fiber 1P in the opposite direction, so that all network nodes receive the data signal.
  • the transmission path is selected by means of changeover switches provided in the network nodes.

Abstract

The invention relates to an optical unidirectional ring network comprising a plurality of network nodes (NA, NB, ...) in which a transmission channel (μA) having a transmission band which occurs only once is assigned to each network node. The network is configured by receive filters (54) which can be switched and adjusted.

Description

Beschreibungdescription
Optisches unidirektionales RingnetzOptical unidirectional ring network
Die Erfindung betrifft ein optisches unidirektionales Ring¬ netz nach dem Oberbegriff des Patentanspruchs 1.The invention relates to an optical unidirectional ring ¬ network according to the preamble of claim 1.
Zur Übertragung von großen Datenmengen sind Ringnetze bekannt, bei denen unidirektional oder - meist über zwei Fasern - bidirektional Daten zwischen verschiedenen Netzknoten/Terminals übertragen werden.Ring networks are known for the transmission of large amounts of data, in which data are transmitted unidirectionally or — usually via two fibers — bidirectionally between different network nodes / terminals.
Aus „22nd European Conference on Optical Communication" - ECOC 96, Oslo, Seiten 3.51 - 3.54 ist ein xcoloured section ring' bekannt, bei dem zur Übertragung zwischen zwei Netzknoten jeweils eine nur einmal genutzte Wellenlänge verwendet wird. Hierdurch ist es bei einer Störung möglich, eine Er- satzverbindung mit derselben Wellenlänge über den ungestörten Teil des Ringnetzes zu schalten.Off "22nd European Conference on Optical Communication" - ECOC 96, Oslo, pages 3:51 to 3:54 is an x colored section ring 'known, each used in which, for transfer between two network nodes, a once-used wavelength result, it is at a disorder. possible to switch a replacement connection with the same wavelength over the undisturbed part of the ring network.
Um ein Ringnetz u zukonfigurieren, d. h. neue logische Verbindungen herzustellen, sind in der Regel Änderungen der Wellenlängen erforderlich.To configure a ring network u. H. To create new logical connections, changes in the wavelengths are usually required.
Bei neu konzipierten optischen Ringnetzen soll das Abzweigen und Einfügen von Daten auf der optischen Ebene erfolgen und eine Umkonfigurationen einfach möglich sein. Das Ringnetz einschließlich der Netzknoten soll zudem auch möglichst kostengünstig realisiert werden.In the case of newly designed optical ring networks, the branching and insertion of data should take place on the optical level and it should be possible to reconfigure easily. The ring network including the network nodes should also be implemented as cost-effectively as possible.
Ein solches Ringnetz ist in Anspruch 1 angegeben.Such a ring network is specified in claim 1.
Vorteilhafte Weiterbildungen des Ringnetzes sind in den Unteransprüchen angegeben.Advantageous developments of the ring network are specified in the subclaims.
Ein unidirektionales Ringnetz ist besonders kostengünstig, da nur eine Glasfaser zur Übertragung benötigt wird und die Netzknoten einfach ausgebildet werden können. Durch die feste Zuordnung eines bestimmten Übertragungskanals bzw. einer Wellenlänge, die nur einmal im Ringnetz verwendet wird, zu einem Netzknoten ist eine eindeutige Zuordnung von Übertragungska- nälen und damit der übertragenen Datensignale zu den Netzknoten gegeben. Da jeder Netzknoten die Datensignale aller anderen Netzknoten empfängt, ist die Herstellung einer beliebigen Verbindung zu anderen Netzknoten durch die Wahl eines entsprechenden Empfangsfilters möglich. Wird ein umschaltbares oder durchstimmbares Empfangsfilter gewählt, können beliebige Verbindungen zwischen allen Netzknoten hergestellt werden. Mehrere Filter ermöglichen auch die gleichzeitige Verbindung zu mehreren Netzknoten.A unidirectional ring network is particularly cost-effective since only one fiber is required for transmission and that Network nodes can be easily formed. The fixed assignment of a specific transmission channel or a wavelength, which is used only once in the ring network, to a network node provides a clear assignment of transmission channels and thus the transmitted data signals to the network nodes. Since each network node receives the data signals from all other network nodes, it is possible to establish any connection to other network nodes by selecting an appropriate reception filter. If a switchable or tunable receive filter is selected, any connection between all network nodes can be made. Multiple filters also enable simultaneous connection to multiple network nodes.
Durch die Verwendung eines mit einem Gräting versehenen Kopplers, der hierdurch Filtereigenschaften aufweist, ergibt sich ein sehr einfacher Aufbau der Netzknoten.The use of a coupler provided with a grating, which thereby has filter properties, results in a very simple structure of the network nodes.
Werden höhere Anforderungen an die Übertragungssicherheit ge- stellt, so kann für Ersatzschaltungen ein zweiter Ring vorgesehen sein, bei dem die Datenübertragung in der entgegengesetzten Richtung erfolgt.If higher demands are placed on transmission security, a second ring can be provided for equivalent circuits, in which the data transmission takes place in the opposite direction.
Ausführungsbeispiele der Erfindung werden anhand von Figuren näher erläutert. Es zeigen:Embodiments of the invention are explained in more detail with reference to figures. Show it:
Figur 1 ein unidirektionales Ringnetz,FIG. 1 shows a unidirectional ring network,
Figur 2 ein erstes Ausführungsbeispiel eines Netzknotens, Figur 3 ein bevorzugtes Ausführungsbeispiel dieses Netzkno- tens und2 shows a first exemplary embodiment of a network node, FIG. 3 shows a preferred exemplary embodiment of this network node and
Figur 4 ein unidirektionales Ringnetz mit einem Ersatz-Übertragungsring.Figure 4 shows a unidirectional ring network with a replacement transmission ring.
In Figur 1 ist ein unidirektionales Ringnetz mit mehreren Netzknoten NA, NB, NC, ..., NN dargestellt. Die Übertragung zwischen beliebigen Netzknoten erfolgt im Wellenlängen-Multiplexbetrieb über eine Glasfaser 1 in mehreren Übertragungska- nälen ΛA bis ΛN, die voneinander einen vorgegebenen Wellenlängenabstand aufweisen. Die Übertragungsrichtung ist durch Pfeile gekennzeichnet.1 shows a unidirectional ring network with a plurality of network nodes NA, NB, NC, ..., NN. The transmission between any network node takes place in wavelength multiplex operation over an optical fiber 1 in several transmission channels. channel Λ A to Λ N , which have a predetermined wavelength distance from each other. The direction of transmission is indicated by arrows.
In Figur 2 ist der Netzknoten NA als Prinzipschaltbild dargestellt. Netzknoten dienen zur Realisierung unterschiedlicher Verbindungen, die stets über Übertragungskanäle erfolgen. Im Netzknoten auszukoppelnde Datensignale werden als „abzuzweigende" Signale (drop) bezeichnet, die auszusendenden als „einzufügende" Datensignale (add) . Es wird auch von einem Abzweigen, Durchschalten oder Einfügen von Kanälen gesprochen, wobei im engeren Sinn die in diesen Kanälen übertragenen Signale gemeint sind. Für die Übertragungskanäle und die zugehörigen Datensignale werden Bezugszeichen mit glei- chen Indizes verwendet. Ein Datensignal λA wird in dem zugehörigen Ubertragungskanal ΛB übertragen.The network node NA is shown in FIG. 2 as a basic circuit diagram. Network nodes are used to implement different connections, which are always made via transmission channels. Data signals to be decoupled in the network node are referred to as “drops” to be branched off, and the data signals to be sent out as “to be inserted” (add). There is also talk of branching off, switching through or inserting channels, in the narrower sense meaning the signals transmitted in these channels. Reference symbols with the same indices are used for the transmission channels and the associated data signals. A data signal λA is transmitted in the associated transmission channel Λ B.
Der auf die wesentlichen Funktionen eines Add-Drop-Modules reduzierte Netzknoten enthält die Reihenschaltung eines Ver- stärkers 4, einer Auskoppeleinrichtung 5 und einer Einkoppeleinrichtung 6. Am Eingang 2 liegt ein über Übertragungskanäle ΛA - ΛN empfangenes Wellenlängen-Multiplexsignal sämtlicher Datensignale λA - λN an. In jedem Übertragungskanal (Übertragungsband) kann ein einziges Signal übertragen werden oder auch mehrere Einzelsignale im Wellenlängen-Multiplexbetrieb oder selbstverständlich auch im Zeitmultiplexbetrieb.The network node, which is reduced to the essential functions of an add-drop module, contains the series connection of an amplifier 4, a decoupling device 5 and a coupling device 6. At input 2 there is a wavelength multiplex signal of all data signals λ A received via transmission channels Λ A - Λ N - λ N on. A single signal can be transmitted in each transmission channel (transmission band) or several individual signals in wavelength division multiplex operation or of course also in time division multiplex operation.
Die empfangenen Signale werden zunächst verstärkt und gelangen dann zur Auskoppeleinrichtung 5. Dort erfolgt in einem l:2-Koppler (Verzweiger) zunächst eine Aufteilung aller Datensignale/Übertragungskanäle auf zwei Signalwege. Über einen Signalweg werden alle durchzuschaltenden Übertragungssignale/Übertragungskanäle bis auf den diesem Netzknoten zugeordneten Übertragungskanal ΛA durchgeschaltet; über den an- deren Signalweg wird ein Übertragungskanal ΛDROP bzw. dessen Datensignal λDR0P beispielsweise das Datensignal λB,DR0P, ausgekoppelt. Der abzuzweigende Ubertragungskanal ΛDR0P wird durch die hier als Wellenlängenweiche ausgebildete Auskoppeleinrichtung se¬ lektiert. Die Wellenlängenweiche ist hier als Koppler 51 mit einem festen, umschaltbaren oder abstimmbaren Bandpaß 52 und einer Bandsperre 53 schematisch dargestellt. Der Kanal λDR0P liegt als einziger im Durchlaßbereich des Bandpasses 52. Er wird über einen Drop-Ausgang 7 beispielsweise zu einem Teil¬ nehmergerät weitergeleitet.The received signals are initially amplified and then arrive at the decoupling device 5. There, in a 1: 2 coupler (branching device), all data signals / transmission channels are first divided into two signal paths. All transmission signals / transmission channels to be switched are switched through via a signal path except for the transmission channel Λ A assigned to this network node; A transmission channel Λ DROP or its data signal λ D R0P, for example the data signal λ B , D R0P, is coupled out via the other signal path. The transmission channel Λ be diverted dr0p will lected by here as a wavelength switch decoupling se ¬. The wavelength crossover is shown schematically here as a coupler 51 with a fixed, switchable or tunable bandpass filter 52 and a bandstop filter 53. The channel λ D R0P is the only one in the passband of the bandpass filter 52. It is routed, for example, participants device via a drop-output 7 to a part ¬.
In diesem Netzknoten wird anstelle des abgezweigten Datensignals/Kanals ein entsprechendes am Add-Eingang 8 anliegendes Datensignal λA,ADD in den zugeordneten Übertragungskanal in der als Koppler ausgebildeten Einkoppeleinrichtung 6 ein- gefügt. Dies setzt voraus, daß das vom Netzknoten A bereits ausgesendete und über den Ring am Eingang 2 wieder empfangene Signal λA (loop return signal) spätestens vor der Einkoppeleinrichtung 6 gesperrt werden muß. Hierzu ist die im ersten Signalweg liegende Bandsperre 53 vorgesehen, die fest auf die entsprechende Wellenlänge abgestimmt ist. Die Übertragung dieses Signals kann zwar auch schon in dem vorhergehenden Netzknoten MN unterbrochen werden, jedoch ist dies bei einem Hinzufügen weiterer Netzknoten mit zusätzlichen Konfigurationsaufwand verbunden.In this network node, instead of the branched-off data signal / channel, a corresponding data signal λ A , ADD present at the add input 8 is inserted into the assigned transmission channel in the coupling device 6 designed as a coupler. This presupposes that the signal λ A (loop return signal) which has already been transmitted by network node A and is received again via the ring at input 2 must be blocked at the latest before coupling device 6. For this purpose, the bandstop 53 located in the first signal path is provided, which is tuned to the corresponding wavelength. The transmission of this signal can also be interrupted in the previous network node MN, but this is associated with additional configuration effort if additional network nodes are added.
Am Ausgang 3 wird ein Wellenlängen-Multiplexsignal ausgegeben, das die Signale sämtlicher Übertragungskanäle λA/ADD und λB bis λN enthält.At the output 3 a wavelength multiplex signal is output, which contains the signals of all transmission channels λ A / A D D and λ B to λ N.
Durch Auswechseln, Umschalten oder Abstimmen des BandpassesBy changing, switching or tuning the band pass
52 kann jeweils von jedem Netzknoten das entsprechende Sendesignal jedes anderen Netzknotens empfangen werden, d. h. eine entsprechende Verbindung hergestellt werden. So ist eine einfache Konfigurationsänderung möglich.52, each network node can receive the corresponding transmit signal of every other network node, i. H. a corresponding connection can be established. This makes it easy to change the configuration.
In Figur 3 ist eine besonders vorteilhafte Variante eines Netzknotens dargestellt. Es ist ein abstimmbarer Bandpaß 54 vorgesehen und als Einkoppeleinrichtung 61, 62 dient ein mit einem Gräting 62 versehener Koppler 61. Das von dem Verstär¬ ker 4 kommende Wellenlängen-Multiplexsignal enthält auch das Datensignal λA, das bereits das gesamte Ringnetz durchlaufen hat (loop return signal) . Dieses wird von dem Gräting 62, das als Bandsperre wirkt, reflektiert und in einem optischen Sumpf 63 (einem geeigneter Abschluß einer Lichtleitfaser) vernichtet. Das zunächst entgegengesetzt zur Übertragungs¬ richtung des Ringnetzes in den Koppler eingespeiste Signal λA,ADD wird ebenfalls vom Gräting reflektiert und dadurch in der Übertragungsrichtung weitergesendet. Für den mit dem Gräting versehenen Koppler 61 sind unterschiedliche Strukturen bekannt. Entweder ist das Gräting im Koppelbereich angeordnet (Figur 3) oder es werden zwei Koppelbereiche realisiert zwi- sehen denen jeweils separate Grätings für jede Faser vorgesehen sind.FIG. 3 shows a particularly advantageous variant of a network node. It is a tunable band pass 54 is provided, and as a coupling device 61, 62 a provided with a grating 62 coupler 61. The ker of the Verstär ¬ 4 coming wavelength division multiplexed signal includes the data signal λ A, which has already passed through the entire ring network (loop return signal). This is reflected by the grating 62, which acts as a bandstop, and destroyed in an optical sump 63 (a suitable termination of an optical fiber). The first opposite to the transmission ¬ direction of the ring network in the coupler injected signal λ A, ADD is also reflected by the grating, thereby further sent in the direction of transmission. Different structures are known for the coupling 61 provided with the grating. Either the grating is arranged in the coupling area (FIG. 3) or two coupling areas are realized between which separate grating are provided for each fiber.
Selbstverständlich können auch Verbindungen mit mehreren Kanälen zwischen den einzelnen Netzknoten realisiert werden. Hierzu können die in den Figuren 2 und 3 dargestellten Add- Drop-Module in Reihe geschaltet oder entsprechend angepaßt werden. Auch ist durch die Verwendung breiterer Filter das gemeinsame Aus- und Einkoppeln mehrerer benachbarter Kanäle möglich.Of course, connections with several channels between the individual network nodes can also be realized. For this purpose, the add-drop modules shown in FIGS. 2 and 3 can be connected in series or adapted accordingly. The use of wider filters also enables several adjacent channels to be coupled in and out.
Figur 4 zeigt ein erweitertes Ringnetz, bei dem die Lichtleitfaser 1 durch eine für Protection-Zwecke vorgesehene Lichtleitfaser 1P ergänzt wurde. Bei einem Bruch oder einer sonstigen Störung der Lichtleitfaser 1 werden die Datensig- nale - es ist nur das Protection-Datensignal λAP dargestellt - zunächst über den ungestörten Teil des Ringnetzes übertragen und dann bis in die Protection-Lichtleitfaser 1P in entgegengesetzter Richtung eingespeist, so daß alle Netzknoten das Datensignal erhalten. Die Auswahl des Übertragungsweges erfolgt durch in den Netzknoten vorgesehene Umschalter. FIG. 4 shows an expanded ring network in which the optical fiber 1 has been supplemented by an optical fiber 1P provided for protection purposes. In the event of a break or other fault in the optical fiber 1, the data signals - only the protection data signal λ AP is shown - are first transmitted via the undisturbed part of the ring network and then fed into the protection optical fiber 1P in the opposite direction, so that all network nodes receive the data signal. The transmission path is selected by means of changeover switches provided in the network nodes.

Claims

Patentansprüche claims
1. Optisches unidirektionales Ringnetz mit mehreren Netzkno¬ ten (NA - NN) , bei dem Datensignale (λA, λB, ...λN) im Wellen- längen-Multiplexbetrieb übertragen werden und jedem Netzknoten (NA - NN) für sein auszusendendes Datensignalsignal (λA,ADD) ein zugeordneter Ubertragungskanal (ΛA) mit einem nur einmal genutzten Übertragungsband zugeordnet ist, d a d u r c h g e k e n n z e i c h n e t , daß jeder Netzknoten (NA - NN) die Reihenschaltung einer optischen Auskoppeleinrichtung (5) , der in Übertragungskanälen (ΛA - ΛN) empfangene optische Datensignale (λA - λN) zugeführt werden, und einer optischen Einkoppeleinrichtung (6) aufweist, daß jeweils in der Auskoppeleinrichtung (5) eines Netzknotens (NA) mit Hilfe von optischen Filtern (52, 53,; 62) mindestens einer der den anderen Netzknoten (NB - NN) sendeseitig zugeordneten Übertragungskanäle (ΛDROp; ΛB) ausgekoppelt wird, daß jeweils bis auf das eigene im zugeordneten Übertragungs- kanal (ΛA) bereits ausgesendete und über das Ringnetz wieder empfangene Datensignal (λA) die Datensignale (λB - λN) der übrigen Übertragungskanäle (ΛB - ΛN) durchgeschaltet werden und daß in der Einkoppeleinrichtung (6) jeweils den Datensignalen der durchgeschalteten Übertragungskanälen (ΛB - ΛN) ein ein- zufügendes Datensignal (λA,ADD) in dem zugeordneten Übertragungskanal (ΛA) hinzugefügt wird und gemeinsam mit den durchgeschalteten Datensignalen ausgesendet wird.1. An optical unidirectional ring network with a plurality of Netzkno ¬ th (NA - Nn), in which data signals (λ A, λ B, ... λ N) are transmitted in the wave-length-division multiplex operation and each network node (NA - Nn) for its to be transmitted data signal signal (λ A , ADD ) is assigned to an assigned transmission channel (Λ A ) with a transmission band used only once, characterized in that each network node (NA - NN) is connected in series to an optical decoupling device (5) which is in transmission channels (Λ A - Λ N ) received optical data signals (λ A - λ N ) are supplied, and an optical coupling device (6) that in each case in the coupling device (5) of a network node (NA) with the aid of optical filters (52, 53 ,; 62 ) at least one of the transmission channels (Λ DRO p; Λ B ) assigned to the other network nodes (NB-NN) on the transmission side is decoupled, that in each case except for its own in the assigned transmission channel (Λ A ) transmitted and received again via the ring network data signal (λ A ) the data signals (λ B - λ N ) of the other transmission channels (Λ B - Λ N ) are switched through and that in the coupling device (6) the data signals of the switched transmission channels (Übertragungs B - Λ N ) a data signal to be inserted (λ A , ADD) is added to the assigned transmission channel (Λ A ) and sent out together with the data signals switched through.
2. Optisches Ringnetz nach Anspruch 1, d a d u r c h g e k e n n z e i c h n e t , daß die Auskoppeleinrichtung (5) derart ausgebildet ist, daß unterschiedliche Übertragungskanäle (ΛDR0P; ΛB,DROP) ausgekoppe 2. Optical ring network according to claim 1, characterized in that the decoupling device (5) is designed such that different transmission channels (Λ DR0P ; Λ B , DR O P ) decouple
3. Optisches Ringnetz nach Anspruch 2, d a d u r c h g e k e n n z e i c h n e t , daß die Auskoppeleinrichtung (5) auswechselbare Filter (52, 53) oder mehrere Filter enthält, zwischen denen umgeschaltet wird.3. Optical ring network according to claim 2, that the coupling device (5) contains interchangeable filters (52, 53) or a plurality of filters between which a switchover is made.
4. Optisches Ringnetz nach Anspruch 2, d a d u r c h g e k e n n z e i c h n e t , daß die Auskoppeleinrichtung einen Koppler (51) und ein abstimmbares Filter (54) enthält.4. An optical ring network according to claim 2, that the coupling device contains a coupler (51) and a tunable filter (54).
5. Optisches Ringnetz nach einem der vorhergehenden Ansprüche, d a d u r c h g e k e n n z e i c h n e t , daß als Einkoppeleinrichtung (6) ein mit einem als optisches Filter wirkendes Gräting (61) versehener Koppler (61) vorgesehen ist, der das im zugeordneten Übertragungskanal (ΛA) ausgesendete und über das Ringnetz empfangene Datensignal (λA) sperrt und das einzufügende Datensignal (λA,ADD) den durchgeschalteten Datensignalen (λB - λN) hinzufügt.5. Optical ring network according to one of the preceding claims, characterized in that a coupling device (6) provided with a grating (61) acting as an optical filter is provided as the coupling device (6), which transmits the in the assigned transmission channel (zugeordneten A ) and via which Ring network received data signal (λ A ) blocks and adds the data signal to be inserted (λ A , ADD) to the switched data signals (λ B - λ N ).
6. Optisches Ringnetz nach einem der vorhergehenden Ansprüche, d a d u r c h g e k e n n z e i c h n e t , daß eine weitere Faser (Pl) für Protectionzwecke vorgesehen ist. 6. Optical ring network according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that a further fiber (Pl) is provided for protection purposes.
PCT/DE1999/003303 1998-10-14 1999-10-14 Optical unidirectional ring network WO2000022765A1 (en)

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US10171197B2 (en) 2013-12-02 2019-01-01 At&T Intellectual Property I, L.P. Method and apparatus for routing traffic using asymmetrical optical connections

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