WO2000031927A1 - Procede d'etablissement d'itineraires detournes dans un reseau de telecommunications - Google Patents

Procede d'etablissement d'itineraires detournes dans un reseau de telecommunications Download PDF

Info

Publication number
WO2000031927A1
WO2000031927A1 PCT/NO1998/000347 NO9800347W WO0031927A1 WO 2000031927 A1 WO2000031927 A1 WO 2000031927A1 NO 9800347 W NO9800347 W NO 9800347W WO 0031927 A1 WO0031927 A1 WO 0031927A1
Authority
WO
WIPO (PCT)
Prior art keywords
node
nodes
ring
fault
timing
Prior art date
Application number
PCT/NO1998/000347
Other languages
English (en)
Inventor
Morten Moen
Reidar Schumann-Olsen
Original Assignee
Telefonaktiebolaget Lm Ericsson
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
Priority to NO974925A priority Critical patent/NO307639B1/no
Application filed by Telefonaktiebolaget Lm Ericsson filed Critical Telefonaktiebolaget Lm Ericsson
Priority to PCT/NO1998/000347 priority patent/WO2000031927A1/fr
Priority to AU15784/99A priority patent/AU1578499A/en
Priority to EP98960109A priority patent/EP1133853A1/fr
Publication of WO2000031927A1 publication Critical patent/WO2000031927A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
    • H04Q11/0428—Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
    • H04Q11/0478—Provisions for broadband connections
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems
    • H04J3/02—Details
    • H04J3/08—Intermediate station arrangements, e.g. for branching, for tapping-off
    • H04J3/085—Intermediate station arrangements, e.g. for branching, for tapping-off for ring networks, e.g. SDH/SONET rings, self-healing rings, meashed SDH/SONET networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems
    • H04J3/02—Details
    • H04J3/14—Monitoring arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/42—Loop networks
    • H04L12/437—Ring fault isolation or reconfiguration
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/54—Store-and-forward switching systems 
    • H04L12/56—Packet switching systems
    • H04L12/5601—Transfer mode dependent, e.g. ATM
    • H04L2012/5625—Operations, administration and maintenance [OAM]
    • H04L2012/5627—Fault tolerance and recovery

Definitions

  • the present invention relates to a method for establishing alternative routes in a telecommunication network, especially in case of transmission failure, and more spe- cifically in a telecommunication network comprising transmission links for duplex operation.
  • the present invention relates to a method for constructing an autonomous self healing ring in a 2 MBit/s leased line telecommunication network in order to create redundancy in the network in case of transmission failure.
  • the problem area concerns building a transmission network between digital cross-connects in such a way that alternative routes are introduced in case of transmission failures. This is desirable in order to keep the network up and running when failures occur.
  • earlier solutions have involved expensive dual lines or slow remote management involvement. In certain applications, such as cellular networks, it is important that the solution is at low cost and that the network disturbance does not last so long as to disrupt on-going traffic.
  • 1+1 protection uses duplicated lines between nodes. Traffic is sent out identically on both lines, and the receiving node chooses tne 'best' line. The entire protection operation including detection of problems and switching of input source s performed at the receiving end Switching is autonomously and fast and does not include network management system involvement.
  • N+1 protection adds one extra line to a group of N lines.
  • Tne stand-by line will take over for any of the other lines in case of failure. There is no traffic on the stand-by line before the failure, and switching will have to take place at both ends .
  • tne network In tne case of NMS re-routing, tne network is generally built with extra capacity m the lines. In case of failure, the traffic from the failed line is re-routed on other lines. This operation is conducted by a network management system (NMS) .
  • NMS network management system
  • Nodes m the ring keep an updated database of all nodes m the ring with information on which time slots belong to these nodes. When a fault occurs, the ring is split and time slots are selectively transmitted on the right or left branch according to this information.
  • the N+1 solution is a limited solution since it can only protect a number of line segments between the same nodes.
  • the NMS re-routing solution is generally too slow for application requiring connections to stay up. For instance, the GSM traffic in cellular networks will go down if the protection is based on NMS re-routing.
  • An object of the present invention is to provide a method for establishing alternative routes in a telecommunication network which generally is not hampered with the problems enfaced with known solutions.
  • Another object of the present invention is to provide a method which is less complex and less expensive as well as less subject to errors than previously suggested ring solutions .
  • Still another object of the present invention is to pro- vide a method wherein the use of a central management system for restoration is reduced to a minimum.
  • Yet another object of the present invention is to provide a method which is autonomously self healing, and wherein the healing is accomplished in a minimum of time.
  • Another object of the present invention is to provide a method wherein the self healing means are included in the nodes of the network.
  • Fig. 1 is a simplified sketch illustrating an initial protected ring wherein the present invention has been lm- plemented.
  • Fig. 2 is a simplified sketch illustrating details m one of the nodes which are tied into the ring by dropping and inserting time slots.
  • Fig. 3 is a simplified sketch, similar to Fig. 1, illustrating the ring after switching to redundancy mode.
  • Fig. 4 is a simplified sketch illustrating a ring con- figuration before, during and after a transmission fault occurs .
  • a ring including 4 nodes, designated A, B, C, D, respectively.
  • Such a ring may be included as one of more rings m a network and between each node m the ring m question there is established a duplex operation.
  • the fault criteria may be:
  • the timing information is usually taken from one of the incoming line signals. In the protected ring, timing is propagated along with the normal traffic direction. When the traffic switches, the timing will also have to switch.
  • nodes are tied into the ring by dropping and in- serting time slots as shown in Fig. 2. Most of the time slots entering the node in the OK direction is fed right through the node. Time slots destined for the connected equipment are dropped off to the port where this equipment is connected. Time slots from the connected equip- ment is inserted into the OK direction thus keeping the one-way traffic in the ring. If the ring should be treated as a sub-network connecting to a central node such as the BSC in cellular networks, all time slots would be dropped towards this node.
  • node D received timing information from node C, its timing source would have to change. This is trivial for node D because this node is next to the faulty section and is able to detect the switching criteria. However, had there been more nodes between nodes D and A, for example nodes DX, DY and DZ , these would also have to change timing sources . These nodes do not have access to the same fault information as have nodes D and C.
  • one of the spare bits in time slot 0 is used as a timing source bit.
  • this bit On ports used as timing source, this bit is sent in the high state. On all other ports the bit is sent in the low state. It is not legal to use a port with the incoming timing source bit in the high state as a timing source.
  • the timing source bit will force the node at the other end to change timing source if timing previously was taken from node D. This will ripple through all possible nodes between nodes D and A until the complete rightmost branch takes timing from node A. Clock stability requirements secure that the timing change information is transported before bit- slip will occur.
  • the timing source bit will force the next node DX in the redundancy ERROR direction to change its timing source if timing was previously taken from said next to fault node D, which forcing will take place also in any still further nodes DY, DZ arranged between said next to fault node D and said node A being connected to a central node CN.
  • Fig. 4 there is illustrated another ring configuration between four other nodes R, S, T and U, wherein a transmission fault has occurred between the nodes S and T.
  • Fig. 4 further illustrates how ports used as timing source will send one of the spear bits in time slot 0 in the high state, whereas on all other ports this bit is sent in the low state. Further, Fig. 4 illustrates that when node S, due to a transmission fault, will have to use the redundancy or error path, it will establish its output port as a timing source, i.e. especially for the closest node R, which further communicates the redundancy path to node U and node T, in which latter node T the incoming of time slots on the redundancy port thereof will set the associated timing source bit to high state. This high state will be transferred from node T to node U, and further to node R, but then via the OK path, until the correct timing configuration is established.
  • a timing source i.e. especially for the closest node R, which further communicates the redundancy path to node U and node T, in which latter node T the incoming of time slots on the redundancy port thereof will set the associated timing source bit to high state
  • time slots and timing sources are completely autonomous and does not require any interaction with a remote management system. Switching is thus rapid and restoration of connections is done with minimum interruption of traffic.

Landscapes

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

Abstract

L'invention porte sur un procédé permettant d'établir des itinéraires détournés dans un réseau de télécommunications, en particulier en cas de défaillance dans la transmission, et plus précisément dans un réseau de télécommunications comprenant des liaisons de transmission en mode duplex, procédé moins coûteux et plus fiable que d'autres procédés similaires utilisés antérieurement. Ledit procédé se caractérise en ce que ledit réseau est disposé en au moins un anneau initial comprenant un duplexage entre les noeuds de chaque anneau, lesdits noeuds étant disposés de façon que tous les créneaux puissent être transmis dans la même direction (direction OK) dudit anneau, tout en maintenant la direction opposée (direction ERREUR) en itinéraire de secours ou de redondance.
PCT/NO1998/000347 1997-10-24 1998-11-25 Procede d'etablissement d'itineraires detournes dans un reseau de telecommunications WO2000031927A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
NO974925A NO307639B1 (no) 1997-10-24 1997-10-24 Fremgangsmåte for å etablere alternative ruter i et telekommunikasjonsnett
PCT/NO1998/000347 WO2000031927A1 (fr) 1997-10-24 1998-11-25 Procede d'etablissement d'itineraires detournes dans un reseau de telecommunications
AU15784/99A AU1578499A (en) 1997-10-24 1998-11-25 Method for establishing alternative routes in a telecommunication network
EP98960109A EP1133853A1 (fr) 1998-11-25 1998-11-25 Procede d'etablissement d'itineraires detournes dans un reseau de telecommunications

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NO974925A NO307639B1 (no) 1997-10-24 1997-10-24 Fremgangsmåte for å etablere alternative ruter i et telekommunikasjonsnett
PCT/NO1998/000347 WO2000031927A1 (fr) 1997-10-24 1998-11-25 Procede d'etablissement d'itineraires detournes dans un reseau de telecommunications

Publications (1)

Publication Number Publication Date
WO2000031927A1 true WO2000031927A1 (fr) 2000-06-02

Family

ID=26648791

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NO1998/000347 WO2000031927A1 (fr) 1997-10-24 1998-11-25 Procede d'etablissement d'itineraires detournes dans un reseau de telecommunications

Country Status (3)

Country Link
AU (1) AU1578499A (fr)
NO (1) NO307639B1 (fr)
WO (1) WO2000031927A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI398125B (zh) * 2009-03-18 2013-06-01 Korenix Technology Co Ltd 具有冗餘路徑移動機制之偶合網路系統及其運作方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0370845A1 (fr) * 1988-10-25 1990-05-30 Matra Communication Réseau en anneau comportant une boucle de secours
WO1997001907A1 (fr) * 1995-06-26 1997-01-16 Telefonaktiebolaget Lm Ericsson (Publ) Reseau autoreparateur
US5636205A (en) * 1993-09-20 1997-06-03 Fujitsu Limited Bidirectional line switched ring network control system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0370845A1 (fr) * 1988-10-25 1990-05-30 Matra Communication Réseau en anneau comportant une boucle de secours
US5636205A (en) * 1993-09-20 1997-06-03 Fujitsu Limited Bidirectional line switched ring network control system
WO1997001907A1 (fr) * 1995-06-26 1997-01-16 Telefonaktiebolaget Lm Ericsson (Publ) Reseau autoreparateur

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI398125B (zh) * 2009-03-18 2013-06-01 Korenix Technology Co Ltd 具有冗餘路徑移動機制之偶合網路系統及其運作方法

Also Published As

Publication number Publication date
NO307639B1 (no) 2000-05-02
AU1578499A (en) 2000-06-13
NO974925D0 (no) 1997-10-24
NO974925L (no) 1999-04-26

Similar Documents

Publication Publication Date Title
US5903370A (en) System for an optical domain
US7088676B1 (en) Methods and systems for fast restoration in a mesh network of optical cross connects
US5870212A (en) Self-healing optical network
US7319662B2 (en) Virtual line switched ring
US6600719B1 (en) Method and apparatus for restoring a network
US4633246A (en) Time divison multiplex ring
US5216666A (en) 1:n ring-type signal protection apparatus
US5159595A (en) Ring transmission system
US6292464B1 (en) Apparatus and method for self routing control mechanism for restoring fiber optic communications network connections
US6154296A (en) Telecommunications network having shared protect capacity architecture
US20070041316A1 (en) Method and apparatus for restoring a network
US6579018B1 (en) Four-fiber ring optical cross connect system using 4×4 switch matrices
US20010024540A1 (en) Optical node system and switched connection method
US20040221058A1 (en) Nested protection switching in a mesh connected communications network
US7355967B2 (en) Transmission device
EP1113611B1 (fr) Procédé et dispositif pour le transfert d'information de contrôle dans une configuration de réseau bidirectionnel à commutation de ligne
JPH0454738A (ja) 受信端切り替え伝送方式
WO2000031927A1 (fr) Procede d'etablissement d'itineraires detournes dans un reseau de telecommunications
US6950883B1 (en) Ring capacity efficient architecture
EP1133853A1 (fr) Procede d'etablissement d'itineraires detournes dans un reseau de telecommunications
JP3541206B2 (ja) データ伝送装置内のデータ保護方法
JP3354116B2 (ja) 波長多重光通信網
EP1294136A1 (fr) Méchanisme et méthode de détermination et de restauration rapide de la capacité minimum d'un réseau maillé
WO2002007348A1 (fr) Anneau de protection partagee a optique hybride
CA2278092A1 (fr) Methode et appareil pour eloigner d'un commutateur en panne l'acheminement du trafic des donnees dans un reseau de communication

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AT AU AZ BA BB BG BR BY CA CH CN CU CZ CZ DE DE DK DK EE EE ES FI FI GB GD GE GH GM HR HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SK SL TJ TM TR TT UA UG US UZ VN YU ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 1998960109

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 09856643

Country of ref document: US

WWP Wipo information: published in national office

Ref document number: 1998960109

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

WWW Wipo information: withdrawn in national office

Ref document number: 1998960109

Country of ref document: EP