JPH0591103A - Integrated self-healing network and design system - Google Patents

Abstract

PURPOSE:To attain the self healing satisfying a reliability requirement of various traffics and in which the network cost is minimized. CONSTITUTION:Which self healing technology is to be applied is decided for each traffic based on the class of reliability being the requirement, a sub network 1 is designed for the traffic classified for the application of the 1+1SR system, a sub network 2 is designed for the traffic classified for the application of the SSR system, a sub network 3 is designed for the traffic classified for the application of the DR system, and the initial state of the design algorithm is made a quasi-optimum solution by mapping of the optimized sub networks 1, 2, 3, and the design minimizing the absolute quantity of the operating cable is being tried while the operating route and the standby route are sequentially changed from the initial state to form the integrated self healing network in which the cost of the entire network is minimized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure recovery process in the case of a link failure in network communication composed of a plurality of nodes, and more particularly, an autonomous distributed failure recovery in a distributed control system for traffic having various reliability requirements. (Hereinafter referred to as self-healing) processing.

The present invention also relates to a self-healing process particularly in a distributed control system of line setting requests (hereinafter referred to as demand) having various reliability requirements.

The present invention also relates to a failure recovery process when a failure occurs in a network in which various transmission devices having different functions coexist.

[0004]

2. Description of the Related Art Conventionally, this kind of failure recovery is roughly divided into 1 + 1 Sta as mechanisms having different characteristics.
tic Ring (1 + 1SR) method, Shared
Static Ring (SSR) method, Dynami
There are three individual c-ring (DR) schemes. These methods have various features and constraints as described below.

First, a description will be given in connection with the distributed control system of traffic.

In the 1 + 1SR system, a spare route is prepared for different routes, and the same signal is always sent to both routes at the traffic transmission end. The receiving end normally receives the signal from the working route, but when a failure occurs, the signal is switched from receiving the signal from the backup route to recover.
Control is simple and fast recovery can be realized. However, since the backup route is fixedly set for each working line, there is a problem that the transmission line capacity is more than double that of the working line and the flexibility is lacking.

In the SSR system, one protection ring is set for a plurality of working routes. A plurality of protection rings are prepared and placed assuming all transmission line faults in the network, and when a fault occurs, the protection route is switched to a predetermined protection route for restoration. Since the SSR shares a spare with a plurality of failure patterns, the transmission line capacity can be saved as compared with the 1 + 1 SR. In addition, since switching to the backup route is limited to both end nodes of the failure, relatively fast recovery can be expected. The following methods have been announced as this method. (A) T. Flanagan, "Principles
and Technologies for Pla
Ning Survivability-AMet
oropolitan Case Study ”, Pr
ocedingof Globecom '89, De
c. 1989. In the DR method, after a failure occurs, each distributed node in the network autonomously exchanges messages to search for a detour and dynamically form a ring to recover from the failure. This method is the most flexible in that it saves cable capacity because it can share spares with as much traffic as possible. Furthermore, since the alternate route is dynamically searched, there is a feature that it is highly resistant to multiple failures. However, when an event such as failure detection or message reception occurs, each node must perform the control corresponding to it, so this method is restricted in the applicable environment to the network composed of intelligent devices. Also, this method requires more time to restore than the above two methods. The following methods have been announced as this method. (B) W. D. Grover, “THE SELFHE
ALING ^TM NETWORK ", Proceedin
g of Globecom '87, Nov. 198
7. (C) H. C. Yang and S.M. Hasegaw
a, "FITNESS: FAILURE IMMUNI
ZATION TECHNOLOGY FORNETW
ORK SERVICE SURVIVA BILIT
Y ", Proceeding of Globeco
m'88, Dec. 1988. (D) H. R. Amirazi, "CONTROL
LING SYNCHRONOUS NETWORKS
WITH DIGITAL CROSS-CONNECT
CT SYSTEMS "Proceeding of
Globecom '88, Dec. 1988. (E) H. Sakauchi, "A Self-hea"
ling Network with an Econ
optical Spare-Channel Assi
gnment ", Proceeding of Glo
becom'90, Dec. 1990. Next, a demand distributed control method will be described.

In the 1 + 1SR system, spare routes are prepared on different routes, and the same signal is always sent to both routes at the demand transmission end. The receiving end normally receives the signal from the working route, but when a failure occurs, the signal is switched from receiving the signal from the backup route to recover. Control is simple and fast recovery can be realized. However, since the backup route is fixedly set for each working line, there is a problem that the transmission line capacity is more than double that of the working line and the flexibility is lacking.

In the SSR system, a spare band connected in a ring shape (hereinafter referred to as a spare ring) is set for a plurality of working routes. A plurality of spare rings are prepared assuming all the transmission line failures in the network, and when a failure occurs, switching is made to a predetermined spare route to recover. Since the SSR shares a spare with a plurality of failure patterns, the transmission line capacity can be saved as compared with the 1 + 1 SR. In addition, since switching to the backup route is limited to both end nodes of the failure, relatively fast recovery can be expected. The method (a) has been announced as this method.

In the DR system, after a failure occurs, each distributed node in the network autonomously exchanges messages to search for a detour and dynamically form a ring to recover from the failure. This method is very flexible,
Highest savings in cable capacity as spares can be shared on demand as much as possible. Furthermore, since the alternate route is dynamically searched, there is a feature that it is highly resistant to multiple failures. However, when an event such as failure detection or message reception occurs, each node must perform the control corresponding to it, so this method is restricted in the applicable environment to the network composed of intelligent devices. Also, this method requires more time to restore than the above two methods. As this method, (b), (c), (d),
The method (e) has been announced.

The following has been announced as a proposal of a hybrid type restoration technique using the above three self-healing techniques. Although design points include recovery time of failures, economics, growth, and management of networks, no specific design method or control is mentioned. (F) Fred Ellefson, “MIGRATI
ON OF FAULTTOLERANT NETWO
RKS ”, Proceeding of Globec
om'90, Dec. 1990. Next, a description will be given of a failure recovery process of failure occurrence in a network in which various transmission devices having different functions coexist.

In the SSR system, a spare ring connected in a ring shape is set in advance. Each node prepares detour information (a detour map) for detouring a line that is cut off at the time of a fault of the connection line at the end of the fault line to recover. In the detour map, a backup ring that serves as a detour route when a failure occurs is set for each line. Then, when a failure occurs, a process of switching to the backup ring shown in the detour map is executed at both end nodes of the line. Usually, it is applied to a ring network composed of simple devices (for example, ADM and LTE in SONET). Documents described in (a) above and the following documents are available as documents for explaining this method. (G) J. Baroni, "SONET Line P"
protection Switched Ring A
PS Protocol "T1X1.5 / 91-02
6.1991. In the DR method, after a failure occurs, each distributed node in the network autonomously exchanges messages to search for a detour and dynamically form the detour to recover from the failure. This method is flexible and saves cable capacity because it can share spares with as many demands as possible. Furthermore, since the alternative route is dynamically searched, there is a feature that it is highly resistant to multiple failures. But,
When an event such as a failure detection or message reception occurs, each node must perform control corresponding to the event. Therefore, this system is configured with an intelligent device (for example, a cross-connect device such as DCS in SONET) as an application environment. Limited by network. The methods (b), (c), (d), and (e) have been announced as this method.

[0013]

The real network is not always composed of intelligent devices in consideration of economical efficiency. Also, there is user traffic with various requirements. In addition, there are demands having various requirements.

An object of the present invention is to solve the problem that various requirements concerning the reliability of user traffic cannot be satisfied when the above-mentioned three techniques are applied independently.

Another object of the present invention is to solve the problem that various demands concerning the reliability of demand cannot be satisfied when the above-mentioned three kinds of techniques are applied alone.

In addition, the DR system uses intelligent equipment (DCS (Digital C
cross-connect devices such as loss-connect systems). However, the real network is not always composed of intelligent devices in consideration of economy. Therefore, in a real network in which simple devices (ADM (Add-Drop Multiplex) in SONET) coexist, DR can be applied only to the lines having DCS as both end nodes, and thus the reliability of the network is limited. In addition, when applying SSR to all, there is a problem that a large number of spare bands are required and flexibility is lacking.

Still another object of the present invention is to improve the economical efficiency of the network by expanding the application range of the DR system in an environment in which simple devices are mixed, and for the partial line to which the DR system cannot be applied, SSR. The purpose of this method is to improve the reliability by making the network completely self-healing.

[0018]

According to the present invention, in a network that provides communication services to users having various reliability requirements, each operational line requires a required reliability element type and a node forming the line. Self-healing technology that is applied in advance is set according to the device type,
Reliability element types have high-speed failure recovery processing, robustness that can recover even in the event of multiple failures, and flexibility that takes into account dynamic reconfiguration control. Device types include intelligent devices and simple devices. Refers to a node having a cross-connect function and a control unit capable of distributed management, simple equipment refers to a node having a relay function of two high-speed transmission lines and an add / drop function, and the self-healing technology uses 1 + 1 Static Ring ( 1 + 1S
R) method and Shared Static Ring (SS
R) method and Dynamic Ring (DR) method, and when a failure occurs in the network, (1 + 1S
In the line to which the R) method is applied, the receiving node performs a process of switching the received signal to the protection route side, and the protection route is set as a protection for failure recovery in advance and is always in an active state, and the SSR method is applied. The process of switching the signal to a predetermined backup route is executed at both end nodes of the transmission line that has a failure on the line, and the backup route can also be used for failure patterns other than that transmission line, and the DR method is applied. Assuming that both end nodes of the transmission line having a failure are the first and second nodes in the established line, the first and second nodes become SENDER or CHOOSER, and the third node excluding the first and second nodes. A detour search process and a detour switching process based on the exchange of distributed control messages via nodes are executed, and the failure line has different mechanisms depending on the application method. Integrated self-healing network and design method characterized in that it is recovered by the beam is obtained.

Further, according to the present invention, in a network which provides a communication service to a customer having a plurality of intelligent devices and simple devices as constituent elements and having various reliability requirements, the type of the reliability element requested for each demand and the terminal node. The self-healing technology to be applied in advance is set according to the device type of, and the reliability element type has flexibility considering the high speed of failure recovery processing, the resilience that can be recovered even in the case of multiple failures, and the dynamic reconfiguration control, Device type means intelligent device and simple device, intelligent device refers to a node having a cross-connect function and a control unit capable of distributed management, and simple device has a relay function between transmission lines and an add / drop function. Self-healing technology includes 1 + 1SR method, SSR method, and DR method. + LSR, sub network 1 assigns a ring for the application is determined Demand
And a ring is composed of an operation route and a backup route. For demands classified as the application of the SSR method, a sub-network 2 is designed by allocating a backup ring shared by the operation route and a plurality of operation routes. For the demand classified as the application of the system, the sub-network 3 is designed by designing the operation route and allocating the spare band only to the operation route in which the protection ring in the SSR method cannot be used as the bypass protection route. A network is constructed by superimposing networks 1, 2 and 3 on a physical network, and if a network actually fails, the receiving node sends a signal to the backup route side on the line to which the 1 + 1SR method is applied. The process of switching to the A process of switching to one side route of a spare ring previously assigned as a detour is executed at both end nodes, and both end nodes of a transmission line where a DR system is applied are assumed to be the first and second nodes. , The first and second nodes are SENDER or CH
It becomes OOSER, and a spare unit band (hereinafter, unit band is referred to as a channel) or SS pre-allocated for the DR system is used.
Of the spare rings pre-allocated for the R method, the spare ring that is not used due to the transmission path failure is used to execute the detour search process and the switching process to the detour based on the exchange of the distributed control message to recover the fault. An integrated self-healing network and design method are obtained.

Further, according to the present invention, in a communication network in which intelligent devices (DCS) and simple devices (ADM) are mixed to provide various communication services, all the lines are "ADM-A" depending on the device type of the terminal node.
"ADM-A" is classified into "DM" termination type, "ADM-DCS" termination type and "DCS-DCS" termination type.
If there is more than one DCS on the path in the DM "termination type circuit, the circuit is divided into two Ds close to each termination node.
The CS is divided into a DCS-DCS partial line between two DCSs and an outer ADM-DCS partial line, and when there are no more than two DCSs on the route, the line itself is regarded as an ADM-ADM partial line and the above-mentioned " If there is a DCS other than the DCS termination node in the ADM-DCS "termination type circuit, the DCS-D is used as the DCS closest to the ADM termination node.
DC is divided into CS partial line and ADM-DCS partial line.
If the relay node does not have S, the line itself is ADM-
DCS partial line, the "DCS-DCS" termination type line is a DCS-DCS partial line, and SSR method and D
There is an R method, and the ADM only relays and adds / drops signals between two transmission lines with a simple mechanism, whereas the DCS has a cross-connect function between multiple transmission lines and distributed management. Since the DR method can be controlled by a possible control unit, a backup channel required for restoration is set in advance for the DCS-DCS sub-line to apply the DR method to the ADM-DCS sub-line. A spare ring required for recovery is set for the ADM-ADM sub-circuit to provide the SSR system, and a detour map showing which detour to take when a failure occurs is created, and the DCS-DCS is used during operation of the network. When a failure occurs on the path of a partial line, one of both end nodes of the DCS-DCS partial line is SENDER and the other is CHOO
Become the SER and activate the DR line end recovery method to activate the SEN
A detour is formed between DER and CHOOSER, and when a fault occurs in the ADM-DCS sub-line or the ADM-ADM sub-line, switching processing to the ring is executed at both end nodes of the fault line according to the detour map. An integrated self-healing scheme and device is provided which is characterized by fault recovery.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a processing flow in the case of designing an integrated self-healing network on the premise of the network backbone (node type and connection relationship) and traffic (including presence / absence of required reliability element type). The above-mentioned three types of self-healing techniques have different properties due to the difference in mechanism. For example, the 1 + 1SR method is effective for high-speed failure recovery, and D is for resistance to multiple failures and flexibility.
The R method is excellent. In terms of economic efficiency, the DR method is effective when focusing on the spare capacity, and the 1 + 1SR method and the SSR method are effective when focusing on the equipment cost. Furthermore, in the DR method, since an algorithm for performing distributed control is activated, the applicable device is limited to intelligent devices having a control unit capable of distributed management. Based on this, step S01
Then, we decide which self-healing technology should be applied to a given traffic based on the requirements of traffic and the constraints of the scheme. An example of the mapping criteria is as follows. (1) Use a simple device as a terminal node → 1 + 1SR system or SSR system (2) Request high speed → 1 + 1SR system Request semi-high speed → SSR system (3) Request flexibility → DR system (4) Requiring robustness → DR method is added Next, in step S06, traffic is classified according to the applied technology, and design is performed for each technology independently for the purpose of minimizing the number of used bands. That is, in step S02 of designing a sub-network for the traffic to which the 1 + 1SR scheme is applied, the minimum ring is obviously 1
A ring is set up for limited traffic, and then a ring with the smallest number of patterns consisting of the same number of nodes is selected by selecting the route with the smallest maximum bandwidth on the route. In step S03 of designing the sub-network by the SSR method, the operation route is provisionally set according to the same rule as above, and the operation route is changed in consideration of sharing one protection ring with as many operation routes as possible. At the same time, design a protection ring that minimizes the total bandwidth of the operation route and the protection route. D
Step S for designing a sub-network by the R method
In 04, the operating route is provisionally set in the same manner, and then, while the operating route is sequentially changed, the spare band is allocated in consideration of the dynamic failure recovery method, and the total sum of the operating route and the spare band is minimized. Design the network. Then, in step S05, the three sub-networks are integrated. That is, the initial state is a suboptimal solution that is composed of optimized networks. Step S
In 07, attention is paid to a cable to which only a minimum amount of bandwidth is allocated, and a design that enables deletion of the cable while changing the traffic and protection allocated to the cable sequentially is tried. Then, in step S08, it is determined whether or not the cable can be deleted. If the cable can be deleted, the cable is further deleted in step S07. The process consisting of steps S07 and S08 is performed in step S
By the judgment of 08, it is repeated until the limit of cable removal.
In step S09, the designed network is recorded. Next, in step S10, the first focused cable is changed to a cable to which the second smallest band is allocated, and the processes of steps S07 and S08 are performed. In step S09, if the number of cables obtained this time is smaller than the number of recorded cables, the record is updated. Further, the integrated self-healing network aiming to minimize the cable cost while ensuring the reliability of the traffic is obtained by repeatedly executing the processes of steps S07 to S11 based on the determination of step S10.

Details will be described below with reference to examples. Figure 2
The case where the traffic shown in Table 1 is designed on the backbone network shown in FIG.

[0023]

[Table 1]

In FIG. 2, node A201 and node D2
04 is a simple device (for example, SONET: Synchron
In the us Optical NETwork, the number of connecting cables is limited to two, and since it does not have an intelligent control unit, it is a very inexpensive device, and therefore ADM: Add D
Rop Multiplexer)
Other nodes B202, C203, E205, F2
06 is an intelligent device (for example, as a device having a cross-connect function and an intelligent control unit, D
CS: Digital Cross-connect
There is a system). In the example, in order to simplify the problem, the cables of the inter-node connection transmission paths 207 to 214 are fixed at 600 Mbps (accommodating 12DS3), and all the traffic capacities are set to DS3. First, in step S01, the applied technology is mapped. In the example, traffic NO. Three lines indicated by 01 (hereinafter traffic 0
In 1), the node A201, which is a simple device, is used as the terminal node, so that the application of the SSR method is determined. When both the 1 + 1SR method and the SSR method can be applied, the SSR method that can uniquely save cost is selected. Since the traffic 02 and 14 are requested to have high speed as reliability requirements, the 1 + 1SR method is applied. In the same manner, the applicable technology as shown in Table 1 is determined for each traffic from the requirement conditions of the traffic and the constraint conditions of the method.

Next, in step S06, traffic is classified according to the applied technology, and a sub-network for the purpose of minimizing the number of used bands is designed independently for each technology. In step S02, the traffics 02 and 14 to which the 1 + 1SR method is applied are designed. FIG. 3 shows a design result. The traffic 02 is composed of a ring 301 and the traffic 14 is composed of a ring 302. The direction of the arrow on the ring indicates the directionality of the signal on the working line. In step S03, traffic 01, 03, 04, 0 is based on the SSR method.
Design 7,09,10,12,13. Traffic 01, 04, 09, 10, where the shortest route is decided obviously
The routes 12 and 13 are provisionally set, and then the routes with the fewest allocations are selected and provisionally set for the traffics 03 and 07 having a plurality of patterns of the shortest route. Next, the operation route is changed according to the rules described above, and the design is performed so that the total sum of the operation route and the protection ring band is minimized. In this example, the operation route of traffic 01 (the number of lines is 3) is changed to a route for relaying node F206 by one line, and the design result as shown in FIG. 4 is obtained.
In FIG. 4, the operational routes of traffic 01 are 402 and 406, and the operational route of traffic 03 is 40.
1, traffic 04 is 407, traffic 07 is 403
And 408, traffic 09 is 404, traffic 10
Is 405, traffic 12 is 410, and traffic 13 is 409. Also as a protection ring 41
1, 412, 413 and 414 are set. Step S
In 04, traffic 05, 06, 0 to which the DR method is applied
Design 8, 10, 11 and 15. Here, the traffic 10 requires toughness, so in addition to the SSR method, D
The R method is added. In FIG. 5, the operation route of the traffic 05 is 503, and the traffic 06 is 504 and 50.
2, traffic 08 is 501, traffic 10 is SSR
506 already set by the method, 50 for traffic 11
5 and traffic 15 is 507. As the spare band, 3DS3 is set on the transmission path 207, and the spare shown in FIG. 5 is set for other transmission paths. In step S05, the three sub-networks are superposed. As a result, as shown in FIG. 6, the transmission line 207 has one cable of 12DS3 and the transmission line 20.
The same applies to 2 cables for 18DS3 for 8 and other transmission lines. Next, after step S07, the number of cables in the entire network is reduced based on the heuristic flow.

As a result, the traffic by the SSR system is allocated as in the sub-network shown in FIG. 7, the traffic by the DR system is allocated as in the sub-network shown in FIG. 8, and the total number of cables is reduced to 11 as shown in FIG. It In FIG. 7, 701 to 710 are traffic, 7
Reference numerals 11 to 715 indicate protection rings, and in FIG. 8, reference numerals 801 to 807 indicate traffic.

Next, the operation of the integrated self-healing network of the present invention for actually performing failure recovery will be described. In the present invention, the self-healing process activated when a failure occurs is defined in each node for each traffic, and the failed line is restored by a different mechanism for each application method. FIG. 10 is an explanatory diagram showing the operation. In FIG. 10, when a failure occurs in a certain transmission line, the line to which the 1 + 1SR system is applied in advance is subjected to the process of switching the received signal to the backup route side at the receiving node in step S22 according to the determination in step S21. The applied line is subjected to a process of switching to a predetermined protection ring in step S23, and D
In step S24, the failure recovery process by the autonomous distributed control is executed for the line to which the R method is applied. As an example, a case where a failure occurs in the transmission line 210 will be described. When a failure occurs in the transmission line 210, the traffics 301 and 302 shown in FIG. 3, the traffics 706 and 708 shown in FIG. 7, and the traffics 801 and 8 shown in FIG.
02 is affected. However, the traffic 301 switches the received signal to the protection side at the node A 201 and becomes the bidirectional route 1102 shown in FIG. 11, and similarly, the traffic 302 becomes the route 1108, whereby the traffic is instantaneously restored. Further, the traffic 706 is switched to the protection ring 712 in the faulty end nodes B202 and F206, and the traffic 708 is switched to the protection ring 713 to configure and recover routes 1103 and 1105 shown in FIG. 11, respectively. Further, the traffics 801 and 802 are restored by using the routes 1101, 1106, 1104 and 1107 shown in FIG. 11 as detours. The other transmission paths can be similarly restored.

Next, another embodiment of the present invention will be described with reference to the drawings. FIG. 12 is a processing flow in the case of designing an integrated self-healing network on the premise of the node type of the network, the connection relationship, and the demand (including the presence or absence of the necessary reliability element type). The above-mentioned three types of self-healing techniques have different properties due to the difference in mechanism. For example, the 1 + 1 SR method is effective for high-speed failure recovery, and the DR method is excellent for resistance to multiple failures and flexibility. In terms of economic efficiency, the DR method is effective when focusing on the spare capacity, and the 1 + 1SR method and the SSR method are effective when focusing on the equipment cost. Furthermore, in the DR method, since an algorithm for performing distributed control is activated, the applicable device is limited to intelligent devices having a control unit capable of distributed management. Based on this, in step S01, which self-healing technique is to be applied to a given demand is determined based on the demand condition of the demand and the constraint condition of the method. An example of the mapping standard is the same as the above-mentioned mapping standard.

In the next phase, demands are classified according to the difference in applied technology, and a logical sub-network is designed independently for each technology. That is, steps S02, S03, S
At 04, logical sub-networks are designed for demands to which the 1 + 1 SR system, the SSR system, and the DR system are applied, respectively. Then, in step S05, the three sub-networks are integrated on the physical network to form an integrated self-healing network.

In step S02, the 1 + 1SR subnetwork is specifically designed based on the flow shown in FIG. When setting D1 demands in accordance with FIG. 2, i is initialized in step S10, and in step S11, the smallest ring is selected from the rings forming the operation route and the backup route for the i-th demand. Next, in step S12, it is determined whether or not there are a plurality of minimum rings. If they exist, the process directly proceeds to step S14, and if not, the process proceeds to step S13 to set the rings. In step S14, i is incremented by 1, and steps S11 to S14 are performed in step S14.
According to 15, all D1 demands are determined.
Further, in step S16, for demands for which no ring has been set, a ring having the smallest maximum usable bandwidth of the passage is selected from a plurality of minimum rings and is set.

In step S03, the SSR subnetwork is specifically designed based on the flow shown in FIG. When setting D2 demands according to FIG. 14, i is initially set to 1 in step S20, and in step S21, the operation route of the minimum hop extending between the end nodes is searched for the i-th demand. Next, in step S22, it is determined whether or not there are a plurality of shortest routes. If they exist, the process directly proceeds to step S24, otherwise proceeds to step S23 to set an operating route. In step S24, i is incremented by 1, and the processes of steps S21 to S24 are performed for all D2 demands according to step S25. Further, in step S26, with respect to demands for which an operating route has not yet been set, a process for selecting and setting a route having the smallest maximum use band of the passages from a plurality of minimum routes is performed. When the setting of the operation route is completed by the processing from steps S20 to S26, the setting of the spare ring is performed from step S27. In step S27, the longest operational route to which the backup ring is not yet assigned is selected, and the process proceeds to step S28. In step S28, if there is a spare ring that has already been set, it is judged whether or not it can be used when a single transmission line failure is considered. Specifically, when considering the failure edge recovery for each unit route when the operation route is divided by each connection node, as an inner detour of the backup ring passing through both end nodes of each unit route Determine if there is a one-sided route available. If all the unit routes can share the spare ring, the process directly proceeds to step S30. If not, the minimum spare ring necessary for restoring the operation route is set at step S29 and the process proceeds to step S30. .. The processing from steps S27 to S29 is executed for all operation routes in accordance with step S30.
Get the SR subnetwork.

In step S04, concretely referring to FIG. 15 and FIG.
The DR sub-network is designed based on the flow indicated by 6. When setting D3 demands according to FIGS. 15 and 16, steps S40 to S46 are the same as the processing from steps S20 to S26 in FIG. 14, and all the operation routes are set by this processing. Next, when the number of transmission lines in the network is M, m is initialized to 1 in step S47, the number of spare rings assigned to the m-th transmission line in FIG. 14 is set to r1, and in step S49, in step S49. The number of backup rings that do not pass through the m-th transmission line but have both end nodes as connection nodes is r2, and in step S50, the number of SSR operational routes assigned to the m-th transmission line is r3.
In step S51, the number of DR operation routes assigned to the m-th transmission path is set to W0, and step S52 is performed.
And subtract the doubled number of r1 and r2 from W0, and r3
Let w (m) be the number added. Further, when W (m) becomes negative by the processing of steps S53 and S54, it is set to 0, and when a ring usable in the DR method among the SSR method standby rings is used as the DR method standby route, m The number W (m) of operating channels to which a spare channel for the DR system should be allocated on the th transmission line is obtained. The process of obtaining W (m) composed of steps S48 to S54 is executed for all transmission lines according to step S56. Finally, in step S57, a DR sub-network is obtained by performing a spare channel allocation process with W (m) (1 ≦ m ≦ M) as the number of channels used in the transmission path.

Details will be described below with reference to examples. Figure 1
The case of designing the demands in Table 2 on the physical network shown in FIG. 7 is taken as an example.

[0034]

[Table 2]

In FIG. 17, node 1201 and node 1
204 is a simple device (for example, SONET: Synchro)
In nus Optical NETwork, the number of connecting cables is limited to two, and since it does not have an intelligent control unit, it is a very inexpensive device, and ADM: Add
Drop Multiplexer), and other nodes 1202, 1203, 1205
1206 is an intelligent device (for example, DCS: Digital Cross-connec as a device having a cross-connect function and an intelligent control unit).
t System). In the example, the cable is 600 Mbps (12D) to simplify the problem.
Fixed to S3) and all demand capacity is STS-
Set to 1. First, in step S01, the applied technology is mapped. Table 2 also shows the applied self-healing technology. For example, 3 existing between nodes 1-2
The SSR system is applied to line 01, and 1 line 1 + 1
The SR method is applied.

Next, in step S02, 1 + 1SR
The 1 + 1 SR sub-network is designed for the demands 02 and 14 for which the application of the method is decided. FIG. 18 shows a design result. The demand 02 is composed of a ring 1301 and the demand 14 is composed of a ring 1302. The direction of the arrow on the ring indicates the directionality of the signal on the working line.

In step S03, demands 01, 03, 04, 07, 09, 12, 13, 1 are based on the SSR method.
Design 6 The routes of demands 01, 04, 09, 12, 13, and 16 that clearly determine the route of the minimum hop are set, and next, for demands 03 and 07 in which there are multiple patterns of routes of the minimum hop, the maximum allocated bandwidth on the route is the highest. Select and set a small route. In FIG. 19, the operation route of demand 01 is 1401,
The operation route of the demand 03 is 1402, the demand 04 is 1403, the demand 07 is 1404 and 1405, the demand 09 is 1406, the demand 12 is 1407, the demand 13 is 1418, and the demand 16 is 1414. Next, the spare ring is set. The results are shown in Fig. 20. The procedure is as follows: 2 for 2 lines of the operation route 1402.
One spare ring 1410 is set, and then the operation route 14
A spare ring 1412 was set for 04. For the operation route 1405, the spare ring 141 already set
No new spare ring is provided because 2 can be shared.
Two lines of the operation route 1408 share the protection ring 1410, and the other one line is newly set with the protection ring 1411. Further, three spare rings 1409 are set on the three lines of the operation route 1401, and the two operation routes 1403 are set.
The line shares this spare ring 1409. Then, two spare rings 1413 are set to the two lines of the operation route 1406. Two lines of the operation route 1414 share this spare ring 1413, and the remaining one line is the spare ring 141.
Of the two routes formed by separating 1 from the node 3 (1203) and the node 5 (1205), the route passing through the node 4 is shared as a detour. Finally, the two lines of the operation route 1402 also share the protection ring 1413.

In step S04, the demands 05, 06, 08, 10, 11 and 15 to which the DR method is applied are designed. 21 and 22, the operation route of demand 05 is 1501, demand 06 is 1502, and demand 08.
Is 1503, demand 10 is 1504, demand 11 is 1505, and demand 15 is 1506. Step S
In the processing from 48 to S56, W (m) (1 ≦ m ≦ 8) is obtained. For example, in the case of the transmission line 1210, r
1 and r2 are 5 and 2, respectively. Further, according to FIG.
3 is 1. Further, according to FIG. 21, since W0 is 7, W = 7− (5 + 2 × 2-1) <0 and W is 0.
The W thus obtained is the transmission lines 1207, 1208,
1209, 1210, 1211, 1212, 1213 and 1214, respectively 1507, 1508, 1509, 15
The values are 10, 1511, 1512, 1513 and 1514. Finally, when these values are used as the operating channels and the spare channel allocation algorithm is executed, a sub-network whose parenthetical value is the spare channel number is obtained.

In step S05, the three sub-networks are superposed. As a result, as shown in FIG. 23, the transmission line 1207 has a bandwidth of 6 STS-1 and a bandwidth of 5 STS-1.
Of spare bandwidth is allocated. The other transmission paths are also shown in the same manner.

Next, recovery control of the integrated self-healing network of the present invention will be described. In the present invention, the self-healing process that is activated when a failure occurs is defined in each node for each demand, and the failed line is restored by a different mechanism for each application method. Figure 2
4 is an excerpt of a part of the network designed above. In FIG. 24, when a failure 1716 occurs, the process of switching the received signal to the protection route side is executed in the receiving node on the line to which the 1 + 1SR method is applied in advance. Since the 1 + 1SR method and the other two methods are completely independent in terms of the reserve band and the control method, 1 + 1SR is used in this example.
The recovery operation of the method is not shown. For the demand to which the SSR method is applied, a process for switching to a predetermined spare ring is executed, and for the demand to which the DR method is applied, a failure recovery process based on message transmission / reception is executed.
In the example, paths 1707 and 1708 are affected.

In FIG. 25, the path 1708 to which the SSR method is applied is switched to the route 1802 on the protection ring at the faulty end nodes 1202 and 1206.

In FIG. 26, the path 19 to which the DR method is applied
05 to 1908, the node (sender) 1202 sends the first help message 1903 to the node 1201,
The first help message 1901 and 19 is sent to the node 203.
02 and a second help message 1904.
The node 12 that has received the first help message 1903
01 transfers the first help message to the next transmission line assigned to the ring 1909. For the first help message 1901, follow the ring 1909,
Ring 19 for first help message 1902
Transferred along 10. The second help message is flooded based on the distributed failure recovery method (Document e in the prior art).

When the first help message or the second help message arrives at the node 1206 by such processing, as shown in FIG.
06 returns first link messages 2001, 2002 and 2003 for the first help message,
A return message 2004 is returned to the second help message. At this time, in the node 1206, the failed path is switched to the detour by the protection ring.

Upon receiving the first link message, the node 1202 switches the faulty path to the detour by the protection ring, as shown in FIG. When the return message is received, the failure path is similarly switched to the detour searched by the return message, and the second link message 2101 is returned. The second link message links the backup channels at each relay node to form a detour.

Next, another embodiment of the present invention will be described with reference to the drawings. FIG. 29 is an operation example of the integrated self-healing method of the present invention in the SONET environment.
Three DCS (Digital Cross-Conn)
ect Systems) 3101, 3102, 310
3 and 1 ADM (Add-Drop Multipl
ex) 3104 has five physical lines 3113 and 311.
In the network composed of 4, 3115, 3116 and 3117 (FIG. 29 (a)), the DCS31
02 and DCS3103 between the backup channel 3105 and DC
Spare channel 310 between S3101 and DCS3102
6, and a spare ring 3107 in which spare channels are connected in a ring shape is set.

When a failure occurs in the line between the DCS 3101 and the ADM 3104, the working line 3108 is cut off. In this case, the line 3108 is subjected to restoration processing by the SSR method. That is, the line 3108 is the DCS 310
1 and the ADM 3104 is switched to the spare ring 3107 to restore the path shown in FIG.

When a failure occurs in the line between the DCS 3101 and the DCS 3103, the line 3108 is subjected to the restoration process by the DR method. DCS3101 is SEN
DER and DCS3103 become CHOOSER, forming a detour while exchanging messages. As a result, the line 3108 has the spare channels 3105 and 310.
By the detour formed by the connection of No. 6, the route is restored as shown in FIG.

FIG. 30 shows an embodiment of the present invention in the DCS 3101 of FIG. 29, and the SSR executed in the node.
FIG. 6 is a block diagram showing a failure recovery process of DR and DR. D
In the CS3101, each physical line is connected to line terminators (LTE) 3201, 3202 and 3203. Here, the data is the cross connect circuit (CROSS).
3204, the DR control message is connected to a message processing circuit (MSG-PRO) 3206, and the alarm signal is connected to an alarm processing unit (ALM-PRO) 3205.

Cross-connect circuit (CROSS) 320
4 performs data cross-connect (exchange connection) based on the cross-connect map held in the built-in RAM. Also, the DR algorithm unit (DR-ALG) 320
When a cross-connect change instruction is received from No. 7 or the detour map group (R-MAP) 3208, the cross-connect state is changed.

Message processing circuit (MSG-PRO) 3
206 is the DR extracted by the line terminating equipment (LTE)
Control message to DR algorithm part (DR-ALG)
3207 and the DR algorithm part (DR
-ALG) Distribute the DR control message generated in 3207 to the line termination equipment (LTE).

Alarm processing unit (ALM-PRO) 320
In 5, the alarm signal is P-AIS, LOS, or L-AIS, and DC to which DR is applied.
If it occurs on the S-DCS sub-circuit (described in FIG. 33), the alarm is sent to the DR algorithm part (DR-A
LG) 3207 is notified. Also, the alarm signal is L
If the OS or L-AIS occurs in the ADM-DCS partial line to which SSR is applied, select the detour map corresponding to the alarm from the detour map group (R-MAP) 3208, The switch difference information for switching to the backup ring designated by the detour map is transferred to the cross connect circuit (CROSS) 3204.
Here, the detour map group (R-MAP) 3208 is SS
It is a switching map for failure recovery specific to the R method. As described above, the alarm processing unit activates the DR method and SSR.
The activation of the scheme is controlled.

DR algorithm unit (DR-ALG) 32
07 indicates whether the own node is a SENDER or a CHOOSER regarding the DCS-DCS partial line.
It also has provisioning data that defines whether it is another relay node. DR algorithm part (DR-A
When the line alarm is transferred to the LG) 3207, the provisioning data corresponding to the faulty line is searched, and if the own node is defined as SENDER, the process as SENDER in the DR line end method is executed. CHO
The same applies when it is OSER. If it is a relay node, no processing is performed.

In addition, the message processing circuit (MSG-PR
O) When receiving a DR control message from 3206,
The algorithm according to the content of the message is executed. At that time, when a DR control message to be sent is generated, the DR control message to which the transfer destination address is added is transferred to the message processing circuit (MSG-PRO). Further, particularly, when the connection processing of the detour and the switching processing to the detour occur, the switch difference information is transferred to the cross connect circuit (CROSS) 3204.

Next, the relationship between the failure point and the self-healing method applied in the integrated self-healing method of the present invention will be described in detail. It has been stated above that the DR system is limited in its application environment to intelligent devices (cross-connect devices such as DCS in SONET). Due to this restriction, in a real network in which simple devices (ADM in SONET) coexist, the DR method can be applied only to the lines having DCS as both end nodes, and thus the reliability of the network is limited. Therefore, in the present invention, for the line terminated by the ADM, DR is applied to the internal line sandwiched by the DCS, and SSR is applied to the outer partial line to improve reliability.

FIG. 31 shows three types of lines: "ADM-ADM" termination type 3301, "ADM-DCS" termination type 3302 and "DCS-DCS" termination type 3303. In the present invention, a real SON in which DCS nodes (shown by circles) and ADM nodes (shown by squares) coexist.
In the ET network, the line termination type is defined according to the device types of both termination nodes. In particular, a line of "ADM-ADM" and "ADM-DCS" termination type including two or more DCSs on the line path is divided into a plurality of partial lines. The line of "ADM-ADM" termination type 3301 is divided by the DCSs at both ends of the line, and the internal DCS
-It is divided into a DCS partial line and ADM-DCS partial lines at both ends. In addition, the line of the “ADM-DCS” termination type is the DCS that is the outermost DCS terminated by the ADM.
It is divided into a CS-DCS partial line and an ADM-DCS partial line. DR system, ADM for DCS-DCS subline
-The SSR method is applied to the DCS partial line.

One embodiment is shown in FIGS. 32, 33, 34 and 35. In FIG. 32, the operation line 3401 is "ADM-
It is a line of ADM "termination type. Operation line 3401
Are divided into ADM-DCS partial lines 3501 and 3503 and DCS-DCS partial line 3502 shown in FIG. When a failure occurs in the ADM-DCS partial line 3501, that is, when a failure 3504 occurs,
The node at the end of the fault line is diverted to the protection ring 3403, and the line 3401 becomes the route 3601 shown in FIG.
Even when the failure 3511 occurs, the failure end node is detoured to the backup ring 3403 and restored. In addition, DCS-D
Failure patterns 3505, 35 on the CS partial line 3502
When 06, 3507, 3508, 3509 and 3510 occur, the DR line end recovery method is activated between the virtual terminal nodes 3512 and 3513 of the partial line 3502. For example, when a failure 3506 occurs, the line 3401 is bypassed to the backup channel 3402 and the route 3 shown in FIG.
It becomes 701.

[0057]

As described above, according to the present invention, by adopting the integrated self-healing structure in which the self-healing technology having different features is applied according to the reliability requirement of the traffic, the reliability of various traffics can be obtained. It is possible to realize a self-healing network that minimizes the self-healing cost while satisfying the requirements.

Further, according to the present invention, by adopting an integrated self-healing structure in which self-healing technologies having different features are applied according to the reliability requirement of demand, while satisfying the reliability requirements of various demands, It is possible to realize a self-healing network that saves self-healing costs.

Further, according to the present invention, the reliability of the network is improved by adopting an integrated self-healing network configuration in which the two types of self-healing techniques are selectively used for the partial lines formed by virtually dividing the line according to the node type on the route. Is effective.

[Brief description of drawings]

FIG. 1 is a diagram showing a design flow of an integrated self-healing network of the present invention.

FIG. 2 is an explanatory diagram showing a backbone network in the embodiment.

FIG. 3 is a sub-network diagram based on the 1 + 1SR system.

FIG. 4 is an explanatory diagram showing a design method of an initial sub-network (for the purpose of minimizing a used band) related to the SSR method.

FIG. 5 is an explanatory diagram showing a method of designing an initial subnetwork related to the DR method.

FIG. 6 is a diagram showing the number of cables in a network in which three types of initial sub-networks are superposed.

FIG. 7: S as a component of integrated self-healing
It is a figure which shows the subnetwork by SR system.

FIG. 8 is a diagram showing a DR-type sub-network as a component of an integrated self-healing network.

FIG. 9 is a diagram showing the number of cables of an integrated self-healing network.

FIG. 10 is a diagram showing an operation flow of the integrated self-healing network of the present invention.

FIG. 11 is an explanatory diagram related to the operation of the integrated self-healing network when a failure occurs.

FIG. 12 is a diagram showing a design flow of the integrated self-healing network of the present invention.

FIG. 13 is a diagram showing a design flow of the 1 + 1SR subnetwork of the present invention.

FIG. 14 is a diagram showing a design flow of the SSR subnetwork of the present invention.

FIG. 15 is a diagram showing a design flow of a DR subnetwork of the present invention.

FIG. 16 is a diagram showing a design flow of a DR subnetwork of the present invention.

FIG. 17 is a diagram showing a backbone network in an example.

FIG. 18 is a subnetwork diagram based on the 1 + 1SR scheme.

FIG. 19 is a sub-network diagram based on the SSR method.

FIG. 20 is a sub-network diagram based on the SSR method.

FIG. 21 is a DR network diagram.

FIG. 22 is a subnetwork diagram based on the DR method.

FIG. 23 is a diagram showing an integrated self-healing network in which three types of sub-networks are superposed.

FIG. 24 is an example of a network for showing a recovery operation of the integrated self-healing network.

FIG. 25 is a diagram showing a recovery operation of the SSR method.

FIG. 26 is a diagram showing a DR system recovery operation.

FIG. 27 is a diagram showing a DR system recovery operation.

FIG. 28 is a diagram showing a DR system recovery operation.

FIG. 29 is a diagram showing an example of system operation of the integrated self-healing system of the present invention.

FIG. 30 is a block diagram showing a process transition of the integrated self-healing device of the present invention.

FIG. 31 is an explanatory diagram showing lines of three termination types of the present invention.

FIG. 32 is an explanatory diagram showing a line example of an “ADM-ADM” termination type.

[Fig. 33] Fig. 33 is an explanatory diagram showing the rule of the line division of the present invention, and the relationship between the fault location and the activated self-healing method.

FIG. 34 is an operation example of the SSR method when a failure occurs on the ADM-DCS partial line.

[Fig. 35] Fig. 35 is an operation example of the DR system when a failure occurs on the DCS-DCS partial line.

[Explanation of symbols]

201,204 Simplified equipment 202,203,205,206 Intelligent equipment 207-214 Internode connection transmission line 1201,1204 Simplified equipment 1202,1203,1205,1206 Intelligent equipment 1207-1214 Internode connection transmission path 3101,3102,3103 DCS 3104 ADM 3105, 3106 backup channel 3107 backup ring 3108 working line

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04Q 11/04 9076-5K H04Q 11/04 K

Claims (10)

[Claims] 1. A self-healing technique for each traffic, based on the required reliability type, in a network that provides communication services to users having various reliability requirements, which includes a plurality of intelligent devices and simple devices as constituent elements. The reliability type has flexibility considering the speed of failure recovery, the resilience capable of recovering even in the case of multiple failures, and the dynamic reconfiguration control,
The self-healing technology includes (1 + 1SR) method and S
There are an SR system and a DR system, and since the simple device cannot activate the DR system, it is a (1 + 1SR) system or an SSR for traffic having the simple device as a termination node.
Select the application of the method, select the (1 + 1SR) method for traffic that requires high speed, the SSR method for traffic that requires semi-high speed, and the DR method for traffic that requires flexibility. If the traffic that requires robustness is (1 + 1SR) or the SSR method is required, then the DR method is also selected.
The sub-network 1 is designed by individually assigning a ring that minimizes the bandwidth used for the traffic classified as the application of the + 1SR) method, and the ring includes an operation route and a backup route, and the traffic classified as the application of the SSR method. The sub-network 2 is designed by assigning an operation route that minimizes the total bandwidth and a spare ring that is shared by multiple operation routes. For traffic classified as applying the DR method, the total bandwidth is the minimum. The sub-network 3 is designed by allocating a spare band that is shared by the operation route and a plurality of operation routes, and the initial state of the design algorithm is optimized according to the superposition of the sub-networks 1, 2, and 3. The optimal solution is used by sequentially changing the operating route and the backup route from the initial state. Integrated self-healing network design scheme absolute amount of Bull attempts to smallest design, characterized in that the cost of the entire network to configure the network to be minimized. 2. In a network which comprises a plurality of intelligent devices and simple devices as constituent elements and provides communication services to users having various reliability requirements, each operational line forms the type and line of the required reliability element. The self-healing technology applied in advance is set according to the device type of the node, and the reliability element type takes into consideration high-speed failure recovery processing, robustness capable of recovering from multiple failures, and dynamic reconfiguration control. Flexible, the device type means the intelligent device and the simple device, the intelligent device refers to a node having a cross-connect function and a control unit capable of distributed management, and the simple device is a high-speed transmission line. Refers to a node that has two relay functions and an add / drop function, and the self-healing technology is (1 + 1 There are R) system and SSR mode and DR mode, if a network failure occurs, (1 + 1
In the line to which the SR) method is applied, the process of switching the received signal to the protection route side is executed in the reception node, and the protection route is set as a protection for failure recovery in advance and is always in an active state, and the SSR method is applied. The process of switching the signal to a predetermined protection route is executed at both ends of the transmission line that has a failure on the line, and the protection route is also used for the failure pattern other than the transmission line, and is applied to the line to which the DR method is applied. If the two end nodes of the failed transmission line are the first and second nodes, the first and second nodes are SE
Become NDER or CHOOSER, and first and second
The detour route search process and the detour route switching process based on the exchange of the distributed control message are executed via the third node excluding the node No. Integrated self-healing network to do. 3. When designing a logical network satisfying a demand to which the (1 + 1SR) method is applied as a self-healing technology on a physical network in which the device type and the connection relation of the device are defined, said device type Means an intelligent device and a simple device, where the number of transmission paths through which the ring passes is the number of hops, and the ring with the smallest number of hops is first selected from the rings including two terminal nodes for one demand. The ring constitutes an operation route of the demand and a backup route. When the number of the ring is limited to one, the process 1 for setting the ring is executed, the process 1 is repeatedly executed for all the demands, and then For the demand for which the ring was not set in process 1, use the maximum on the route among the rings with the minimum number of hops. Select the ring band passing through the lowest transmission path to set the ring processing 2
Is executed, and the process 2 is repeatedly executed for all demands for which the ring is not set in the process 1,
A (1 + 1SR) design method in which a self-healing network based on the (1 + 1SR) method is designed. 4. A self-healing technique, S, is provided on a physical network in which device types and device connection relationships are defined.
When designing a logical network to which the application of the SR method meets a certain demand, the device type means an intelligent device and a simple device, the operation route is set in the first phase, and the backup ring is set in the second phase. First, in the first phase, the number of hops is the number of transmission paths through which the route or ring passes, and the route with the smallest number of hops between the two end nodes is selected for the first demand. , If this route is limited to one, the process 1 for setting this route as the operation route is executed, the process 1 is repeatedly executed for all demands, and the operation route is not set in the process 1 About demand Among routes with the minimum number of hops, the route that passes through the transmission route with the smallest maximum bandwidth on the route By executing the process 2 of selecting the operation route and executing the process 2 repeatedly for all the demands for which the operation route was not set in the process 1, the setting of the operation route of all demands is completed, In the second phase, the operating route with the maximum number of hops is searched from the set operating routes, and the backup ring that includes this operating route in the route and has the minimum number of hops is set, and then the remaining When searching the operating route with the maximum number of hops from among the operating routes of, and setting the detour for recovery from the faulty end for each unit route that divides this operating route at each connection node , It is determined whether the spare ring that has already been set can be shared as a detour for each unit route of the operation route, and the detour is a spare ring that includes both end nodes of the unit route in the route. If there is a unit route in which a detour cannot be formed with the protection ring that has already been set, the processing 3 for setting the protection ring that includes this unit route in the route and minimizes the number of hops is executed. An SSR design method, wherein a self-healing network based on the SSR method is designed by executing the process 3 until all the operation routes are assigned with the spare rings. .. 5. A self-healing technique D is provided on a physical network in which device types and device connection relationships are defined.
In the case of designing a logical network in which the R method is applied to meet a certain demand, the device type means an intelligent device and a simple device, and in the first phase, a band between terminal nodes of a line satisfying the demand is defined. When the operation route is set, the operation routes of all demands are set, and in the second phase, the reserve band used for the detour is set. First, in the first phase, the number of transmission paths through which the route passes is set. As the number of hops, a route that minimizes the number of hops between two end nodes for one demand is selected, and if this route is limited to one, the process 1 that sets this route as an operation route is executed,
The process 1 is repeatedly executed for all demands, and then for the demand for which the operation route is not set in the process 1, the route having the smallest maximum bandwidth is passed through among the routes having the plurality of minimum hops. Set the operation route for all the demands by executing the process 2 that selects the existing route and sets the operation route, and repeats the process 2 for all the demands for which the operation route was not set in the process 1. When the number of transmission lines in the network is M in the second phase, the number of operation routes passing through the m-th transmission line is W0 (m), and the number of backup rings passing through the transmission line is r1 (m), and the spare ring is a spare ring for a fault bypass route designed based on the shared static ring (SSR) method which is a self-healing technique. The number of pre-ring to pass through the both end nodes without passing through the transmission path and r (m), the number of operation route based on the SSR method in a transmission path and r3 (m), W0 (m)
Then, the number obtained by subtracting r1 (m) and r2 (m) doubled and further adding r3 (m) is defined as W (m), and W (m)
Is the number of operating routes that cannot form a detour using the backup ring when a failure occurs in the transmission line,
The process of obtaining W (m) is repeatedly executed for all transmission lines in the network, and then the number of used channels in each transmission line is set to W (m) (1 ≦ m ≦ M) and the transmission line of the network is spared. A DR design method characterized by allocating channels. 6. In a network, which comprises a plurality of intelligent devices and simple devices as constituent elements and provides communication services to customers who have various reliability requirements, depending on the type of reliability element requested for each demand and the type of terminal node device. The self-healing technology to be applied in advance is set, and the reliability element type has high speed of failure recovery processing, resilience that can recover even in the case of multiple failures, and flexibility considering dynamic reconfiguration control. Means the intelligent device and the simple device, the intelligent device means a node having a cross-connect function and a control unit capable of distributed management, and the simple device means a relay function between transmission lines and an add / drop function. , And the self-healing technology includes (1 + 1SR) method, SSR method, and DR. There is a formula, and the sub-network 1 is designed by allocating a ring for the demand for which the application of the (1 + 1SR) method is determined. The ring is composed of an operation route and a backup route, and the demand classified into the application of the SSR method. For designing the sub-network 2 by allocating an operation route and a spare ring shared by a plurality of operation routes, for demand classified into the application of the DR method, the operation route is designed and the spare ring in the SSR method is bypassed. The sub-network 3 is designed by allocating the spare band only to the operation route that cannot be used as the spare route of, and then the sub-networks 1, 2 and 3 are superposed on the physical network to form the network. In case of network failure, the above (1 + 1SR) For the line to which the method is applied, the process of switching the signal to the protection route side is executed at the receiving node, and for the line to which the SSR method is applied, the protection ring previously allocated as a detour at both end nodes of the fault transmission path is used. When the process of switching to the one-sided route is executed and the nodes at both ends of the transmission line where the DR system is applied are the first and second nodes, the first and second nodes are the DR system. Search processing based on exchange of distributed control messages and switching to a bypass using a spare band pre-allocated for SSR or a spare ring pre-allocated for SSR method that is not used due to transmission line failure An integrated self-healing network design control method characterized by the fact that processing is executed and failures are recovered. 7. A self-healing system for each demand based on a reliability type requested in a network which provides a communication service to customers having various reliability requirements with a plurality of intelligent devices and simple devices as constituent elements. It is decided whether to apply the technology, and the reliability type has flexibility in consideration of high speed of failure recovery, robustness capable of recovering even in the case of multiple failures, and dynamic reconfiguration control,
The self-healing technology includes (1 + 1SR) method and S
There are an SR system and a DR system, and since the simple device cannot activate the DR system, a (1 + 1SR) system or SS is applied to a demand in which the simple device is a termination node.
The R method is selected, the (1 + 1SR) method is selected for demands requiring high speed, the SSR method is selected for demands requiring semi-high speed, and DR is used for demands requiring flexibility. If the system is selected and the demand for toughness requires the application of the (1 + 1SR) or SSR system, the DR system is also selected and the ring classified for the demand classified as the application of the (1 + 1SR) system is selected. The sub-network 1 is designed by allocating the ring, and the ring is composed of an operation route and a backup route.
For the demand classified into the application of the method, the sub-network 2 is designed by allocating the operation route and the spare ring shared by the plurality of operation routes, and regarding the demand classified into the application of the DR method, the operation route is designed and A sub-network 3 is designed by allocating a spare band to an operation route that cannot share the spare ring in the SSR system as a bypass spare route, and then the sub-networks 1, 2, 3 are superposed on a physical network. Integrated self-healing network design method. 8. A demand designed based on the 1 + 1SR method in the case where a transmission line failure occurs in a network which provides a communication service to users having various reliability requirements by using a plurality of intelligent devices and simple devices as components. When both ends of the node detect a failure, they automatically execute the process 1 of switching the receiving interface from the operation route to the protection route side, and if both end nodes of the failed transmission line are the first and second nodes, As a process independent of the process 1, the first and second nodes perform a process 2 of switching the operation route to the one side route of the spare ring which is assigned in advance for the detour for the line designed by applying the SSR method. For a line that is executed and designed by applying the DR method, two types of help messages are When the second of the help message,
The first node sends the first help message on all spare rings where the SSR scheme is not used and the second
Is sent to all transmission lines having spare channels allocated for the DR scheme, the first help message has at least the identifier of the failed transmission line and the spare ring identifier, and the second help message is The third node, which has at least the identifier of the faulty transmission path, the hop count indicating the number of nodes that have passed through, and the control information 1 of the minimum spare band of the transmission path that has passed through, and the third node excluding the first and second nodes is the first When the second help message is received, the first help message is transferred to the next node that connects the protection ring, and when the second help message is received, the message reception record is made and the hop count is set to a predetermined value. If the following is satisfied, the control information 1 is updated, the second help message is transferred to the adjacent node having the backup channel, and the second help message is transferred. When receiving the first help message, the switch switches the failure channel to the route on the protection ring traced by the first help message, and the two link messages are the first link message and the second link message. Then, the process 3 for returning the first link message is executed, and when the second help message is received, a return is made to the node connected to the transmission path to which the second help message is sent. The process 4 for sending a message is executed, and the processes 3 and 4 are continued until the first link message and the return message are sent together for the number of failed channels, and when the third node receives the first link message. When the first link message is transferred to the next connection node and the return message is received Selects, from the stored second help message reception record, an adjacent node which reaches the first node in the minimum hop among the connection transmission lines having the spare band, and transfers the return message to this node, If there is no connection transmission line having a spare band, a negative ACK message is returned to the node that sent the return message, and the node that receives this negative ACK message searches for another route again to create a detour that can be formed. On the other hand, in the first node, the faulty channel is switched to the detour every time the first link message is received, and each time the return message is received, the detour 1 is still detoured to the detour 1 selected by the return packet. Switch the failing channel that is not assigned to pass the second link message through detour 1. Then, when each node on the detour 1 receives the second link message, the switch is controlled to connect the detour and the second node receives the link message. An integrated self-healing network control method, wherein successive failure detours are formed by switching failure channels to detours. 9. In a communication network in which intelligent devices (DCS) and simple devices (ADM) are mixed to provide various communication services, all lines are classified as "ADM-ADM" termination type and "ADM-ADM" termination type depending on the device type of the termination node. A
When the line is classified into the DM-DCS "termination type and the" DCS-DCS "termination type, and there are two or more DCSs in the route of the" ADM-ADM "termination type, the line is close to each termination node. D between two DCS with two DCS
If the CS-DCS sub-circuit and the outer ADM-DCS sub-circuit are divided into two or more DCSs on the route,
The line itself is an ADM-ADM partial line, and the "ADM
-If there is a DCS other than the DCS termination node in the DCS "termination type circuit, the DCS closest to the ADM termination node is used as the DCS-DCS partial circuit and the ADM-D circuit.
If the DCS is not included in the relay node, the line itself is an ADM-DCS partial line, and the "DCS-DCS" termination type line is a DC partial line.
The S-DCS partial line is used, and the self-healing technology of the network includes an SSR method and a DR method.
Has only a simple mechanism for relaying and add / drop between two transmission lines, whereas the DCS has a DR system by a control unit having a cross-connect function for signals between multiple transmission lines and capable of distributed management. Therefore, the DR method is applied to the DCS-DCS sub-line, and a backup channel required for restoration is set in advance.
The DM-DCS sub-line and the ADM-ADM sub-line are provided with an SSR system, and a spare ring required for restoration is set, and a detour map is created to indicate which spare ring is detoured when a failure occurs. If a failure occurs on the path of the DCS-DCS sub-line during operation, one of the two end nodes of the DCS-DCS sub-line will be S
When the ENDER and the other become CHOOSER and activate the DR line end recovery method to form a detour between SENDER and CHOOSER, and when a failure occurs in the ADM-DCS partial line or the ADM-ADM partial line. An integrated self-healing method characterized in that both ends of the failure line execute switching processing to the ring according to the detour map to recover from the failure. 10. In a communication network in which intelligent devices (DCS) and simple devices (ADM) are mixed to provide various communication services, all lines are "ADM-ADM" termination type and "A" depending on the device type of the termination node.
It is classified into the DM-DCS "termination type and the" DCS-DCS "termination type, and when there are two or more DCSs on the route of the" ADM-ADM "termination type line, the line is close to each termination node. Two DCSs are divided into a DCS-DCS sub-circuit between two DCSs and an ADM-DCS sub-circuit on the outside. If there are no more than two DCSs on the route, the circuit itself becomes an ADM-ADM sub-circuit. , D
The CS-DCS sub-circuit is DR system, and the ADM-DCS sub-circuit and the ADM-ADM sub-circuit are SSR system for failure recovery control. The "ADM-DCS" termination type circuit is a DCS other than the DCS termination node. If there is a DCS-DCS sub-line and a ADM-DCS sub-line at the DCS closest to the ADM termination node, the line itself is ADM-DCS if the relay node does not have DCS. It becomes a partial line, and the above "DC
The line of S-DCS "termination type is DCS-D
Since it is a CS partial line, the DCS node
The line terminating device has a function of relaying or terminating the CS-DCS partial line, the ADM-DCS partial line, and the ADM-ADM partial line, and the line terminating device for terminating the line sends data to the cross-connect circuit and the DR control message receives An alarm signal is delivered to the alarm processing unit in the message processing circuit, and the cross-connect circuit has a function of cross-connecting data based on the cross-connect map held in the built-in RAM, and DR and SSR restoration. It is possible to change the cross-connect state when instructed to change the cross-connect from the control result, and the message processing circuit sends the DR control message extracted by the line termination device to the DR algorithm unit. Transferred and D generated by this DR algorithm part
The R control message is distributed to the line terminating device, and the alarm processing unit generates an alarm signal P-A.
If the alarm signal is IS, LOS, or L-AIS and the alarm signal is received from the DCS-DCS sub-line, the DR method is applied to the DCS-DCS sub-line, and the alarm signal is sent to the DR algorithm section. Notify, if the alarm signal is LOS or L-AIS and the alarm signal relates to the ADM-DCS or ADM-ADM sub-line, ADM-ADM and ADM
-Since the SSR system is applied to the DCS sub-circuit, the detour map corresponding to the alarm is selected from the SSR detour map group, and the switch difference information for switching to the backup ring instructed by the detour map is described above. The processing for transferring to the cross-connect circuit is executed, and the SSR detour map group is a failure recovery switching map unique to the SSR system, and the DR algorithm unit is a trigger node of DR for the DCS-DCS partial line. There is provisioning data that defines whether there is a SENDER or a CHOOSER, and whether it is a relay node other than that, and when the DR algorithm unit actually receives a line alarm, the provisioning data corresponding to the faulty line. Is searched for, and the own node is SEN
If defined as DER, SE in DR line-end method
When the processing as NDER is executed and the DR control message is received from the message processing circuit, the algorithm according to the content of this message is executed, and at that time,
When a DR control message to be sent is generated, the DR control message to which the transfer destination address is added is transferred to the message processing circuit, and especially when the connection processing of the detour or the switching processing to the detour occurs, the switch difference An integrated self-healing device characterized by performing combined control of a DR system and an SSR system by transferring information to the cross-connect circuit and executing switching to a detour.