Reserving method for synchronous fiber-optic communication network with spectral packing systems

FIELD: optical systems, namely communication networks, possible use in synchronous fiber-optic communication networks, both existing and in development.

SUBSTANCE: in accordance to the invention, sets of lengths of optical cables of communication network are selected, breakdown of each of which disrupts all routes between corresponding communication network units and value of total structural reliability coefficient of which is less than allowed, and installed into system are spectral packing terminals, optical routing commutators, optical multi-port commutators, optical power indicators and control blocks in units of communication system, incidental to lengths of cable of communication line, which compose selected sets, with following switching of information traffic to spectral packing terminal in case of loss of optical power in one of optical fibers.

EFFECT: reduced material costs of building of communication network, while preserving its reliability.

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The invention relates to optical systems, and in particular to communication networks, and can be used in existing and new synchronous fiber-optic communication networks (SVOCS).

There is a method of redundancy of information flows in the synchronous fiber-optic communication networks (see, for example, Slepov NN. Synchronous digital hierarchy SDH. M: ECO-TRENDS, 1999, p.56-58; Barkov I., Sergeeva OTHER Mathematical models assessing the reliability of ring structures in SDH networks. - Telecommunications, 2001, No. 11, p.36-38).

In this way establish a backup optical fiber on each main optical fiber communication network. Then transmit optical signals between nodes of the communication network simultaneously for primary and backup optical fiber. At the receiving side compares the levels of received signals for further processing selects the signal with the higher optical power level.

The disadvantage of this method of backup is the high cost of its implementation due to the need for duplication of network elements.

There is also known a method of reservation information flows (see, for example, Small AV Digital communications: fundamentals of planning and construction. M: ECO-TRENDS, 2001, s-188), consisting in the installation of a back of the optical fibers on each major fiber optic network Saint is zi and the transmission of optical signals only on the primary fiber. In the optical fiber, measure optical power and loss form the control signal, which signal transmission is performed by the backup optical fiber.

The disadvantage of this method of backup is the high cost of its implementation due to the need for duplication of network elements.

The closest in technical essence to the claimed method of redundancy in SWISS systems spectral multiplexing is a method of redundancy in US patent No. 6046832 from 04.04.2000, IPC 7 NW 10/20.

Prototype method is that many rings SWISS allocate ring protection with two or more nodes of the communication network containing a terminal spectral multiplexing. In the presence of terminal spectral seals on each ring node protection backup set terminal spectral multiplexing, optical routing switcher, multiport optical switch. Connect the outputs of the main and standby terminal spectral multiplexing of input optical routing switch, the outputs of which are combined with optical fibers that make up the ring of protection. Inputs multiport optical switch connected to the outputs of multiplexers I / o SWISS. In addition, the inputs of the back terminals of the spectrum is inogo seal connected to the outputs of the optical multiport switch.

In the process, the communications network in optical fibers to measure the optical power level and loss form the control signal, which include backup terminals spectral multiplexing. Inputs backup terminal spectral multiplexing on the same node, connected via optical multiport switch. Then the input optical routing switch, which receives the traffic information from the output terminal spectral seals, switches to the backup optical fiber ring of protection by which this traffic information is passed to the node of the communication network on which the terminal is installed spectral multiplexing.

This type of backup allows you to protect information flows transmitted over the spectral lines of the seal, which generally increases the reliability of the network connection.

The disadvantage of the prototype method is that its implementation requires high material costs. This is due to the necessity of using additional functional devices and backup optical fibers in each area of the communication network when implementing this method.

The purpose of the claimed invention is to develop a method of redundancy in SVOCS, ensuring the reduction of material costs for the construction of the set is due, while maintaining its reliability.

The claimed method expands the Arsenal of tools for this purpose.

This objective is achieved in that in the known method of redundancy in SWISS containing N≥4 nodes, the combined lengths of optical cable (KLO), made in the form of a set of optical fibers, and optical routing switches, the inputs of which are connected to the multiplexers I / o communication network, optical routing switches, the outputs are connected to respective optical fibers, terminals spectral multiplexing, inputs and outputs are connected respectively to the outputs of the optical routing switches, and inputs the optical multiport switches, namely, that measure the power levels going in optical fibers when the loss of which form the control signal on the enable terminal spectral multiplexing, for each pre-KLO b_mwhere m=1,2,...,M, and M is the total number KLO combining the nodes of the communication network, set the probability p_m. Allocate pairs of corresponding nodes Z_i,jwhere i=1,2,...,N, j=l,2,...,N, i≠j. Set the limit value of rank r_SSthe path between any pair of corresponding nodes. Allocate the aggregate U₁U₂,...U_λ,..., U_Λ OOK communication network, where Λ - the total number of aggregates, the failure of each of which breaks all paths between corresponding nodes of the communication network and the total value of the index of structural reliability (SPSN) where R_λ<P_SSwhere R_SS- the minimum value SPSN together U_λOOK communication network. What form the structural matrix of the network G=||ε_i,j|| N×N, where ε_i,jthe matrix element which takes the value ε_i,j=0 if i=j or i and j do not belong to the same OOK and takes the value ε_i,j=b_mif i and j belong to the same OOK. Formed structural matrix of the network G=||ε_i,j|| calculate the total set of paths T_Σbetween all pairs of corresponding nodes of the communication network whose rank does not exceed ϒ_SS. With this purpose, the structural matrix of the network G=||ε_i,j|| erected in the degree ϒ_SSby logical multiplication of the elements of the i-th row and j-th column and then summing the results of multiplying. Built in the degree ϒ_SSstructural matrix networks allocate a set of elements that differ from zero. In each selected item, its components determine savecompleted src="00000002.tif" height="7" width="68" > paths between the respective pair of Z_i,jcorresponding nodes of the communication network and the amount which is the value of T_Σ. Then form the matrix of the wayssize M·T_Σbetween all pairs of corresponding nodes of the communication network, wherethe matrix element which takes the value ofif OOK b_mbelongs to the path ' but otherwise,. From the formed matrix waysallocate the aggregate U₁U₂,...U_λ,..., U_ΛOOK communication network, when the failure of each of which is in communication network are broken all the previously found path T_Σbetween corresponding nodes of the communication network. This logically Peremohy KLO communication network corresponding to the elements of the matrix pathswhose value is equal to unity and belonging to the same pathbetween a pair of Z_i,jcorresponding nodes of the communication network. Then summarize the logical works and the obtained logical sum replace characters adding to the signs of multiplication and Vice versa, and then lead such components. Received components in the logical sum of the determined aggregate U₁U₂ ,...U_λ,..., U_ΛKLO communication network, when the failure of each of which is in communication network are broken all the previously found path T_Σbetween corresponding nodes of the communication network. Then for each set KLO U_λcompute the value SPSN P_λaccording to the formulaand finally allocate the aggregate KLO communication network, for which the condition P_λ<P_SS. Terminals spectral seals are installed on the nodes, incident KLO communication network, which are allocated together KLO communication network. With the loss of optical power in one of the optical fibers KLO included in one of the selected sets U_λKLO communication network, the generated control signal is transmitted to the control inputs of terminal spectral multiplexing, optical routing switch and multiport optical switch. According to the control signals include a terminal spectral multiplexing, commute input optical routing switch, which receives the traffic information with the output connected to the input terminal spectral multiplexing, the output of which is connected to the input of the optical multiport switch, the input of which is then commute to the working optical fiber, in which the p traffic information is passed to the node of the communication network, installed terminal spectral multiplexing.

Comparative analysis of the proposed solutions with the prototype shows that the proposed method differs from the known selection sets KLO communication network, the failure of each of which breaks all paths between corresponding nodes of the communication network and is SPSN less valid, as well as the installation of terminals spectral seals on the nodes of the communication network, incident KLO communication network, which are allocated together, and then switch information graphics terminal spectral multiplexing in case of loss of optical power in one of the optical fibers.

The analysis of the level of technology has allowed to establish that the analogues, characterized by a set of characteristics is identical for all features of the claimed technical solution is available, which indicates compliance of the claimed method the condition of patentability "novelty".

Search results known solutions in this and related areas of technology in order to identify characteristics that match the distinctive features of the prototype of the features of the declared object, showed that they do not follow explicitly from the prior art. The prior art also revealed no known distinctive essential features of, cause is from the same technical result, achieved in the claimed method. Therefore, the claimed invention meets the condition of patentability "inventive step".

The claimed method is illustrated by drawings on which is shown:

figure 1 is a variant of the fragment SWISS cellular structure;

figure 2 - composition and connection of the equipment at the nodes incident KLO communication network, comprising the selected set;

figure 3 - structure of the fragment of a communication network represented as a graph;

figure 4 is a set of paths between pairs of corresponding nodes of the communication network;

figure 5 - population structure of the communication network, when the failure of each of which are broken all paths between pairs of corresponding nodes of the communication network;

6 is a set of KLO communication network, the failure of which break all paths between pairs of corresponding nodes of the communication network and the total value of the index of structural reliability is less valid.

Fig.7 - the transmission of data traffic between nodes of the communication network and₂and a₃on the working fiber 3"₂when the failure of the optical fiber 3'₂.

In General, in SWOSS to protect high-speed data flows use the methods of protective redundancy and backup recovery, which increases the reliability of the communication network. On the other hand, the application data is x redundancy methods leads to unnecessary expenses. It is therefore necessary to develop a way to protect information flows in SWISS, which will reduce the economic costs of its implementation and at the same time to maintain the reliability of the communication network at the required level, as suggested in the proposed solution.

Consider implementing the proposed method on the example SWISS shown in figure 1. The communication network consists of two rings 1₁and 1₂, each of which is transmitting simultaneous signals with a speed of 155 Mbit/s First ring l₁and the second ring 1₂contain multiplexers I / o 2₁₁, 2₂₁, 2₃₁, 2₄₁and 2₁₂, 2₂₂, 2₃₂, 2₄₂United optical fibers, respectively, 3'₁, 3'₂, 3'₃, 3'₄and 3"₁, 3"₂, 3"₃, 3"₄. A pair of optical fibers 3'₁-3"₁, 3'₂-3"₂, 3'₃-3"₃, 3'₄-3"₄form the corresponding KLO communication network b₁b₂b₃b₄(see also figure 3). A pair of multiplexers I / o 2₁₁-2₁₂, 2₂₁-2₂₂, 2₃₁-2₃₂, 2₄₁-3₄₂located on the appropriate nodes of the communication network and₁and₂and₃and₄and in each pair are connected by lines of the inner Assembly 4.

In addition, the nodes of the communication network in the General case installed (IG):

- optical routing switches (OMC) 5,6;

terminal spectral multiplexing (TSU) 7;

optical multiport switch (AMPK) 8;

sensors optical power (HOUSE) 9, 10;

- a control unit (cu) 11.

Listed structural elements used in fiber optic communication networks are known. For example, in the book: Figman R. "Fiber-optic communication systems. 3rd supplementary ed. - M.: Technosphere, 2006, described the principle of operation and schema: optical routing and multiport switches on s-417; multiplexers I / o on s-420; optical power meters on s-394; optical cables 49-53. As the terminal spectral seals can be used multiplexers I / o. The control unit implements the function of forming the impulse voltage (current) with the loss of power in an optical fiber used for the respective switching element.

The outputs of multiplexers I / o 2 connected to inputs of respective OMC 5, 6. One of the outputs of each OMC 5, 6 is connected to the input TSU 7 and the other input AMPK 8. Output TSU 7 is connected to the input AMPK 8, the outputs of which are connected with fibers KLO 3.

In addition, the outputs of the HOUSE 9,10 connected to inputs of BU 11, the outputs of which are connected to control inputs OMC 5, 6, trailer hitch 7 and OMPC 8.

For the selected network link structure (figure 3) with number of nodes N=4 and KLO M=4 previously found together U ₁U₂,...U_λ,..., U_ΛKLO communication network, the failure of each of which breaks all paths between corresponding nodes of the communication network and is SPSN P_λless than valid, i.e. R_λ<P_SS.

To do this, set the probability of failure-free operation of each KLO, for example, equal to R₁=0,9, p₂=0,4, p₃=0,9 p₄=0.3 and the minimum value SPSN P_SS=0,6 together U_λOOK communication network. Then allocate a pair of Z_1,3and Z_2,4corresponding nodes of the communication network. Set the limit value for the rank ϒ_SS=2 path between any pair of corresponding nodes. The rank of a path is the number OOK communication network included in this path. The magnitude of the rank of the path is determined by the quality requirements organize channels in the network (see, for example, Davydov G.B., Roginsky V., Tolchin YA telecommunications Network. M: Communications, 1977, s).

Then form the structural matrix of the network G=||ε_i,j|| N×N. In this case N=4, i.e. a matrix of size 4×4

In the matrix G=||ε_i,j|| element ε_i,jwhere i,j are the numbers of nodes, i.e. i, j=1,2,3,4, takes the value ε_i,j=0 if i=j or if i and j do not belong OOK and takes the value ε_i,j=b_{m/sub> where m is the number OOK, i.e. m=1,2,3,4, if i and j belong to the same OOK.}

_{Formed structural matrix of the network G=||εi,j|| calculate the total set of paths TΣbetween all pairs of corresponding nodes of the communication network whose rank does not exceed ϒSS=2.}

With this purpose, the structural matrix of the network G=||ε_i,j|| erected in the degree ϒ_SS=2 by logical multiplication of the elements of the i-th row and j-th column and then summing the results of multiplying, ie,

where the sign ∨ means the operation of a disjunction.

In a raised to the power of ϒ_SS=2 structural matrix networks allocate a set of elements that differ from zero, which in turn define the set ofandpaths between a pair of Z_1,3and Z_2,4corresponding nodes of the communication network (heremeans path 1 between a pair of Z_1,3corresponding nodes of the communication network), and the total amount of paths T_Σwill be T_Σ=4 (figure 4).

Then form the matrix of the wayssize M·T_Σbetween all pairs of corresponding nodes of the communication network. In this when the learn M=4, T_Σ=4, i.e. a matrix of size 4·4

In the matrixherwhere i,j are the numbers of nodes, i.e. i,j=1,2,3,4, f is the number of paths between a pair of Z_i,jcorresponding nodes of the communication network, i.e. f=1.2, m is the number KLO, i.e. m=1,2,3,4, takes the value ofif KLO m belongs to the path ' number f between a pair of Z_i,jcorresponding nodes of the communication network, and otherwise,.

From the formed matrix waysallocate the aggregate U₁U₂,...U_λ,..., U_ΛOOK communication network, when the failure of each of which is in communication network are broken all the previously found path T_Σbetween corresponding nodes of the communication network. This logically Peremohy OOK communication network corresponding to the elements of the matrix pathswhose value is equal to the unit they belong to the same pathbetween a pair of Z_i,jcorresponding nodes of the communication network, and then summarize the logical works

In the obtained logical sum replace characters adding to the signs of multiplication and Vice versa, and then lead such components

Received components in the logical sum of the determined aggregate U₁={b₁·b₃} and U₂={b₂·b₄} OOK communication network, when the failure of each of which is in communication network are broken all the previously found path between the corresponding nodes of the communication network (figure 5).

Then for each set OOK U₁={b₁·b₃} and U₂={b₂·b₄} calculate the total value of the index of structural reliability R_λaccording to the formulai.e.

and finally allocate a set U₂={b₂·b₄} OOK communication network (6), for which the condition P₂<0,6.

After that, the nodes and₂and a₃incident KLO b₂and on the nodes and₁and and₄incident KLO b₄(2)install the hitch 7, two OMC 5, 6, OMPC 8, BU 11 and 9, 10.

With the loss of optical power in the optical fiber 3'₂(figure 2 marked with a cross 7 shows dashed) control signal form the in HOUSE 9, connected to this fiber and located at the nodes and₂and a₃. Then the control signal is passed to the input BU 11, in which form and transmit signals on the control inputs TSU 7, OMC 5, 6I AMPK 8. According to the control signals include a trailer hitch 7, commute entrance of each OMC 5, 6, which receives the traffic information from the multiplexers I / o 2₃₁, 2₃₂with the output connected to the input TSU 7. Then commute entrance AMPK 8, which receives the traffic information from the output TSU 7, the working optical fiber 3"₂on which traffic information is passed between nodes of the communication network and₂and a₃.

For example, during normal operation of the network communication traffic information is passed between nodes of the communication network a₁-a₃and a₂-a₄on the corresponding optical fibers 3'1, 3'₂, 3'₃, 3'₄and 3"₁, 3"₂, 3"₃, 3"₄(Fig.7). With the loss of optical power in the optical fiber 3'₂information traffic intended for transmission over this optical fiber connected to the optical fiber 3"₂that is the exchange of information between nodes of the communication network and₂and a₃.

From this example shows that almost two-fold reduction in the number of functional devices and optical fibers in SWISS, in case of failure of individual network elements, in fact, saved the reliability of the communication network, which indicates the possibility of achieving the formulated technical result.

_mwhere m=1, 2,..., M, and M is the total number of segments of optical cable, combining the nodes of the communication network, the probability p_mand produce pairs of corresponding nodes Z_ijwhere i=1, 2,..., N, j=1, 2,..., N, i≠j and set the limit value for the rank γ_SSthe path between them, allocate together U₁U₂,...U_λ,..., U_Λlengths of optical cable communication network, where Λ - the total number of sovocool the th, the failure of each of which breaks all paths between corresponding nodes of the communication network and the total structural reliability which R_λ<P_SSwhere R_SS- the minimum value of the total index of structural reliability together lengths of optical cable, and the terminal spectral multiplexing and optical routing switches are installed on the nodes incident to a length of optical cable communication network that are allocated together, and with the loss of optical power in one of the optical fibers cut of the optical cable in one of the selected sets U_λlengths of optical cable communication network, the generated control signal is transmitted to the control inputs of terminal spectral multiplexing optical routing switch and multiport optical switch according to the control signals include a terminal spectral multiplexing, commute input optical routing switch, which receives the traffic information from the multiplexer I / o, with the output connected to the input terminal spectral multiplexing, the output of which is connected to the input of the optical multiport switch, the input of which is then commute to the working optical ox is the OSC, at which this traffic information is passed to the communication node that is running terminal spectral multiplexing.

2. The method according to claim 1, characterized in that the selection of sets U₁U₂,...U_λ,..., U_Λlengths of optical cable communication network, the failure of each of which breaks all paths between corresponding nodes of the communication network and the total structural reliability which R_λ<P_SSform the structural matrix of the network G=||ε_i,j|| N×N, where ε_i,jthe matrix element which takes the value ε_i,j=0 if i=j or if i and j do not belong to one segment of the optical cable, and the host is ε_i,j=b_mwhen i and j belong to the same segment of the optical cable, and formed structural matrix of the network G=||ε_i,j|| calculate the total set of paths T_Σbetween all pairs of corresponding nodes of the communication network whose rank does not exceed γ_SSwith this purpose, the structural matrix of the network G=||ε_i,j|| erected in the degree γ_SSby logical multiplication of the elements of the i-th row and j-th column and then summing the results of multiplying, and raised to the power of γ _SSstructural matrix networks allocate a set of elements that differ from zero, determining the set ofpaths between the respective pair of Z_i,jcorresponding nodes of the communication network and the amount which is the value of T_Σthen form the matrix of the wayssize M×T_Σbetween all pairs of corresponding nodes of the communication network, wherethe matrix element which takes the value ofif the segment of coaxial cable b_mbelongs to the path ' but otherwise,, and formed the matrix of pathsallocate the aggregate U₁U₂,...U_λ,..., U_Λlengths of optical cable communication network, when the failure of each of which is in communication network are broken all the previously found path T_Σbetween corresponding nodes of the communication network, to do this logically Peremohy segments optical cable communication network corresponding to the elements of the matrix pathswhose value is equal to the unit they belong to the same pathbetween a pair of Z_i,jcorresponding nodes of the communication network, and then summarize logicheskie works and the obtained logical sum replace characters adding to the signs of multiplication and Vice versa, and then lead such terms, derived terms in the logical sum of the determined aggregate U₁U₂,...U_λ,..., U_Λlengths of optical cable communication network, when the failure of each of which is in communication network are broken all the previously found path T_Σbetween corresponding nodes of the communication network, then for each set of segments of optical cable U_λcalculate the total structural reliability R_λaccording to the formulaand finally allocate the aggregate lengths of optical cable communication network, for which the condition P_λ<P_SS.