JP5778089B2 - Transmission / reception control device, transmission / reception control method, and transmission / reception control program - Google Patents

Description

  The present invention performs erasure correction coding on a digital signal from a client, then distributes and transmits the transmission signal to a transmission section composed of a plurality of transmission paths, and aggregates output signals from the transmission section again. The present invention relates to a technique for controlling encoding and dispersion of a digital signal from a client in a transmission system that performs erasure correction decoding.

  In the backbone or metro network of the current photonic network, the same signal is sent to multiple transmission lines or multiple interfaces in order to improve tolerance or reliability against failure due to transmission device interface failure or optical fiber cutting. The system is constructed so that the actual transfer service is not affected even when one of the transmission paths or any interface fails. Conventionally, as such a protection technique, a 1 + 1 system, a 1: 1 system, an N: 1 system, or the like has been actually used, and has responded to high reliability requirements.

  In such a network that requires reliability, resource allocation methods for setting and transmitting demand between a certain ground to the network include identification information of source and destination nodes, 1 + 1 method, 1: 1 method, etc. One or more transmission paths that can be allocated to the demand are explicitly set on the basis of the information on the reliability realizing means and the resource information of each link or transmission / reception apparatus of the network. This corresponds to a traffic engineering function in an MPLS (Multi Protocol Label Switching) network, a route calculation function and a wavelength allocation function in a photonic network.

Ramesh Bandari, “Survivable Networks”, KLUWER ACADEMI PUBLISHERS, 1999. Wadayama Tadashi, “Fundamentals of Error Correction Technology”, published by Morikita Publishing, July 6, 2010. Masahiro Hayashi and Takeo Abe, “Reliability of Communication Networks”, IEICE, May 10, 2010.

  On the other hand, in order to realize a transfer service with higher reliability in a limited network resource, error correction codes that have been used mainly for the purpose of extending the transmission section have been improved in resistance to transmission line failures. A method that can be used as a means for improvement is conceivable. An error correction code for correcting data loss is called an erasure correction code. It is possible to utilize the correction ability of the erasure correction code in compensation for a failure in the transmission path by distributing and transferring the encoded data sequence to which the redundancy information is given by the erasure correction code to a plurality of transmission paths on the network. It is possible to realize a transmission system having high reliability.

  This transmission system is shown in FIG. The transmission node 1 includes an erasure correction encoding unit 11 that assigns an erasure correction code to configure encoded data, and a data distribution unit 12 that distributes the encoded data. The encoded data is transmitted by being distributed over a plurality of transmission paths 3-1, 3-2, 3-3, 3-4, and 3-5. The receiving node 2 includes a data combining unit 21 that combines encoded data and an erasure correction decoding unit 22 that decodes the erasure correction code.

  In a network that achieves high reliability using an erasure correction code, in order to flexibly allocate resources to the demand from the client, a limited transmission path selection and the like as in the conventional MPLS network and photonic network Rather than performing only fixed resource allocation, it is necessary to flexibly perform transmission path selection and code characteristic setting according to the reliability demand value. However, in the existing invention, there is no apparatus or method for flexibly performing transmission path selection and code characteristic setting according to the reliability demand value.

  Therefore, in order to solve the above-described problem, an object of the present invention is to provide a technique for flexibly performing transmission path selection and code characteristic setting according to a reliability demand value.

  To achieve the above object, in a communication system that distributes a signal with redundancy added to a plurality of transmission paths in the network, transmission path selection and coding are performed so that the reliability required by the client is satisfied. The characteristic setting was made flexible.

  Furthermore, in a communication system in which a signal with redundancy is distributed and transmitted to a plurality of transmission lines in the network, the reliability that can be realized when the transmission line selection and the code characteristic setting requested by the client are applied. It was decided to calculate.

Specifically, the present invention relates to at least one transmission path among transmission / reception ground information, transmission / reception ground demand band information, and a plurality of transmission paths that distribute and transmit data between transmission / reception ground. A demand information obtaining unit for obtaining information on demand reliability, which is a demand value of reliability indicating the degree to which data can be decoded using an erasure correction code even when a failure occurs in A plurality of transmission paths for distributing and transmitting data between the transmission / reception ground and the code length and input of the erasure correction code so that the information transmission / reception ground, demand bandwidth, and demand reliability are notified. A transmission path code length setting section for setting a data length, and a transmission path code length notification section for notifying the transmission / reception ground of a plurality of transmission paths, code lengths and input data lengths set by the transmission path code length setting section. equipped with a door, the Yoriyukido is characterized is calculated based on the number of the transmission path is allowed the generation of each of the reliability and failure of a plurality of transmission paths, <br/> it is an overall reliability of the plurality of transmission paths Is a transmission / reception control device.

Further, the present invention relates to a failure in at least one transmission path among a plurality of transmission paths for distributing and transmitting data between transmission / reception ground information, transmission / reception demand band information, and transmission / reception ground. Demand information acquisition step for acquiring information on demand reliability, which is a demand value of reliability indicating the degree that data can be decoded using an erasure correction code, even when it occurs, the demand information acquisition step A plurality of transmission paths for distributing and transmitting data between the transmission and reception ground, the code length and the input data length in the erasure correction code, so that the transmission and reception ground, demand band and demand reliability reported in A transmission path code length setting step for notifying transmission / reception ground of a plurality of transmission paths, code lengths and input data lengths set in the transmission path code length setting step. A step, a turn running, the reliability is calculated based on the number of the transmission path is allowed the generation of each of the reliability and failure of a plurality of transmission paths, the overall reliability of the plurality of transmission paths This is a transmission / reception control method characterized by the above.

According to this configuration, it is possible to provide a technique for flexibly performing transmission path selection and code characteristic setting according to the reliability demand value from the client.
In addition, when performing flexible selection of transmission lines and setting of code characteristics, or when calculating feasible reliability, the reliability of the entire transmission lines can be improved by considering the reliability of individual transmission lines. It can be evaluated accurately.

Specifically, in the present invention, information of one or more transmission paths selected by a request source among a plurality of transmission paths for distributing and transmitting data between transmission and reception grounds and the request source is set. A setting information acquisition unit that acquires information on a code length and an input data length in an erasure correction code, and one or more transmission paths, code lengths, and input data lengths acquired by the setting information acquisition unit Reliability indicating the degree to which data can be decoded using an erasure correction code even when a failure occurs in at least one transmission path among a plurality of transmission paths for transmitting and distributing data between transmission and reception ground A reliability calculation unit that calculates the reliability calculated by the reliability calculation unit, and a reliability notification unit that notifies the request source of the reliability calculated by the reliability calculation unit , wherein the reliability is a reliability of each of a plurality of transmission paths. And allow failure Is calculated based on the number of the transmission path is a transmission and reception control apparatus according to claim entire reliability der Rukoto the plurality of transmission paths.

The present invention also provides information on one or more transmission paths selected by a request source among a plurality of transmission paths for transmitting and distributing data between transmission and reception grounds, and an erasure correction code set by the request source. A setting information acquisition step for acquiring the code length and the input data length information, and one or more transmission paths, code lengths, and input data lengths acquired in the setting information acquisition step. Calculates reliability indicating the degree to which data can be decoded using erasure correction codes even when a failure occurs in at least one transmission path among a plurality of transmission paths that distribute and transmit data between grounds a reliability calculating step, reliability calculated by the reliability calculation step, a reliability notifying step for notifying the requestor executes sequentially, the reliability, of the plurality of transmission paths It is calculated 's reliability and the occurrence of a failure based on the number of the transmission path is allowed, a reception control method which is a total reliability of the plurality of transmission paths.

  According to this configuration, it is possible to provide a technique for calculating realizable reliability in accordance with transmission path selection and code characteristic setting from the client.

In addition , when performing flexible selection of transmission lines and setting of code characteristics, or when calculating feasible reliability, the reliability of the entire transmission lines can be improved by considering the reliability of individual transmission lines. It can be evaluated accurately.

  The present invention is a transmission / reception control program for causing a computer to sequentially execute the demand information acquisition step, the transmission channel code length setting step, and the transmission channel code length notification step.

  According to this configuration, it is possible to provide a program for flexibly performing transmission path selection and code characteristic setting in accordance with the reliability demand value from the client.

  The present invention is a transmission / reception control program for causing a computer to sequentially execute the setting information acquisition step, the reliability calculation step, and the reliability notification step.

  According to this configuration, it is possible to provide a program for calculating realizable reliability in accordance with transmission path selection and code characteristic setting from the client.

  The present invention can provide a technique for flexibly performing transmission line selection and code characteristic setting in accordance with a demand value of reliability.

It is a figure which shows a transmission system. It is a figure which shows the resource allocation calculating apparatus of Embodiment 1. It is a figure which shows the 1st specific example of the resource information of a transmission line. It is a figure which shows the 2nd specific example of the resource information of a transmission line. It is a figure which shows the 1st specific example of the allocation method to the transmission line of encoded data. It is a figure which shows the 2nd specific example of the allocation method to the transmission line of encoded data. It is a figure which shows the 3rd specific example of the allocation method to the transmission line of encoded data. It is a figure which shows the 1st specific example of the resource allocation calculation method of Embodiment 1. FIG. It is a figure which shows the 2nd specific example of the resource allocation calculation method of Embodiment 1. FIG. It is a figure which shows the 3rd specific example of the resource allocation calculation method of Embodiment 1. FIG. It is a figure which shows the resource allocation calculating apparatus of Embodiment 2. FIG. 10 is a diagram illustrating a code characteristic setting method according to the second embodiment. It is a figure which shows the resource allocation calculation method of Embodiment 2. It is a figure which shows the 1st specific example of the transmission system of Embodiment 4. FIG. FIG. 10 is a diagram illustrating a second specific example of the transmission system according to the fourth embodiment.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components.

(Embodiment 1)
The configuration of the transmission system is the same as that in the first embodiment and the prior art as shown in FIG.

  FIG. 2 shows the resource allocation calculation apparatus according to the first embodiment. The resource allocation calculation device 4 according to the first embodiment includes a transmission path calculation unit 41, a code design unit 42, and a resource management unit 43. The transmission path calculation unit 41 calculates the transmission path of the encoded data string. The code design unit 42 determines the characteristics of the encoded data string based on the demand reliability. The resource management unit 43 manages the resource allocation state of the transmission path. In this way, the resource allocation calculation device 4 corresponds to a transmission / reception control device that controls resource allocation and coding characteristics between the transmission and reception ground.

  The transmission path calculation unit 41 calculates one or more allocation candidate transmission paths for the ground demand based on the network information and the ground demand. That is, the transmission path calculation unit 41 sets a plurality of transmission paths corresponding to a part of the demand information acquisition unit that acquires transmission / reception ground information and transmission / reception demand band information. Corresponding to a part of the length setting part, it corresponds to a part of the transmission line code length notification part for notifying a plurality of transmission lines to the transmission / reception ground. As a transmission path calculation method, a method for searching all transmission paths between grounds at once, a method for obtaining a predetermined number of transmission paths among all transmission paths between grounds in order of increasing transmission path length, For example, a method of obtaining a single shortest transmission path among all the transmission paths in between and adding a transmission path later can be given. Which of the above methods is used may be arbitrary.

  Here, different transmission paths on the network topology can be selected as a plurality of transmission paths. In this case, by using a k-disjoint paths algorithm (see Non-Patent Document 1) or the like, it is possible to improve reliability by preventing a plurality of transmission paths from being the same transmission path on the network topology as much as possible. Can do. In addition, when different transmission / reception devices or different interfaces are used on the same network topology, or when different wavelengths are used in wavelength division multiplexing, even if they are the same transmission path on the network topology, Can be selected as different transmission paths.

  In a network in which an allocated bandwidth can be set, such as an MPLS network, the topology information held in the resource management unit 43 and the use state of the transmission path of the network with respect to the demand for the ground including the requested bandwidth information Alternatively, an appropriate transmission path can be calculated by the transmission path calculation unit 41 in consideration of the resource usage status of the transmission / reception apparatus.

  Here, assuming that the required bit rate is r and the number of transmission paths is k, the bandwidth allocated to each transmission path is calculated as r / k. In order to set the demand correctly, it is necessary to be able to assign the band r / k to all the transmission lines. In addition, when there are a plurality of wavelengths or frequency allocation resources for each transmission path as in a photonic network, it is possible to consider wavelength and frequency resource information together with transmission path information. .

  The resource management unit 43 includes at least network topology information and resource information of each transmission path. First and second specific examples of transmission path resource information held by the resource management unit 43 are shown in FIGS. 3 and 4, respectively. The resource information of the transmission path may be held in the resource management unit 43, and may be acquired from an external device as necessary.

  The resource information of the transmission path shown in FIG. 3 is applied in the case of a photonic network, and includes information indicating the wavelength path allocation status for each wavelength in each transmission path. The transmission path calculation unit 41 uses the transmission path resource information to calculate the transmission path based on the free wavelength information.

  The resource information of the transmission path shown in FIG. 4 is applied to the case of the MPLS network, and includes information indicating the allocated capacity and the link capacity. The transmission path calculation unit 41 calculates the transmission path based on the resource information and the demand band of the transmission path.

  The code design unit 42 calculates the code length of the erasure correction code and the erasure correction code length. That is, the code design unit 42 corresponds to a part of the demand information acquisition unit that acquires information about the demand reliability that is the demand value of the degree that the data can be decoded using the erasure correction code, and the code length It corresponds to a part of the transmission path code length setting unit that sets the input data length, and corresponds to a part of the transmission path code length notification unit that notifies the transmission / reception ground of the code length and the input data length. Here, the erasure correction code length represents the length of the redundant erasure correction code added to the input data before encoding. For example, when a Reed-Solomon erasure correction code is used as the erasure correction code, the erasure correction code length is nk with respect to the code length n and the input data length k, and a loss corresponding to the number of symbols of the erasure correction code length nk. Can be correctly restored (see Non-Patent Document 2).

  These encoded data are divided and assigned to each transmission path calculated by the transmission path calculation unit 41. For example, assuming that the encoded data allocated to each transmission path has the same size, the code length is proportional to the number of transmission paths, and the erasure correction code length is proportional to the number of allowable transmission path failures. Here, the allowable number of transmission line failures indicates the maximum number of transmission line failures so that the encoded data can be correctly restored even if a transmission line failure occurs. For example, if the number of transmission lines is 10 and the number of allowable transmission line failures is 2, the code length and input data length may be set as 10 and 8, respectively, and set as 20 and 16, respectively. Also good.

  A first specific example of a method for assigning encoded data to a transmission path is shown in FIG. In FIG. 5, encoded data having a code length of 10, an input data length of 6, and an erasure correction code length of 4 are transmitted using transmission lines 3-1,..., 3-5 having five transmission lines. Here, symbols x1 to x6 represent input data, and symbols y7 to y10 represent erasure correction codes. This erasure correction code can correct the erasure of only 4 symbols by the above characteristics. Here, two symbols disappear due to a single transmission line failure. Therefore, the allowable transmission path failure number is 2, which is obtained by dividing 4 which is the erasure correction code length by 2 which is the number of symbols lost due to a transmission path failure at one location.

  A second specific example of a method for assigning encoded data to a transmission path is shown in FIG. In FIG. 6, encoded data having a code length of 9, an input data length of 5 and an erasure correction code length of 4 are transmitted using transmission lines 3-1,... Here, symbols x1 to x5 represent input data, and symbols y6 to y9 represent erasure correction codes. This erasure correction code can correct the erasure of only 4 symbols by the above characteristics. Here, two symbols disappear due to a failure in the transmission lines 3-1,..., 3-4, and one symbol disappears due to a failure in the transmission line 3-5. Therefore, the allowable number of transmission line failures is 2 both when the transmission line 3-5 fails and when the transmission line 3-5 does not fail. However, the ratio of the erasure correction code length to the code length is large and inefficient.

  A third specific example of a method for assigning encoded data to a transmission path is shown in FIG. In FIG. 7, encoded data having a code length of 9, an input data length of 6, and an erasure correction code length of 3 are transmitted using transmission lines 3-1,..., 3-5 having five transmission lines. Here, symbols x1 to x6 represent input data, and symbols y7 to y9 represent erasure correction codes. This erasure correction code can correctly correct the erasure of only three symbols due to the above characteristics. Here, two symbols disappear due to a failure in the transmission lines 3-1,..., 3-4, and one symbol disappears due to a failure in the transmission line 3-5. That is, the ratio of the erasure correction code length to the code length is small and efficient. However, the allowable transmission line failure number is 2 when the transmission line 3-5 fails, but becomes 1 when the transmission line 3-5 does not fail.

  As described above, the code length does not necessarily need to be an integral multiple of the number of transmission paths. However, when the code length is not an integral multiple of the number of transmission paths as shown in FIGS. 6 and 7, the characteristics are generally inferior and the characteristics are evaluated. Becomes difficult. Therefore, in the following description, it is assumed that the code length is an integral multiple of the number of transmission paths, and the erasure correction code length is an integral multiple of the allowable number of transmission path failures.

  A method for setting the code characteristics according to the first embodiment will be described below. In Embodiment 1, the demand value regarding the ratio of the number of permissible transmission line failures to the number of transmission lines is used as the demand reliability.

  In other words, it can be defined as demand reliability = number of allowable transmission line failures / number of transmission lines. Here, when the code length and the number of transmission channels are in a proportional relationship, and the erasure correction code length and the allowable number of transmission channel failures are in a proportional relationship, replacement with demand reliability = erasure correction code length / code length Can do. The higher the reliability, the higher the system availability.

  For example, in a demand with a reliability of 0.2, when the number of transmission lines is 10, the allowable number of transmission line failures is 10 × 0.2 = 2. That is, when the reliability is 0.2, the data can be correctly restored even if a failure occurs in up to two of the ten transmission lines.

が成り立つ。さらに、数式１〜３を用いてｋについて解いて、ｋが整数値であることを考慮すると、［ｋ］をｋ以下の最大の整数として、

が成り立つ。 If the reliability of demand is R, the number of allowable transmission line failures is F, the number of transmission lines is D, a Reed-Solomon erasure correction code having a code length of n and an input data length of k is used, a constant a is used,

Holds. Furthermore, when k is solved using Equations 1 to 3 and k is an integer value, [k] is set as the largest integer equal to or less than k.

Holds.

  By configuring a positive integer value n based on Formula 1 and setting a positive integer value k based on Formula 4, a erasure correction code that satisfies the demand reliability and can be realized is configured. Can do. Thus, the code design unit 42 can design an appropriate erasure correction code based on the reliability of demand and the state of the transmission path.

  First and second specific examples of the resource allocation calculation method of Embodiment 1 are shown in FIGS.

  A demand reliability is acquired (step S1). A plurality of transmission paths are calculated (step S2), the code length is calculated from the number of transmission paths, and the relationship of Equation 1 is obtained (step S3). Although the transmission path calculation algorithm is arbitrary, for example, by selecting a transmission path having a large remaining bandwidth from a plurality of transmission path candidates, the possibility of successful resource allocation can be increased. The number of transmission paths calculated varies depending on the transmission path calculation algorithm used, the topology, and the like.

  Next, it is determined whether or not an erasure correction code having the calculated code length and satisfying the demand reliability can be configured (step S4). That is, it is determined whether or not the input data length k calculated based on Equation 4 is a positive integer value.

  Next, when the condition of step S4 is satisfied, it is determined whether or not the constructed erasure correction code can be assigned to each transmission path (step S5). That is, when the demand bandwidth is r, it is determined whether or not the calculated transmission path can be assigned an r / D bandwidth. However, step S5 may be omitted in a network where it is not necessary to consider the demand band.

  When the conditions of Steps S4 and S5 are satisfied (Yes in Steps S4 and S5), a demand band can be allocated to a plurality of transmission lines using an erasure correction code (Step S6). The transmission path information is notified to the transmission / reception ground.

  When the condition of step S4 is not satisfied (No in step S4), it is determined whether or not the number of transmission lines can be increased or the number of transmission lines can be increased (step S7). That is, it is determined whether or not an attempt can be made to increase k to a positive integer value by increasing n.

  When the condition of step S7 is satisfied (Yes in step S7), the number of transmission lines is increased or the number of transmission lines is increased (step S8), and an erasure correction code is reconfigured (step S3). When the condition of step S7 is not satisfied (No in step S7), the demand band cannot be allocated to a plurality of transmission lines using the erasure correction code (step S9), and error information is notified to the transmission side ground. To do.

  The case where the condition of step S4 is satisfied (Yes in step S4) but the condition of step S5 is not satisfied (No in step S5) will be described. In the method shown in FIG. 8, steps S7 to S9 are executed. That is, the same processing as when the condition of step S4 is not satisfied (No in step S4) is executed. In the method shown in FIG. 9, step S10 is executed. That is, the transmission path that cannot be accommodated is removed (step S10). Then, the transmission path is recalculated (step S2). In addition, in the method shown in FIG.8 and FIG.9, you may notify error information to the transmission side ground.

  FIG. 10 shows a third specific example of the resource allocation calculation method according to the first embodiment. In the method shown in FIG. 10, the code characteristic is determined in advance before the transmission path is calculated.

  A demand reliability is acquired (step S11). The number of transmission lines is fixed to a specific value, and the relationship of Formula 1 is obtained (step S12). Here, since the specific value is only an initial value of the process of FIG. 10, it is a value that can be changed depending on whether the process of FIG. 10 is possible (see step S17 described later). Code characteristics are determined from the demand reliability and the number of transmission lines (step S13). That is, n and k are determined based on Equations 1 and 4.

  Next, it is determined whether transmission path candidates to which the determined code can be assigned can be calculated for a fixed number of transmission paths (step S14). That is, when the demand band is r, it is determined whether or not there are D transmission lines to which the r / D band can be allocated. However, in a network that does not need to consider the bandwidth of demand, it is only necessary to determine whether or not there are D transmission paths in step S14 regardless of whether or not the r / D bandwidth can be allocated.

  When the condition of step S14 is satisfied (Yes in step S14), the demand band can be allocated to a plurality of transmission paths using erasure correction codes (step S15), and the code characteristic information and the transmission path information are assigned. Notify the ground for transmission and reception.

  When the condition of step S14 is not satisfied (No in step S14), it is determined whether the number of transmission lines can be increased or the number of transmission lines can be increased (step S16). That is, by increasing D, the band allocated to one transmission path is reduced.

  When the condition of step S16 is satisfied (Yes in step S16), the number of transmission lines is increased or the number of transmission lines is increased (step S17), and the erasure correction code is reconfigured (step S13). If the condition of step S16 is not satisfied (No in step S16), the demand band cannot be allocated to a plurality of transmission lines using erasure correction codes (step S18), and error information is notified to the transmitting side to the ground. To do.

  In the above calculation flow, the demand reliability is fixed, but depending on the transmission system implementation, if it is determined that the assignment is not possible in the calculation flow, the demand reliability is lowered and the process is performed again. Thus, it is possible to design the demand reliability to be variable.

  In the above calculation flow, resource allocation calculation is performed for a single demand. However, in the above calculation flow, a plurality of demands may be collectively executed for resource allocation calculation. At this time, it is possible to prevent the resource allocation for the demand requiring high reliability from being rejected by calculating in order from the demand requiring high reliability.

(Embodiment 2)
The configuration of the transmission system is the same as that of the second embodiment and the prior art as shown in FIG.

  FIG. 11 shows a resource allocation calculation apparatus according to the second embodiment. The resource allocation calculation device 4 according to the second embodiment includes a transmission path calculation unit 41, a code design unit 42, a resource management unit 43, and a reliability calculation unit 44. The transmission path calculation unit 41, the code design unit 42, and the resource management unit 43 are substantially the same in the first and second embodiments. Only the reliability calculation unit 44 is different between the first and second embodiments.

  In the second embodiment, a demand value related to the overall reliability of a plurality of transmission paths calculated based on the reliability of each of the plurality of transmission paths and the number of allowable transmission path failures is used as the demand reliability. The reliability calculation unit 44 calculates an actual reliability to be compared with the reliability of demand.

  The actual reliability calculated by the reliability calculation unit 44 is, for example, MTBF (Mean Time Between Failure), MTTR (Mean Time To Repair), or the failure frequency, which is generally used as an index indicating the reliability of the system. Equivalent to. In the case of a transmission system in which data is divided into a plurality of transmission paths and transmitted, it is necessary to calculate the overall reliability of the plurality of transmission paths based on the reliability of each of the plurality of transmission paths. The method is described in Non-Patent Document 3, for example. When there are a plurality of demand reliability levels, actual reliability levels to be compared with the respective reliability levels are calculated.

  In the second embodiment, unlike the first embodiment, the actual reliability that should be compared with the reliability of demand differs depending on which transmission line is selected. FIG. 12 shows a code characteristic setting method according to the second embodiment. The resource allocation calculation method of Embodiment 2 is shown in FIG.

  A demand reliability is acquired (step S21). A plurality of transmission paths are calculated (step S22). Here, if the reliability of each transmission path is known, the possibility of successful resource allocation can be increased by preferentially selecting the transmission path with higher reliability. Alternatively, a method of preferentially selecting a transmission path with a large remaining bandwidth may be used. Furthermore, a method of preferentially selecting a transmission path in consideration of both the remaining bandwidth and the reliability may be used.

The specific example of FIG. 12 shows the simplest model in which the reliability of each transmission path is uniform. In general, when the reliability of each of the n transmission lines is p and uniform, in the state where a failure is permitted only to k transmission lines or less, that is, the number of allowable transmission line failures is k, n transmission lines The reliability R of all the transmission paths is calculated by the following equation and compared with the demand reliability.

  In the specific example of FIG. 12, the reliability of each transmission path 3-1, 3-2, 3-3 and 3-4 is 0.9 and uniform, and the demand reliability is 0.9. And In addition, when the reliability of each transmission path is different, or when a certain transmission path is realized by a combination of transmission paths having different reliability, the reliability R of all transmission paths is as in Non-Patent Document 3. Calculated.

  First, the allowable transmission line failure number is set to 0 (step S23). The reliability R of all transmission paths is calculated as 0.6561 by substituting k = 0 into Equation 5 (step S24). Since the calculated reliability R is smaller than the demand reliability (No in step S25), the reliability R of all the transmission lines is improved by increasing the number of allowable transmission line failures (step S26).

  When the allowable transmission line failure number can be increased (Yes in step S26), the allowable transmission line failure number is increased (step S27). When the number of allowable transmission line failures cannot be increased (No in step S26), the demand band cannot be allocated to a plurality of transmission lines using the erasure correction code (step S28), and error information is sent to the transmission side. Notify the ground. Here, the number of transmission lines is 4, the number of allowable transmission line failures is 3 or less, and the allowable transmission line failure number can be increased from 0 to 1 (Yes in step S26).

  Next, the allowable transmission path failure number is set to 1 (step S27). The reliability R of all the transmission paths is calculated as 0.9477 by substituting k = 1 into Equation 5 (step S24). Since the calculated reliability R is greater than the demand reliability (Yes in step S25), it is not necessary to increase the number of allowable transmission line failures, and it is not necessary to improve the reliability R of all transmission lines.

  Based on the allowable transmission line failure number 1 and the transmission line number 4, the erasure correction code length can be set to 1 equal to the allowable transmission line failure number, and the code length can be set to 4 equal to the transmission line number. An erasure correction code can be configured (Yes in step S29).

  When the condition of step S29 is satisfied, it is determined whether or not the configured erasure correction code can be assigned to each transmission path (step S30). That is, when the demand band is r, it is determined whether or not the r / 4 band can be allocated to each calculated transmission path. However, step S30 may be omitted in a network where it is not necessary to consider the bandwidth of demand.

  When the conditions of Steps S29 and S30 are satisfied (Yes in Steps S29 and S30), the bandwidth of demand can be allocated to a plurality of transmission lines using erasure correction codes (Step S31). The transmission path information is notified to the transmission / reception ground.

  When the condition of step S29 is not satisfied (No in step S29), it is determined whether or not the number of transmission lines can be increased or transmission lines can be added (step S32). When the condition of step S32 is satisfied (Yes in step S32), the number of transmission lines is increased or the number of transmission lines is increased (step S33), and an erasure correction code is reconfigured (step S23). If the condition in step S32 is not satisfied (No in step S32), the demand band cannot be allocated to a plurality of transmission lines using erasure correction codes (step S34), and error information is notified to the transmitting side to the ground. To do.

  If the condition of step S29 is satisfied (Yes in step S29), but the condition of step S30 is not satisfied (No in step S30), steps S32 to S34 are executed. That is, the same processing as when the condition of step S29 is not satisfied (No in step S29) is executed.

  If the condition of step S29 is not satisfied (No in step S29), and if the condition of step S30 is not satisfied (No in step S30), after removing the transmission line with low reliability, or a different transmission line After re-extracting, the erasure correction code may be reconfigured (step S23).

  In the above calculation flow, the demand reliability is fixed, but depending on the transmission system implementation, if it is determined that the assignment is not possible in the calculation flow, the demand reliability is lowered and the process is performed again. Thus, it is possible to design the demand reliability to be variable.

  In the above calculation flow, resource allocation calculation is performed for a single demand. However, in the above calculation flow, a plurality of demands may be collectively executed for resource allocation calculation. At this time, it is possible to prevent the resource allocation for the demand requiring high reliability from being rejected by calculating in order from the demand requiring high reliability.

(Embodiment 3)
In the first and second embodiments, transmission path selection and code characteristic setting are flexibly performed so that the reliability requested by the client is satisfied. In the third embodiment, the feasible reliability when the transmission path selection and the code characteristic setting requested by the client are applied is calculated.

  First, information on a plurality of transmission paths and information on code length and input data length are acquired. Next, even when a failure occurs in at least one of the plurality of transmission lines when the notified plurality of transmission lines, code length, and input data length are applied, the erasure correction code is used. A reliability that is the degree to which the data can be decoded is calculated. Next, the calculated reliability is notified to the information acquisition destination.

  A method for calculating the reliability corresponding to the reliability in the first embodiment will be described. The reliability in the first embodiment is the ratio of the number of allowable transmission line failures to the number of transmission lines.

  Based on the information on the code length and the input data length, the allowable transmission path failure number can be calculated from Equation 2. Based on the calculation result of the number of allowable transmission line failures and information on a plurality of transmission lines, the realizable reliability can be calculated from Equation 3.

  A method for calculating the reliability corresponding to the reliability in the second embodiment will be described. The reliability in the second embodiment is the overall reliability of the plurality of transmission lines calculated based on the reliability of each of the plurality of transmission lines and the allowable number of transmission line failures.

  Based on the information of the plurality of transmission paths, the reliability of each of the plurality of transmission paths can be read. Based on information on a plurality of transmission paths and information on code length and input data length, the allowable number of transmission path failures can be calculated. The reliability that can be realized can be calculated by substituting the read reliability of each of the plurality of transmission lines and the calculated allowable transmission line failure number into Equation 3.

(Embodiment 4)
First and second specific examples of the transmission system according to the fourth embodiment are shown in FIGS.

  The network N includes a transmission node 1, a reception node 2, and a transmission path 3. In the transmission system shown in FIG. 14, the resource allocation calculation device 4 according to the first to third embodiments is incorporated in a part of the management control device 5 that manages the network N and sets the communication transmission path 3. In the transmission system shown in FIG. 15, the resource allocation calculation device 4 according to the first to third embodiments is operated stand-alone while being separated from the management control device 5 that manages the network N and sets the communication transmission path 3.

  The resource allocation calculation device 4 of the present invention can be realized by a computer and a program, and can be recorded on a recording medium or provided through a network.

  The transmission / reception control apparatus, transmission / reception control method, and transmission / reception control program according to the present invention are not limited to Reed-Solomon erasure correction codes, but include code characteristics (a set of code length n and input data length k) and transmission path characteristics (number of transmission paths D and The present invention can also be implemented by other code systems that can establish the relations of Formulas 1 to 4 between the allowable transmission path failure number F). Furthermore, restrictions may be defined for the minimum number of transmission paths, the maximum number of transmission paths, the minimum reliability, and the maximum reliability.

N: network 1: transmission node 2: reception node 3: transmission path 4: resource allocation calculation device 5: management control device 11: erasure correction encoding unit 12: data distribution unit 21: data combination unit 22: erasure correction decoding unit 41 : Transmission path calculation unit 42: Code design unit 43: Resource management unit 44: Reliability calculation unit

Claims (6)

Even when a failure occurs in at least one of the transmission / reception ground information, the transmission / reception demand band information, and the transmission / reception data distributed among the plurality of transmission paths. A demand information acquisition unit for acquiring information on demand reliability, which is a demand value of reliability indicating the degree of data decoding using a correction code;
A plurality of transmission paths for distributing and transmitting data between the transmission / reception ground and the code length in the erasure correction code so that the transmission / reception ground, demand band and demand reliability notified by the demand information acquisition unit are satisfied And a transmission line code length setting unit for setting the input data length,
A transmission path code length notifying section for notifying the transmission / reception ground of a plurality of transmission paths, code lengths and input data lengths set by the transmission path code length setting section;
Equipped with a,
The reliability is the overall reliability of a plurality of transmission paths calculated based on the reliability of each of the transmission paths and the number of transmission paths allowed to cause a failure. Control device. Information of one or more transmission paths selected by the request source among a plurality of transmission paths for transmitting and receiving data distributed between transmission and reception, and the code length and input data in the erasure correction code set by the request source A setting information acquisition unit for acquiring length information;
At least one transmission among a plurality of transmission paths for distributing and transmitting data between the transmission and reception grounds when one or more transmission paths acquired by the setting information acquisition unit, code length, and input data length are applied A reliability calculation unit that calculates reliability indicating the degree to which data can be decoded using an erasure correction code even when a failure occurs on the road;
A reliability notifying unit that notifies the request source of the reliability calculated by the reliability calculating unit;
Equipped with a,
The reliability is the overall reliability of a plurality of transmission paths calculated based on the reliability of each of the transmission paths and the number of transmission paths allowed to cause a failure. Control device. Even when a failure occurs in at least one of the transmission / reception ground information, the transmission / reception demand band information, and the transmission / reception data distributed among the plurality of transmission paths. A demand information acquisition step for acquiring information on demand reliability, which is a demand value of reliability indicating the degree of data decoding using a correction code;
A plurality of transmission paths for distributing and transmitting data between the transmission and reception ground and the code length in the erasure correction code so that the transmission and reception ground, demand band and demand reliability notified in the demand information acquisition step are satisfied And a transmission line code length setting step for setting the input data length,
A transmission line code length notification step of notifying the transmission / reception ground of a plurality of transmission lines, code lengths and input data lengths set in the transmission line code length setting step;
In order ,
The reliability is an overall reliability of the plurality of transmission lines calculated based on the reliability of each of the plurality of transmission lines and the number of transmission lines allowed to cause a failure. A characteristic transmission / reception control method. Information of one or more transmission paths selected by the request source among a plurality of transmission paths for transmitting and receiving data distributed between transmission and reception, and the code length and input data in the erasure correction code set by the request source A setting information acquisition step for acquiring length information;
At least one transmission among a plurality of transmission paths for distributing and transmitting data between transmission and reception ground when one or more transmission paths, code lengths and input data lengths acquired in the setting information acquisition step are applied A reliability calculation step for calculating a reliability indicating the degree to which data can be decoded using an erasure correction code even when a failure occurs on the road;
A reliability notification step of notifying the request source of the reliability calculated in the reliability calculation step;
In order ,
The reliability is the overall reliability of a plurality of transmission paths calculated based on the reliability of each of the transmission paths and the number of transmission paths allowed to cause a failure. Control method. A transmission / reception control program for causing a computer to sequentially execute the demand information acquisition step, the transmission channel code length setting step, and the transmission channel code length notification step according to claim 3 . A transmission / reception control program for causing a computer to sequentially execute the setting information acquisition step, the reliability calculation step, and the reliability notification step according to claim 4 .

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