A Multi-Fiber Spatial Division Multiplexing Optical Signal Transmission Method and System

Abstract

The present invention relates to the field of optical signal transmission, and in particular to a multi-fiber spatial division multiplexing optical signal transmission method and system. The method includes: constructing a multi-fiber spatial division multiplexing network; predicting the blocking probability of the multi-fiber spatial division multiplexing network. If the obtained prediction result is within a preset threshold range, the node generating the service request is denoted as the source node, and the arriving node is denoted as the destination node. According to the number of spectrum blocks required by the service request, the shortest path between the source node and the destination node is planned; based on the shortest path, the optical signal is modulated by the super-channel multi-fiber transmitting module at the source node, and the modulated optical signal is used to carry the service request, and the optical signal is sent to the next node; it is determined that the current arriving node is the destination node, the optical signal is received and demodulated, and the service information is extracted. The present invention can realize the sharing of the transceiver system for signals transmitted in different fibers while using the same spectrum, saving the cost and power consumption of the transmission system.

Description

Technical Field

[0001] The present invention relates to the field of optical signal transmission, and in particular to a multi-fiber space-division multiplexing optical signal transmission method and system. Background Art

[0002] In recent years, data traffic in network fields such as mobile wireless, fixed access, supercomputers, and data centers has increased exponentially, continuously pushing the limit of the transmission capacity of existing networks based on standard single-mode fiber (SSMF). To address this challenge, space-division multiplexing (SDM) combined with super-channel (SCh) technology has become a potentially research and development solution for enhancing the capacity of optical networks. Super-channel technology is a new technology emerging in recent years, which can form optical channels in the same spectrum of different optical fibers for data transmission. At the same time, SDM can be achieved in various ways, including multi-core fiber space-division multiplexing (MCF-SDM) and multi-fiber space multiplexing (FSDM). MCF-SDM uses multi-core optical fibers, however, there are still problems such as solving crosstalk between cores in this technology. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the problems of insufficient transmission capacity and crosstalk between cores in the optical network in the prior art, and provide a multi-fiber space-division multiplexing optical signal transmission method, which includes the following steps:

[0004] S1: Construct a multi-fiber space-division multiplexing network, the multi-fiber space-division multiplexing network includes multiple nodes, and the nodes are connected by a bidirectional link fiber bundle sharing a laser source and a local oscillator. Each node corresponds to a group of reconfigurable optical add-drop multiplexers and super-channel multi-fiber transceiver modules, and the super-channel multi-fiber transceiver module includes a super-channel multi-fiber transmission module and a super-channel multi-fiber reception module; wherein, the bidirectional link fiber bundle transmits optical signals using the same spectrum through multiple optical fibers;

[0005] S2: Predict the blocking probability of the multi-fiber space-division multiplexing network. If the obtained prediction result is within a preset threshold range, mark the node generating the service request as the source node, and mark the node that the service request needs to reach as the destination node. According to the number of spectrum blocks required by the service request, plan the shortest path between the source node and the destination node in the multi-fiber space-division multiplexing network;

[0006] S3: Based on the shortest path, modulate the optical signal through the super-channel multi-fiber transmission module at the source node, use the modulated optical signal to carry the service request, and the super-channel multi-fiber transmission module sends the optical signal to the next node through the Add port of the reconfigurable optical add-drop multiplexer at the source node;

[0007] S4: Determine that the currently reached node is the destination node, and use the multi-fiber receiving module at the destination node to receive and demodulate the optical signal through the Drop port of the reconfigurable optical add-drop multiplexer at the destination node, and extract the service information.

[0008] In an embodiment of the present invention, the method for obtaining the shortest path is as follows: First, according to the source node and the destination node of the service request, based on the physical length between network node pairs, use the shortest routing algorithm to determine the physical path of the service request; Second, on this physical path, according to the number of spectrum blocks required by the service request, use the available spectrum blocks between multiple node pairs to establish a transmission path, and determine whether there is an available transmission path: If there are multiple available transmission paths, the shortest path can be selected randomly; Otherwise, block the service request; where the available spectrum blocks between node pairs refer to the idle spectrum blocks with the same frequency gap between different fiber groups.

[0009] In an embodiment of the present invention, the calculation method for the number of spectrum blocks n required by the service request is:

[0010]

[0011] where r represents the number of spectrum slots required by the service request; s represents the number of optical fibers in the two-way fiber bundle sharing the laser source and the local oscillator; represents rounding up the non-integer x.

[0012] In an embodiment of the present invention, each two-way fiber bundle has an equal number of optical fibers, and each optical fiber contains the same number of spectrum slots.

[0013] The average blocking probability P In an embodiment of the present invention, the prediction result is the average blocking probability of the multi-fiber space-division multiplexing network. b The calculation method is:

[0014]

[0015] where D represents the set of node pairs for establishing service connections, l sd is the number of hops of the path between the node pair (s, d), s represents the node generating the service request, d represents the node that the service request needs to reach, R is the number of node pairs in the multi-fiber space-division multiplexing network, represents the blocking probability on the l sd hop path, y f represents the number of idle spectrum slots on the l sd hop path.

[0016] In an embodiment of the present invention, the blocking probability sd on the l The calculation method is as follows:

[0017] It is known that there are x ff idle spectrum slots on the previous (l - 1)-hop path, and the joint probability T pf (x (l-1) (x ff , x pf ) of having x f idle spectrum slots on the (l - 1)-hop path is obtained. Based on the recursive process of the probability chain rule, calculate the joint probability T f (n (l) (n f , y f ) of having n

[0018]

[0019] idle spectrum slots on the l-hop path and y f |x pf ) represents the probability of having y pf idle spectrum slots on the current l-hop link when there are x f idle spectrum slots on the (l - 1)-hop link of the path; U(z c |x pf , y f ) represents the probability that there are z pf occupied spectrum slots and the service of occupying one spectrum slot continues from the (l - 1)-hop link to the current l-hop link when there are x f and y c idle spectrum slots on the (l - 1)-hop link and the current l-hop link respectively; R(n f |x ff , y f , z c ) represents the probability of having n ff idle spectrum slots on the two-hop path when there are x f idle spectrum slots on the previous (l - 1)-hop link, y c idle spectrum slots on the l-hop link, and there are z f occupied spectrum slots and the service of occupying one spectrum slot continues from the (l - 1)-hop link to the l-hop link;

[0020] Let n f = 0, then the blocking probability on the l sd -hop path is obtained

[0021]

[0022] In an embodiment of the present invention, there are x on the previous (l - 1)-hop linkff There are y idle spectrum slots on the l-th hop link. f idle spectrum slots, and there are z c When a service occupying one spectrum slot is continued from the (l-1)th hop link to the lth hop link, there are n f The probability R(n f |x ff ,y f ,z c ) is calculated as:

[0023]

[0024] Where FFS represents the maximum number of spectrum slots per link fiber bundle, F LFB Indicates the number of fiber bundles in the link, F B Indicates the number of fibers in each link fiber bundle, FS total Indicates the number of spectrum slots in each optical fiber.

[0025] There are x on the (l-1)th hop link of the path. pf In the case of idle spectrum slots, there are y f The probability S(y f |x pf ) is calculated as:

[0026]

[0027] There are x on the (l-1)th hop link and the current l-hop link of the path. pf and y f In the case of idle spectrum slots, there are z c The probability U(z) that a service occupying one spectrum slot continues from the (l-1)th hop link to the current l-hop link c |x pf ,y f ) is calculated as:

[0028]

[0029] Where FFS represents the maximum number of spectrum slots per link fiber bundle, F LFB Indicates the number of fiber bundles in the link, F B Indicates the number of fibers in each link fiber bundle, FS total Indicates the number of spectrum slots in each optical fiber.

[0030] Based on the same inventive concept, the present invention also provides a multi-fiber spatial division multiplexing optical signal transmission system, which includes the following modules:

[0031] An optical signal transmission network construction module, which is used to construct a multi-fiber spatial division multiplexing network. The multi-fiber spatial division multiplexing network includes multiple nodes, and the nodes are connected by a bidirectional link fiber bundle sharing a laser source and a local oscillator. Each node corresponds to a set of reconfigurable optical add-drop multiplexers and super-channel multi-fiber transceiver modules. The super-channel multi-fiber transceiver module includes a super-channel multi-fiber transmission module and a super-channel multi-fiber reception module. Among them, the bidirectional link fiber bundle transmits optical signals using the same spectrum through multiple optical fibers;

[0032] A path planning module, which is used to predict the blocking probability of the multi-fiber spatial division multiplexing network. If the obtained prediction result is within a preset threshold range, the node that generates the service request is denoted as the source node, and the node that the service request needs to reach is denoted as the destination node. According to the number of spectrum blocks required by the service request, the shortest path between the source node and the destination node for the service request is planned in the multi-fiber spatial division multiplexing network;

[0033] A signal transmission module, which is used to modulate the optical signal based on the shortest path through the super-channel multi-fiber transmission module at the source node, use the modulated optical signal to carry the service request, and the super-channel multi-fiber transmission module sends the optical signal to the next node through the Add port of the reconfigurable optical add-drop multiplexer at the source node;

[0034] A service information extraction module, which is used to determine that the current arrival node is the destination node, use the super-channel multi-fiber reception module at the destination node to receive and demodulate the optical signal through the Drop port of the reconfigurable optical add-drop multiplexer at the destination node, and extract service information.

[0035] The present invention also provides a multi-fiber spatial division multiplexing optical signal transmission device, and the device includes the multi-fiber spatial division multiplexing optical signal transmission system.

[0036] The above technical solutions of the present invention have the following advantages compared with the prior art:

[0037] 1. The multi-fiber spatial division multiplexing network proposed by the present invention can realize the sharing of transceiver systems for signals transmitted in different optical fibers while using the same spectrum, thereby saving the cost and power consumption of the system.

[0038] 2. The present invention can also quickly evaluate the blocking rate of multi-fiber spatial division multiplexing networks of different scales, and has a forward-looking guiding role in the design of multi-fiber spatial division multiplexing networks and the planning of signal transmission routes.

[0039] 3. Compared with the traditional space-division multiplexing network based on multi-core optical fibers, the present invention can avoid the interference of crosstalk between cores and improve the anti-interference ability of transmitted optical signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0041] Figure 1 is a structural diagram of a multi-fiber space-division multiplexing network system under different optical fiber and spectrum combinations. Among them, (a) represents that each optical fiber uses a pair of transceiver systems, (b) represents that two optical fibers share a pair of transceiver systems, and (c) represents that four optical fibers share a pair of transceiver systems;

[0042] Figure 2 is a flowchart of a multi-fiber space-division multiplexing optical signal transmission method provided by an embodiment of the present invention;

[0043] Figure 3 is a flowchart of optical signal transmission in an embodiment of the present invention;

[0044] Figure 4 is a service supply diagram of an optical network constructed based on FSDM in an embodiment of the present invention;

[0045] Figure 5 are two test networks in an embodiment of the present invention. Among them, (a) represents the NSFNET network and (b) represents the COST239 network;

[0046] Figure 6 is the optical path blocking probability under different spectrum block sizes in an embodiment of the present invention. Among them, (a) represents the NSFNET network and (b) represents the COST239 network. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] The following further describes the present invention in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments cited do not limit the present invention.

[0048] Embodiment 1

[0049] The FSDM network system adopts a shared transceiver system, which constructs a super-channel (SCh) with the same spectrum on multiple optical fibers by sharing a laser source and a local oscillator. In the figure, LS represents the laser source, DSP represents the digital signal processor, DAC represents the digital-to-analog converter, ADC represents the analog-to-digital converter, MOD represents the signal modulator, and DMOD represents the signal demodulator. As Figure 1 shows an example of an FSDM network based on four optical fibers, presenting Figure 1The following three cases of (a) to (c):

[0050] Figure 1 (a) shows the case where each optical fiber is assigned a laser source and a local oscillator. Using the spectra of four spectral slots in the same optical fiber, this requires four laser sources and local oscillators. Here, FS is the granularity of the spectrum. For example, for a superchannel, its size can be 50 GHz. This configuration is essentially similar to the traditional multi - fiber setup. Figure 1 (b) shows the case where every two optical fibers share a laser source and a local oscillator. In this configuration, the SCh utilizes the spectra of two FSs in each of the two optical fibers, and only two laser sources and local oscillators are required, which is two less than the first configuration. Figure 1 (c) shows the case where four optical fibers share a laser source and a local oscillator. In this setup, the SCh utilizes the spectrum of one FS in each optical fiber, and thus requires the fewest laser sources and local oscillators among these three cases.

[0051] Referring to Figures 2 - 3 As shown, a multi - fiber space - division multiplexing optical signal transmission method provided in this embodiment includes the following steps:

[0052] S1: Construct a multi - fiber space - division multiplexing network. The multi - fiber space - division multiplexing network includes multiple nodes, and the nodes are connected by a bidirectional link fiber bundle sharing a laser source and a local oscillator. Each node corresponds to a group of reconfigurable optical add - drop multiplexers and superchannel multi - fiber transceiver modules. The superchannel multi - fiber transceiver module includes a superchannel multi - fiber transmitting module and a superchannel multi - fiber receiving module; wherein, the bidirectional link fiber bundle transmits optical signals using the same spectrum through multiple optical fibers;

[0053] S2: Predict the blocking probability of the multi - fiber space - division multiplexing network. If the obtained prediction result is within a preset threshold range, mark the node that generates a service request as the source node, and mark the node that the service request needs to reach as the destination node. According to the number of spectral blocks required for the service request, plan the shortest path between the source node and the destination node in the multi - fiber space - division multiplexing network;

[0054] S3: Based on the shortest path, modulate the optical signal through the superchannel multi - fiber transmitting module at the source node, use the modulated optical signal to carry the service request, and the superchannel multi - fiber transmitting module sends the optical signal to the next node through the Add port of the reconfigurable optical add - drop multiplexer at the source node;

[0055] S4: Determine that the currently reached node is the destination node, and use the hyper-channel multi-fiber receiving module at the destination node to receive and demodulate the optical signal through the Drop port of the reconfigurable optical add-drop multiplexer at the destination node, and extract the service information.

[0056] In an embodiment of the present invention, the method for obtaining the shortest path is as follows: First, according to the source node and the destination node of the service request, based on the physical length between network node pairs, use the shortest routing algorithm to determine the physical path of the service request; Second, on this physical path, according to the number of spectrum blocks required by the service request, use the available spectrum blocks between multiple node pairs to establish a transmission path, and determine whether there is an available transmission path: If there are multiple available transmission paths, the shortest path can be selected randomly; Otherwise, block the service request; where the available spectrum blocks between node pairs refer to the idle spectrum blocks with the same frequency gap between different fiber groups.

[0057] In an embodiment of the present invention, the calculation method for the number of spectrum blocks n required by the service request is:

[0058]

[0059] where r represents the number of spectrum slots required by the service request; s represents the number of fibers in the two-way fiber bundle sharing the laser source and the local oscillator; represents rounding up the non-integer x.

[0060] In an embodiment of the present invention, each two-way fiber bundle has an equal number of fibers, and each fiber contains the same number of spectrum slots.

[0061] In an embodiment of the present invention, the prediction result is the average blocking probability of the multi-fiber space division multiplexing network, and the average blocking probability P b is calculated as follows:

[0062]

[0063] where D represents the set of node pairs for establishing service connections, l sd is the number of hops of the path between node pair (s, d), s represents the node generating the service request, d represents the node that the service request needs to reach, R is the number of node pairs in the multi-fiber space division multiplexing network, represents the blocking probability on the l sd hop path, y f represents the number of idle spectrum slots on the l sd hop path.

[0064] In an embodiment of the present invention, the blocking probability sd on the l The calculation method is as follows:

[0065] It is known that there are x ff idle spectrum slots on the previous (l - 1)-hop path, and the joint probability T pf (x (l-1) (x ff , x pf ) of having x f idle spectrum slots on the (l - 1)-hop path is obtained. Based on the recursive process of the probability chain rule, calculate the joint probability T f (n (l) (n f , y f ) of having n

[0066]

[0067] idle spectrum slots on the l-hop path and y f idle spectrum slots on the l-th hop path: pf where S(y pf |x f ) represents the probability of having y c idle spectrum slots on the current l-th hop link when there are x pf idle spectrum slots on the (l - 1)-th hop link of the path; U(z f |x pf , y f ) represents the probability that there are z c services occupying one spectrum slot continue from the (l - 1)-th hop link to the current l-th hop link when there are x f and y ff idle spectrum slots on the (l - 1)-th hop link and the current l-th hop link of the path respectively; R(n f |x c , y ff , z f ) represents the probability of having n c idle spectrum slots on the two-hop path when there are x f idle spectrum slots on the previous (l - 1)-th hop link, y

[0068] Let n f = 0, then the blocking probability on the l sd -hop path is obtained

[0069]

[0070] where the previous (l - 1)-th hop link has x ffThere are y idle spectrum slots on the l-th hop link. f idle spectrum slots, and there are z c When a service occupying one spectrum slot is continued from the (l-1)th hop link to the lth hop link, there are n f The probability R(n f |x ff ,y f ,z c ) is calculated as:

[0071]

[0072] Where FFS represents the maximum number of spectrum slots per link fiber bundle, F LFB Indicates the number of fiber bundles in the link, F B Indicates the number of fibers in each link fiber bundle, FS total Indicates the number of spectrum slots in each optical fiber.

[0073] There are x on the (l-1)th hop link of the path. pf In the case of idle spectrum slots, there are y f The probability S(y f |x pf ) is calculated as:

[0074]

[0075] There are x on the (l-1)th hop link and the current l-hop link of the path. pf and y f In the case of idle spectrum slots, there are z c The probability U(z) that a service occupying one spectrum slot continues from the (l-1)th hop link to the current l-hop link c |x pf ,y f ) is calculated as:

[0076]

[0077] Where FFS represents the maximum number of spectrum slots per link fiber bundle, F LFB Indicates the number of fiber bundles in the link, F B Indicates the number of fibers in each link fiber bundle, FS total Indicates the number of spectrum slots in each optical fiber.

[0078] use Figure 4The example in Figure 4 Figure (a) shows the topology of a network, which consists of 6 nodes and 9 links. Each link has a total of four optical fibers, and two of the optical fibers share a laser source and a local oscillator, that is, s = 2.

[0079] Suppose service r1 requires 3 frequency slots (FSs), that is, r1 = 3, and the route 0-1-2 is selected to provide this service. It is necessary to determine the link fiber bundles (LFBs) and frequency slots (FSs) applicable to this service, as shown in Figure 4 Figure (b). There are two link fiber bundles (LFBs) on each link, namely the fiber pairs (1, 2) and (3, 4). In each LFB, a qualified FSB suitable for accommodating this service needs to be determined according to the FS usage in each optical fiber. Specifically, on the link (0-1), the qualified LFB is LFB1, and the first qualified FSB in it contains FS6 and 7. Similarly, on the link (1-2), the qualified LFB is LFB2, and its first qualified FSB also contains FS6 and FS7. To establish an optical path, due to the constraint of spectral continuity, the used FSBs must be consistent on all links, although the indexes of the LFBs on the links along the route do not have to be the same. All the LFBs selected on the route are called the route fiber bundle (RFB), as shown in Figure 4 Figure (b). An RFB consists of consecutive LFBs selected along the route.

[0080] The network simulation results are compared with the analysis model to verify the accuracy of the calculations of the analysis model. Two test networks are considered, as shown in Figure 5 Figure: (a) The NSFNET network with 14 nodes and 21 links and (b) the COST239 network with 11 nodes and 26 links. Among them, Figure 5 The numbers on the links represent the actual physical path lengths between node pairs. In the simulation, it is assumed that service requests arrive according to a Poisson distribution, and the service duration follows a negative exponential distribution. Each service is established along the fixed shortest physical path between each pair of nodes, and this physical path is determined using the Dijkstra algorithm. If there are not enough spectral resources to establish a service connection, the service request is blocked. Otherwise, to allocate spectral resources for each service connection, a random FSB is selected when there are multiple FSBs available on the path, and a random LFB is selected when there are multiple LFBs available on the link. All resources will be released when each service expires. A total of 10 6 optical path service requests are simulated. The blocking probability is calculated by dividing the total number of blocked service requests by the total number of arrived service requests.

[0081] The accuracy of the analytical model in predicting the optical path blocking probability of an FSDM-based optical network was evaluated. Figure 6 The optical path blocking probabilities of the NSFNET network and the COST239 network are shown under different traffic loads and different LFB sizes. In Figure 6 (a), the results of the NSFNET network are presented, where each link has 6 pairs of optical fibers (i.e., F = 6), and there are 30 Fs in each optical fiber. The sizes of the LFB are set to 1, 2, 3, and 6. The load of each node is evenly distributed among different nodes in the network. The traffic load range of each node is from 8 to 14 Erlangs, and the bandwidth requirement for each service is 7 Fs. It should be noted that this number of Fs was selected to consider the worst-case scenario of the FSDM optical network because when using the largest LFB (i.e., s = 6), it results in the largest capacity waste. Specifically, when s = 6, an FSB with a size of 6 × 2 Fs is set up to accommodate the service. This results in a waste of 5 Fs for each FSB, seriously degrading the blocking performance of the FSDM-based optical network, although it requires the fewest laser sources and local oscillators. With this configuration, it is aimed to evaluate whether it is worth adopting FSDM in the worst network scenario. It should be noted that the results of the analytical model effectively predict the simulation results under different LFB sizes, thus verifying the accuracy of the analytical model in estimating the optical path blocking probability of the FSDM-based optical network. In Figure 6 (b), the results of COST239 are shown, with 8 pairs of optical fibers on each link and 36 Fs in each optical fiber. The sizes of the spectral block LFB are set to 1, 2, 4, and 8, the traffic load range of each node is from 22 to 34 Erlangs, and the bandwidth requirement for each service is 9 Fs. Similarly, the analysis results are very close to the simulation results, confirming the accuracy of the analytical model.

[0082] Embodiment 2

[0083] Based on the same inventive concept as the multi-fiber spatial division multiplexing optical signal transmission method provided in Embodiment 1, the present invention also provides a multi-fiber spatial division multiplexing optical signal transmission system, which includes the following modules:

[0084] An optical signal transmission network construction module, configured to construct a multi-fiber spatial division multiplexing network, where the multi-fiber spatial division multiplexing network includes multiple nodes, and the nodes are connected by a bidirectional link optical fiber bundle sharing a laser source and a local oscillator. Each node corresponds to a set of reconfigurable optical add-drop multiplexers and super-channel multi-fiber transceiver modules, and the super-channel multi-fiber transceiver module includes a super-channel multi-fiber transmission module and a super-channel multi-fiber reception module; wherein, the bidirectional link optical fiber bundle transmits optical signals using the same spectrum through multiple optical fibers;

[0085] A path planning module is used to predict the blocking probability of the multi-fiber space-division multiplexing network. If the obtained prediction result is within a preset threshold range, the node that generates a service request is denoted as the source node, and the node that the service request needs to reach is denoted as the destination node. According to the number of spectrum blocks required by the service request, the shortest path between the source node and the destination node for the service request is planned in the multi-fiber space-division multiplexing network;

[0086] A signal transmission module is used to modulate an optical signal through a super-channel multi-fiber transmitting module at the source node based on the shortest path, use the modulated optical signal to carry the service request, and the super-channel multi-fiber transmitting module sends the optical signal to the next node through the Add port of the reconfigurable optical add-drop multiplexer at the source node;

[0087] A service information extraction module is used to determine that the current arrival node is the destination node, use the super-channel multi-fiber receiving module at the destination node to receive and demodulate the optical signal through the Drop port of the reconfigurable optical add-drop multiplexer at the destination node, and extract service information.

[0088] Embodiment III

[0089] The present invention also provides a multi-fiber space-division multiplexing optical signal transmission device, and the device includes the multi-fiber space-division multiplexing optical signal transmission system provided in Embodiment II.

[0090] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A multi-fiber spatial division multiplexing optical signal transmission method, characterized in that Including the following steps: S1: Construct a multi-fiber spatial division multiplexing network. The multi-fiber spatial division multiplexing network includes multiple nodes, and the nodes are connected by a bidirectional link fiber bundle that shares a laser source and a local oscillator. Each node corresponds to a group of reconfigurable optical add-drop multiplexers and a super-channel multi-fiber transceiver module. The super-channel multi-fiber transceiver module includes a super-channel multi-fiber transmitting module and a super-channel multi-fiber receiving module. Among them, the bidirectional link fiber bundle transmits optical signals using the same spectrum through multiple fibers; S2: Predict the blocking probability of the multi-fiber spatial division multiplexing network. If the obtained prediction result is within the preset threshold range, mark the node that generates the service request as the source node, and mark the node that the service request needs to reach as the destination node. According to the number of spectrum blocks required by the service request, plan the shortest path between the source node and the destination node in the multi-fiber spatial division multiplexing network; S3: Based on the shortest path, modulate the optical signal through the super-channel multi-fiber transmitting module at the source node, use the modulated optical signal to carry the service request, and the super-channel multi-fiber transmitting module sends the optical signal to the next node through the Add port of the reconfigurable optical add-drop multiplexer at the source node; S4: Determine that the current arrival node is the destination node, and use the super-channel multi-fiber receiving module at the destination node to receive and demodulate the optical signal through the Drop port of the reconfigurable optical add-drop multiplexer at the destination node, and extract the service information.

2. The multi-fiber space division multiplexing optical signal transmission method according to claim 1, characterized in that: The method for obtaining the shortest path is as follows: First, based on the source node and the destination node of the service request, and based on the physical length between network node pairs, use the shortest routing algorithm to determine the physical path of the service request. Second, on this physical path, according to the number of spectrum blocks required by the service request, use the available spectrum blocks between multiple node pairs to establish a transmission path, and determine whether there is an available transmission path: If there are multiple available transmission paths, the shortest path can be randomly selected; otherwise, block the service request. Among them, the available spectrum blocks between node pairs refer to the idle spectrum blocks with the same frequency gap between different fiber groups.

3. The multi-fiber spatial division multiplexing optical signal transmission method according to any one of claims 1 to 2, characterized in that: The calculation method for the number of spectrum blocks n required by the service request is: where r represents the number of spectrum slots required for a service request; s represents the number of optical fibers in a bidirectional link optical fiber bundle that shares a laser source and a local oscillator; represents rounding up the non-integer x.

4. The multi-fiber spatial division multiplexing optical signal transmission method according to claim 1, wherein: Each bidirectional link fiber bundle has an equal number of fibers, and each fiber contains the same number of spectrum slots.

5. The multi-fiber space division multiplexing optical signal transmission method according to claim 1, characterized in that: The predicted result is the average blocking probability of the multi-fiber space-division multiplexing network, and the calculation method of the average blocking probability P b is as follows: Among them, D represents the set of node pairs that establish service connections, and l sd is the number of hops of the path between the node pair (s, d), s represents the node that generates the service request, d represents the node that the service request needs to reach, R is the number of node pairs in the multi-fiber space-division multiplexing network, represents l sd the blocking probability on the hop path, and y f represents the number of idle spectrum slots on the l sd hop path.

6. The multi-fiber spatial division multiplexing optical signal transmission method according to claim 5, characterized in that: The said l sd Blocking probability on the hopping path The calculation method is as follows: It is known that there are x free spectrum slots on the previous (l - 1)-hop path, and the joint probability T ff (x pf , x (l-1) ) of having x free spectrum slots on the (l - 1)-hop path is obtained. Based on the recursive process of the probability chain rule, calculate the joint probability T ff (n pf , y f ) of having n free spectrum slots on the l-hop path and y free spectrum slots on the l-th hop path: f T (l) (n f , y f ) = Among them, S(y f |x pf ) represents the probability that there are y pf idle spectrum slots on the current l-hop link when there are x f idle spectrum slots on the (l - 1)-th hop link of the path; U(z c |x pf ,y f ) represents the probability that there are z pf services occupying one spectrum slot continue from the (l - 1)-th hop link to the current l-hop link when there are x f and y c idle spectrum slots on the (l - 1)-th hop link and the current l-hop link of the path respectively; R(n f |x ff ,y f ,z c ) represents the probability that there are n ff idle spectrum slots on the two-hop path when there are x f idle spectrum slots on the l-th hop link, y c idle spectrum slots on the previous (l - 1)-th hop link, and z f services occupying one spectrum slot continue from the (l - 1)-th hop link to the l-th hop link; Let n f = 0, then l is obtained sd Blocking probability on the jump path 7. The multi-fiber spatial division multiplexing optical signal transmission method according to claim 6, characterized in that: There are x ff idle spectrum slots on the previous (l - 1)-hop link, y f idle spectrum slots on the l-hop link, and when there are z c services occupying one spectrum slot continuing from the (l - 1)-hop link to the l-hop link, the probability R(n f |x f , y ff , z f ) of having n c idle spectrum slots on the two-hop path is calculated by the formula: Among them, FFS represents the maximum number of spectrum slots of each link fiber bundle, F LFB represents the number of link optical fiber bundles, F B represents the number of optical fibers in each link optical fiber bundle, FS total represents the number of spectral slots in each optical fiber.

8. The multi-fiber space division multiplexing optical signal transmission method according to claim 6, characterized in that: When there are x pf idle spectrum slots on the (l - 1)-th hop link of the path, the probability S(y f ) that there are y f idle spectrum slots on the current l-th hop link is calculated by the formula: pf ) is given by: There are x and y free spectrum slots on the (l - 1)-th hop link and the current l-th hop link of the path respectively. In this case, the probability U(z | x, y) that z services occupying one spectrum slot continue from the (l - 1)-th hop link to the current l-th hop link is calculated by the following formula: pf and y f respectively, the probability U(z c | x c , y pf , y f ) that z services occupying one spectrum slot continue from the (l - 1)-th hop link to the current l-th hop link is calculated by the following formula: Among them, FFS represents the maximum number of spectral slots of each link optical fiber bundle, F LFB represents the number of link optical fiber bundles, F B represents the number of optical fibers in each link optical fiber bundle, FS total represents the number of spectral slots in each optical fiber.

9. A multi-fiber spatial division multiplexing optical signal transmission system, characterized in that, Including the following modules: An optical signal transmission network construction module, used to construct a multi-fiber spatial division multiplexing network. The multi-fiber spatial division multiplexing network includes multiple nodes, and the nodes are connected by a bidirectional link fiber bundle that shares a laser source and a local oscillator. Each node corresponds to a group of reconfigurable optical add-drop multiplexers and a super-channel multi-fiber transceiver module. The super-channel multi-fiber transceiver module includes a super-channel multi-fiber transmitting module and a super-channel multi-fiber receiving module. Among them, the bidirectional link fiber bundle transmits optical signals using the same spectrum through multiple fibers; A path planning module is used to predict the blocking probability of the multi-fiber spatial division multiplexing network. If the obtained prediction result is within a preset threshold range, the node that generates a service request is denoted as the source node, and the node that the service request needs to reach is denoted as the destination node. According to the number of spectrum blocks required by the service request, the shortest path between the source node and the destination node is planned in the multi-fiber spatial division multiplexing network; A signal transmission module is used to modulate an optical signal based on the shortest path through a super-channel multi-fiber transmitting module at the source node, use the modulated optical signal to carry the service request, and the super-channel multi-fiber transmitting module sends the optical signal to the next node through the Add port of the reconfigurable optical add-drop multiplexer at the source node; A service information extraction module is used to determine that the current arrival node is the destination node, use a super-channel multi-fiber receiving module at the destination node to receive and demodulate the optical signal through the Drop port of the reconfigurable optical add-drop multiplexer at the destination node, and extract service information.

10. A multi-fiber space division multiplexing optical signal transmission device, characterized in that, It includes the multi-fiber spatial division multiplexing optical signal transmission system as described in claim 9.

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