CN1625091A - Device, system and method for raising availability of photo-communication wavelength - Google Patents

Abstract

The invention relates to a dense wavelength division multiplexing system, and discloses a device, system and method for improving the wavelength utilization rate of optical communication, so that the wavelength utilization rate of multiple nodes in the dense wavelength division multiplexing system can be improved when communicating with each other. improved signal quality and reduced OTU count. This multi-point optical communication network includes at least 3 optical add-drop multiplexing nodes connected in series; the optical add-drop multiplexing node is used to access the business from the previous node, and drop the business destined for this node , mix the services not destined for this node with the services newly accessed from this node and transmit them to the next node.

Description

Device, system and method for improving optical communication wavelength utilization

technical field

The invention relates to a dense wavelength division multiplexing system, in particular to an optical sending unit capable of improving wavelength utilization in the dense wavelength division multiplexing system and a system formed by using the optical sending unit.

Background technique

Dense Wave Division Multiplexing (DWDM for short) transmits multiple wavelengths with relatively close wavelengths in one optical fiber, thereby improving the utilization rate of a single optical fiber and greatly expanding the bandwidth of the original optical fiber communication. Usually, the channel spacing of DWDM is less than 1nm. Most of the DWDMs commonly used in optical communication networks are divided into 32 or more wavelengths in the 1530nm-1565nm band. Common DWDM systems are all end-to-end communications, as shown in Figure 1. Generally, the wavelength of the signal received from the client-side equipment does not conform to the standard wavelength of the DWDM system, so wavelength conversion is required, and the Optical Transponder Unit ("OTU" for short) completes the function of wavelength conversion. The OTU converts non-standard wavelengths into standard wavelengths for switching and transmission throughout the network, and performs regeneration functions in the event of optical signal degradation. All the optical signals to be sent at the transmitting end A are combined and sent by the multiplexer, and the optical signals are amplified by the optical amplifier ("OA" for short) in the intermediate transmission path and then received by the receiving end B. The optical signal is demultiplexed to the corresponding OTU through the demultiplexer. This communication mode is equivalent to providing multiple virtual channels for the communication between A and B, so as to achieve the purpose of expanding the bandwidth of the communication system.

End-to-end DWDM networking only solves the communication bandwidth between two nodes, but in practical applications, two nodes often need to communicate with each other. For example, the logical connection diagram of three nodes communicating with each other is shown in Figure 2. The existing technology usually uses Optical Add Drop Multiplexer ("OADM" for short) to form a chain or ring network, so as to take advantage of the benefits brought by DWDM technology and solve the bandwidth problem between multipoint communications. OADM can be used to insert or remove individual wavelength channels at an intermediate node of an optical transmission network. At present, most manufacturers have developed fixed OADMs, which must be set in advance for the wavelength channel to be inserted or taken out. There is another kind of OADM called arbitrarily settable, which can be set by an external command for the wavelength channel to be inserted or taken out. Channels can be assigned arbitrarily. The most commonly used OADM structure is a back-to-back connection structure. The optical signal containing multiple channels is divided into various wavelength branches through an optical demultiplexer, and then passes through an optical cross matrix. In this structure, due to the introduction of optical multiplexing and demultiplexing, the loss is large, and sometimes an external optical amplifier must be used to compensate, otherwise a through signal will be severely degraded after several times of loading and unloading. The schematic diagram of the existing OADM service connection is shown in Figure 3. The chain network composed of OADM is shown in Figure 4, and the ring network is shown in Figure 5. Among them, a pair of OTUs are required between two nodes communicating with each other to be responsible for generating and receiving optical signals of a certain wavelength to establish a connection between the two nodes. If any two nodes of n nodes are connected, the required number of OTUs is n*(n-1).

Although the two-to-two communication problem between multiple points can be solved through OADM chain or ring networking, and now many system equipment suppliers can provide OTUs that can access multiple services at the same time to meet the existing problems between two points. Multi-rate services without additional aggregation equipment. But in any case, in the current DWDM networking mode, the services carried by each wavelength channel are end-to-end, that is, all the services accessed by each OTU are added to one node and dropped to another node. Regardless of the maximum bandwidth that the wavelength channel can carry and the actual communication requirements between the two points, as long as a connection needs to be established between the two points, the wavelength needs to be allocated.

In practical applications, the communication bandwidth requirements between different points are often not evenly distributed. As shown in Figure 4 or Figure 5, multiple nodes communicate with each other. Taking nodes A, B, and C as examples for discussion, a communication bandwidth of 10G is required between node A and node B, and 2.5G between node B and node C is required. The communication bandwidth of G, even between node A and node C only needs 155M communication bandwidth, but in the current OADM networking mode, between node A and node B, between node A and node C, between node B and node C Each is assigned a wavelength. This wavelength allocation and utilization method often does not fully utilize the bandwidth that each wavelength channel can carry, making the wavelength utilization efficiency of the entire system relatively low.

The solution to this problem in the prior art is usually by setting some data cross-connect (Data Cross Connect, referred to as "DXC") equipment, add drop multiplexer (Add DropMultiplexer, referred to as "ADM") equipment or other similar equipment at each site , to integrate services between some different points and then transmit them. Still taking the above-mentioned communication among the three nodes A, B, and C as an example for illustration, the communication between node A and node C may not directly allocate wavelengths between node A and node C, but node A adds a converging The device mixes the traffic from node A to node C and the traffic from node A to node B and transmits it to node B. The DXC, ADM or other equipment set up at the node B site will first transfer the traffic from node A to node B and from node A to node B. The service of C is separated, the service from node A to node B is directly dropped to the local, and then the service from node A to node C is directly merged with the service from node B to node C, and then the wavelength from node B to node C is used for transmission. send. Although this method can improve wavelength utilization efficiency, some additional equipment needs to be added at nodes A, B, and C, which will increase investment and construction costs. Secondly, compared to the current DXC, ADM and other equipment, the communication bandwidth between nodes A, B, and C is a large-grained business scheduling, which will occupy the precious cross-resources of DXC and ADM and reduce the operating efficiency of the system. Therefore, it is not widely used at present.

In practical application, the above scheme has the following problems: the wavelength utilization rate of communication between multiple points in the existing DWDM system is low, and the bandwidth that each wavelength can carry is not fully utilized, especially when low-speed connections occupy a relatively large proportion When , the wavelength utilization efficiency of the whole system is relatively low; OADM has a large loss of optical signals, and the signal transmission quality needs to be improved; and the usage of OTU is large, and the system cost is high.

The main reason for this situation is that in the existing DWDM system, no matter how much end-to-end business bandwidth is required, and no matter how much communication bandwidth each wavelength is, the business carried by each wavelength is end-to-end, so it cannot Make full use of the bandwidth of each wavelength; the usual OADM has a relatively large loss of optical signals, resulting in a decrease in signal transmission quality; each end-to-end communication requires a pair of OTUs. When the number of nodes communicating in pairs increases, the required OTU increases with the square law of the number of nodes, so the OTU usage of multi-node pairwise communication is relatively large.

Contents of the invention

The technical problem to be solved by the present invention is to provide a device, system and method for improving the wavelength utilization rate of optical communication, so that the wavelength utilization rate of multiple nodes in the dense wavelength division multiplexing system can be improved when they communicate with each other. The signal quality is improved and the number of OTUs is reduced.

In order to solve the above technical problems, the present invention provides an optical sending unit in a dense wavelength division multiplexing system, including first and second photoelectric conversion modules, a scheduling unit, first and second electro-optical conversion modules, first and second Two adaptation unit modules; where

The first and second photoelectric conversion modules are respectively used to convert optical signals from the line side and local add-on into electrical signals;

The scheduling unit is used to output the signals from the first photoelectric conversion module that need to be dropped locally to the first adaptation unit, and combine the signals from the second adaptation unit module with the signals from the second adaptation unit module. The signals of the first photoelectric conversion module that are not dropped locally are combined and then output to the second electro-optical conversion module;

The first and second adaptation unit modules are respectively used to perform encapsulation and decapsulation adaptation on signals from the scheduling unit and the second photoelectric conversion module;

The first and second electrical-to-optical conversion modules are respectively used to convert electrical signals from the first adaptation unit module and the dispatching unit into optical signals, and output them to the local side and the line side respectively.

Wherein, the scheduling unit includes a switching unit module;

The switching unit module is used for buffering the signal from the first photoelectric conversion module, and selects to output the signal to the local first adaptation unit or to communicate with the signal from the second adaptation unit according to the destination address of the buffered signal. The signals of the unit modules are combined and output to the second electro-optical conversion module.

Alternatively, the scheduling unit includes a multiplexer module and a demultiplexer module;

The demultiplexer module is used to demultiplex the single signal from the first photoelectric conversion module into parallel signals on multiple signal channels, wherein some signal channels are connected to the first adaptation unit for For transmitting signals that need to be dropped locally, other signal channels are connected to the multiplexer module for transmitting signals that do not need to be dropped locally;

The multiplexer module is used to combine multiple parallel signals from the demultiplexer module and the second adaptation unit into one, and output it to the second electro-optic conversion module.

Alternatively, the scheduling unit includes a multiplexer module, a demultiplexer module and a switching unit module;

The demultiplexer module is used to demultiplex the electrical signal from the first photoelectric conversion module into multiple parallel signals;

The multiplexer module is used to combine multiple parallel signals from the switching unit module into one;

The switching unit module is used to output the signal from the demultiplexer module that needs to be dropped locally to the first adaptation unit, and combine the signal from the second adaptation unit module with the signal from the The signals of the demultiplexer module that are not dropped locally are combined and output to the multiplexer module.

The present invention also provides an optical add-drop multiplexing node in a dense wavelength division multiplexing system, comprising: a first wave splitter, a first wave combiner, and a first optical sending unit;

The first wave splitter is used to separate the received multi-wavelength channels;

The first multiplexer is used to multiplex and send the input multi-wavelength channels;

The first optical sending unit is used to receive the signal on the line side from an output port of the first demultiplexer for identification processing and demultiplexing, and to drop the signal destined for this node and output it from the client side port , mixing the signal whose destination is not the local node with the client service signal accessed by the client port, and outputting to an input port of the first multiplexer after completing the wavelength conversion;

The first demultiplexer is not connected to the output port of the first optical sending unit and the input port of the first multiplexer.

Wherein, it also includes a second wave splitter, a second wave combiner, and the first and second traditional first optical sending units;

The traditional first optical sending unit is used to complete the wavelength conversion function;

The line-side input end of the first conventional first optical transmission unit is connected to an output port of the first wave splitter, and the line-side output end is connected to an input port of the second wave combiner; the first 2. The line-side input end of the traditional first optical transmission unit is connected to an output port of the second wave splitter, and the line-side output end is connected to an input port of the first wave combiner;

The second demultiplexer is not connected to the output port of the traditional first optical sending unit and the input port of the second multiplexer.

In addition, it also includes a second wave splitter, a second wave combiner and a second optical sending unit;

The second optical sending unit is used to receive the signal on the line side from an output port of the second demultiplexer for identification processing and demultiplexing, and to drop the signal destined for this node and output it from the client side port , mixing the signal whose destination is not the local node with the client service signal accessed by the client side port, and outputting to an input port of the second multiplexer after completing the wavelength conversion;

The client-side port of the first optical transmission unit is connected to the client-side port of the second optical transmission unit through a logic circuit;

The second demultiplexer is not connected to the output port of the second optical sending unit and the input port of the second multiplexer.

The present invention also provides a multi-point optical communication network in a dense wavelength division multiplexing system, comprising at least three optical add-drop multiplexing nodes serially connected in sequence;

The node is used to access services from the previous node, drop services destined for the node, and mix services not destined for the node with services newly accessed from the node and send them to the next node. one of said nodes.

Wherein, the optical add-drop multiplexing nodes are connected in a ring or a chain.

The present invention also provides a method for processing an optical interface in a dense wavelength division multiplexing system, comprising the following steps:

Receive traffic from the previous node on the line side;

Drop off the local business;

Mix the services whose destination is not local and the services newly accessed from the local, perform wavelength conversion and transmit to the next node through the line side.

By comparison, it can be found that the difference between the technical solution of the present invention and the prior art is that the present invention changes the service connection originally created on the OADM into a service connection on the OTU client side, and connects the same node to a plurality of different nodes. Inter-communication services are aggregated into the same OTU, and the functions of service access and wavelength conversion are completed at the same time, and the OTU units of multiple different nodes are connected in series to form a ring to realize the two-to-two communication of multiple nodes in the DWDM system. , and the OTU of the intermediate node is equivalent to a relay to the node signal that is not directly connected with it.

The difference in this technical solution has brought obvious beneficial effects. First of all, by adopting the system for improving the wavelength utilization rate in the dense wavelength division multiplexing system proposed by the present invention, the wavelength utilization efficiency of the system can be effectively improved, especially when low-speed connections occupy a relatively large proportion; secondly, using this The system can reduce the number of OTUs in n pairs of connected nodes from n*(n-1) to n, thereby greatly reducing the number of OTU modules in the system and reducing system costs; thirdly, when all nodes connected in series In the case that the connection between the two is not complete, the OTU pair of the intermediate node does not have a direct connection with it, which is equivalent to a relay. The regeneration of the optical signal can effectively reduce the optical signal in the middle of the long-distance transmission. degradation problem, thereby improving the system optical signal quality.

Description of drawings

Fig. 1 is a schematic diagram of an end-to-end DWDM communication system;

Fig. 2 is a logical connection schematic diagram of three nodes communicating with each other;

FIG. 3 is a schematic diagram of existing OADM service connections;

FIG. 4 is a schematic diagram of an existing chain network formed by utilizing OADM;

Fig. 5 is the existing ring network schematic diagram that utilizes OADM to form;

Fig. 6 is a schematic diagram of an OTU module that simultaneously completes service add/drop and wavelength conversion functions according to a preferred embodiment of the present invention;

Fig. 7 is a schematic diagram of the internal composition of an OTU module that simultaneously completes service add/drop and wavelength conversion functions according to a preferred embodiment of the present invention;

Fig. 8 is a schematic diagram of the internal connection of the unidirectional transmission OADM of a preferred embodiment of the present invention;

Fig. 9 is the traditional OTU of a preferred embodiment of the present invention and the OADM internal connection diagram that the OTU that the present invention proposes mixes and forms;

Fig. 10 is a bidirectional OADM internal connection schematic diagram formed with the OTU proposed by the present invention;

Fig. 11 is a schematic diagram of a logical connection of a system for improving wavelength utilization in a dense wavelength division multiplexing system according to a preferred embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

In the present invention, the communication services from the same node to multiple different nodes are converged into the same OTU unit, and the functions of service access and wavelength conversion are completed at the same time, and the OTU units of multiple different nodes are connected through serial optical ports The ring formation can effectively avoid the reduction of the wavelength utilization rate of the system caused by the low-rate service connections between multiple nodes. In essence, the present invention changes the service connection originally created on the OADM to the service connection on the client side of the OTU unit, thereby eliminating the need to allocate wavelength connections for low-rate services, saving wavelengths and improving wavelength utilization efficiency.

The scheme will be described below in conjunction with a preferred embodiment of the scheme.

The schematic diagram of the OTU module of the present invention that simultaneously completes the functions of adding and dropping services and wavelength conversion is shown in FIG. 6 .

Among them, C1 to Cn connected to the OTU module 10 respectively represent n services accessed by the node, n can be 1 or greater than 1, and the destinations of these services may be the same node or different nodes, and λ1 represents The wavelength output by the line side of the OTU module 10, λ2 is the wavelength received by the line side of the OTU module 10, and λ1 and λ2 may be the same wavelength or different wavelengths. The bandwidth of the client signal accessed by the OTU module 10 is smaller than the bandwidth that the output port can carry. Among them, the bearer bandwidth of the output port is given by the system parameters. The client-side or line-side signals connected to the OTU module 10 can be Synchronous Digital Hierarchy (Synchronous Optical Network, referred to as "SDH"), Synchronous Optical Network (Synchronous Optical Network, referred to as "SONET"), Asynchronous Transmission Mode (Asynchronous Transfer Mode, referred to as "ATM"), Gigabit Ethernet (GigabitEthernet, referred to as "GE") and other types of signals.

The OTU module 10 can identify and process the signal received from the line side. After the signal transmitted from the line side is demultiplexed, the signal destined for this node will be dissociated from the corresponding client side port. The signal of the node will be looped back locally, mixed with the signal connected to the OTU module 10 of the node, and then sent to the next node after wavelength conversion. The OTU modules 10 of all nodes connected in series in the same ring perform similar processing to complete mutual communication between multiple nodes, wherein multiple nodes refer to more than or equal to 3 nodes. Utilizing the OTU module 10, it is possible to avoid the need to use (n-1) wavelengths in order to provide a connection between a node and other (n-1) nodes when n nodes are interconnected in pairs, thereby improving wavelength utilization efficiency.

The internal composition of the OTU module 10 is shown in FIG. 7 .

The OTU module 10 includes the following sub-modules: photoelectric conversion module 11, demultiplexer module 12, multiplexer module 13, electro-optical conversion module 14, photoelectric conversion module 15, adaptation unit module 16, adaptation unit module 17, electro-optical conversion module 18 and switching unit module 19. For the convenience of explanation, it is divided into east-west and north-south directions. The east-west direction represents the signal processing process from the line direction, and the north-south direction represents the customer signal processing process.

The photoelectric conversion module 11 and the photoelectric conversion module 15 are responsible for converting optical signals into electrical signals. Wherein, the photoelectric conversion module 11 is responsible for the conversion of the line-side optical signal received by the OTU module 10 , and the photoelectric conversion module 15 is responsible for the conversion of the optical signal of the client side where the OTU module 10 is located.

The demultiplexer module 12 and the multiplexer module 13, as a pair of modules with complementary functions, respectively complete signal demultiplexing and multiplex signal multiplexing.

The electro-optic conversion module 14 and the electro-optic conversion module 18 are responsible for converting electrical signals into optical signals. Wherein, the electro-optical conversion module 14 is responsible for the conversion of the line-side electrical signal output by the OTU module 10 , and the electro-optical conversion module 18 is responsible for the conversion of the electrical signal of the client side where the OTU module 10 is located.

The adaptation unit module 16 and the adaptation unit module 17 are respectively responsible for the encapsulation and decapsulation adaptation of the input and output signals at the client side. The information to be encapsulated may be determined by actual conditions, for example, in a preferred embodiment of the present invention, destination information may be encapsulated.

The switching unit module 19 is responsible for the switching processing of all signals, and decides whether to add, drop or transfer signals. For example, the switch unit module 19 judges the destination of the signal from the west direction, if it is sent to the node, it will perform drop processing, and the signal will be forwarded to the corresponding client side port, if it is not sent to the node, continue transit.

In the OTU module 10, the optical signal from the line becomes an electrical signal after passing through the photoelectric conversion module 11, and the electrical signal becomes a plurality of low-speed parallel signals after passing through the demultiplexer module 12, and these signals are processed by routing in the switching unit module 19 Finally, part of the signal is routed to the southbound n adaptation unit modules 17 for processing, and becomes the branch signal to be dropped by the OTU module 10, and the branch signal processed by the adaptation unit module 17 is electro-optical converted Can be directly connected to other upper-level devices. At the same time, the local on-line signal transmitted from the north becomes an electrical signal after passing through the photoelectric conversion module 15, and then completes the packaging and adaptation process of the on-line signal through the adaptation unit module 16, and then connects with the branch signal from the west that is not added locally. Combined, after passing through the multiplexer module 13, it becomes a high-speed electrical signal going east, and then through the electro-optical conversion module 14 to complete the conversion of the electrical signal into an optical signal, and transmit it to the next station.

It should be noted that the switching unit module 19, the demultiplexer module 12, and the multiplexer module 13 can be collectively referred to as a dispatching unit, and the overall function of the dispatching unit is to place signals from the photoelectric conversion module 11 that need to be dropped locally. The signal is output to the adaptation unit 17 , and the signal from the adaptation unit module 16 is combined with the signal from the photoelectric conversion module 11 that is not dropped locally and then output to the electro-optic conversion module 14 .

In another preferred embodiment of the present invention, the scheduling module may only be composed of the switching unit module 19, which is equivalent to removing the demultiplexer module 12 and the multiplexer module 13 in FIG. 7 . There is an input and output buffer in the switching unit module 19, put the signal from the photoelectric conversion module 11 into the input buffer, and then selectively send the signal in the buffer according to the destination address, if it needs to be dropped locally, then Send to the adapter unit 17, and send to the electro-optic conversion module 14 if it does not need to be dropped locally.

In another preferred embodiment of the present invention, the scheduling module may only consist of the demultiplexer module 12 and the multiplexer module 13, which is equivalent to removing the switching unit module 19 in FIG. 7 . At this time, some of the multiple output paths of the demultiplexer module 12 are connected to the adapter unit 17, and the signals that need to be dropped locally are transmitted from these paths, and the remaining paths are connected to the multiplexer module 13, so that the signals that do not need to be dropped locally are transmitted. road signal transmission. The adaptation unit 16 is connected to the multiplexer module 13 , and the multiplexer module 13 combines the multiple signals from the demultiplexer module 12 and the adaptation unit 16 into one and outputs it to the electro-optical conversion module 14 .

Utilize above-mentioned OTU module 10 to construct OADM for each node to use and form the loop to carry out communication and can improve wavelength utilization ratio, and when there is connection between not completely every two between all serial nodes, intermediate node The OTU pair that is not directly connected to it is equivalent to a relay. The optical signal regeneration can effectively reduce the optical signal degradation problem faced in the middle of long-distance transmission, and it is also beneficial to improve the system optical signal quality.

A schematic diagram of the internal connection of the unidirectional transmission OADM according to a preferred embodiment of the present invention is shown in FIG. 8 .

The unidirectional transmission OADM of this embodiment is composed of a demultiplexer 20 , a multiplexer 30 and an OTU module 10 . The wave splitter 20 is used to receive the optical signal in the optical fiber and separate the different wavelength channels for transmission. The wave combiner 30 is responsible for combining and sending the input multiple different wavelengths. The wavelength input by the line side is obtained through the port, and the wavelength output by the line side of the OTU module 10 is connected to an input port of the multiplexer 30 .

Above-mentioned unidirectional transmission OADM can also be improved to the OADM that traditional OTU and the OTU module 10 that the present invention proposes are mixed and constituted, and in a preferred embodiment of the present invention, the OADM internal connection schematic diagram that traditional OTU and the OTU that the present invention proposes are mixed constitute As shown in Figure 9.

According to a preferred embodiment of the present invention, the OADM composed of traditional OTU and the OTU proposed by the present invention is composed of wave splitter 20 (20-1, 20-2), wave combiner 30 (30-1, 30-2 ) OTU module 10 and traditional OTU module 40 (40-1, 40-2).

Wherein, the connection relationship between the wave splitter 20-1, the wave combiner 30-1, and the OTU module 10 is exactly the same as that of the above-mentioned one-way transmission OADM. The traditional OTU module 40-1 obtains the line side input from an output port of the wave splitter 20-1, and connects the line side output to an input port of the wave combiner 30-2; One output port of -2 gets the line-side input, and the line-side output is connected to one input port of the multiplexer 30-1. In this way, the traditional OTU module 40 , the demultiplexer 20 and the multiplexer 30 constitute an OADM that is logically identical in logic function to the traditional OADM shown in FIG. 3 .

The OTU module 10 proposed by the present invention can also form a bidirectional OADM. According to a preferred embodiment of the present invention, a schematic diagram of the internal connection of the bidirectional OADM constituted by the OTU proposed by the present invention is shown in FIG. 10 .

According to a preferred embodiment of the present invention, the bidirectional OADM formed by the OTU proposed by the present invention is composed of two demultiplexers 20, two multiplexers 30 and OTU modules 10 (10-1, 10-2). In fact, the above-mentioned two-way OADM composed of the OTU proposed by the present invention is composed of two unidirectional transmission OADMs. The business logic relationship is realized by configuring the connection relationship between two corresponding OTU modules 10-1 and 10-2. Similarly, each OTU module 10 may not be set in a logical correspondence, but still maintain the previous one-way logical relationship, and use another OTU to complete the channel protection function. It should be pointed out that in the case of one-way serial connection, the total bandwidth of the service connection between all nodes provided by this configuration method cannot exceed the line rate, while in the two-way configuration method, the total bandwidth of the service connection is related to the service allocation method. For bandwidth, refer to the bandwidth calculation method for ADM device networking.

Using the various OADMs proposed above, the present invention changes the service connection originally created on the OADM into a service connection on the client side of the OTU unit, so that there is no need to allocate wavelength connections for low-rate services, saving wavelengths and improving wavelengths. utilization efficiency. On each node, the ordinary OADM is still used to complete the optical path add-drop multiplexing, but it is not the same as the traditional optical path add-drop multiplexing, it only completes the one-way optical path add-drop multiplexing, so that the same The OTU provides a ring connection, and the low-speed service connections between nodes share this optical channel, while other high-speed service connections can still use the traditional OADM to complete wavelength allocation.

With the above-mentioned several OADM structures, a chain network and a ring network can be formed. It should be noted that not all nodes in a ring or chain network will be connected in series with the OTU module 10 of the present invention at the same time, they can be all connected in series, or 3 or more than 3 nodes can be connected in series Other wavelengths can also be connected in series between some other nodes, or can be connected in the traditional networking mode.

No matter it is a chain network or a ring network, the OTU module 10 of the present invention logically forms a ring. A schematic diagram of logical connections of a system for increasing wavelength utilization in a dense wavelength division multiplexing system according to a preferred embodiment of the present invention is shown in FIG. 11 .

For the convenience of illustration, only the OTU module 10 proposed by the present invention is drawn in the OTU in FIG. 11 , the traditional OTU module 40 is not drawn, and the nodes that only use the traditional OTU module 40 are not drawn. Those skilled in the art can understand that the logical connection of the traditional OTU module 40 in the node of the OADM that adopts the traditional OTU module 40 and the OTU module 10 proposed by the present invention to form a mixture and the logic of the node that adopts the traditional OTU module 40 to form the OADM Connections are not difficult to achieve.

It should be pointed out that the incoming and outgoing connections between the head node and the tail node of the chain connection network are the same physical route. This kind of connection is two completely different routes. The so-called different routes refer to different nodes connected to and from this node.

The present invention includes a method for processing an optical interface, comprising the following steps:

Step 1: Receive the service from the previous node on the line side. The business here is a mixture of multiple businesses, some of which are destined locally. The service of the previous node can be unidirectional or bidirectional, and there is no difference in processing, but there are differences in service configuration. The logical configuration of the bidirectional service connection is as described above.

Step 2: Drop off the local service. Contains channels for business up and down locally.

Step 3: Mix the non-local services and the newly accessed services from the local, perform wavelength conversion and transmit to the next node through the line side. The service of the next node may be unidirectional or bidirectional.

Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein, and without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. the light transmitting element in the dense wavelength division multiplexing system is characterized in that, comprises first and second photoelectric conversion modules, scheduling unit, first and second electrooptic conversion modules, the first and second adaptation unit modules; Wherein

Described first and second photoelectric conversion modules are respectively applied for and will be converted to the signal of telecommunication from line side and local light signal of setting out on a journey;

Described scheduling unit is used for and will need outputs to described first adaptation unit at the signal on this underground road from the signal of described first photoelectric conversion module, will from the signal of the described second adaptation unit module with after the signal on this underground road merges, do not output to described second electrooptic conversion module from described first photoelectric conversion module;

The described first and second adaptation unit modules are respectively applied for and encapsulate with decapsulation the signal from described scheduling unit and described second photoelectric conversion module adaptive;

It is light signal that described first and second electrooptic conversion modules are respectively applied for the electrical signal conversion from described first adaptation unit module and described scheduling unit, and outputs to this locality and line side respectively.

2. the light transmitting element in the dense wavelength division multiplexing system according to claim 1 is characterized in that described scheduling unit comprises the crosspoint module;

Described crosspoint module is used for the signal of buffer memory from described first photoelectric conversion module, according to the destination address that is buffered signal select that this signal outputed to local described first adaptation unit or merge with signal from the described second adaptation unit module after output to described second electrooptic conversion module.

3. the light transmitting element in the dense wavelength division multiplexing system according to claim 1 is characterized in that, described scheduling unit comprises multiplexer module and conciliates multiplexer module;

It is parallel signal on a plurality of signalling channels that described demodulation multiplexer module is used for the one-channel signal demultiplexing from described first photoelectric conversion module, wherein the part signal passage is connected with described first adaptation unit, being used to transmit need be at the signal on this underground road, other signalling channels connect with described multiplexer module, and being used to transmit need be at the signal on this underground road;

Described multiplexer module is used for and will merges into one the tunnel from the multi-path parallel signal of described demodulation multiplexer module and described second adaptation unit, outputs to described second electrooptic conversion module.

4. the light transmitting element in the dense wavelength division multiplexing system according to claim 1 is characterized in that, described scheduling unit comprises multiplexer module, demodulation multiplexer module and crosspoint module;

It is multi-path parallel signal that described demodulation multiplexer module is used for the signal of telecommunication demultiplexing from described first photoelectric conversion module;

Described multiplexer module is used for and will merges into one the tunnel from the multi-path parallel signal of described crosspoint module;

Described crosspoint module be used for from described demodulation multiplexer module need output to described first adaptation unit at the signal on this underground road, will from the signal of the described second adaptation unit module with after the signal on this underground road merges, do not output to described multiplexer module from described demodulation multiplexer module.

5. the Optical Add Drop Multiplexer node in the dense wavelength division multiplexing system is characterized in that, comprises: first channel-splitting filter, first wave multiplexer and the first smooth transmitting element;

Described first channel-splitting filter is used for the multi-wavelength channel separation that will receive;

Described first wave multiplexer is used for the multi-wavelength passage of input is closed ripple and transmission;

The described first smooth transmitting element is used for discerning processing and demultiplexing from the signal of an output port receiving lines side of described first channel-splitting filter, it with the destination road and export under the signal of this node from client side port, with the destination is not that client's service signal that the signal of this node and client side port insert mixes, and finishes an input port that outputs to described first wave multiplexer after the wavelength Conversion;

The output port that does not connect the described first smooth transmitting element in described first channel-splitting filter is connected with the input port of described first wave multiplexer.

6. the Optical Add Drop Multiplexer node in the dense wavelength division multiplexing system according to claim 5 is characterized in that, also comprises second channel-splitting filter, second wave multiplexer and first, second tradition first smooth transmitting element;

The described traditional first smooth transmitting element is used to finish the wavelength Conversion function;

The line side input of described first tradition, the first smooth transmitting element and an output port of described first channel-splitting filter are connected, and an input port of line side output and described second wave multiplexer is connected; The line side input of described second tradition, the first smooth transmitting element and an output port of described second channel-splitting filter are connected, and an input port of line side output and described first wave multiplexer is connected;

The output port that does not connect described traditional first smooth transmitting element in described second channel-splitting filter is connected with the input port of described second wave multiplexer.

7. the Optical Add Drop Multiplexer node in the dense wavelength division multiplexing system according to claim 5 is characterized in that, also comprises second channel-splitting filter, second wave multiplexer and the second smooth transmitting element;

The described second smooth transmitting element is used for discerning processing and demultiplexing from the signal of an output port receiving lines side of described second channel-splitting filter, it with the destination road and export under the signal of this node from client side port, with the destination is not that client's service signal that the signal of this node and client side port insert mixes, and finishes an input port that outputs to described second wave multiplexer after the wavelength Conversion;

The client side port of the described first smooth transmitting element is connected by logical circuit with the client side port of the described second smooth transmitting element;

The output port that described second channel-splitting filter does not connect the described second smooth transmitting element is connected with the input port of described second wave multiplexer.

8. the multiple spot optical communication network in the dense wavelength division multiplexing system is characterized in that, comprises at least 3 Optical Add Drop Multiplexer nodes connected in series successively;

Described node is used to insert the business from previous described node, is road under the business of this node with the destination, is not the professional of this node with the destination and mixes and be sent to next described node from the new business that inserts of this node.

9. the multiple spot optical communication network in the dense wavelength division multiplexing system according to claim 8 is characterized in that, described Optical Add Drop Multiplexer node connects into annular or chain.

10. the optical interface processing method in the dense wavelength division multiplexing system is characterized in that, comprises following steps:

Reception is from the business of the previous node in line side;

With the destination is road under the local business;

With the destination is not that local business professional and the new access from this locality is mixed, and carries out wavelength Conversion and is sent to next described node by the line side.

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