CN108718214B - Optical Interconnection Structure and Communication Method of Data Center Based on Mesh Topology - Google Patents

Abstract

The invention discloses a data center optical interconnection structure and a communication method based on a grid topology structure. The structure consists of two-layer cabinet groups, each layer of the cabinet group includes a plurality of cabinets, and each cabinet has a specification of N ×N arrayed waveguide grating and N servers; the server and the arrayed waveguide grating are connected through a fiber circulator, and the two-layer cabinet groups are connected through a fiber circulator and/or an interlayer interconnection structure. The invention utilizes the bidirectional interconnection characteristics and routing distribution characteristics of the arrayed waveguide grating, which can increase the number of links, the reliability and the scale of the system, and reduce the number of arrayed waveguide gratings that pass through during data interconnection, thereby effectively avoiding crosstalk and filtering. The problem.

Description

Optical Interconnection Structure and Communication Method of Data Center Based on Mesh Topology

technical field

The invention belongs to the field of data center internal communication research, in particular to a data center optical interconnection structure and a communication method based on a grid topology structure.

Background technique

With the increase of emerging Internet services, there are also new demands for data storage and processing, and the scale and number of data centers have surged, placing higher requirements on the data exchange capability of each data center. At present, in large data centers, electrical switches are still mostly used to complete data exchange, but cables are used to connect the electrical switches, and the heat dissipation of the cables causes high power consumption in the data center. In addition, complicated cable distribution is not conducive to system maintenance and upgrades.

Optical communication technology has the advantages of high bandwidth and low power consumption, and can be applied to the interconnection within the data center, which can increase the network capacity of the data center and effectively reduce the energy consumption of the data center. Arrayed waveguide grating has good routing characteristics and is widely used in the field of optical communication. At present, it has been proposed to build a data center optical interconnect structure based on the device of arrayed waveguide grating. However, due to the insertion loss and crosstalk caused by the device itself As well as filtering and other issues, after the signal passes through multiple arrayed waveguide gratings, the signal-to-noise ratio has to be considered. Therefore, various compensation methods need to be added, which greatly increases the system cost and limits the scale of the system.

Therefore, it is of great research value and significance to develop an optical interconnect structure that can reduce the impact of the device as much as possible without reducing the system scale and increasing the system cost.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and to provide a data center optical interconnection structure and a communication method based on a grid topology structure, which can effectively reduce the loss of data communication and reduce the application of active devices. , improve the efficiency of communication.

The object of the present invention is achieved through the following technical solutions: a data center optical interconnection structure based on a grid topology structure, the structure includes two-layer cabinet groups, each layer of cabinet groups includes N cabinets, and each cabinet is provided with a specification is N×N arrayed waveguide grating and N servers; at least two tunable optical transceivers are set on each server, and the routing characteristic of the arrayed waveguide grating is: the light with wavelength λ _P enters the arrayed waveguide grating through the incident port j , and will eventually be output from the egress port k', where P=|j-k'|, |·| represents the absolute value; in the two-layer cabinet group, all servers in each cabinet are connected to the cabinet through the optical fiber circulator. The arrayed waveguide gratings inside are connected, and the first-layer cabinet group and the second-layer cabinet group are connected through an optical fiber circulator and/or an interlayer interconnection structure.

In the present invention, the first-layer cabinet group and the second-layer cabinet group form a two-layer grid-type data center interconnection structure, each cabinet group includes N cabinets, and each cabinet includes N servers and 1 N× N-type arrayed waveguide grating, so each AWG corresponds to one cabinet, and the arrayed waveguide grating in each cabinet communicates with the arrayed waveguide gratings in all the cabinets in another cabinet group through the fiber circulator and/or the interlayer The interconnecting structures are connected to form a grid-type structure. Compared with other data center interconnect structures based on arrayed waveguide gratings, this structure makes full use of the bidirectional interconnection characteristics and routing distribution characteristics of arrayed waveguide gratings, increasing the number of links, system reliability and scale, and reducing The number of arrayed waveguide gratings that pass through during data interconnection can effectively reduce the serious crosstalk and filtering problems caused in the optical interconnection structure based on multiple arrayed waveguide gratings.

Preferably, a 4-port fiber circulator is connected to all the ports of the arrayed waveguide grating (including the entrance port and the exit port), so that each port of the arrayed waveguide grating is expanded into three ports of the circulator, two of which are The port of the circulator is used to connect the optical transceiver port of the server, and the port of the third circulator is connected to the arrayed waveguide grating in another layer of the cabinet group through the optical fiber or the interlayer interconnection structure.

Preferably, the rules for connecting the server in the cabinet to the arrayed waveguide grating are as follows: in any cabinet, the number of the server is from 1 to N; for the arrayed waveguide grating corresponding to the cabinet, the 4-port optical fiber ring connected to the incident port set the port sequence as: b→a→A→c, where the port A is connected to the entrance port of the arrayed waveguide grating, and the 4-port fiber circulator connected to the exit port, the port sequence is set to f→B→ d→e, where the B port is connected to the exit port of the arrayed waveguide grating, then the b port of the fiber circulator connected to the entrance port i and the f port of the fiber circulator connected to the corresponding exit port i' are connected to the number of The two optical emission ports of the server of i; the c port of the optical fiber circulator connected to the incident port i and the e port of the optical fiber circulator connected to the corresponding outgoing port i', connected to the two optical ports of the server numbered i input port.

Preferably, the arrayed waveguide gratings in the cabinets in the first-layer cabinet group and the arrayed waveguide gratings in the cabinets in the second-layer cabinet group are connected by the following rules:

The first-layer cabinet group and the second-layer cabinet group have N cabinets, corresponding to N arrayed waveguide gratings, numbered from 1 to N;

For the arrayed waveguide grating numbered m in the first-layer cabinet group, it is connected to the a port of the optical fiber circulator connected to the incident port numbered n; and the arrayed waveguide grating numbered n in the second-layer cabinet group, which is the same as the is the a port of the optical fiber circulator connected to the incident port of m, and the two a ports are used as paired a ports;

For the arrayed waveguide grating numbered m in the first-layer cabinet group, it is connected to the d port of the fiber circulator connected to the exit port numbered n'; and the arrayed waveguide grating numbered n in the second-layer cabinet group, which is the same as The d port of the optical fiber circulator connected to the output port numbered m', these two d ports are used as a pair of d ports;

The above-mentioned paired a-ports and paired d-ports are defined as a group of a-d ports, and the group of a-d ports are connected together by optical fibers and/or interlayer interconnection structures.

As a first preference, the interlayer interconnection structure is to directly cross two interconnected optical fibers. For a group of a-d ports, the connection method is that the a port of the first layer is directly connected to the d port of the second layer through an optical fiber, and the d port of the first layer is directly connected to the a port of the second layer through an optical fiber. This structure can realize the mutual transmission of signals between the first-layer cabinet group and the second-layer cabinet group, but correspondingly, the two servers connected to the optical fiber circulator where the a-d ports of this group are located will lose communication with other cabinets in the same layer. The server in the direct data transmission link.

As a second preference, the interlayer interconnection structure is a 2×2 optical switch matrix capable of selecting an output direction. Compared with the first method, the state switching can be realized through the selection of the output direction, and the flexible selection signal is transmitted to the cabinet on the same layer or the cabinet on another layer, which greatly improves the flexibility.

As a third preference, the interlayer interconnection structure uses a filter capable of separating light with a wavelength of λ ₀ . Through the layout and connection of multiple filters, the same-layer transmission and inter-layer transmission can be realized without mutual interference. The light of wavelength λ ₀ is used for the interconnection of data between layers, and the light of other wavelengths is used for the same-layer transmission. Inter-cabinet interconnection.

As a fourth preference, the interlayer interconnection structure is: for a group of ad ports, two a ports are directly interconnected with optical fibers, and a fiber grating capable of reflecting light with a wavelength of _λ0 is used between the two d ports. connect. This method is similar to the third method, and can also realize the transmission without mutual interference between the interconnection between layers and the interconnection at the same layer.

As a fifth preference, the interlayer interconnection structure is: for a group of a-d ports, two d ports are directly interconnected with optical fibers, two 3-port optical fiber circulators and a specification of For a 2×2 optical switch matrix, the second port of each 3-port optical fiber circulator is directly connected to the two a ports, and the remaining two ports are connected to the input and output ports of the optical switch matrix. Control the interconnection ports of the optical switch matrix. When the state of the optical switch matrix makes the first port and the third port of each 3-port optical fiber circulator connected, the interconnection of the interlayer cabinets can be realized; The state enables the first port of a 3-port fiber optic circulator to be connected to the third port of another 3-port fiber optic circulator, which can support interconnection between different cabinets in the same layer. The number of these five interlayer interconnection structures can be flexibly increased or allocated in a data center structure to meet specific interlayer interconnection requirements.

A communication method based on the optical interconnection structure of the data center. First, the coordinates of the server in the structure are defined as (x, y, z), which represents the server on the xth floor, the cabinet number is y, and the server number is z, The number of the arrayed waveguide grating is also y, (x, y, z, a) represents the a port of the optical fiber circulator connected to the server, (x, y, z, b) represents the connection to the server. The b port of the optical fiber circulator, and so on; there are three different ways of server interconnection in this structure: intra-cabinet transmission, intra-cabinet transmission on the same layer, and inter-cabinet inter-layer transmission;

Communication includes three ways:

(1) Transmission between servers in the same cabinet: Set the source server (x1, y1, z1) and the destination server (x2, y2, z2) in the same cabinet, that is: x1=x2, y1=y2, at this time, The optical transmitter connected to the f port of the source server sends an optical signal with a wavelength of λ _O , passes through the optical fiber circulator, and exits from the B port of the optical fiber circulator to the exit port numbered z1' of the arrayed waveguide grating, passes through the arrayed waveguide grating, Finally, it exits from the incident port numbered z2 of the arrayed waveguide grating, reaches the A port of the optical fiber circulator connected to it, passes through the optical fiber circulator, exits the c port of the optical fiber circulator, and reaches the destination server connected to the c port. machine, transmit to the destination server, complete the data transmission in the cabinet, where O=|z1-z2|;

(2) Transmission on the same layer between two cabinets: set the source server (x1, y1, z1) and the destination server (x2, y2, z2) on the same layer, but not in the same cabinet, that is: x1=x2, y1≠ y2, at this time, if the a port and the d port connected to the source server are not connected to the interlayer interconnection structure; or the connected interlayer interconnection structure is mode three or mode four; or the connected interlayer interconnection structure is mode two Or mode 5, but the state of the optical switch matrix supports the same-layer interconnection at this time, the optical transmitter connected to the b port of the source server sends an optical signal with a wavelength of λ _Q , where Q=|y1-y2|, the optical signal passes through the optical fiber The circulator is output from port a, and then transmitted to the arrayed waveguide grating in the cabinet numbered z1 on another layer. The connected ports are (x3, z1, y1, a), x3≠x1, according to the wavelength λ _Q optical signal from The output port (x3, z1, y2, d) is connected to the arrayed waveguide grating in the cabinet numbered y2 on the x1 layer, the connection port is (x1, y2, z1, d), and the server (x1, y2) , z1) the receiver receives and completes the process of the same-layer transmission between the cabinets. If z1=z2, the transmission is completed. If z1≠z2, the transmission process is completed through another transmission in the cabinet. The inter-layer interconnection structure connecting the a port and the d port is the mode 1; or the inter-layer interconnection structure connected is the mode 2 or mode 5, but the state of the optical switch matrix does not support the same-layer interconnection at this time, and it cannot be changed when it is occupied. , the server needs to be transmitted through the cabinet first, then transmitted to the server that can be interconnected between layers, and transmitted through the above method;

(3) Layer-to-layer transmission between two cabinets: set the source server (x1, y1, z1) and the destination server (x2, y2, z2) to not be on the same layer, that is, x1≠x2, the source server (x1, y1, z1) It is transmitted to the server connected to the inter-layer interconnection structure through the transmission within the cabinet or the same-layer transmission between the cabinets, and different optical signal transmission methods are selected according to the difference of the inter-layer interconnection structure.

Specifically, in step (3), if the interlayer interconnection structure is the first preference: the two interconnected optical fibers are directly crossed, and the transmitter connected to port b transmits signal-carrying light, passing through the optical fiber circulator , exit from port a, reach port d on another layer and enter the optical fiber circulator, then exit from port e and be received by the optical receiver connected to port e, the signal will stay on the server on another layer, and then pass through In-cabinet transmission and inter-cabinet transmission on the same layer are transmitted to the destination server;

If the interlayer interconnection structure is the second preference: use a 2×2 optical switch matrix that can select the output direction, set the optical switch matrix interconnection, determine the state of the optical switch, and adjust the state of the optical switch so that The connection state is changed to the state of the above-mentioned structure of "crossing two interconnected optical fibers directly", and then the transmission is completed in the same manner as above;

If the interlayer interconnection structure is the third preference: use a filter that can separate light with wavelength λ ₀ , then the transmitter connected to port b sends an optical signal with wavelength λ ₀ , through the fiber circulator, from port a It exits, reaches the filter, and is assigned the sending direction, and finally reaches the d port of another layer, enters the fiber circulator, and exits from the e port, and is received by the optical receiver connected to the e port, thereby transmitting the signal to the upper layer The server, and then through the transmission in the cabinet and the transmission on the same layer between the cabinets, to complete the transmission task;

If the interlayer interconnection structure is the fourth preference: the two a ports are directly interconnected with optical fibers, and the two d ports are connected by a fiber grating that can reflect light with a wavelength of λ ₀ , then the emission connected to the b port is The machine sends an optical signal with a wavelength of λ ₀ , passes through the optical fiber circulator, exits from the a port, reaches the a port on the other layer paired with the a port, enters the optical fiber circulator, and then exits from the A port, from the entrance port y1 Enter the arrayed waveguide grating, and according to the routing characteristics, the optical signal will exit from the corresponding output port y1', enter the fiber circulator through the B port, and exit from the d port to reach the fiber grating. The d port enters the optical fiber circulator, and then exits from the e port, and is received by the optical receiver connected to the e port, thereby transmitting the signal to the upper-layer server, and then through the transmission in the cabinet and the transmission between the cabinets on the same layer to complete the transmission task.

If the interlayer interconnection structure is the fifth preference: using the combination of optical fiber circulator and optical switch matrix, first determine the state of the optical switch, and adjust its state to support interlayer interconnection, that is, each 3-port fiber The first port of the circulator is connected to the third port. The transmitter of the source server connected to port b sends an optical signal of wavelength λ _G (G=|z1-y2|), which is emitted from port a through the fiber circulator to the interlayer interconnection structure, enters the three-port fiber circulator, and is sent to the interlayer interconnection structure. Through the optical switch matrix, it is incident back to the three-port fiber circulator, so that the optical signal is incident from the a port again, and passes through the fiber circulator, enters the arrayed waveguide grating from the z1 port, and exits from the y2' port according to the wavelength route. The connected optical fiber circulator exits from port d, enters the interlayer interconnection structure and exits, reaches (x2, y2, y1, d) port according to the interconnection characteristics, enters the optical fiber circulator, and then exits from port e, and is The optical receiver connected to the e port receives and transmits to (x2, y2, y1). If y1 = z2, the transmission ends. If y1 ≠ z2, the transmission task can be completed after one transmission in the cabinet.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

The invention uses a plurality of N×N arrayed waveguide gratings to form a grid-type data center internal optical interconnection structure. In this structure, through the fiber circulator and an appropriate interconnection method, the port utilization of the arrayed waveguide grating is increased. Efficiency, increasing the scale of the system, can realize the communication between each server in the data center, and also increase the number of paths for server interconnection communication between cabinets, reduce the blocking rate, and also reduce the array that data transmission needs to go through. The number of waveguide gratings reduces the effects of insertion loss, crosstalk and filtering on signal quality brought about by the device.

Description of drawings

FIG. 1 is an interconnection structure inside a cabinet in an optical interconnection structure of a grid-type data center according to this embodiment.

FIG. 2 is a simplified diagram of the cabinet structure in the optical interconnection structure of the grid-type data center according to the present embodiment.

FIG. 3 is a structural diagram of the optical interconnection of the grid-type data center according to the present embodiment.

FIG. 4 is a schematic diagram of the first structure of the interlayer interconnection structure of this embodiment.

FIG. 5 is a schematic diagram of a second structure of the interlayer interconnection structure of this embodiment.

FIG. 6 is a schematic diagram of a third structure of the interlayer interconnection structure of the present embodiment.

FIG. 7 is a schematic diagram of a fourth structure of the interlayer interconnection structure of this embodiment.

FIG. 8 is a schematic diagram of a fifth structure of the interlayer interconnection structure of the present embodiment.

Detailed ways

In order to enable the examiners of the patent office, especially the public, to more clearly understand the technical essence and beneficial effects of the present invention, the applicant will describe in detail below by way of examples, but the descriptions of the examples are not intended to describe the solution of the present invention. Restriction, any equivalent transformation made according to the concept of the present invention is only formal but not substantive, and should be regarded as the scope of the technical solution of the present invention.

Example

The data center optical interconnection structure based on the grid topology described in this embodiment is used to realize the interconnection between various servers in the data center. The server described in this embodiment is mainly composed of a host, an optical transceiver module, an optical output interface, an optical input interface, and the like. The host is mainly responsible for data analysis, processing and storage; the optical transceiver module needs at least two groups, one is used to output data to the cabinet, and the other is used to transmit data to the outside of the cabinet, which can realize the data that needs to be transmitted in the host. It can be converted into an optical signal and transmitted through the optical output port, or it can also receive an optical signal from the optical input interface, and convert it into an electrical signal and transmit it to the host.

The data center includes two-layer cabinet groups, each layer of which contains N cabinets. The optical interconnection structure of the data center is shown in Figure 3. Each cabinet is equipped with an N×N arrayed waveguide grating and N servers. The number of servers in each enclosure is the same. For an N×N arrayed waveguide grating with N input and output ports, the grid-type data center optical interconnection structure can support up to 2N cabinets, and a single cabinet can support up to N servers. The scale of the entire system is 2N ² , the server is connected to the output optical interface and the input optical interface of the arrayed waveguide grating in the cabinet through the optical input port and the optical output port through the optical fiber circulator. By changing which optical transceiver module the server uses, and the optical transceiver module transmits You can choose to transmit data with other servers in the cabinet or with servers in other cabinets.

Referring to FIG. 1, in this embodiment, in any cabinet, a 4-port optical fiber circulator is connected to all the ports (incident port and exit port) of the arrayed waveguide grating, and connected as shown in FIG. 1, so that Any port of the arrayed waveguide grating can be expanded into three ports of the circulator, two of which are used to connect the optical transceiver port of the server, and the third port is connected to the arrayed waveguide grating of another layer through an optical fiber or an interconnection module connected to the fiber optic circulator.

In use, each server is set to have its own number, and each cabinet also has its own number. For the convenience of distinction, in this embodiment, the coordinates (x, y, z) are set to represent the xth floor, and the cabinet number is y, the server whose server number is z, the value of x is 1 or 2, and the value range of y and z is 1 to N. Cabinets are numbered (x,y). The connection between arrayed waveguide gratings in different cabinets and between servers and arrayed waveguide gratings in the same cabinet must comply with the following rules:

1) In any cabinet, the number of servers is from 1 to N, and the connection method is shown in Figure 1. For the arrayed waveguide grating in the cabinet, the b port of the optical fiber circulator connected to the entrance port i and the corresponding output port The f port of the optical fiber circulator connected to port i' is connected to the two optical output ports of the server numbered i; the c port of the optical fiber circulator connected to the incident port i and the optical fiber ring connected to the corresponding outgoing port i' The e port of the server is connected to the two optical input ports of the server numbered i. At this time, the a port of the optical fiber circulator connected to the entrance port i and the d port of the optical fiber circulator connected to the exit port i' are empty.

2) For any cabinet, the interconnection method is the interconnection method of the arrayed waveguide gratings in the cabinet. The rules are as follows: In the first-layer cabinet group, the number of cabinets is N, and there are N corresponding arrayed waveguide gratings, numbered as 1 to N; in the cabinet group on the second layer, the number of cabinets is N, and there are N corresponding arrayed waveguide gratings, numbered 1 to N; in the cabinet group on the first layer, in the arrayed waveguide grating numbered m, and The port a connected to the port numbered n, and the port a connected to the port numbered m in the arrayed waveguide grating numbered n in the second-layer cabinet group, we call these two ports a pair At the same time, in the first-layer cabinet group, in the arrayed waveguide grating numbered m, the d port connected to the port numbered n', and in the second-layer cabinet group, in the arrayed waveguide grating numbered n In the grating, the d port connected to the port numbered m', these two d ports are called paired d ports; the two paired a ports and paired d ports, we call them a pair of d ports. Group a-d ports; this group of a-d ports are connected by optical fibers or interlayer interconnection structure. When using optical fibers, port a and port a are directly connected by optical fibers, and ports d and d are directly connected by optical fibers.

The function of the interlayer interconnection structure is to enable the servers on the first layer and the second layer to communicate with each other and transmit data. From the structure of the interconnection between the arrayed waveguide grating and the fiber circulator in Figure 1, we can know that when there is light from port a When inputting, it will output from the d port connected to a certain port on the other side of the arrayed waveguide grating according to the different wavelengths; when there is light input from the d port, no matter what the wavelength is, it will be transmitted to the e of the same port. port output and received by the receiver connected to it. Using this difference, the form of the interlayer interconnection structure can be designed to realize the interlayer interconnection of signals.

In this embodiment, five implementations of the interlayer interconnection structure are proposed, as shown in Figures 4, 5, 6, 7, and 8. Figure 4 directly crosses and interchanges two interconnected optical fibers to realize different signals. Layer transmission, but at this time, the transmission function of the two interconnected servers is limited, and can only be used as servers interconnected between layers, the number of links is reduced (there is no link interconnected between the same layers), but the cabinet The internal transmission is not affected; Figure 5 shows the use of an optical switch matrix, which can flexibly select the output direction to achieve the same function in Figure 4, but increases the cost of the device, and only one of the two transmission directions can be selected; A filter that separates light with a wavelength of λ ₀ can achieve output that does not interfere with each other, but limited by the wavelength, the efficiency of the first layer and second layer interconnection transmission may be limited (when used for transceiver transmission between cabinets) When the number of machines is more than 1, the interlayer interconnection structure in Figure 4 and Figure 5 can realize multi-wavelength parallel transmission, greatly improving the transmission rate, while the method in Figure 6 does not have this optimization); Figure 7 is the use of optical fibers The grating can achieve the same function as the structure in Figure 6, and the cost of the device is lower than that of Figure 6, but limited by the characteristics of the fiber grating device, the signal quality is slightly worse than that of the filter scheme; Figure 8 It is a combination of optical fiber circulator and optical switch matrix. By changing the interconnection state of the optical switch matrix, the server can be flexibly interconnected between layers or the same layer, and the number of links will not be reduced. The cost is also relatively high. Therefore, in actual use, these five interlayer interconnection structures can be effectively combined, the requirements of interlayer interconnection can be comprehensively analyzed, and four schemes can be flexibly allocated: The method shown in Figure 4 is suitable for relatively close interlayer interconnections. And the architecture that needs to control the cost, the methods shown in Figure 6 and Figure 7 are suitable for the architecture with less interconnection between layers, and the method shown in Figure 7 is suitable for the architecture that controls the system cost, while the method shown in Figure 5 is suitable for the architecture with less interconnection between layers. It can be flexibly applied to intermediate state architectures with more or less interconnections between layers. The method shown in Figure 8 is suitable for the situation where the proportion of inter-layer interconnection and the same-layer interconnection is not much different. Since these five inter-layer interconnection structures do not conflict, they can also be flexibly used in a data center interconnection structure. The number of these five interlayer interconnect structures is allocated to meet specific interlayer interconnect requirements.

Based on the above rules, and according to the wavelength routing mode of the arrayed waveguide grating, the communication method in this embodiment is as follows:

(1) Transmission in the cabinet:

The source server (x1, y1, z1) and the destination server (x2, y2, z2) are in the same cabinet, that is: x1 = x2, y1 = y2, at this time, the optical transmitter connected to the source server and the f port transmit wavelength is The optical signal of λ _O passes through the fiber circulator, exits from the B port to the exit port numbered z1' of the arrayed waveguide grating, passes through the arrayed waveguide grating, exits from the z2 port, and reaches the connected fiber circulator A port of the circulator , through the optical fiber circulator, outgoing from the c port, and transmitted to the destination server through the destination server optical receiver connected to the c port. where O=|z1-z2|.

(2) Transmission on the same layer between cabinets:

The source server (x1, y1, z1) and the destination server (x2, y2, z2) are on the same floor, but not in the same cabinet, that is: x1=x2, y1≠y2, at this time, if the a port connected to the source server There is no interlayer interconnection structure connected to the d port; or the connected interlayer interconnection structure is the structure shown in Figure 6 or Figure 7; or the connected interlayer interconnection structure is the structure shown in Figure 5 or Figure 8, but At this time, the state of the optical switch matrix supports the same-layer interconnection. The optical transmitter connected to the b port of the source server sends an optical signal with a wavelength of λ _Q , where Q=|y1-y2|, and the optical signal is output from the a port through the fiber circulator , and then transmitted to the arrayed waveguide grating in the cabinet numbered z1 on another layer, the connected port is (x3, z1, y1, a), x3≠x1, according to the wavelength λ _Q optical signal from port (x3, z1, y2,d) output, connected to the arrayed waveguide grating in the cabinet numbered y2 on the x1 floor, the connection port is (x1, y2, z1, d), and the receiver of the server (x1, y2, z1) through the e port If z1=z2, the transmission is completed; if z1≠z2, the transmission process is completed through another transmission in the cabinet; if the a port and the d port connected to the source server are connected The inter-layer interconnection structure is mode 1; or the connected inter-layer interconnection structure is mode 2 or mode 5, but at this time, the state of the optical switch matrix does not support the same-layer interconnection, and the occupied cannot be changed, then the server needs to pass the The transmission in the cabinet is transmitted to the server that can be interconnected between layers, and is transmitted in the above-mentioned manner.

(3) Inter-layer transmission between cabinets:

If the source server (x1, y1, z1) and the destination server (x2, y2, z2) are not on the same layer, that is, x1≠x2, inter-cabinet layer-to-layer transmission is required. The source server (x1, y1, z1) needs to be transmitted in the cabinet or the same layer between cabinets, and then transmitted to the server connected to the interlayer interconnection structure. If the interlayer interconnection structure is in the way shown in Figure 4, it is connected to port b. The optical transmitter transmits any wavelength, passes through the optical fiber circulator, exits the interlayer interconnection structure through the a port, reaches the d port connected to it on another layer, and passes through the optical fiber circulator to the optical receiver connected to the e port. If the signal is received, the signal will stay on the server on another layer, and then transmitted to the destination server through the transmission in the cabinet and the same layer between the cabinets; When it is necessary to adjust the state of the optical switch, judge whether it will affect the existing transmission task. If not, adjust the state of the optical switch to make the connection state change to the same way as in Figure 4, and then complete the transmission in the same way; If the interlayer interconnection structure is as shown in Figure 6, the transmitter connected to port b sends an optical signal with a wavelength of λ ₀ , passes through the fiber circulator, exits port a, reaches the filter, and is assigned the sending direction, and finally reaches the The d port of the other layer enters the optical fiber circulator, and then exits from the e port, and is received by the optical receiver connected to the e port, thereby transmitting the signal to the upper layer server, and then through the transmission in the cabinet and the same layer between the cabinets. , to complete the transmission task; if the interlayer interconnection structure is as shown in Figure 7, the transmitter connected to the b port sends an optical signal with a wavelength of λ ₀ , passes through the fiber circulator, exits the a port, and arrives in a pair with the a port. The a port of the other layer enters the fiber circulator, then exits from the A port, and enters the arrayed waveguide grating from the entrance port y1. According to the routing characteristics, the optical signal will exit from the corresponding exit port y1' and enter through the B port. The fiber circulator exits from the d port and reaches the fiber grating. The fiber grating will reflect the wavelength, re-enter the fiber circulator from the d port, and then exit from the e port and be received by the optical receiver connected to the e port, thereby converting The signal is transmitted to the upper-layer server, and then through the transmission within the cabinet and the same-layer transmission between the cabinets to complete the transmission task; if the inter-layer interconnection structure is as shown in Figure 8, control the interconnection port of the optical switch matrix, when the state of the optical switch matrix If the first port and the third port of each 3-port fiber optic circulator are connected, the interconnection of the interlayer cabinets can be realized: the transmitter connected to the b port of the source server sends an optical signal of wavelength λ _G (G= |z1-y2|), exits from the a port through the fiber circulator to the interlayer interconnection structure, enters the three-port fiber circulator, and is incident back to the three-port fiber circulator through the optical switch matrix, so that the optical signal is transmitted from the a port again. Incident and pass through the fiber circulator, enter the arrayed waveguide grating from the z1 port, exit from the y2 port according to the wavelength route, enter the fiber circulator connected to it, exit from the d port, enter the interlayer interconnection structure and exit, according to Interconnection characteristics, reaching the (x2, y2, y1, d) port, entering the optical fiber circulator, and then exiting from the e port, received by the optical receiver connected to the e port, and transmitted to the (x2, y2, y1), if y1=z2, the transmission is over, and if y1≠z2, the transmission task can be completed after one transmission in the cabinet.

The above-mentioned embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, The simplification should be equivalent replacement manners, which are all included in the protection scope of the present invention.

Claims (9)

1. The data center optical interconnection structure based on the grid type topological structure is characterized by comprising two layers of cabinet groups, wherein each layer of cabinet group comprises N cabinets, and an arrayed waveguide grating with the specification of NxN and N servers are arranged in each cabinet; each server is provided with at least two tunable optical transceivers, and the routing characteristics of the arrayed waveguide grating are as follows: wavelength of λ_PThe light enters the arrayed waveguide grating through the incident port j and is finally output from the emergent port k ', wherein P is | j-k' |; in the two layers of cabinet groups, all servers in each cabinet are respectively connected with the arrayed waveguide grating in the cabinet through the optical fiber circulator, and the first layer of cabinet group and the second layer of cabinet group are connected through the optical fiber circulator and/or the interlayer interconnection structure;

the arrayed waveguide grating in the cabinet in the first layer of cabinet group and the arrayed waveguide grating in the cabinet in the second layer of cabinet group are connected by the following rules:

the first-layer cabinet group and the second-layer cabinet group are both provided with N cabinets, and N arrayed waveguide gratings are correspondingly arranged and numbered from 1 to N;

for the arrayed waveguide grating numbered m in the first layer of cabinet group, the port a of the optical fiber circulator is connected with the incident port numbered n; the arrayed waveguide grating is numbered n in the second layer of cabinet group and is connected with the port a of the optical fiber circulator, the port a is numbered m, and the two ports a are used as paired ports a; m is more than or equal to 1 and less than or equal to N, N is more than or equal to 1 and less than or equal to N;

for the arrayed waveguide grating numbered m in the first layer of cabinet group, the d port of the optical fiber circulator is connected with the exit port numbered n'; the arrayed waveguide grating is numbered n in the second layer of cabinet group and is connected with the d port of the optical fiber circulator, the d port is numbered m', and the two d ports are used as paired d ports;

the pairs of a-ports and pairs of d-ports are defined as a set of a-d ports that are connected together by optical fibers and/or an inter-level interconnect structure.

2. The optical interconnection structure of data center based on grid topology according to claim 1, wherein a 4-port optical fiber circulator is connected at all ports of the arrayed waveguide grating, so that each port of the arrayed waveguide grating is expanded to be a port of three circulators, wherein two ports of the circulators are used to connect optical transceiver ports of the server, and a port of the third circulator is connected to the arrayed waveguide grating in another layer of rack group through an optical fiber or an interlayer interconnection structure.

3. The optical interconnection structure of data center based on grid topology according to claim 2, wherein the connection rule between the servers in the cabinet and the arrayed waveguide grating is as follows: inside any cabinet, the number of the servers is from 1 to N; for the 4-port optical fiber circulator connected with the incident port of the corresponding arrayed waveguide grating in the cabinet, the port sequence is set as follows: b → a → c, wherein the port A is connected with the incident port of the arrayed waveguide grating, the 4-port fiber circulator connected with the exit port is sequentially set to f → B → d → e, wherein the port B is connected with the exit port of the arrayed waveguide grating, then the port B of the fiber circulator connected with the incident port i and the port f of the fiber circulator connected with the corresponding exit port i' are connected with two light emission ports of the server numbered i; and the c port of the optical fiber circulator connected with the incident port i and the e port of the optical fiber circulator connected with the corresponding exit port i' are connected with two optical input ports of the server numbered as i.

4. The optical interconnection structure of data center based on grid topology according to claim 1, wherein the interlayer interconnection structure is selected from any one of the following manners:

the first method is as follows: the interlayer interconnection structure directly crosses two interconnected optical fibers;

the second method comprises the following steps: the interlayer interconnection structure adopts an optical switch matrix with the specification of 2 multiplied by 2 and capable of selecting the output direction;

the third method comprises the following steps: the interlayer interconnection structure is formed by using a structure capable of separating a wavelength of lambda₀Of light of lambda₀The wavelength is preset, and can be output from an i' port after entering from an ith port of the arrayed waveguide grating;

the method is as follows: the interlayer interconnection structure is: for a group of a-d ports, two a ports are directly interconnected by optical fibers, and one port capable of reflecting light with the wavelength of lambda is used between two d ports₀Fiber grating connection of light;

the fifth mode is as follows: the interlayer interconnection structure is a structure combining circulators and optical switches, for a group of a-d ports, two d ports are directly interconnected by optical fibers, two 3-port optical fiber circulators and an optical switch matrix with the specification of 2 multiplied by 2 are connected between the two a ports, the second port of each 3-port optical fiber circulator is directly connected with the two a ports, and the rest two ports are connected with the input port and the output port of the optical switch matrix.

5. A communication method based on the optical interconnection structure of data center in claim 4, wherein the coordinates of the server in the structure are first defined as (x, y, z), which represents the server with x layer, cabinet number y and server number z, the number of the arrayed waveguide grating is also y, (x, y, z, a) represents the a port of the optical fiber circulator connected to the server, (x, y, z, b) represents the b port of the optical fiber circulator connected to the server, and so on, (x, y, z, c) represents the c port of the optical fiber circulator connected to the server, and (x, y, z, d) represents the d port of the optical fiber circulator connected to the server; there are three different ways of interconnecting the servers in this architecture: conveying in the equipment cabinet, conveying in the same layer among the equipment cabinets and conveying among the equipment cabinets;

communication includes three modes:

(1) and (3) transmission among servers in the same cabinet: setting the source server (x1, y1, z1) and the destination server (x2, y2, z2) in the same cabinet, namely: x1 x2 and y1 y2, in which case the optical transmitter connected to the f-port of the source server transmits the signal with wavelength λ_OThe optical signal passes through the optical fiber circulator, is emitted from a port B of the optical fiber circulator to reach an emitting port numbered as z 1' of the arrayed waveguide grating, passes through the arrayed waveguide grating, is finally emitted from an incident port numbered as z2 of the arrayed waveguide grating, reaches a port A of the optical fiber circulator connected with the optical fiber circulator, passes through the optical fiber circulator, is emitted from a port c of the optical fiber circulator, reaches a target server optical receiver connected with the port c, and is transmitted to a target server, so that data transmission in the cabinet is completed, wherein O is | z1-z2 |;

(2) same-layer transmission between two cabinets: setting the source server (x1, y1, z1) and the destination server (x2, y2, z2) to be on the same layer but not in the same cabinet, namely: x1 ═ x2, y1 ≠ y2, when the a-port and the d-port connected to the source server are not connected to the inter-layer interconnect structure; or the connected interlayer interconnection structure is the third mode or the fourth mode in claim 4; or the connected interlayer interconnection structure is the mode two or the mode five in the claim 4, but in this case, the state of the optical switch matrix supports the same layer interconnection, and the optical transmitter connected with the b port of the source server transmits the wavelength λ_QWherein Q is y1-y2, the optical signal is output from the a port through a fiber optic circulator and then transmitted to another layer of arrayed waveguide grating in a cabinet numbered z1, the connected ports are (x3, z 3526 |)1, y1, a), x3 ≠ x1, depending on the wavelength λ_QOptical signals are output from ports (x3, z1, y2, d), arrayed waveguide gratings in a cabinet numbered y2 and positioned at an x1 layer are connected, the connection ports are (x1, y2, z1, d), the optical signals are received by a receiver of a server (x1, y2, z1) through an e port, the process of transmission among the cabinets at the same layer is completed, if z1 is equal to z2, the transmission is completed, and if z1 is equal to z2, the transmission process is completed through one-time in-cabinet transmission; if the inter-layer interconnect structure connected to the a port and the d port of the source server is the first way in claim 4; or the connected interlayer interconnection structure is the mode two or the mode five in the claim 4, but at this time, the state of the optical switch matrix does not support the interconnection of the same layer, and the optical switch matrix is occupied and can not be changed, the server needs to transmit the optical switch matrix to the server capable of performing the interlayer interconnection through the cabinet, and transmit the optical switch matrix through the transmission mode of the same layer between the two cabinets;

(3) transmission between two cabinets: setting the source server (x1, y1, z1) and the destination server (x2, y2, z2) to be different in the same layer, namely x1 ≠ x2, firstly transmitting the source server (x1, y1, z1) to the server connected with the interlayer interconnection structure through in-cabinet transmission or inter-cabinet layer transmission, and selecting different optical signal transmission modes according to different interlayer interconnection structures.

6. The communication method according to claim 5, wherein in the step (3), if the inter-layer interconnection structure is the first way of claim 4: directly crossing two interconnected optical fibers, transmitting light carrying signals by a transmitter connected with a port b, passing through an optical fiber circulator, exiting from a port a, reaching a port d of another layer, entering the optical fiber circulator, exiting from an port e, and being received by an optical receiver connected with the port e, so that the signals are stopped on a server of the other layer, transmitted to a target server through transmission in a cabinet and transmission on the same layer between cabinets;

in the step (3), if the interlayer interconnection structure is the second mode in claim 4: the method comprises the steps of setting optical switch matrix interconnection by using an optical switch matrix with the specification of 2 multiplied by 2 and capable of selecting the output direction, judging the state of the optical switch, changing the connection state into the state of a structure of directly crossing two interconnected optical fibers by adjusting the state of the optical switch, and completing transmission by a corresponding method in the mode.

7. The communication method according to claim 5, wherein in the step (3), if the inter-layer interconnect structure is the third way in claim 4: using means capable of separating the wavelengths by λ₀Of the transmitter connected to the b port, the transmission wavelength being λ₀The optical signal is emitted from the port a through the optical fiber circulator, reaches the filter, is distributed with a sending direction, finally reaches the port d of the other layer, enters the optical fiber circulator, then is emitted from the port e, and is received by the optical receiver connected with the port e, so that the signal is transmitted to the server on the upper layer, and is transmitted in the cabinet and transmitted on the same layer between the cabinets to complete the transmission task.

8. The communication method according to claim 5, wherein in the step (3), if the inter-layer interconnect structure is the mode four in claim 4: two a ports are directly interconnected by optical fiber, and two d ports use a fiber capable of reflecting wavelength lambda₀The optical fiber grating of (a) is connected, the transmitter connected to the b port transmits a signal with a wavelength λ₀The optical signal is emitted from the a port through the optical fiber circulator, reaches the a port of the other layer which is paired with the a port, enters the optical fiber circulator, then is emitted from the A port, enters the arrayed waveguide grating from the incident port y1, and according to the routing characteristics, the optical signal is emitted from the corresponding emergent port y 1', enters the optical fiber circulator through the B port, is emitted from the d port and reaches the optical fiber grating, and the optical fiber grating reflects the light with the wavelength of lambda₀The optical signal enters the optical fiber circulator from the d port again, then exits from the e port, and is received by the optical receiver connected with the e port, so that the signal is transmitted to the server on the upper layer, and then is transmitted in the cabinet and transmitted on the same layer between the cabinets to complete the transmission task.

9. The communication method according to claim 5, wherein in the step (3), if the inter-layer interconnection structure is the fifth means in claim 4: the interconnection ports of the optical switch matrix are controlled by using a mode of combining the circulators and the optical switch matrix, and when the state of the optical switch matrix enables the first port and the third port of each 3-port optical fiber circulator to be connected, interconnection of the interlayer cabinets can be realized:

transmitter of source server connected to b port transmitting wavelength lambda_GWhere G-z 1-y2, exits the a-port through a first fiber optic circulator to the inter-layer interconnect structure, enters a 3-port fiber optic circulator, and is incident back to the 3-port optical fiber circulator through the optical switch matrix, so that the optical signal is incident from the a port again and passes through the second optical fiber circulator to be incident to the arrayed waveguide grating from the z1 port, according to wavelength routing, out of the y 2' port, into the third fiber circulator connected thereto, out of the d port, into the interlayer interconnection structure and out, according to interconnection characteristics, to the (x2, y2, y1, d) port, into the fourth fiber circulator, and then exits from the e-port, and is received by an optical receiver connected to the e-port, and is transmitted to (x2, y2, y1), if y1 is z2, the transmission is finished, if y1 is not equal to z2, the transmission task can be completed by performing the transmission in the cabinet once.

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