Method for adaptively allocating channels to optical link

Abstract

The invention provides an optical link adaptive channel allocation method, which adopts an optical fiber beam combiner, an optical fiber beam splitter and a receiving and transmitting integrated optical module to form a link, ensures that no time conflict is generated when each device allocates channel authority through time parameter configuration and by adopting a method of differentiating delay time in sequence, and ensures that the channel authority is allocated to the devices without top layer control. According to the invention, automatic sorting of channel permissions of each device is realized, priority is given to part of special devices by adopting setting of frequency permissions and sequences, data and high-bandwidth optical medium physical links can be ensured to be sent in a relatively fixed time window, and asynchronous communication timeliness among the devices is ensured. The method is suitable for bus data transmission application scenes of various types of current complex systems. In addition, the optical fiber medium has the advantages of being free of electromagnetic interference, small in occupied space, light in weight, simple in wiring and the like, cable complexity and cable weight can be greatly reduced, and therefore system cost is reduced, and great significance is achieved for research and development of a novel satellite bus.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical fiber link technology, and in particular to a method for adaptively allocating channels of an optical link. BACKGROUND

[0002] The operation control platform of an aircraft, a satellite, a rocket, a ship, etc. is a complex system, which contains various sensors of force, heat, light, electricity, time devices, data acquisition devices, actuating devices, data storage and processing devices, communication devices, data exchange devices, safety assurance devices, and user professional devices corresponding to different platforms. The devices form a unified system, which necessarily requires a data bus for interconnection and intercommunication. The more the interconnection interfaces between the devices, the more complex the data bus. For such complex systems as an aircraft, a satellite, a rocket, and a ship with limited space, the use of different data interfaces between various devices makes the layout of cables extremely complex, and also brings electromagnetic safety problems in local space. In order to ensure electromagnetic compatibility, various shielding protection measures are adopted for the data bus.

[0003] With the continuous upgrading of system functions, the layout of data cables in limited space gradually brings about problems such as weight increase, wiring process, maintenance, and even system safety. In addition, the amount of information and data exchanged between the system and the devices is increasing, and the requirements for the transmission rate and fault tolerance of the data bus are becoming higher and higher. The traditional cable medium has highlighted the disadvantages in terms of weight, process, and maintenance.

[0004] Optical fiber communication has been widely used, and optical fiber-based data buses have been gradually applied on a large scale in large data centers and assembly manufacturing centers. The bus represented by MIL-STD-1553B plays an important role in the industrial field and the aerospace field. With the continuous upgrading of equipment, optical fiber communication is continuously researched, upgraded, and improved and applied to spacecraft, aircraft, rockets, ships, and other system platforms.

[0005] Currently, the use of optical fiber communication on the above platforms mainly focuses on point-to-point high-speed transmission between individual devices, and is usually interconnected by Ethernet interfaces for transmitting high-speed service data. The use of optical fiber medium as a satellite bus is still in the research stage. With the rapid rise of commercial spaceflight, the above platforms, especially spacecraft, have become the focus of competition for many commercial spaceflight units. The low-cost route is one of the main development routes for commercial spaceflight, and the upgrading of the satellite bus may become an important aspect of the low-cost route. Other platforms also face the problem of bus upgrading. SUMMARY

[0006] The technical problem to be solved by the present application is how to reasonably allocate optical fiber link channels, and a method for adaptively allocating channels of an optical link is provided.

[0007] The method for adaptively allocating channels of an optical link according to an embodiment of the present application, the optical link comprising: a plurality of fiber combiners connected end to end and a plurality of fiber splitters connected end to end, the last fiber combiner being connected to the first fiber splitter to form the optical link, the number of fiber combiners and fiber splitters being equal and each being connected to a transceiver integrated optical module, each transceiver integrated optical module being connected to a device, the device realizing information exchange through the optical link; the method comprising: A10, after initialization of any transceiver integrated optical module and its corresponding device, initializing a data sending period to T seconds and initializing a receiving end to a normally open state, i.e. receiving a communication signal in time; A20, after initialization of any transceiver integrated optical module and its corresponding device in the optical link, first waiting for t seconds, the transceiver integrated optical module preparing a data packet on demand, and simultaneously judging whether a signal arrives at the receiving end; A30, if no signal is received at the receiving end, judging whether a data packet needs to be sent according to frequency authority and a running program of the device, and if yes, directly sending the prepared data packet; A40, after sending of the data packet, judging whether the program is ended; if yes, ending, and if no, jumping to step A20 to wait for t seconds and continuing.

[0008] The method for adaptively allocating channels of an optical link according to an embodiment of the present application adopts fiber combiners, fiber splitters and transceiver integrated optical modules to form a link, adopts a method of sequentially differentiating delay time through time parameter configuration, ensures that time conflicts do not occur when each device allocates channel authority, realizes automatic ordering of channel authority of each device in the absence of top-level control, adopts setting of frequency authority and order to give priority to some special devices, ensures that the special devices can send data in a relatively fixed time window, and high-bandwidth optical medium physical links ensure timeliness when each device asynchronously communicates. The application is suitable for bus data transmission application scenarios of current complex systems. In addition, the optical fiber medium has characteristics of not being interfered by electromagnetic interference, occupying small space, being light in weight, and being simple to wire, and the optical fiber communication link provided by the application is used as a bus, which can greatly reduce cable complexity and effectively reduce cable weight, thereby reducing system cost, and has important significance for research and development of a new type of satellite bus.

[0009] According to some embodiments of the present application, in step A20, the waiting time t dynamically changes according to current absolute time, data sending period, delay time and serial number of the device.

[0010] In some embodiments of the present application, in step A20, the waiting time t is calculated as follows: t = AT mod T + DT; Wherein, AT is the current absolute time decimal part, DT is the delay time, mod is the C language operator, and represents the remainder operation.

[0011] According to some embodiments of the present application, in step A30, if the receiving end receives a signal, the source address and the sink address of the signal are analyzed, and it is first determined whether the source address is the address of the device, if yes, it is indicated that the signal is from the device, and the flow jumps to the step of determining whether the data packet needs to be sent according to the running flow of the device; if no, it is further determined whether the sink address is the address of the device. If the sink address is not the address of the device, the data is abandoned, and the flow returns to the step of determining whether a signal arrives; if the sink address is the address of the device, the information is processed until the processing is completed. After the data processing is completed, it is determined whether the receiving is ended, if no, the flow returns to the step of determining whether a signal arrives, if yes, the flow jumps to the step of determining whether the program is ended.

[0012] In some embodiments of the present application, in step A40, it is determined whether the program flow is ended according to any one of the following conditions: The data packet is sent, the result of determining whether the data packet needs to be sent according to the running program is no, and the result of determining whether the receiving is ended is yes.

[0013] According to some embodiments of the present application, in step A30, the total time for each device to continuously send the data packet is less than or equal to 2T.

[0014] In some embodiments of the present application, the value F of the frequency authority in step A30 represents the maximum number of data sent by the corresponding device within 1 second; 1≤F≤0.2 / T, 0.01≤T≤0.2, T is an integer multiple of 0.01, and the time interval between adjacent two times of obtaining the channel authority by the device is not less than 1 / F second.

[0015] According to some embodiments of the present application, the method further comprises: adjusting the value F of the frequency authority according to the frequency of sending data by the device.

[0016] In some embodiments of the present application, the smaller the serial number of the corresponding optical module of the device with the same frequency authority is, the smaller the waiting time t is, and the higher the channel authority is.

[0017] According to some embodiments of the present application, the content of the information exchange comprises: instructions, state parameters, user data, partial software packages, and sensor data. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall composition of the optical fiber communication link according to the embodiments of the present application. Figure 2A branch schematic diagram of a fiber combiner according to an embodiment of the present application; Figure 3 A branch schematic diagram of a fiber splitter according to an embodiment of the present application; Figure 4 A flow logic diagram of a channel permission allocation method according to an embodiment of the present application; Figure 5 A fiber communication link schematic diagram applied to 8 devices according to an embodiment of the present application; Figure 6 A fiber communication link channel permission allocation result schematic diagram in a typical state applied to 8 devices according to an embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined purposes, the present application is described in detail below in combination with the drawings and preferred embodiments.

[0020] The description of the method flow in the specification of the present application and the steps of the flowchart in the drawings of the present application do not have to be strictly executed in the order of the step numbers. The method steps can change the execution order. Moreover, certain steps can be omitted, multiple steps can be combined into one step for execution, and / or one step can be divided into multiple steps for execution.

[0021] The present application provides a fiber communication link with adaptive channel permission allocation and a method for adaptive channel allocation. The fiber combiner, fiber splitter and transceiver integrated optical module are connected in a loop to provide a general interface for devices. Each device continuously monitors the channel state, automatically sorts the use of the channel in time sequence as needed, orderly accesses and exits, and the devices do not conflict. The channel is not wasted, and efficient transmission of various information data is achieved.

[0022] Specifically, as shown in Figure 1 The optical link includes a plurality of first-end-to-last-end fiber combiners and a plurality of first-end-to-last-end fiber splitters. The last-end fiber combiner is connected to the first-end fiber splitter to form an optical link. The number of fiber combiners and fiber splitters is equal and one-to-one paired with the transceiver integrated optical module. The transmitting end of the transceiver integrated optical module is connected to the branch of the fiber combiner, and the receiving end of the transceiver integrated optical module is connected to the branch of the fiber splitter. The number of transceiver integrated optical modules is one more than the number of fiber combiners. Any one transceiver integrated optical module and the fiber link form a ring circuit. Each transceiver integrated optical module is connected to a device, and the device realizes information exchange through the optical link.

[0023] The optical signal output from the transmitting end of any one transceiver integrated optical module can enter the receiving end of all transceiver integrated optical modules including itself in turn.

[0024] All the transceiver integrated optical modules have the same emission wavelength, the same modulation mode, the same detection receiving waveband, and the same demodulation mode, and the optical modules with different serial numbers are distinguished by the device addresses connected by the optical modules.

[0025] The optical link constitutes a unidirectional and centerless optical communication link, and any one of the transceiver integrated optical modules can perform asynchronous communication with other optical modules.

[0026] The channel usage process of any one of the transceiver integrated optical modules and the corresponding device in the optical link is performed according to the logic shown in Figure 4 , that is, a channel permission allocation method, and specifically includes the following steps: A10, after initialization of any one of the transceiver integrated optical modules and the corresponding device is completed, the data sending period is initialized to T seconds, and the receiving end is initialized to a normally open state, that is, a communication signal is received in real time; for example, one timing unit of all devices in the system occupying a channel to send data can be defined as T seconds (0.01≤T≤0.2), and it is agreed that the duration of any device occupying a channel does not exceed 2T seconds.

[0027] A20, after initialization of any one of the transceiver integrated optical modules and the corresponding device in the optical link is completed, first, waiting for t seconds, the sending end of the transceiver integrated optical module prepares a data packet as needed, and simultaneously judges whether a signal arrives at the receiving end; in the above-mentioned channel permission allocation method, the waiting time t is dynamically changed, and t is related to the current absolute time, the data sending period, the delay time, and the serial number of the device.

[0028] The parameter t is agreed as follows: the data sending period is T seconds (0.01≤T≤0.2, T is an integer multiple of 0.01), the decimal part of the current absolute time is defined as ΔT seconds (ΔT<1), the delay time is defined as δT seconds (δT=0.0002×n, n is the serial number of the optical module corresponding to the current device), and the calculation method of t is that the decimal part of the current absolute time is operated by T, and then the delay time is added, that is: t=ΔT mod T+δT (the definition of the operator mod refers to the computer programming C language standard).

[0029] A30, if the receiving end does not receive a signal, whether a data packet needs to be sent is judged according to the frequency permission and the running program of the device, and if yes, the prepared data packet is directly sent; According to some embodiments of the present application, in step A30, if the receiving end receives a signal, the source address (sending device address) and the sink address (destination device address) of the signal are analyzed, it is first judged whether the source address is the device address, if yes, it is indicated that the signal is from the device, the flow is jumped to continue to execute according to whether a data packet needs to be sent according to the running program of the device, and if no, it is indicated that the signal is from other devices, and the sink address is further judged. If the signal destination address is not the device address, the data is abandoned, and the flow returns to the judgment of whether there is a signal to arrive; if the signal destination address is the device address, the information is processed until the processing is completed. After the data processing is completed, it is judged whether the receiving is ended, if not, the flow returns to the judgment of whether there is a signal to arrive, if yes, it jumps to the judgment of whether the program is ended.

[0030] After the data packet is sent, it is judged whether the program is ended, if yes, it is ended, if not, it jumps to step A20 to wait for t seconds to continue.

[0031] According to the method for adaptively allocating channels of an optical link provided by the embodiment of the application, the optical fiber communication link for adaptively allocating channel permissions is composed of an optical fiber combiner, an optical fiber splitter and a transceiver integrated optical module, time parameter configuration is adopted, a method of sequentially differentiating delay time is adopted, time conflicts are avoided when each device allocates channel permissions, automatic sorting of channel permissions of each device is realized without top-level control, frequency permissions and sequence are set to give priority to some special devices, so that the special devices can send data in a relatively fixed time window, the high-bandwidth optical medium physical link guarantees the timeliness of asynchronous communication between devices. The application is suitable for bus data transmission application scenarios of current complex systems. In addition, the optical fiber medium has the characteristics of not being affected by electromagnetic interference, small space occupation, light weight and simple wiring, and when the optical fiber communication link provided by the application is used as a bus, the cable complexity can be greatly reduced, the cable weight can be effectively reduced, and the system cost can be reduced, which is of great significance for the research and development of a new type of satellite bus.

[0032] In some embodiments of the application, in step A40, any one of the following conditions is met to determine whether to end the program flow: The data packet is sent, the result of judging whether the data packet needs to be sent according to the running program is no, and the result of judging whether the receiving is ended is yes.

[0033] By using the flow, when the channel is idle and all devices are in the initialized state, the device corresponding to the transceiver integrated optical module with the serial number 1 will obtain the channel permission first and send data.

[0034] When the channel is idle and all devices are in the initialized state, if the device corresponding to the transceiver integrated optical module with the serial number 1 does not send data in the current period, the device corresponding to the transceiver integrated optical module with the serial number 2 will obtain the channel permission first and send data.

[0035] When the channel is idle and all devices are in the initialized state, if the transceiving optical module corresponding to the device with serial number 1 and 2 does not send data in the current period, the device corresponding to the transceiving optical module with serial number 3 will obtain the channel permission first and send data.

[0036] By analogy, when the channel is idle and all devices are in the initialized state, if the transceiving optical module corresponding to the device with serial number 1, 2, 3, …, n-1 does not send data in the current period, the device corresponding to the transceiving optical module with serial number n will obtain the channel permission first and send data.

[0037] The data frequency permission of the device is defined as F (1≤F≤0.2 / T, 0.01≤T≤0.2, T is an integer multiple of 0.01), and the time interval between the adjacent two times of obtaining the channel permission (calculated from the starting time, all time intervals in the full text are calculated from the starting time) of the device is not less than 1 / F seconds.

[0038] The data frequency permission F=1 indicates that the device can send data at most 1 time in 1 second, and the time interval between the adjacent two times of obtaining the channel permission of the device is not less than 1 second.

[0039] The data frequency permission F=2 indicates that the device can send data at most 2 times in 1 second, and the time interval between the adjacent two times of obtaining the channel permission of the device is not less than 0.5 second.

[0040] The data frequency permission F=3 indicates that the device can send data at most 3 times in 1 second, and the time interval between the adjacent two times of obtaining the channel permission of the device is not less than 1 / 3 second.

[0041] By analogy, the data frequency permission F=0.2 / T indicates that the device can send data at most 0.2 / T times in 1 second (obtain the channel permission), and the time interval between the adjacent two times of obtaining the channel permission of the device is not less than 5T seconds. (Example: assuming T=0.02, F=10 (F is the maximum value of 0.2 / T=10, so 1 / F=0.1), then the device can obtain the channel permission at most 10 times in 1 second, and the time interval between the adjacent two times of obtaining the channel permission is not less than 0.1 second.

[0042] In the same system, the data sending period T is a fixed value and cannot be changed, and the frequency permission is a configuration parameter and can be changed as needed.

[0043] According to the optical fiber communication link with adaptive channel allocation provided by this invention, a corresponding number of optical modules, optical fiber combiners, and optical fiber splitters are selected to form the optical fiber communication link based on the number of devices. The transmission period T, waiting time t, and frequency allocation F for each device are set according to application requirements. For devices with higher transmission frequencies, the frequency allocation F is appropriately increased. All devices are allocated optical module numbers according to priority. For devices with the same frequency allocation, the smaller the optical module number, the shorter the waiting time t, and the higher the channel allocation. Each device will automatically allocate channels on demand, transmit data on demand, and automatically release the channel after data transmission is completed, without interference, thus making full use of channel resources.

[0044] The optical fiber communication link with adaptive channel permission allocation provided by this invention can be applied to a set of integrated equipment formed by local interconnection of multiple devices, and can realize high-speed information exchange between multiple devices.

[0045] Information exchange typically takes the form of instructions, status parameters, user data, partial software packages, and sensor data.

[0046] Commands are generally fixed-length data packets, sent periodically or on demand. The minimum frequency permission value can be determined periodically to enable commands to be sent cyclically according to the period specified by the device. Commands sent on demand can be sent with data packets attached within the channel permission window. Status parameters are typically fixed-length data packets, sent periodically or on demand; Sensor data is typically in fixed-length data packets, sent periodically or on demand; User data (such as images, voice messages, video streams, etc.) is generally in large data files and is sent on demand. Software data is typically in the form of large data files and is sent as needed; Fiber optic links are high-speed data links, far exceeding the bandwidth of traditional data buses. Calculated at a typical optical module rate of 1 Gbps, a transmission window with a period of 0.01 seconds can transmit more than 1 MB of data. Data packets such as commands, status parameters, some software packages, and sensor data are generally in the KB range, while a few software data and user data (such as images, voice, and video streams) are usually larger than 1 MB. Efficient transmission can be achieved by continuously sending multiple data packets within a window or by sending data in batches across multiple windows. Therefore, the fiber optic communication link provided by this invention can transmit, as a bus, including but not limited to, commands, status parameters, user data, sensor data, and software data.

[0047] The optical fiber communication link provided by the application has the advantages of simple wiring topology, small cable weight, small occupied space, unified connector, simple wiring process, high transmission rate, no electromagnetic interference and the like compared with the bus of the traditional cable medium. The application has important significance for the development of optical bus.

[0048] The application will be described in detail below with reference to the specific embodiments and the accompanying drawings. It should be understood that the following description is only exemplary and should not be construed as specific limitation of the application.

[0049] As shown in Figure 1 The application provides an optical fiber communication link, which is composed of a plurality of optical fiber combiners (C1, C2, …, Cn-1), a plurality of optical fiber splitters (B1, B2, …, Bn-1) and a plurality of transceiver integrated optical modules (D1, D2, …, Dn).

[0050] Figure 2 As shown in the optical fiber combiner branch diagram, the main path incident optical fiber E1 and the branch path incident optical fiber E2 are combined in equal proportion, and the output is from the main path outgoing optical fiber E3. The combination proportion of each optical fiber combiner is 50%:50%, Figure 3 As shown in the optical fiber splitter branch diagram, the main path incident optical fiber Q1 is incident, the branch path outgoing optical fiber Q2 and the main path outgoing optical fiber Q3, and the splitting proportion of Q3 is greater than that of Q2. The splitting proportion of each optical fiber splitter is (1 / n)%:((n-1) / n)%, n is the total number of optical modules in the optical fiber communication link, for example, n=10, and the splitting proportion is 10%:90%.

[0051] As shown in Figure 1 As shown, the optical fiber combiners and the optical fiber splitters are connected in sequence and end to end, all the optical fiber combiners are connected in sequence and adjacent to each other C1→C2→……→Cn-1, all the optical fiber splitters are connected in sequence and adjacent to each other Bn-1→……→B2→B1, the last optical fiber combiner Cn-1 and the last optical fiber splitter Bn-1 are connected in sequence and adjacent to each other Cn-1→Bn-1, forming the optical link C1→C2→……→Cn-1→Bn-1→……→B2→B1, the number of optical fiber combiners and the number of optical fiber splitters are equal and paired one by one, the branch path incident optical fiber and the branch path outgoing optical fiber are connected with the corresponding transceiver integrated optical modules D1, D2, …, Dn respectively, the transmitting end of the transceiver integrated optical module is connected with the branch path (O→E2) of the optical fiber combiner, the receiving end of the transceiver integrated optical module is connected with the branch path (Q2→I) of the optical fiber splitter, and the number of transceiver integrated optical modules is one more than the number of optical fiber combiners. Any one transceiver integrated optical module forms a ring circuit (D1→C1→C2→……→Cn-1→Bn-1→……→B2→B1→D1) with the optical fiber link.

[0052] In the above optical fiber communication link, the transmitting wavelengths of all the transceiver integrated optical modules Dn,..., D2, D1 are the same, the modulation modes are the same, the detection receiving wave bands are the same, and the demodulation modes are the same. The optical signal output from the transmitting end of any transceiver integrated optical module can enter the receiving end of all the transceiver integrated optical modules including itself in turn. For example, the signal output from the transmitting end O of the transceiver integrated optical module D2 enters the link through the branch outgoing optical fiber E2 of C2, is transmitted along the link, enters the transceiver integrated optical modules Dn,..., D2 in turn through the branch outgoing optical fiber Q2 of the optical fiber beam splitters Bn-1,..., B2, B1, and enters the transceiver integrated optical module D1 through the main outgoing optical fiber Q3 of the last optical fiber beam splitter B1 of the link.

[0053] In the optical fiber communication link, the branch outgoing optical fiber splitting ratio of the optical fiber beam splitter is (1 / n)%, and the main outgoing optical fiber splitting ratio is ((n-1) / n)%. The optical signal starts from the optical fiber beam splitter Bn-1, and the optical power split by the branch outgoing optical fiber Q2 gradually decreases. Taking 10 devices as an example, the total number of optical modules n=10, (1 / n)%:((n-1) / n)=10%:90%. In an ideal case, the optical loss of the optical connectors is ignored. Therefore, the optical power ratio received by the devices from the 10th device to the 2nd device is 10.00%, 9.00%, 8.10%, 7.29%, 6.56%, 5.91%, 5.31%, 4.78%, and 4.31% in turn, and the optical power ratio received by the 1st device is 38.74%. In actual use, the optical loss of a single connection is about 1%, and the actual optical power ratio received by the devices is slightly lower than the above data.

[0054] In the above optical fiber communication link, the serial numbers of the optical modules with different serial numbers are distinguished by the addresses of the connected devices. The transmitted data packet contains the transmitting end address and the receiving end address, and any receiving end can analyze the address information. The above optical link constitutes a unidirectional and centerless optical communication link. Any transceiver integrated optical module can perform asynchronous communication with one or more optical modules, that is, the optical fiber communication link only allows one device to transmit data at the same time period, and allows all devices to receive data at the same time, thereby realizing channel sharing.

[0055] As shown in Figure 4 To realize time division multiplexing of the link, the application provides a "channel permission allocation method" corresponding to the optical communication link. The channel of the optical link used by any transceiver integrated optical module and the corresponding device in the optical link is allocated according to the method, that is, the channel use of each device is operated according to the logical diagram in the figure.

[0056] After initialization is completed, each device must wait for t seconds, send data according to the channel state, or continue to wait.

[0057] According to the definition given in the present application, the time unit for all devices in the system to occupy the channel to send data is T seconds (0.01≤T≤0.2), and it is agreed that the duration of any device occupying the channel does not exceed 2T seconds. In this embodiment, T=0.05, and the duration of any device occupying the channel does not exceed 0.1 second.

[0058] As shown in Figure 5 In this embodiment, 8 devices are connected in the optical link connection mode of the present application to form a system. The 8 devices are represented by M1, M2, M3, M4, M5, M6, M7, and M8, and the corresponding optical modules are D1, D2, D3, D4, D5, D6, D7, and D8. The transmitting end O of D1, D2, D3, D4, D5, D6, D7, and D8 is connected to the branch incident optical fiber E1 of the fiber combiner C1 and the branch incident optical fiber E2 of the fiber combiners C1, C2, C3, C4, C5, C6, and C7 of the optical link, and the receiving end I of D1, D2, D3, D4, D5, D6, D7, and D8 is connected to the branch outgoing optical fiber Q3 of the fiber splitter B1 and the branch outgoing optical fiber Q2 of the fiber splitters B1, B2, B3, B4, B5, B6, and B7 of the optical link.

[0059] In this embodiment, the frequency authority F of device M1 is agreed to be 4, i.e., device M1 is allocated a channel authority at most 4 times within 1 second, and the duration of each data transmission is at most 0.1 second. The frequency authority F of device M4 is agreed to be 2, i.e., device M4 is allocated a channel authority at most 2 times within 1 second, and the duration of each data transmission is at most 0.1 second. The frequency authority F of devices M2, M3, M5, M6, M7, and M8 is agreed to be 1, i.e., device M2, M3, M5, M6, M7, and M8 are allocated a channel authority at most 1 time within 1 second, and the duration of each data transmission is at most 0.1 second.

[0060] Figure 6 The system shown in Figure 5 is automatically sorted and the channel authority is allocated in 5 typical states according to the "channel authority allocation method". As shown in Figure 6 The system formed in this embodiment can be divided into 20 transmission windows (one window corresponds to one time unit of 0.05 second) within 1 second, Figure 6 where Nul represents an idle channel.

[0061] State S1: part of the devices in the system (such as only M1, M2, M3, and M5) complete initialization, and devices M1, M2, M3, and M5 enter the listening state according to the flow shown in Figure 5 .

[0062] M1 has the highest frequency privilege and its corresponding sequence number is 1. According to the calculation method of t, t=ΔT mod T+δT, at the same time, each device has the same ΔT but different δT. M1's δT=0.0002×n=0.0002×1=0.0002, M2's δT=0.0004, M3's δT=0.0006, and M5's δT=0.0010. Obviously, M1's δT is the smallest, so M1 obtains channel privilege first and sends data. The duration of M1 occupying the channel does not exceed 0.05 seconds. After 0.05 seconds, M1 finishes sending data and releases the channel. Since the interval between two consecutive data transmissions by M1 must not be less than 0.25 seconds, M1 continues to wait until the fifth T (0.25 seconds) ends before meeting the condition for transmitting data again. Then, M2, M3, and M5 are automatically sorted in ascending order of δT within 0.25 seconds to obtain channel access, transmit data, and release the channel in turn. Then they continue to wait for the next window that meets the conditions. During the period from the 6th T to the 20th T, according to the frequency access, only M1 has 3 more windows for transmitting data. M2, M3, and M5 need to continue to wait. Starting from the 21st T, the next cycle begins, repeating the situation of the 1st second. This state is maintained until the system state changes. State S2: All system devices have completed initialization, according to... Figure 5 As shown in the process, devices M1, M2, M3, M4, M5, M6, M7, and M8 all enter listening mode. Compared to S1, the system state has changed. It is agreed that M1 has a frequency permission of 4, and M4 has a frequency permission of 2. That is, within 1 second, M1 will be allocated a window for sending data 4 times, and M4 will be allocated a window for sending data 2 times. The order of each device will be recalculated.

[0063] Each device automatically sorts and sends data, assuming that the channel occupancy time does not exceed 1 T, i.e., 0.05 seconds. Following the same δT calculation method as S1, the δT values ​​for M1, M2, M3, M4, M5, M6, M7, and M8 are 0.0002, 0.0004, 0.0006, 0.0008, 0.0010, 0.0012, 0.0014, and 0.0016, respectively. At any given time, M1 has the highest privilege, and M8 has the lowest privilege.

[0064] From the first T to the fifth T, M1, M2, M3, M4 and M5 will obtain the channel permission to send data in turn, at the starting moment of the sixth T, M1, M6, M7 and M8 all need to send data, but M1 has the highest permission, M1 obtains the channel permission to send data preferentially, M6, M7 and M8 send data in turn after M1 sends data for the second time, after M8 ends, all devices have no data sending demand during the period of the tenth T, so the channel is idle, at the eleventh T, M1 sends data for the third time, at the twelfth T, the channel is idle, at the thirteenth T, the channel is idle, because the frequency permission of M4 is 2 and the time interval is 0.5 seconds, i.e. 10 T, and M4 sends data for the last time at the fourth T, so at the starting moment of the fourteenth T, M4 will obtain the channel permission to send data again, after that, at the fifteenth T, the channel is idle, M1 sends data for the third time at the sixteenth T, at the seventeenth T, the channel is idle, at the eighteenth T, the channel is idle, at the nineteenth T, the channel is idle, at the twentieth T, the channel is idle, at this time, all devices send data in 1 second, from the twenty-first T, the next cycle is entered, which will repeat the situation of the first second, and this state is maintained until the system state changes; State S3: All devices of the system complete initialization, it is agreed that two devices (M1 and M6) with different frequency permissions in the devices need to temporarily occupy the channel for more than T seconds (M1 for the second time and M6 for the first time) according to the system requirements, but not more than 2T seconds, compared with S2, the system state changes, and the sorting of the devices will be recalculated.

[0065] According to the same reasoning, the system state changes, so that M6 needs to continue to send data at the eighth T, the sending window of M7 is delayed by 1 T and is arranged at the ninth T, M1 continues to send data at the seventeenth T, and other states remain unchanged, when (M1) (M6) no longer needs to send data for an extended time in the next cycle, the sorting state of the devices will automatically return to S2; State S4: All devices of the system complete initialization, it is agreed that three devices (M1, M6 and M7) with different frequency permissions in the devices need to temporarily occupy the channel for more than T seconds (M1 for the third time, M6 for the first time and M7 for the first time) according to the system requirements, the temporary occupation of the channel lasts for more than T seconds but not more than 2T seconds, compared with S3, the system state changes; According to the same reasoning, on the basis of the S3 system state, the state changes cause the 8th T, M6 needs to continue to send data, the M7 sending window is sequentially delayed by 1 T backward, needs to continuously occupy 2 T, the 9th and 10th T are occupied by M7, M8 originally in the 10th T, but is occupied by M7, can only be sequentially delayed backward, the 11th T starts, M1 and M8 need to send data, because the priority of M1 is greater than that of M8, M1 sends first, and M8 can only continue to be sequentially delayed backward and send data in the 12th T. Other states remain unchanged, when in the next round of circulation, (M1, M6, M7) no longer needs to extend the time to send data, the sorting state of each device will automatically return to S2. State S5: All devices of the system complete initialization, at a certain moment when the system is stably running, part of the devices (M3, M6) are closed due to the need of system running or faults, the system state changes, and the sorting of each device will be recalculated.

[0066] According to the same reasoning, relative to the state S2, M3 and M6 automatically exit the sorting, M4 will obtain the channel permission immediately after M2 sends data, and then M5 and M7 will obtain the channel permission in turn after M4 releases the channel, so in the sorting sequence, M1, M2, M4, M5, M7, M1, M8, M4, M1…… are automatically formed, and others remain unchanged.

[0067] The above process only lists several typical states, in the process of system running, various program changes such as adjusting the on-off sequence of devices, adjusting the time of sending data, adjusting the length of sending data, adjusting the frequency permission of devices and the like will change the state of the system, but no matter what state the system changes into, the channel permission allocation method can adaptively complete the channel allocation. It not only ensures that the devices with high permissions of the system send data on time, but also dynamically adapts to the system state changes caused by adding, reducing and deleting devices, and is suitable for complex system application scenarios.

[0068] The above embodiment illustrates the implementation process and result of the channel allocation method provided by the application, in combination with the data bandwidth description described in the foregoing, in one timing unit 0.05 seconds of sending data, the communication data amount of the optical fiber communication link provided by the application can exceed 5 MB, far exceeding the total bus data transmission demand (KB order of magnitude) of current various types of complex systems. It can be seen that the system described in the above embodiment can transmit instructions, state parameters, user data, sensor data, software data and the like, but is not limited thereto.

[0069] In summary, the application provides a kind of adaptive channel right allocation optical fiber communication link, adopts optical fiber combiner, optical fiber beam splitter, transceiver integrated optical module to form link, by time parameter configuration, using the method of sequentially differentiated delay time, ensure that each device does not produce time conflict when allocating channel right, in the case of no top control, realize the automatic ordering of the channel right of each device, using frequency right and order setting, give priority to some special equipment, ensure that it can send data in a relatively fixed time window, high bandwidth optical medium physical link, ensure the timeliness of asynchronous communication between each device.The application is suitable for the bus data transmission application scene of current various types of complex systems.In addition, the optical fiber medium has the characteristics of not being affected by electromagnetic interference, small space occupation, light weight, simple wiring and the like, using the optical fiber communication link provided by the application as a bus can greatly reduce the cable complexity, effectively reduce the cable weight, thereby reducing the system cost, and has important significance for the research and development of new satellite bus.

[0070] Through the description of the specific embodiments, the technical means and effects taken by the application to achieve the predetermined purposes can be more deeply and specifically understood, however, the accompanying drawings are only provided for reference and illustration, and are not used to limit the application.

Claims

1. A method for adaptive channel allocation in an optical link, characterized in that, The optical link includes: multiple fiber combiners connected end-to-end and multiple fiber splitters connected end-to-end. The last fiber combiner is connected to the first fiber splitter to form an optical link. The number of fiber combiners and fiber splitters is equal and they are paired one-to-one to connect to a transceiver optical module. Each transceiver optical module connects to one device, and the devices exchange information through the optical link. The method includes: A10: After any transceiver optical module and its corresponding device are initialized, the data transmission period is initialized to T seconds, and the receiver is initialized to the normally open state to receive communication signals immediately. A20: After any transceiver optical module and its corresponding device in the optical link are initialized, wait for t seconds. The transmitting end of the transceiver optical module prepares data packets as needed and at the same time determines whether the receiving end has a signal. A30: If the receiving end does not receive a signal, it determines whether to send a data packet based on the device's frequency permissions and the running program. If so, it directly sends the prepared data packet. A40: After the data packet is sent, determine whether to terminate the program; if yes, terminate; otherwise, jump to step A20 and wait t seconds to continue.

2. The method for adaptive channel allocation of an optical link according to claim 1, characterized in that, In step A20, the waiting time t changes dynamically based on the current absolute time, data transmission cycle, delay time, and device serial number.

3. The method for adaptive channel allocation of an optical link according to claim 2, characterized in that, In step A20, the waiting time t is calculated using the following formula: t = ΔT mod T + δT; Where ΔT is the fractional part of the current absolute time in seconds, δT is the delay time, and mod is a C language operator that represents the remainder operation.

4. The method for adaptive channel allocation of an optical link according to claim 1, characterized in that, In step A30, if the receiving end receives a signal, it parses the source address and destination address of the signal. First, it determines whether the source address is the address of this device. If it is, it means that the signal comes from this device. The process jumps to determine whether to send a data packet to continue execution according to the device's operation process. If not, it further determines the destination address. If the destination address is not the address of this device, the data is discarded and the process returns to determine whether a signal has arrived; If the destination address is the address of this device, then process the information until processing is complete; After data processing is complete, determine whether to end reception. If not, the process returns to determine whether a signal has arrived. If so, it jumps to determine whether to end the procedure.

5. The method for adaptive channel allocation of an optical link according to claim 4, characterized in that, In step A40, if any of the following conditions are met, the process flow will determine whether to terminate the program: After the data packet is sent, the program determines whether to send another data packet; if the result is no, the program determines whether to stop receiving; if the result is yes, the program determines whether to stop receiving.

6. The method for adaptive channel allocation of an optical link according to claim 1, characterized in that, In step A30, the total time taken for each device to continuously send data packets is set to be less than or equal to 2T.

7. The method for adaptive channel allocation of an optical link according to claim 1, characterized in that, In step A30, the frequency permission value F represents the maximum number of times the corresponding device sends data within 1 second; 1≤F≤0.2 / T, 0.01≤T≤0.2, T is an integer multiple of 0.01, and the time interval between two consecutive times the device obtains channel permission is not less than 1 / F seconds.

8. The method for adaptive channel allocation of an optical link according to claim 7, characterized in that, The method further includes: adjusting the frequency permission value F according to the frequency at which the device sends data.

9. The method for adaptive channel allocation of an optical link according to claim 8, characterized in that, For devices with the same frequency access, the smaller the sequence number of the corresponding optical module, the shorter the waiting time t, and the higher the channel access.

10. The method for adaptive channel allocation of an optical link according to any one of claims 1-9, characterized in that, The information exchanged includes: instructions, status parameters, user data, some software packages, and sensor data.

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