An ultraviolet light cooperative networking method and system based on dynamic time slot allocation

Abstract

This invention discloses a method and system for cooperative ultraviolet (UV) optical networking based on dynamic time slot allocation, belonging to the field of free-space optical communication and networking technology. The networking method includes communication between nodes based on a pre-constructed frame structure framework, and employs a pre-constructed synchronization mechanism to ensure frame synchronization between nodes. The pre-constructed frame structure framework includes synchronization subframes, notification subframes, and data subframes. The notification subframes contain corresponding mapping information between active nodes and data subframes, and the data subframes contain several data time slots. Corresponding active nodes alternately occupy the data time slots according to the corresponding mapping information. By constructing a frame structure framework that enables dynamic time slot allocation, the advantages of synchronous communication and dynamic time slot allocation are simultaneously achieved during UV network node communication, based on this frame structure framework and synchronization mechanism, thus improving both network stability and channel utilization.

Description

Technical Field

[0001] This invention relates to an ultraviolet light cooperative networking method and system based on dynamic time slot allocation, belonging to the field of free space optical communication and networking technology. Background Technology

[0002] Ultraviolet (UV) communication has significant advantages such as non-line-of-sight communication, strong anti-interference capability, good confidentiality, and low background light interference, making it an ideal means to meet the needs of temporary communication scenarios in complex electromagnetic environments such as covert communication on modern battlefields and post-disaster sites.

[0003] In the early stages of ultraviolet (UV) communication technology research, scholars primarily focused on the performance of UV light at the physical level. At that time, limited by the hardware devices available for UV communication, its transmission distance and data rate were relatively low, and mature applications were mainly limited to point-to-point UV communication systems. Later, with in-depth research into UV point-to-point communication models and UV networks, scholars from various countries began to focus on key access mechanisms and networking methods in UV networking. Combining UV communication technology with wireless ad hoc networks to form wireless UV networks can utilize the excellent characteristics of UV communication, such as non-line-of-sight communication, omnidirectional coverage, high security, low resolution, and strong anti-interference capabilities, while also compensating for the insufficient communication distance. With technological innovations in UV components and the maturation of point-to-point UV communication systems, the research direction of UV communication has gradually shifted towards UV communication networks.

[0004] Ultraviolet (UV) network topology methods can generally be divided into contention-based and scheduling-based methods. Contention-based methods are based on asynchronous burst-based random access. In the asynchronous communication of contention-based methods, there is an idle state where the channel is not occupied by any node, facilitating random node access, dynamic access, and changes in network topology. Furthermore, random access protocols do not require much coordination overhead, resulting in stronger network adaptability and lower energy consumption. However, when the channel is idle, nodes in contention-based methods lose information about the channel state. This is especially true when UV communication nodes are in rapid motion; large dynamic fluctuations in signal amplitude, wide background noise levels, and rapid phase changes lead to drastic channel state changes, causing severe interference to communication. Moreover, contention-based methods struggle to address the hidden terminal problem, and their network performance significantly degrades with increasing traffic load due to increased transmission collisions. More seriously, under high-density loads, contention-based methods struggle to ensure reliable data service reception and bounded transmission time delays. Scheduling-based networking methods, also known as non-contention-based networking methods, allocate channel resources to a single terminal node for a given time period, with no other nodes competing for these resources. Compared to other scheduling-based networking methods, time-division multiple access (TDMA)-based methods offer advantages such as fair channel access for communication terminals, high channel utilization, good communication reliability, and bounded network latency. However, TDMA methods based on fixed time slot allocation have unavoidable drawbacks: the size of the time slot allocated to a node is inversely proportional to the number of nodes, leading to increased network latency, low link utilization, and unsatisfactory throughput. Furthermore, synchronous communication relies on the pre-allocation of time slots, and the waste of channel resources when node traffic is uneven is a problem that TDMA-based networking methods struggle to solve.

[0005] Therefore, there is an urgent need to provide an ultraviolet light networking communication method that combines the advantages of stable synchronous communication signals and the ease of dynamic time slot adjustment in asynchronous communication. Summary of the Invention

[0006] This invention provides a method and system for cooperative ultraviolet (UV) network networking based on dynamic time slot allocation. By constructing a frame structure framework that enables dynamic time slot allocation, the advantages of synchronous communication and dynamic time slot allocation are simultaneously achieved during UV network node communication, overcoming the shortcomings of existing technologies.

[0007] To achieve the above objectives, the present invention is implemented using the following technical solution.

[0008] On one hand, the present invention provides a method for cooperative networking of ultraviolet light based on dynamic time slot allocation, comprising:

[0009] Communication between nodes is based on a pre-built frame structure framework, and a pre-built synchronization mechanism is used to ensure frame synchronization between nodes. The pre-built frame structure framework includes synchronization subframes, notification subframes, and data subframes. The synchronization subframe is used to provide the frame start time that is easy for each node to identify. The notification subframe contains the corresponding mapping information between active nodes and data subframes. The data subframe contains several data time slots.

[0010] The corresponding active nodes take turns occupying the data time slots according to the corresponding mapping information.

[0011] Optionally, the pre-built frame structure framework format is: 8UT synchronization subframe + 8UT notification subframe + n×63UT data subframe, wherein the unit time UT is 10 bits, n represents the number of network nodes in the cluster, and the data subframe contains n data time slots.

[0012] Optionally, the format of the synchronization subframe is: 2UT low level + 2UT high level + 2UT low level + 1UT high level + 1UT low level.

[0013] Optionally, in the data subframe, each data time slot includes a 2UT reporting period and a 61UT data period. The format of the active signal output during the reporting period is B00001000HHHH00010000, and the format of the inactive signal output during the reporting period is B00001000000000010000. Among them, the two bit 1 signals are micro-synchronization signals that all nodes in the cluster emit light. The n data time slots are numbered one-to-one with the n nodes in the cluster. The active or inactive signal output during the reporting period in each data time slot represents whether the corresponding node is active or inactive.

[0014] Optionally, the notification subframe includes n bit segments corresponding to n data time slots, and the output signal of each bit segment corresponds to the node number within the cluster. Based on the correspondence between the bit segments and the data time slots, and the correspondence between the bit segment output signal and the node number, the mapping relationship between active nodes and data time slots is obtained.

[0015] Optionally, the pre-built synchronization mechanism includes:

[0016] Mechanism 1: All nodes in the network track the transition edge of the electrical signal from bit 0 to bit 1 and adjust the phase of the next bit according to the transition edge to maintain strict bit synchronization. If a deviation occurs, the node with the earliest transition edge from bit 0 to bit 1 is used as the standard for timely adjustment.

[0017] Mechanism 2: All nodes in the network simultaneously send the synchronization subframe at the start of the frame;

[0018] Mechanism 3: All nodes make minor adjustments to the bit phase after receiving the micro-synchronization signal.

[0019] Optionally, the corresponding active nodes alternately occupying the data time slots according to the corresponding mapping information includes:

[0020] The master node collects relevant active node information based on the active signals displayed during the reporting period;

[0021] The master node transmits the notification subframe to other nodes in the entire ultraviolet network topology;

[0022] The corresponding active node occupies the data time period according to the output signal of each bit segment in the notification subframe.

[0023] On the other hand, the present invention provides an ultraviolet light cooperative networking system based on dynamic time slot allocation, including nodes in the ultraviolet light network topology;

[0024] The node includes a processor, which is configured to perform the following steps:

[0025] Communication between nodes is based on a pre-built frame structure framework, and a pre-built synchronization mechanism is used to ensure frame synchronization between nodes. The pre-built frame structure framework includes synchronization subframes, notification subframes, and data subframes. The notification subframes contain the corresponding mapping information between active nodes and data subframes, and the data subframes contain several data time slots.

[0026] The corresponding active nodes take turns occupying the data time slots according to the corresponding mapping information.

[0027] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: The networking method in this application is designed based on synchronous communication, and a sound mechanism ensures frame synchronization, greatly eliminating the impact of node movement on network performance. Simultaneously, through the construction of a frame structure framework that allows for node time slot adjustment, data time slots can be flexibly allocated to active nodes in the network within the designed networking method framework. This improves channel utilization and increases network throughput while enhancing network stability, achieving a highly efficient ultraviolet light networking communication process. Attached Figure Description

[0028] Figure 1 The diagram shows a flowchart of an ultraviolet light cooperative networking method based on dynamic time slot allocation in one embodiment of the present invention.

[0029] Figure 2 The diagram shown is a schematic representation of the frame structure in one embodiment of the present invention.

[0030] Figure 3The diagram shown is a network timing diagram based on an ultraviolet light cooperative networking method in one embodiment of the present invention. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention. Example 1

[0032] refer to Figure 1 This embodiment provides a method for cooperative networking of ultraviolet light based on dynamic time slot allocation, including:

[0033] Communication between nodes is based on a pre-built frame structure framework, and a pre-built synchronization mechanism is used to ensure frame synchronization between nodes. The pre-built frame structure framework includes synchronization subframes, notification subframes, and data subframes. The synchronization subframe is used to provide the frame start time that is easy for each node to identify. The notification subframe contains the corresponding mapping information between active nodes and data subframes. The data subframe contains several data time slots.

[0034] The corresponding active nodes take turns occupying the data time slots according to the corresponding mapping information.

[0035] A frame structure framework capable of node time slot adjustment was constructed based on a cross-layer design. During ultraviolet network node communication, this frame structure framework and synchronization mechanism simultaneously achieve the advantages of synchronous communication and dynamic time slot allocation, thus improving both network stability and channel utilization. Example 2

[0036] Based on Example 1, this example also incorporates the following design.

[0037] The pre-built frame structure framework format is: 8UT synchronization subframe + 8UT notification subframe + n×63UT data subframe, where UT is a unit of 10 bits, n represents the number of network nodes in the cluster, and the data subframe contains n data time slots.

[0038] Taking n=16 as an example, 1024 UTs are defined as one frame length. The frame structure format of this cooperative networking method is: 8UT synchronization subframe + 8UT notification subframe + 16×63UT data subframe. The data subframe contains 16 data time slots, specifically as follows... Figure 2 As shown. The explanations of each subframe in the frame structure are as follows.

[0039] 1. Synchronization subframe: The format is 2UT low level + 2UT high level + 2UT low level + 1UT high level + 1UT low level. The unique format design of this subframe is completely different from other parts of the frame structure, which facilitates the synchronization calibration of each node in the network.

[0040] 2. Notification Subframe: Contains the corresponding mapping information between active nodes and data subframes. The notification subframe is divided into 16 bit segments, each bit segment corresponding to one of the 16 data time slots in the cluster. Each bit segment consists of 4 bits. The possible output signals 0000~1111 of the 16 bit segments represent the node numbers in the 16 clusters, thus forming the corresponding mapping relationship between active nodes and data time slots.

[0041] 3. Data Subframe: Contains 16 data time slots. Each data time slot consists of a reporting period and a data period. The first two UT units (20 bits) of a data time slot are the reporting period, and the last 61 UT units are the data period. The format of the active signal output during the reporting period is B00001000HHHH00010000, and the format of the inactive signal output during the reporting period is B00001000000000010000. The two 1-bit signals are micro-synchronization signals that illuminate all nodes within the cluster. Assuming there are 16 nodes in the cluster network topology and 16 data time slots in the data subframe, the 16 data time slots are numbered from 0000 to 1111, meaning that the active or inactive signal output during the reporting period in each data time slot represents whether the corresponding node is active or inactive.

[0042] The designed networking framework is not limited to 16 nodes and can be easily expanded to 32 or more nodes by modifying the frame structure.

[0043] This networking method relies heavily on strict frame synchronization among all nodes in the network, which is achieved through the following mechanism.

[0044] 1. All nodes in the network track the transition edge of the electrical signal from bit 0 to bit 1 and adjust the phase of the next bit according to the transition edge to maintain strict bit synchronization. If a deviation occurs, the node with the earliest transition edge from bit 0 to bit 1 is used as the reference for timely adjustment to achieve bit synchronization, that is, each UT of each node is strictly aligned.

[0045] 2. All nodes in the network simultaneously send a synchronization pulse at the start of the frame. The format of this subframe is completely different from other parts of the frame structure, making it easy for each node to identify and track the electrical signal transition edge from bit 0 to bit 1, so as to achieve the calibration of node synchronization in the network.

[0046] 3. The reporting time format of active nodes in the data time slot is B00001000HHHH00010000, where the two bit 1 signals are micro synchronization signals that are emitted by all nodes. After receiving the micro synchronization signals, all nodes can make micro-adjustments to the bit phase to correct synchronization deviations in the communication process.

[0047] The specific implementation method of this networking method is combined with, for example: Figure 3 The network timing diagram shown is used for illustration.

[0048] Step 1: All nodes simultaneously send synchronization subframes for frame synchronization, tracking the transition edge of the optical signal from bit 0 to bit 1, and precisely adjusting the next bit signal based on the transition edge. If a deviation occurs, adjustments are made promptly based on the time of the node that first sent bit signal 1. Therefore, all nodes in the network are synchronized with the node with the faster clock.

[0049] Step 2: In the i-th frame, the active nodes in the network (node ​​1 and node j) display active signals during the corresponding reporting period so that the master node can collect information about the active nodes.

[0050] Step 3: The master node transmits the notification subframe to the entire network.

[0051] Step 4: In the (i+1)th frame, the corresponding active nodes (node ​​1 and node j) alternately occupy the 61×16UT data time period according to the corresponding mapping information in the notification subframe, so as to realize the dynamic allocation of data subframes and improve channel utilization. Example 3

[0052] This embodiment provides an ultraviolet light cooperative networking system based on dynamic time slot allocation, including nodes in an ultraviolet light network topology;

[0053] The node includes a processor, which is configured to perform the following steps:

[0054] Communication frames between nodes are generated based on a pre-built frame structure framework, and a pre-built synchronization mechanism is used to ensure frame synchronization between nodes. The pre-built frame structure framework includes synchronization subframes, notification subframes, and data subframes. The notification subframes contain mapping information between active nodes and data subframes, and the data subframes contain several data time slots.

[0055] The corresponding active nodes take turns occupying the data time slots according to the corresponding mapping information.

[0056] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0057] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0058] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0059] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0060] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for cooperative networking of ultraviolet light based on dynamic time slot allocation, characterized in that, include: Communication between nodes is based on a pre-built frame structure framework, and a pre-built synchronization mechanism is used to ensure frame synchronization between nodes. The pre-built frame structure framework includes synchronization subframes, notification subframes, and data subframes. The synchronization subframe is used to provide the frame start time that is easy for each node to identify. The notification subframe contains the corresponding mapping information between active nodes and data subframes. The data subframe contains several data time slots. The corresponding active nodes take turns occupying the data time slots according to the corresponding mapping information; The pre-built frame structure framework format is: 8UT synchronization subframe + 8UT notification subframe + n×63UT data subframe, wherein UT is a unit of 10 bits, n represents the number of network nodes in the cluster, and the data subframe contains n data time slots; The format of the synchronization subframe is: 2UT low level + 2UT high level + 2UT low level + 1UT high level + 1UT low level; In the data subframe, each data time slot includes a 2UT reporting period and a 61UT data period. The format of the active signal output during the reporting period is B00001000HHHH00010000, and the format of the inactive signal output during the reporting period is B00001000000000010000. Among them, the two bit 1 signals are micro-synchronization signals that all nodes in the cluster emit light. The n data time slots are numbered one-to-one with the n nodes in the cluster. The active or inactive signal output during the reporting period in each data time slot represents whether the corresponding node is active or inactive.

2. The ultraviolet light cooperative networking method based on dynamic time slot allocation according to claim 1, characterized in that, The notification subframe includes n bit segments corresponding to n data time slots. The output signal of each bit segment represents the node number within the cluster. Based on the correspondence between the bit segments and the data time slots, as well as the correspondence between the bit segment output signal and the node number, the mapping relationship between active nodes and data time slots is obtained.

3. The ultraviolet light cooperative networking method based on dynamic time slot allocation according to claim 2, characterized in that, The pre-built synchronization mechanism includes: Mechanism 1: All nodes in the network track the transition edge of the electrical signal from bit 0 to bit 1 and adjust the phase of the next bit according to the transition edge to maintain strict bit synchronization. If a deviation occurs, the node with the earliest transition edge from bit 0 to bit 1 is used as the standard for timely adjustment. Mechanism 2: All nodes in the network simultaneously send the synchronization subframe at the start of the frame; Mechanism 3: All nodes make minor adjustments to the bit phase after receiving the micro-synchronization signal during the reporting period.

4. The ultraviolet light cooperative networking method based on dynamic time slot allocation according to claim 3, characterized in that, The corresponding active nodes alternately occupy the data time slots according to the corresponding mapping information, including: The master node collects relevant active node information based on the active signals displayed during the reporting period; The master node transmits the notification subframe to other nodes in the entire ultraviolet network topology; The corresponding active node occupies the data time period according to the output signal of each bit segment in the notification subframe.

5. A UV cooperative networking system based on dynamic time slot allocation, characterized in that, Including nodes in the ultraviolet light network topology; The node includes a processor, which is configured to perform the following steps: Communication between nodes is based on a pre-built frame structure framework, and a pre-built synchronization mechanism is used to ensure frame synchronization between nodes. The pre-built frame structure framework includes synchronization subframes, notification subframes, and data subframes. The notification subframes contain the corresponding mapping information between active nodes and data subframes, and the data subframes contain several data time slots. The corresponding active nodes take turns occupying the data time slots according to the corresponding mapping information; The pre-constructed frame structure framework format is: 8UT synchronization subframe + 8UT notification subframe + n×63UT data subframe, wherein 10 bits of time are used as the unit time UT, n represents the number of network nodes in the cluster, and the data subframe contains n data time slots; The format of the synchronization subframe is: 2UT low level + 2UT high level + 2UT low level + 1UT high level + 1UT low level; In the data subframe, each data time slot includes a 2UT reporting period and a 61UT data period. The format of the active signal output during the reporting period is B00001000HHHH00010000, and the format of the inactive signal output during the reporting period is B00001000000000010000. Among them, the two bit 1 signals are micro-synchronization signals that all nodes in the cluster emit light. The n data time slots are numbered one-to-one with the n nodes in the cluster. The active or inactive signal output during the reporting period in each data time slot represents whether the corresponding node is active or inactive.

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