A method and system for ultraviolet light communication cooperative networking
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ARMY ENG UNIV OF PLA
- Filing Date
- 2024-04-30
- Publication Date
- 2026-06-23
Smart Images
Figure CN118432712B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of collaborative ultraviolet light communication technology, and in particular to a method and system for collaborative ultraviolet light communication networking. Background Technology
[0002] Since the proposal of ultraviolet (UV) communication and networking technology, due to its special non-line-of-sight communication transmission mechanism, the existing MAC protocol cannot be directly applied to UV communication networks. Domestic and foreign scholars have tried to design networking methods suitable for UV networks based on the characteristics of UV communication networks and the relatively mature networking mechanisms in traditional radio frequency (RF) communication networks.
[0003] In 2011, Vavollas et al. conducted in-depth research on the connectivity of ultraviolet non-line-of-sight communication networks. They adopted a multi-node, multi-hop transmission method to expand the network coverage and discussed the impact of network parameters such as node density, bit error rate, and throughput, as well as different modulation methods on network performance.
[0004] In the same year, Ke et al. proposed a contention-based MAC layer protocol for ultraviolet (UV) networks, exploring the feasibility of using spatial multiplexing in UV communication networks and studying network performance parameters such as channel collision probability and throughput. Li et al. conducted research on neighbor discovery protocols for UV ad hoc networks and, based on the characteristics of UV non-line-of-sight transmission, proposed for the first time a neighbor discovery protocol applied to UV networks, discussing the information load rate, channel collision rate, and neighbor discovery efficiency of the neighbor discovery protocol applied to UV ad hoc networks. Wang et al. further studied the interconnection characteristics of UV communication networks.
[0005] In 2022, Li et al. conducted in-depth research on the cooperative networking method of ultraviolet self-organizing communication networks and proposed a real-time cooperative method based on bit simultaneous transmission for application in ultraviolet communication networks.
[0006] In existing research on ultraviolet (UV) self-organizing networks, short communication distances and limited network coverage are among the main challenges. Li et al.'s research achieves "full connectivity" in multi-node, multi-hop networks, completely eliminating channel resource consumption caused by channel conflicts and complex backoff algorithms, while simultaneously expanding network coverage. However, its "bit-by-bit forwarding" mechanism and the low data rate of UV communication can easily worsen the already limited network throughput. Furthermore, the protocol lacks a routing mechanism; when any node transmits data, all nodes in the network need to forward it, resulting in higher overall network power consumption. Summary of the Invention
[0007] The purpose of this invention is to provide an ultraviolet light communication cooperative networking method and system that can effectively improve network throughput and reduce overall network power consumption.
[0008] To achieve the above objectives, the present invention employs the following technical solution:
[0009] On one hand, the present invention provides a method for cooperative networking of ultraviolet light communication, comprising:
[0010] In the ultraviolet light network, all nodes complete neighbor discovery and establish a neighbor table; the neighbor table only stores distance information between nodes.
[0011] Based on the distance information stored in the neighbor table, the distance from the source node to the destination node is obtained, and the transmission time for each bit of data is dynamically adjusted according to the distance from the source node to the destination node.
[0012] Based on the distance information stored in the neighbor table, select the relay node in the shortest path from the source node to the destination node;
[0013] Data forwarding is performed based on the adjusted transmission time per bit of data and the relay nodes in the shortest path.
[0014] Optionally, the neighbor discovery process includes:
[0015] When any node in an ultraviolet network transmits data, synchronization between nodes is achieved using the synchronization fields in the headers of control frames and data frames.
[0016] Obtain the start and end times of each bit of data transmitted by any node, as well as the times when the other nodes first receive data;
[0017] Based on the start and end times of each bit of data transmitted by any node, and the times when each of the other nodes first receives data, the distance between any node and the other nodes is calculated.
[0018] After completing the synchronization between nodes and calculating the distance between any node and all other nodes, the unique ID number of any node is obtained from the data frame to complete the discovery of the neighbors of any node.
[0019] Optionally, the method for completing synchronization between nodes includes:
[0020] When a node that has not completed synchronization detects the ultraviolet light signal of a neighboring node, it immediately begins to forward the signal and stops forwarding after a period of time, continuing to monitor the signal status of the neighboring node.
[0021] When the disappearance of the ultraviolet light signal of a neighboring node is detected, the end time of each bit of data transmission and the start time of the protection time of any node are determined to complete the synchronization between nodes.
[0022] Optionally, the distance calculation method between any node and all other nodes includes:
[0023] Obtain the start time of the protection time of each of the remaining nodes and the time of the first data reception; the start time of the protection time of each of the remaining nodes is the same as the start time of the protection time of any node.
[0024] Based on the time when each of the remaining nodes first receives data and the start time of the protection period, the number of clock cycles between the time when each of the remaining nodes first receives data and the start time of the protection period can be obtained.
[0025] Obtain the duration of the protection time in clock cycles;
[0026] The time it takes for any node to transmit each bit of data is obtained by determining the start and end times of each bit of data transmitted by any node.
[0027] Subtract the number of clock cycles between the time each node transmits each bit of data and the time of protection start from the time each of the other nodes first receives data, and the number of clock cycles for the duration of protection, to obtain the distance between each node and the other nodes.
[0028] Optionally, dynamically adjusting the transmission time per bit of data based on the distance from the source node to the destination node includes:
[0029] In the ultraviolet light network, a destination node and a source node are set respectively in all nodes;
[0030] Based on the distance information stored in the neighbor table, the distance from the source node to the destination node is obtained;
[0031] Based on the distance from the source node to the destination node, the number of clock cycles required from the source node emitting the ultraviolet light signal to the destination node receiving the ultraviolet light signal is obtained.
[0032] The transmission time per bit of data is adjusted based on the number of clock cycles required from the source node emitting the ultraviolet light signal to the destination node receiving the ultraviolet light signal; the transmission time per bit of data consists of multiple clock cycles.
[0033] Optionally, selecting relay nodes in the shortest path from the source node to the destination node based on the distance information stored in the neighbor table includes:
[0034] Based on the distance information stored in the neighbor table, the distance from the source node to this node and the distance from this node to the destination node are obtained; the "this node" refers to any node in the ultraviolet light network other than the source node and the destination node.
[0035] Based on the distances from the source node to this node, the distances from this node to the destination node, and the distances from the source node to the destination node, determine whether this node is a relay node in the shortest path and obtain the determination result.
[0036] Optionally, determining whether the current node is a relay node in the shortest path includes:
[0037] If the sum of the distance from the source node to this node and the distance from this node to the destination node is equal to the distance from the source node to the destination node, then this node is a relay node in the shortest path from the source node to the destination node.
[0038] On the other hand, the present invention provides an ultraviolet light communication cooperative networking system, comprising:
[0039] The neighbor discovery module is used by all nodes in the ultraviolet light network to complete neighbor discovery and establish a neighbor table; the neighbor table stores the distance information between nodes.
[0040] The adjustment module is used to obtain the distance from the source node to the destination node based on the distance information stored in the neighbor table, and dynamically adjust the transmission time of each bit of data based on the distance from the source node to the destination node.
[0041] The judgment module is used to select the relay node in the shortest path from the source node to the destination node based on the distance information stored in the neighbor table.
[0042] The data transmission module forwards data based on the adjusted transmission time per bit and the relay nodes in the shortest path.
[0043] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:
[0044] This invention is based on a neighbor discovery protocol to complete the neighbor discovery of all nodes in an ultraviolet light network, and the neighbor table only stores the distance information between nodes, which reduces the control overhead of maintaining the neighbor table.
[0045] This invention dynamically adjusts the time for transmitting each bit of data based on the distance between the node and the destination node (distance between the source node and the destination node) when transmitting data frames, thereby improving network throughput.
[0046] This invention, based on a neighbor table, enables the selection of relay nodes in the shortest path from the source node to the destination node. When a node transmits data, only nodes on the shortest path between the source and destination nodes will participate in relay forwarding, thereby reducing the overall power consumption of the network. Attached Figure Description
[0047] Figure 1 The diagram shown is a schematic flowchart of an ultraviolet light communication cooperative networking method in one embodiment of the present invention;
[0048] Figure 2 The diagram shown is a timing diagram of neighbor discovery in one embodiment of the present invention;
[0049] Figure 3 The diagram shows the ultraviolet network structure and neighbor representation in one embodiment of the present invention.
[0050] Figure 4 The figure shown is a timing diagram of adjusting the time for transmitting each bit of data in one embodiment of the present invention;
[0051] Figure 5 The diagram shown is a schematic representation of the shortest path in one embodiment of the present invention. Detailed Implementation
[0052] 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.
[0053] The design concept of this invention originates from the fact that in bit-based simultaneous transmission protocols, the network can achieve "one-hop reachability" between any two nodes, and a node only needs to send a control frame to update its neighboring nodes in the network. While nodes can determine the distance from the source node when forwarding data frames, this protocol cannot perform path selection. When any node transmits data, all nodes in the network participate in forwarding, further degrading the already limited network throughput and increasing overall network power consumption. Therefore, to overcome this difficulty, this invention proposes an ultraviolet light communication cooperative networking method and system based on a neighbor discovery protocol. This method completes neighbor discovery for all nodes in the ultraviolet light network, and the neighbor table only stores the distance information between nodes, reducing the control overhead of maintaining the neighbor table. When nodes transmit data frames, the transmission data field can be dynamically adjusted, improving network throughput. Furthermore, the selection of relay nodes in the shortest path from the source node to the destination node is implemented, reducing overall network power consumption.
[0054] Example 1
[0055] refer to Figure 1 This invention provides a method for cooperative networking of ultraviolet light communication, comprising the following steps:
[0056] S01. All nodes in the ultraviolet network complete neighbor discovery and establish a neighbor table; the neighbor table only stores distance information between nodes;
[0057] S02. Based on the distance information stored in the neighbor table, obtain the distance from the source node to the destination node, and dynamically adjust the transmission time of each bit of data according to the distance from the source node to the destination node.
[0058] S03. Based on the distance information stored in the neighbor table, select the relay node in the shortest path from the source node to the destination node;
[0059] S04. Data forwarding is performed based on the adjusted transmission time per bit of data and the relay nodes in the shortest path.
[0060] The embodiments of the present invention can improve network throughput by dynamically adjusting the transmitted data fields when nodes transmit data frames; and can select relay nodes in the shortest path from the source node to the destination node, thereby reducing the overall power consumption of the network.
[0061] Example 2
[0062] In one specific embodiment of the present invention, step S01, in which all nodes complete neighbor discovery and establish a neighbor table, specifically includes:
[0063] The ultraviolet light network contains several nodes. Based on a neighbor discovery protocol, neighbor discovery is performed on all nodes, and a neighbor table is established, such as... Figure 3 As shown, R1-R10 and S are several nodes in the ultraviolet light network, where S represents the source node and R2 represents the destination node, i.e., D.
[0064] When one of the nodes is used as the source node to transmit data, node synchronization is completed using the synchronization fields in the header of the control frame and the data frame.
[0065] Obtain the start and end times of each bit of data transmitted by this node, as well as the times when each of the other nodes first receives data;
[0066] Based on the start and end times of the transmission of each bit of data by this node, and the times when the other nodes first receive data, the distance between this node and the other nodes is calculated.
[0067] After completing node synchronization and the distance between the node and the other nodes, the unique ID number of the node is obtained from the data frame to complete the discovery of the neighbor of the node;
[0068] Furthermore, based on the aforementioned neighbor discovery method, the neighbor discovery of other nodes in the ultraviolet light network is completed, and a neighbor table is established, which stores the distance information between nodes.
[0069] In one specific embodiment of the present invention, before neighbor discovery is completed in step S01, the bit time (T) between nodes needs to be completed. bit Synchronization, specifically including the following methods:
[0070] When a node that has not completed synchronization detects the ultraviolet light signal of a neighboring node, it immediately begins to forward the signal and stops forwarding after a period of time, continuing to monitor the signal status of the neighboring node.
[0071] When the ultraviolet light signal of a neighboring node is detected to have disappeared, the end time of transmission of each bit of data by that node (as the source node) and the start time of the protection time are determined, and synchronization is completed.
[0072] In one specific embodiment of the present invention, the method for calculating the distance between each other node and the current node (between nodes) during neighbor discovery includes:
[0073] Obtain the start time of the protection time of each of the remaining nodes and the time of the first data reception; the start time of the protection time of each of the remaining nodes is the same as the start time of the protection time of the node (as the source node);
[0074] Based on the time when each of the remaining nodes first receives data and the start time of the protection period, the number of clock cycles between the time when each of the remaining nodes first receives data and the start time of the protection period can be obtained.
[0075] Obtain the duration of the protection time in clock cycles;
[0076] Based on the start and end times of the transmission of each bit of data by the node, the time of transmission of each bit of data by the source node can be obtained;
[0077] Subtract the number of clock cycles between the time each node first receives data and the time of protection start, and the number of clock cycles for the duration of protection, from the time it takes for the node to transmit each bit of data, to obtain the distance between the remaining nodes and the current node (as the source node).
[0078] Specifically, such as Figure 2 The neighbor discovery timing diagram shown is as follows, where Source is the source node, and Relay1 and Relay2 are both nodes (relay nodes). In this UV network, there are three clock cycles T between the time Relay1 first receives data (t1) and the start time of Relay1's protection period (t3). clk The time for the source to transmit each bit of data is t0-t4 (five clock cycles T). clk The Really1 protection time lasts for 1T clock cycles. clk Therefore, it takes 1 T for Source to start emitting light until Real1 receives the signal. clk (Time it takes for the source to transmit each bit of data - three clock cycles T) clk--The protection time is the duration of the clock cycle, meaning the distance from Source to Relay1 is 1 hop. The distance from Source to Relay2 is calculated in the same way, which is 2 hops.
[0079] In one specific embodiment of the present invention, step S02 specifically includes:
[0080] In the ultraviolet light network, a destination node and a source node are set respectively in all nodes;
[0081] Since neighbor discovery for all nodes in the ultraviolet network has been completed, the distance from the source node to the destination node can be directly obtained from the information stored in the neighbor table.
[0082] Based on the distance from the source node to the destination node, the number of clock cycles required from the source node emitting the ultraviolet light signal to the destination node receiving the ultraviolet light signal is obtained.
[0083] The transmission time per bit of data is adjusted based on the number of clock cycles required from the source node emitting the ultraviolet light signal to the destination node receiving the ultraviolet light signal; the transmission time per bit of data consists of multiple clock cycles.
[0084] Specifically, such as Figure 4 As shown, Source is the source node, and Relay1, Relay2, Relay3, and Relay4 are all nodes, with Relay2 (Destination) being the destination node. In this ultraviolet network, the time t2 when the Destination first receives data and the start time t4 of the Destination's protection period are separated by two clock cycles T. clk The time for the source to transmit each bit of data is t0-t5 (five clock cycles T). clk The duration of the Destination protection time is 1T clock cycle. clk Therefore, it takes 2T from when the source starts emitting light to when the destination receives the signal. clk (Time it takes for the source to transmit each bit of data - two clock cycles T) clk --The protection time lasts for the duration of a clock cycle), meaning the distance from the source to the destination is 2 hops. During data transmission, it is only necessary to ensure that the data can be transmitted to the destination node. Therefore, the transmission time for each bit of data can be adjusted based on the distance to the destination node, where T... bit =3T clk (The clock cycles between two jumps and the protection time) compared to the original T bit =5T clkThis reduces the time to transmit each bit of data, increases data transmission speed, and improves network throughput.
[0085] In one specific embodiment of the present invention, step S03, selecting a relay node in the shortest path from the source node to the destination node, specifically includes:
[0086] Based on the distance information stored in the neighbor table, the distance from the source node to this node and the distance from this node to the destination node are obtained; the "this node" refers to any node in the ultraviolet light network other than the source node and the destination node.
[0087] Based on the distance from the source node to this node, the distance from this node to the destination node, and the distance from the source node to the destination node, determine whether this node is a relay node in the shortest path;
[0088] If the sum of the distance from the source node to this node and the distance from this node to the destination node is equal to the distance from the source node to the destination node, then this node is a relay node in the shortest path from the source node to the destination node.
[0089] Specifically, when forwarding the frame header transmitted by the source node, the node makes a judgment: if the distance between the source node and the destination node is equal to the sum of the distances between the source node and the destination node and its own distance, then it forwards the subsequent data fields, such as... Figure 5 R1 in the shortest path from the source node to the destination node is the relay node.
[0090] If the distance between the source node and the destination node is less than the sum of the distances between the source node and the destination node and this node, then subsequent data fields will not be forwarded. Figure 5 The nodes are R3, R4, R5, R6, R7, R8, R9, and R10. Through the joint judgment of all nodes, this method can achieve shortest path selection, such as... Figure 5 The diagram shows the shortest path.
[0091] Example 3
[0092] This invention provides an ultraviolet light communication cooperative networking system, comprising:
[0093] The neighbor discovery module is used by all nodes in the ultraviolet light network to complete neighbor discovery and establish a neighbor table; the neighbor table stores the distance information between nodes.
[0094] The adjustment module is used to obtain the distance from the source node to the destination node based on the distance information stored in the neighbor table, and dynamically adjust the transmission time of each bit of data based on the distance from the source node to the destination node.
[0095] The judgment module is used to select the relay node in the shortest path from the source node to the destination node based on the distance information stored in the neighbor table.
[0096] The data transmission module forwards data based on the adjusted transmission time per bit and the relay nodes in the shortest path.
[0097] 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 communication, characterized in that, include: In the ultraviolet light network, all nodes complete neighbor discovery and establish a neighbor table; The neighbor table only stores distance information between nodes; Based on the distance information stored in the neighbor table, the distance from the source node to the destination node is obtained, and the transmission time for each bit of data is dynamically adjusted according to the distance from the source node to the destination node. Based on the distance information stored in the neighbor table, select the relay node in the shortest path from the source node to the destination node; Data forwarding is performed based on the adjusted transmission time per bit of data and the relay nodes in the shortest path. Based on the distance between the source node and the destination node, the transmission time for each bit of data is dynamically adjusted, including: In the ultraviolet light network, a destination node and a source node are set respectively in all nodes; Based on the distance information stored in the neighbor table, the distance from the source node to the destination node is obtained; Based on the distance from the source node to the destination node, the number of clock cycles required from the source node emitting the ultraviolet light signal to the destination node receiving the ultraviolet light signal is obtained. The transmission time per bit of data is adjusted based on the number of clock cycles required from the source node emitting the ultraviolet light signal to the destination node receiving the ultraviolet light signal; the transmission time per bit of data consists of multiple clock cycles.
2. The ultraviolet light communication cooperative networking method according to claim 1, characterized in that, The process of discovering the neighbor includes: When any node in an ultraviolet network transmits data, synchronization between nodes is achieved using the synchronization fields in the headers of control frames and data frames. Obtain the start and end times of each bit of data transmitted by any node, as well as the times when the other nodes first receive data; Based on the start and end times of each bit of data transmitted by any node, and the times when each of the other nodes first receives data, the distance between any node and the other nodes is calculated. After completing the synchronization between nodes and calculating the distance between any node and all other nodes, the unique ID number of any node is obtained from the data frame to complete the discovery of the neighbors of any node.
3. The ultraviolet light communication cooperative networking method according to claim 2, characterized in that, The method for completing synchronization between nodes includes: When a node that has not completed synchronization detects the ultraviolet light signal of a neighboring node, it immediately begins to forward the signal and stops forwarding after a period of time, continuing to monitor the signal status of the neighboring node. When the disappearance of the ultraviolet light signal of a neighboring node is detected, the end time of each bit of data transmission and the start time of the protection time of any node are determined to complete the synchronization between nodes.
4. The ultraviolet light communication cooperative networking method according to claim 3, characterized in that, The method for calculating the distance between any node and the other nodes includes: Obtain the start time of the protection time of each of the remaining nodes and the time of the first data reception; the start time of the protection time of each of the remaining nodes is the same as the start time of the protection time of any one of the nodes. Based on the time when each of the remaining nodes first receives data and the start time of the protection period, the number of clock cycles between the time when each of the remaining nodes first receives data and the start time of the protection period can be obtained. Obtain the duration of the protection time in clock cycles; The time it takes for any node to transmit each bit of data is obtained by determining the start and end times of each bit of data transmitted by any node. Subtract the number of clock cycles between the time each node transmits each bit of data and the time of protection start from the time each of the other nodes first receives data, and the number of clock cycles for the duration of protection, to obtain the distance between each node and the other nodes.
5. The ultraviolet light communication cooperative networking method according to claim 1, characterized in that, The step of selecting relay nodes in the shortest path from the source node to the destination node based on the distance information stored in the neighbor table includes: Based on the distance information stored in the neighbor table, the distance from the source node to this node and the distance from this node to the destination node are obtained; the "this node" refers to any node in the ultraviolet light network other than the source node and the destination node. Based on the distances from the source node to this node, the distances from this node to the destination node, and the distances from the source node to the destination node, determine whether this node is a relay node in the shortest path and obtain the determination result.
6. The ultraviolet light communication cooperative networking method according to claim 5, characterized in that, The determination of whether this node is a relay node in the shortest path includes: If the sum of the distance from the source node to this node and the distance from this node to the destination node is equal to the distance from the source node to the destination node, then this node is a relay node in the shortest path from the source node to the destination node.
7. An ultraviolet light communication cooperative networking system, characterized in that, include: The neighbor discovery module is used by all nodes in the ultraviolet light network to complete neighbor discovery and establish a neighbor table; The neighbor table stores distance information between nodes; The adjustment module is used to obtain the distance from the source node to the destination node based on the distance information stored in the neighbor table, and dynamically adjust the transmission time of each bit of data based on the distance from the source node to the destination node. The judgment module is used to select the relay node in the shortest path from the source node to the destination node based on the distance information stored in the neighbor table. The data transmission module forwards data based on the adjusted transmission time per bit of data and the relay nodes in the shortest path. Based on the distance between the source node and the destination node, the transmission time for each bit of data is dynamically adjusted, including: In the ultraviolet light network, a destination node and a source node are set respectively in all nodes; Based on the distance information stored in the neighbor table, the distance from the source node to the destination node is obtained; Based on the distance from the source node to the destination node, the number of clock cycles required from the source node emitting the ultraviolet light signal to the destination node receiving the ultraviolet light signal is obtained. The transmission time per bit of data is adjusted based on the number of clock cycles required from the source node emitting the ultraviolet light signal to the destination node receiving the ultraviolet light signal; the transmission time per bit of data consists of multiple clock cycles.