A clustering networking method based on wide-beam directional communication

Abstract

The application provides a clustering networking method based on wide-beam directional communication and belongs to the technical field of directional wireless communication networking. The method realizes the service reliability transmission of the communication nodes in the network compatible with different channel transmission characteristics through clustering. The distances between the communication nodes in the cluster are relatively short, the channels are continuous and stable, a distributed asynchronous networking mode is adopted, the distances between the communication nodes between clusters are relatively long, the channels are random and burst, and an asynchronous point-to-point communication mode is adopted. In the clustering networking scene based on the wide-beam directional communication, the method fuses the application modes of the two different channel transmission characteristics of the intra-cluster and inter-cluster, designs a unified MAC communication protocol, and improves the coverage, transmission efficiency and system capacity of the wireless communication network in some special application scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of directional wireless communication networking technology, in particular to a clustering networking method based on wide-beam directional communication. The method combines the wide-beam directional transmission technology in wireless communication, the clustering network architecture and the differentiated application of channel transmission characteristics, aiming to improve the coverage, transmission efficiency and system capacity of wireless communication network, and is suitable for some special application scenarios. BACKGROUND

[0002] With the rapid development of wireless communication technology, wireless communication networks are facing increasing number of connected devices, data transmission demand and complex and variable communication environment. Traditional wireless communication technology is difficult to meet the needs of large-scale coverage, high data transmission rate and low power consumption at the same time. In order to solve these problems, clustering networking technology emerges as the times require, which divides the network into multiple small-scale, self-organizing cluster structures, and each device in the cluster realizes efficient connection through short-distance communication, and the clusters exchange information through long-distance communication. However, the existing clustering networking method often ignores the difference between the intra-cluster and inter-cluster channel transmission characteristics, resulting in low communication efficiency, and lacks a unified communication protocol to support the integrated application of different channel transmission characteristics.

[0003] Wide-beam directional communication technology is an effective means of realizing long-distance and low-power communication. By adjusting the beam width and direction of the antenna, the reliability and efficiency of communication can be improved while ensuring coverage. However, how to apply it to clustering networking, especially in combination with the difference between intra-cluster and inter-cluster channel transmission characteristics, to realize the unified design of communication protocol, is still a problem to be solved in the current wireless communication field. SUMMARY

[0004] The purpose of the present application is to provide a clustering networking method based on wide-beam directional communication, which integrates the application of two different channel transmission characteristics of intra-cluster and inter-cluster, and designs a unified MAC communication protocol, to improve the coverage, transmission efficiency and system capacity of wireless communication network in some special application scenarios.

[0005] The technical solution adopted by the present application is:

[0006] A clustering networking method based on wide-beam directional communication, comprising the following processes:

[0007] Step 1, clustering network planning according to clustering construction rules; according to the geographical position, communication demand and channel condition of the device, the network is divided into multiple clusters, each cluster contains a certain number of devices, one device as a communication node, and the antenna beam width and direction of each cluster communication node are planned, as well as the identity, antenna direction and topological relationship of inter-cluster communication nodes are planned;

[0008] Step 2, each communication node after booting to build and maintain the network; wherein the topology connection between different clusters is based on planning designated, each communication node in the cluster through the interactive node probe frame until the topology table of each communication node converges, take the two-way link to form the whole network topology, and carry on the network maintenance;

[0009] Step 3, the cluster and inter-cluster business transmission; wherein, the cluster communication process is based on distributed link time reservation and transmission, using CSMA and TDMA hybrid MAC communication protocol to achieve; inter-cluster communication process based on spectrum measurement technology asynchronous point-to-point communication mode, and using frequency hopping anti-jamming technology to achieve; when the cluster nodes simultaneously carry on the cluster communication and inter-cluster communication, priority queuing.

[0010] Further, in step 2, each communication node in the cluster through the interactive node probe frame until the topology table of each communication node converges, take the two-way link to form the whole network topology, and carry on the network maintenance, the specific process is:

[0011] Each communication node in the cluster uses non-persistent CSMA protocol to obtain the sending opportunity in the sending interval range T1 with probability p1, sends the node probe frame carrying the current node topology table information, the neighbor node receiving the node probe frame, takes the union of its own node probe frame and the received node probe frame, and interacts until the topology table of each communication node converges to obtain the stable topology table, and takes the two-way link to form the whole network topology.

[0012] After the network is established, each communication node uses non-persistent CSMA protocol to obtain the sending opportunity of the node probe frame in the sending interval range T2 with probability p2, sends the node probe frame carrying the current node topology table information, the neighbor node receiving the node probe frame, takes the union of its own node probe frame and the received node probe frame, and interacts until the topology table of each communication node converges to obtain the stable topology table, and sets the exit timeout time τ to delete the neighbor information in the topology table, thereby carrying on the network maintenance; wherein, T1, p1, T2 and p2 are set values.

[0013] Further, in step 3, the cluster communication process is:

[0014] The communication node generates a reservation application according to traffic estimation after generating a service sending demand, then refers to the non-continuous CSMA protocol to acquire the opportunity of interacting with the reservation frame RF within a sending interval range T4 with a probability p4, and competes according to the priority according to the current sending competition queue, and when winning the competition, the sending opportunity of the reservation frame RF is really acquired; then, time synchronization is performed based on the received reservation frame, and the TDMA broadcast time slot between links is allocated by using the non-continuous five-step reservation protocol FPRP, in the allocation process, the receiving end filters the received reservation frame according to the established global network topology; wherein T4 and p4 are set values.

[0015] Further, in step 3, the inter-cluster communication process is specifically:

[0016] (1) Channel detection process, when there is an inter-cluster service transmission demand on the planned inter-cluster link, a set of fixed frequency hopping channels are selected after acquiring the sending opportunity within a sending interval range T3 with a probability p3 by using the non-continuous CSMA protocol; after receiving the channel detection frame, the best frequency hopping reply channel confirmation frame is used to communicate the best frequency point selected by the opposite end; at the same time, the reply channel confirmation frame carries the current transmission time arrangement of the receiving end, if the sending end cannot receive the channel confirmation frame within the specified time, the process is repeated; wherein T3 and p3 are set values;

[0017] (2) Service transmission process, after the service sending end receives the channel confirmation frame, the best receiving frequency point of the receiving end is acquired, then the new result is allocated and generated according to the current transmission time arrangement information of the receiving end communication node, and the best receiving frequency point of the receiving end is sent back using frequency hopping; the receiving end makes priority competition according to the latest transmission time arrangement and the current transmission time arrangement, and priority is given to inter-cluster service demand; the sending opportunity of the channel confirmation frame is calculated based on the alignment of the end of the inter-cluster reservation frame and the intra-cluster RF frame, so that the transmission time slots used by the inter-cluster service and the intra-cluster service are aligned to a common specific frame structure, which is the m information frames immediately after the inter-cluster reservation frame or the intra-cluster RF frame, the information frames contain multiple information time slots, which are respectively occupied by the inter-cluster service and the intra-cluster service, and the sending end transmits the service using the best receiving frequency point of the receiving end.

[0018] Further, in step 3, when the inter-cluster node simultaneously performs intra-cluster communication and inter-cluster communication, priority queuing is performed, and the specific process is:

[0019] (1) Sending priority queuing, when the communication node simultaneously participates in three independent sending processes based on the non-continuous CSMA protocol, i.e. the intra-cluster node detection frame, the inter-cluster channel detection frame and the reservation frame used by the FPRP interaction, the frames are queued according to the priority order of inter-cluster channel detection frame > intra-cluster node detection frame > frame used by FPRP interaction;

[0020] (2) Cluster inter-receiving end RS priority queuing, if the receiving end feedback transmission time arrangement idle time slot does not meet the inter-cluster communication requirements, the sending end competes to occupy some reserved time slots to form a new transmission time arrangement application reply; after receiving the reply, the receiving end preferentially reserves the relevant time slots for inter-cluster, and diffuses the results to the communication nodes within one to two hops of the receiving end through the FPRP protocol;

[0021] (3) Additional collision avoidance mechanism, according to the channel on-off interval, stable continuous duration and fading characteristics, the number m of information frames IF in the cluster intra-FPRP non-continuous allocation period, the inter-cluster protocol parameters T3 and p3 are selected to obtain the best parameter combination conforming to the channel transmission characteristics; the cluster intra uses fixed frequency hopping, and the cluster inter uses the best frequency hopping based on spectrum measurement.

[0022] The advantages of the present application compared with the prior art are:

[0023] 1. The device is designed uniformly, two different application scenarios based on wide beam directional communication can be fused together by using the cluster network architecture, the coverage range of the wireless communication network is expanded, and the needs of certain special application scenarios are met.

[0024] 2. The MAC communication protocol is designed uniformly, the differences and characteristics of the channel transmission characteristics of the two application scenarios are fully considered, the cluster construction and design of the wireless network are facilitated, and effective solution examples are provided for the fusion of some existing wireless networks with similar characteristics.

[0025] 3. The advantages of CSMA, FPRP and other mature protocols are combined, and the collision avoidance mechanism is designed by means of time division and frequency division, so that the transmission efficiency and system capacity of the wireless communication network are effectively improved. The frequency hopping technology and spectrum measurement technology are introduced, the differentiated channel transmission characteristics are adapted, the link anti-interference ability is improved, and the robustness and stability of the wireless communication network are increased. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is the MAC communication protocol time slot structure diagram of the present application.

[0027] Figure 2 is the flow chart of the network construction stage of the present application.

[0028] Figure 3 is the flow chart of the network working stage of the present application.

[0029] Figure 4 is the sending priority queuing diagram of the present application.

[0030] Figure 5 is the application scenario diagram of the embodiment of the present application.

[0031] Figure 6 is a topological matrix diagram of an embodiment of the present application. DETAILED DESCRIPTION

[0032] The specific embodiments of the present application are further described in detail below with reference to the accompanying drawings and examples.

[0033] Step 1, cluster network planning according to cluster construction rules. According to the geographical location of the device, communication demand and channel condition, the network is divided into multiple clusters, each cluster contains a certain number of devices, and one device acts as a communication node. The antenna beam width and direction of each cluster communication node are planned, and the identity of the inter-cluster communication node, the antenna direction and the inter-cluster bidirectional topological relationship are planned.

[0034] Step 2, each communication node after starting up carries out network construction and maintenance. The inter-cluster communication node plans the antenna direction in advance to ensure the inter-cluster bidirectional topological relationship. The cluster will use the protocol automatic networking method to establish and maintain the network.

[0035] Since the geographical location of the device in the application scenario, the communication demand and the channel condition are all based on pre-planning, the communication node position does not move in network operation, and the antenna direction is fixed. In order to speed up the network construction speed, the time is divided into network construction phase and network working phase in sequence, which correspond to network establishment and maintenance respectively, and the two rely on network topological stability as automatic switching condition. Compared with the network construction phase, the network working phase still provides new communication node access and exit function, but the convergence speed is slower than that of the network construction phase.

[0036] The network establishment uses the non-continuous CSMA protocol to obtain the broadcast transmission opportunity and establishes the network topology table. As shown in the connection part of Figure 1 .

[0037] As shown in Figure 2 , the communication node working process in the network construction phase includes the following steps:

[0038] Step 2-1, after starting up, the communication node enters the multi-channel carrier sensing sub-process to judge whether the current channel is idle.

[0039] Step 2-2, if it is idle, according to the parameter T1, p1, the sending opportunity of the node probe frame is obtained, and the current local maintained neighbor information and the topology table are written into the node probe frame broadcast transmission.

[0040] Step 2-3, if it is not idle, the multi-channel receiving judges whether it is a node probe frame, if not, it is discarded, if yes, the receiving source node neighbor information is added to the local maintained neighbor information and the topology table, and the topology table is updated.

[0041] Step 2-4, the timer is maintained from the moment of adding the neighbor information, and the timer is reset upon receiving the neighbor information again, and the neighbor information and the related topology information are deleted if the timer is expired.

[0042] After running for a period of time, the network topology converges and stabilizes, and the network enters the network working phase. In the network working phase, the network topology is maintained, and the service transmission is performed.

[0043] The network maintenance uses the non-continuous CSMA protocol to obtain the broadcast transmission opportunity, and maintains the network topology table. For example, Figure 1 as shown in the connection part of the network maintenance.

[0044] As shown in Figure 3 , the working process of the communication node in the network working phase with respect to the network maintenance includes the following steps:

[0045] Step 2-5, after switching to the network working phase, the communication node enters the multi-channel carrier sensing sub-process to determine whether the current channel is idle.

[0046] Step 2-6, if the channel is idle, the communication node enters the transmission priority competition sub-process to queue (as shown in Figure 4 ), and if the maintenance queue wins the competition, the communication node sends a channel probe frame and returns to the multi-channel carrier sensing sub-process.

[0047] Step 2-7, if the channel is not idle, the communication node receives information, discards the information if the destination is not itself, and enters the network maintenance sub-process if the destination is itself and a node probe frame is received. The network maintenance sub-process includes the steps 2-3 and 2-4, and returns to the multi-channel carrier sensing sub-process after the end.

[0048] Step 3, the service transmission is performed within the cluster and between the clusters.

[0049] The intra-cluster communication process includes the intra-cluster link time slot reservation and transmission, and is implemented by using the hybrid MAC communication protocol of CSMA and TDMA. The front part uses the non-continuous CSMA protocol to replace the time synchronization of the whole network, and performs the asynchronous communication with the adjacent nodes on demand to make local synchronization. The rear part uses the FPRP protocol to compete for the time slots for the service transmission. For example, Figure 1 as shown in the intra-cluster link time slot reservation and transmission part.

[0050] The inter-cluster communication process includes the inter-cluster channel probing and service transmission, and is implemented by using the frequency hopping anti-interference technology and the asynchronous point-to-point communication mode based on the spectrum measurement technology. The non-continuous CSMA protocol is used to randomly probe the channel quality, and if the channel is clear, the channel quality is confirmed by aligning with the destination cluster through local synchronization. The sending end is acceptance-oriented and no longer rejects, reduces the number of channel interactions, and leaves more stable transmission time for the service. For example, Figure 1 as shown in the inter-cluster channel probing and service transmission part.

[0051] When the inter-cluster nodes simultaneously perform intra-cluster communication and inter-cluster communication, priority queuing is performed, and the specific process includes three parts. First, when there are multiple simultaneous transmission opportunities in the sending competition queue, the frames are queued according to the priority order of inter-cluster channel probe frame > intra-cluster node probe frame > FPRP interaction frame. Second, when the intra-cluster and inter-cluster simultaneously compete for time slots, the relevant time slots are reserved for inter-cluster. Third, an additional collision avoidance mechanism is introduced, and according to the inter-cluster channel on-off interval, stable continuous duration and fading characteristics, the number m of information frames IF in the intra-cluster FPRP non-continuous allocation period, the inter-cluster protocol parameters T3 and p3 are reasonably selected to obtain the best parameter combination that meets the channel transmission characteristics; the intra-cluster uses fixed frequency hopping, and the inter-cluster uses the best frequency hopping based on spectrum measurement.

[0052] As shown in Figure 3 , the communication node of the network working phase about the intra-cluster and inter-cluster business transmission working process includes the following steps:

[0053] Step 3-1, after switching to the network working phase, the communication node enters the multi-channel carrier sensing sub-process, and judges whether the current channel is idle.

[0054] Step 3-2, if it is idle, enter the sending priority competition sub-process for queuing (as shown in Figure 4 ), if there is a queue that meets the conditions to win the competition, different frames are sent according to the inter-cluster and intra-cluster two different types and enter the corresponding interaction sub-process, and return to the multi-channel carrier sensing sub-process after the interaction is completed.

[0055] Step 3-3, if it is not idle, receive information, if the destination is not itself, discard it, if it is, enter different sub-processes according to the type of the received frame. If a reserved application packet RR is received, enter the FPRP interaction process, and return to the multi-channel carrier sensing sub-process after the end; if a channel probe frame is received, calculate and delay to make the inter-cluster and intra-cluster IF synchronous alignment, and enter the channel confirmation and transmission sub-process, and return to the multi-channel carrier sensing sub-process after the end.

[0056] The following is a specific embodiment:

[0057] In Figure 5In the shown application scenario, cluster 1 contains four communication nodes A1, B1, C1 and D1, and cluster 2 contains A2 and other communication nodes. The dotted lines represent the antenna beam range of each communication node, and the communication nodes within the cluster located in the wide beam range can receive the transmission information thereof. The communication nodes between the clusters located in the wide beam range can receive the transmission information thereof according to the channel transmission characteristics with a certain probability within a certain time. The solid lines represent the theoretical network topology A2-A1-(B1) / (C1-D1) constructed according to the method of the present application, wherein A2-A1 is based on pre-planning, and A1-(B1) / (C1-D1) is dynamically constructed within the cluster. A 4x4 matrix is used to represent the topology connection relationship, the lower triangle represents the receiving direction, the upper triangle represents the transmitting direction, 1 represents connection, and 0 represents no connection. The final converged full-network topology table is shown in Figure 6 (1). The intersection of the upper and lower triangles is symmetric to obtain the full-network topology table of the bidirectional link, as shown in Figure 6 (2), which is consistent with the theoretical topology.

[0058] In the network working phase, taking the unidirectional business demand of A2-A1 and A1-C1 as an example, the MAC protocol interaction process includes the following steps:

[0059] A2:

[0060] Step 1, carrier sensing, if the channel is idle, randomly select a fixed frequency hopping frequency to send a channel probe frame to A1;

[0061] Step 2, if the channel confirmation frame is not received within a specified time th, re-carrier sensing is performed;

[0062] Step 3, if the channel confirmation frame is received within a specified time th, N idle time slots in IS are reserved, assuming the first n (n<N) of them, the result is placed in the reserved application frame and sent to A1, and then the m x IF time slot structure is used to occupy the first n IS time slots in IF for business transmission.

[0063] A1:

[0064] Step 1, carrier sensing, if the channel is idle, randomly select a fixed frequency hopping frequency to send a first RR to C1 to start the FPRP interaction process to complete business transmission;

[0065] Step 2, if the channel is busy, after receiving the channel probe frame, the best frequency of the opposite end is analyzed, the next IF position is calculated and synchronized, the best frequency is selected to hop to A2 to send a channel confirmation frame within a specified time, and the inter-cluster interaction process is started, and the inter-cluster and intra-cluster business transmission is completed together.

[0066] In summary, the application fuses two different application scenarios based on wide-beam directional communication together through steps of cluster construction, network establishment and maintenance, and intra-cluster and inter-cluster traffic transmission, combines advantages of mature protocols such as CSMA and FPRP, adopts time division and frequency division means to design a conflict avoidance mechanism, introduces frequency hopping technology and spectrum measurement technology, adapts to differentiated channel transmission characteristics, finally increases network coverage, robustness and stability in special application scenarios, and effectively improves transmission efficiency and system capacity of the network.

Claims

1. A clustering networking method based on wide-beam directional communication, characterized in that, The process comprises the following steps: Step 1, cluster network planning according to cluster construction rules; according to the geographical location, communication demand and channel condition of the equipment, the network is divided into multiple clusters, each cluster contains a certain number of equipment, one equipment as a communication node, and the antenna beam width and direction of each cluster communication node are planned, and the identity, antenna direction and topological relationship of the inter-cluster communication nodes are planned; Step 2, network construction and maintenance after each communication node is started; wherein the topological connection between different clusters is based on the planning designation, and each communication node in the cluster interacts through the node probe frame until the topological table of each communication node converges, the bidirectional link is taken to form the whole network topology, and the network maintenance is carried out; Step 3, intra-cluster and inter-cluster business transmission; wherein the intra-cluster communication process is based on distributed link time slot reservation and transmission, and a CSMA and TDMA hybrid MAC communication protocol is adopted to realize; the inter-cluster communication process is based on an asynchronous point-to-point communication mode of spectrum measurement technology, and a frequency hopping anti-interference technology is adopted to realize; when the inter-cluster nodes simultaneously carry out intra-cluster communication and inter-cluster communication, priority queuing is carried out; In step 3, when the inter-cluster nodes simultaneously carry out intra-cluster communication and inter-cluster communication, priority queuing is carried out, and the specific process is as follows: (1) sending priority queuing, when the communication node simultaneously participates in three independent sending processes based on the non-continuous CSMA protocol, i.e. the cluster node probe frame, the inter-cluster channel probe frame and the reserved frame used in the FPRP interaction, the priority order is as follows: inter-cluster channel probe frame > intra-cluster node probe frame > frame used in FPRP interaction; (2) inter-cluster receiving end RS competing priority queuing, when the inter-cluster communication, if the transmission time arrangement idle time slot feedback by the receiving end does not meet the requirement of the inter-cluster communication, the sending end competes to occupy some reserved time slots to form a new transmission time arrangement application reply; after receiving the reply, the receiving end preferentially reserves the related time slots for the inter-cluster, and diffuses the result to the communication nodes within one to two hops of the receiving end through the FPRP protocol; (3) additional collision avoidance mechanism, according to the interval of inter-cluster channel on-off, stable continuous duration and fading characteristics, the number m of information frames IF in the non-continuous allocation period of intra-cluster FPRP, the inter-cluster protocol parameters T3 and p3 are selected to obtain the best parameter combination meeting the channel transmission characteristics; the intra-cluster adopts fixed frequency hopping, and the inter-cluster adopts the best frequency hopping based on spectrum measurement.

2. The method of claim 1, wherein, In step 2, each communication node in the cluster interacts through the node probe frame until the topological table of each communication node converges, the bidirectional link is taken to form the whole network topology, and the network maintenance is carried out, and the specific process is as follows: Each communication node in the cluster adopts the non-continuous CSMA protocol to obtain the sending opportunity within the sending interval range T1 with a probability p1, sends the node probe frame carrying the current node topological table information, the neighbor node receiving the node probe frame takes the union of its own node probe frame and the received node probe frame, and continuously interacts until the topological table of each communication node converges to obtain the stable topological table, and the bidirectional link is taken to form the whole network topology; After the network is established, each communication node uses the non-persistent CSMA protocol to obtain the sending opportunity of the node probe frame in the sending interval range T2 with a probability p2, sends the node probe frame carrying the current node topology table information, and the neighbor node receiving the node probe frame takes the union of the node probe frame of itself and the received node probe frame, and continuously interacts until the topology table of each communication node converges to be consistent to obtain the stable topology table, and sets the exit timeout time τ to delete the neighbor information of the current node in the topology table, thereby performing network maintenance; wherein T1, p1, T2 and p2 are set values.

3. The method of claim 2, wherein, In step 3, the intra-cluster communication process is specifically: After the communication node generates a service sending demand, a reservation application is generated according to the traffic estimation, and then the sending opportunity of the reservation frame RF interaction is obtained in the sending interval range T4 with a probability p4 according to the non-persistent CSMA protocol, and the sending opportunity of the reservation frame RF is truly obtained when the competition is won according to the priority under the current sending competition queue; then, time synchronization is performed based on the received reservation frame, and the TDMA broadcast time slot between the links is allocated by using the non-continuous five-step reservation protocol FPRP, and in the allocation process, the received reservation frame is filtered by the receiving end according to the established whole network topology; wherein T4 and p4 are set values.

4. The method of claim 3, wherein, In step 3, the inter-cluster communication process is specifically: (1) Channel probe process, when there is an inter-cluster service transmission demand on the planned inter-cluster link, a set of fixed frequency hopping frequency points are selected to send channel probe frames after obtaining the sending opportunity in the sending interval range T3 with a probability p3 according to the non-persistent CSMA protocol; after receiving the channel probe frame, the best frequency hopping frequency point of the opposite end is used to reply the channel confirmation frame to communicate the best frequency point selected by each other; at the same time, the channel confirmation frame carries the current transmission time arrangement of the receiving end, and if the sending end cannot receive the channel confirmation frame within the specified time, the process is repeated; wherein T3 and p3 are set values; (2) Service transmission process, after the service sending end receives the channel confirmation frame, the best receiving frequency point of the receiving end is obtained, then a new result is allocated according to the current transmission time arrangement information of the receiving end communication node obtained, and the receiving end is sent back using the best frequency hopping frequency point; the receiving end makes priority competition according to the latest transmission time arrangement and the current transmission time arrangement, and priority is given to the inter-cluster service demand; the sending opportunity of the channel confirmation frame is calculated based on the alignment of the end of the inter-cluster reservation frame and the intra-cluster RF frame, so that the transmission time slots used by the inter-cluster service and the intra-cluster service are aligned to a common specific frame structure, which is the m information frames immediately after the inter-cluster reservation frame or the intra-cluster RF frame, and the information frames contain multiple information time slots, which are respectively occupied by the inter-cluster service and the intra-cluster service, and the sending end uses the best frequency hopping frequency point of the receiving end to transmit the service.

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