A fast subnet fusion method based on directional mobile ad hoc network

Abstract

The present invention provides a rapid subnet fusion method based on a directional mobile ad hoc network, comprising: designing a fixed set of dedicated fusion time slots based on the subnet scale, thereby ensuring that any two nodes in each subnet have fusion time slots at fixed locations available; constructing a subnet fusion process, including neighbor discovery, fusion notification, target selection, and access; and designing the message content of the fusion notification so that the scope of the fusion notification is expanded to the two subnets participating in the fusion. In a directional network based on the present invention, the two fused subnet members can know the location of each other member and the fusion time slot corresponding to each potential neighbor, making it possible to align the beams of both parties at the same time. The nodes to be fused can initiate synchronization in the dedicated fusion time slot, thereby achieving more accurate synchronization with the target network and obtaining the resources allocated by the target network. In addition, the node initiating the fusion can select the optimal node to initiate synchronization based on the distance, thereby improving the success rate of the fusion.

Description

Technical Field

[0001] The present invention relates to the field of information technology, and in particular to a fast subnet fusion method based on a directional mobile ad hoc network. Background Art

[0002] Existing fast subnet convergence technology synchronizes the first subnet with the first by having the first node in the first subnet receive a signal from the second subnet and then send the timing difference and adjustment time to other nodes in the same subnet. This method works well with omnidirectional antennas.

[0003] With the development of phased array technology, communication technology based on phased array antennas has huge advantages over omnidirectional antennas in anti-interception, anti-interference and ultra-long-distance ultra-wideband communication. At the same time, compared with omnidirectional antennas + phased array antennas, single phased array antennas have the advantages of low cost, simple structure, low power consumption and small size. Therefore, networking technology based on single phased array antennas has huge application value.

[0004] In communications based on single-phased array antennas, both the sender and receiver must simultaneously enter the transmit and receive state at the agreed-upon time, with their antennas aligned with each other, for communication to occur. Therefore, in addition to addressing synchronization issues, subnet convergence in directional mobile ad hoc networks also requires solving the following problems:

[0005] Due to node mobility and location accuracy, synchronization accuracy achieved solely using the shared timing difference within the network is insufficient. The second node in the network to be merged needs to be precisely synchronized with the node in the target network and obtain the time and frequency resources allocated by the target network. For directional networks, the two synchronized nodes must understand each other's intentions and align their transmissions and receptions at agreed time slots to achieve transmission and reception matching. Existing subnet fusion technologies do not address these issues and therefore cannot be directly applied to directional mobile ad hoc networks. Summary of the Invention

[0006] The present invention aims to provide a fast subnet fusion method based on a directional mobile ad hoc network to solve the above-mentioned problems.

[0007] The present invention provides a method for rapid subnet fusion based on a directional mobile ad hoc network, comprising:

[0008] A fixed set of dedicated fusion time slots is designed based on the subnet size, ensuring that any two nodes in each subnet have fixed fusion time slots available.

[0009] Construct subnet convergence processes, including neighbor discovery, convergence notification, target selection, and access;

[0010] The message content of the fusion notification is designed so that the scope of the fusion notification is expanded to the two subnets participating in the fusion.

[0011] Furthermore, when designing a fixed set of dedicated fusion time slots based on the subnet size:

[0012] The subnet size is N nodes, and the number of nodes that can be parallelized in each fusion time slot is N / 2. The number of fusion time slots required is:

[0013] 2(N-1), N is an even number;

[0014] Or 2N, where N is an odd number.

[0015] Furthermore, each fusion time slot is divided into identical fusion time slot 1 and fusion time slot 2; fusion time slot 1 and fusion time slot 2 are both divided into several sub-time slots, and the fusion time slot of a group of parallel links occupies a pair of sub-time slots for access request and response respectively, and their positions are fixed in advance.

[0016] Furthermore, when accessing, the fusion time slot 1 or the fusion time slot 2 is arbitrarily selected for access according to the target node selected by the user; if the access fails, the fusion time slot 2 or the fusion time slot 1 is switched for access.

[0017] Furthermore, the subnet fusion process includes:

[0018] (1) Neighbor discovery: Node Net2_B on the subnet to be merged, Net2_B, can discover node Net1_A on the target subnet Net1. Through handshake, Net1_A and Net2_B obtain each other's subnet member location information, timing difference, and the starting position of the fusion time slot of subnet Net1.

[0019] (2) Fusion notification: Node Net2_B and node Net1_A send fusion notifications to other members of the subnet through their respective fusion notification processes;

[0020] (3) Target selection: Members of subnet Net2 and subnet Net1 receive the fusion notification and use the newly added node as a potential neighbor. Members of subnet Net2 also use the node that sent the fusion notification as a potential neighbor and establish a potential neighbor list. They obtain the fusion time slots corresponding to the potential neighbors according to the fixed position of the fusion time slot and record them in the potential neighbor list, which includes the subnet ID, node ID, location, and fusion time slot. Nodes of subnet Net2 select the best access target node from the potential neighbor list.

[0021] (4) Access: Each node in subnet Net2 adjusts the frame timing and system frame number before the arrival of the selected fusion time slot, completes coarse synchronization with subnet Net1, and sends an access request when the fusion time slot arrives; each node in subnet Net1 traverses its own potential neighbor list and points to the corresponding potential neighbor for reception when the associated fusion time slot arrives; the node in subnet Net1 receives the access request from the node in subnet Net2, removes the node from the potential neighbor list, adds it to the formal neighbor list, allocates resources of subnet Net1 to it, and replies to this node in the associated response time slot; the node that receives the reply removes the other party from the potential list and adds it to the formal neighbor list.

[0022] Furthermore, in step (3), the nodes of subnet Net2 select the best access target node in the potential neighbor list according to the distance.

[0023] Furthermore, the message content of the fusion notification includes:

[0024] Subnet initiating fusion: timing difference between the two subnets, system frame difference, starting frame number of the fusion timeslot, member ID and location of the target subnet;

[0025] Fusion target subnet: The member ID and location of the subnet that initiates the fusion.

[0026] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0027] 1. In the directional network based on the present invention, the two fused subnet members can know the position of each member of the other party and the fusion time slot corresponding to each potential neighbor, making it possible to align the beams of the transmitter and receiver at the same time.

[0028] 2. In the present invention, the node to be merged can initiate synchronization in a dedicated fusion time slot, thereby achieving more accurate synchronization with the target network and obtaining resources allocated by the target network.

[0029] 3. In the present invention, the node initiating fusion can select the optimal node to initiate synchronization based on the distance, thereby improving the success rate of fusion. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 Schematic diagram of the subnet fusion process.

[0032] Figure 2 This is a schematic diagram of broadcast fusion notification.

[0033] Figure 3 This is a schematic diagram of the first step of subnet fusion.

[0034] Figure 4 This is a schematic diagram of the second step of subnet fusion.

[0035] Figure 5 This is a diagram showing the relationship between subnet size and the number of fusion time slots.

[0036] Figure 6 Schematic diagram of the structure of the fused time slot.

[0037] Figure 7 The figure is a flow chart of the subnet fusion process in the fast subnet fusion method based on directional mobile ad hoc network. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0040] Example

[0041] like Figure 1 As shown, this embodiment proposes a fast subnet fusion method based on a directional mobile ad hoc network, including:

[0042] A fixed set of dedicated fusion time slots is designed based on the subnet size, ensuring that any two nodes in each subnet have fixed fusion time slots available.

[0043] Construct subnet convergence processes, including neighbor discovery, convergence notification, target selection, and access;

[0044] The message content of the fusion notification is designed so that the scope of the fusion notification is expanded to the two subnets participating in the fusion.

[0045] Specifically:

[0046] (1) Figure 1As shown in the figure, before subnet fusion: Subnet 1 (members are nodes A and D) and Subnet 2 (members are nodes B and C) are two independent subnets. Node B of Subnet 2 moves into the coverage area of Subnet 1 and discovers Node A through scanning, completing a two-way handshake. However, Node C has not yet discovered Node A because it is far away.

[0047] (2) Figure 2 As shown, the fusion notification message is broadcast: Node A and Node B respectively perform fusion notification in their respective subnets, and each node establishes its own potential neighbor list (Node B's potential neighbors are Node A / Node D; Node C's potential neighbors are Node A / Node B / Node D), obtains the corresponding fusion time slot, and determines the transceiver status on the fusion time slot; Node B / Node C selects the best access target in the potential neighbor list to obtain the relevant fusion time slot, and determines the transceiver status on the fusion time slot to be sending.

[0048] (3) Figure 3 As shown in the figure, the first step of subnet fusion is: Node B selects Node A as the access target in the fusion time slot and initiates access; at the same time, Node A points to Node B in the fusion time slot corresponding to Node B and enters the receiving state. Node B successfully accesses and becomes a member of Subnet 1.

[0049] (4) Figure 4 As shown in the figure, the second step of subnet fusion is: node C initiates access to node D in the fusion time slot; at the same time, node D points to node C in the fusion time slot corresponding to node C and enters the receiving state. Node C successfully accesses and becomes a member of subnet 1.

[0050] like Figure 5 As shown in , a dedicated fusion slot is reserved for each possible link according to the subnet size, and the position is fixed. For a subnet with a size of N nodes, the number of nodes that can be parallelized in each fusion slot is N / 2, and the number of fusion slots required is: 2(N-1) (N is an even number) or 2N (N is an odd number); Figure 5 The scale of the neutron network is 4 nodes, which requires 6 fusion time slots, each of which is used by 2 parallel links.

[0051] Furthermore, the fusion time slot is divided into fusion time slot 1 and fusion time slot 2, the latter being a repeat of the former. Both fusion time slot 1 and fusion time slot 2 are divided into several sub-time slots. The fusion time slot of a group of parallel links occupies a pair of sub-time slots for access request and response respectively, and their positions are fixed in advance. Each node can find the dedicated time slot for access based on the target node to be accessed. Figure 6As shown, links 2 and 6 occupy sub-timeslots 1 and 4. Considering that a node that selects Node B as its access target must wait until Node B is already connected before initiating access to Node B, which may result in missing Fusion Time Slot 1, Fusion Time Slot 2 is designed, which is identical to Fusion Time Slot 1. This way, each link has two dedicated Fusion Time Slots, and can choose which one to use for access based on the selected target node. If access fails in Fusion Time Slot 1, it can also try again in Fusion Time Slot 2.

[0052] like Figure 7 As shown in the figure, the subnet fusion process includes:

[0053] Neighbor Definition:

[0054] Potential neighbors: new nodes discovered for the first time and not yet confirmed;

[0055] Formal neighbor: A potential neighbor is confirmed during the access process and becomes a formal neighbor.

[0056] process:

[0057] (1) Neighbor discovery: Node A and Node B confirm the potential neighbor relationship through a two-step handshake. Node B obtains the downlink timing difference between Node A and Node B, the starting position of the fusion time slot of the subnet where Node A is located, and the position of Node A's neighbor Node D. Node B takes Node A / Node D as potential neighbors and enters them into Node B's potential neighbor list. Node A obtains the position of Node B's neighbor Node C. Node A takes Node B / Node C as potential neighbors and records them into Node A's potential neighbor list. In addition to the position, the fusion time slot corresponding to each potential neighbor is also recorded. An aging timer is started for each node in the potential neighbor list. When the timer times out, the timed-out node is removed from the potential neighbor list.

[0058] Table 1, list of potential neighbors of node B:

[0059]

[0060] Table 2, list of potential neighbors of node A:

[0061]

[0062]

[0063] (2) In the subnet fusion stage, node B selects a fusion target and sends a fusion notification to its own subnet, at which point node C is downgraded to a potential neighbor; node A sends a fusion notification to its own subnet.

[0064] Table 3, list of potential neighbors of node B:

[0065]

[0066] Table 4, content of the fusion notification message sent by Node B:

[0067] ID of node A Node A location ID of node D Node D location Timing difference of the target subnet Fusion starting timeslot number System frame number deviation

[0068] Table 5, content of the fusion notification message sent by node A:

[0069] Node B's ID Node B location ID of node C Node C location

[0070] (3) Node C receives the fusion notification and records Node A / Node B / Node D in its potential neighbor list, and selects the node closest to it as the access target; Node D receives the fusion notification and records Node B and Node C as potential neighbors, establishes a potential neighbor list, and records the fusion time slot corresponding to each potential neighbor;

[0071] Table 6, list of potential neighbors of node C:

[0072]

[0073]

[0074] Table 7, list of potential neighbors of node D:

[0075]

[0076] (4) Node B adjusts the timing difference and system frame number between Node B and Node A, and initiates access to Node A in the fusion time slot of Node B. Node A enters the receiving state in the fusion time slot of Node B.

[0077] (5) After successfully accessing subnet 1, node B obtains the transmission resources of subnet 1. Nodes A and B become each other's official neighbors. Node B learns about its neighbor node D through the network topology table and deletes node D from the potential neighbor list.

[0078] Table 8, list of potential neighbors of node B:

[0079]

[0080] Table 9, list of potential neighbors of node A:

[0081]

[0082] Table 10, list of potential neighbors of node D:

[0083]

[0084] (6) Node C adjusts the timing difference and initiates access in the fusion time slot with node D. Node D points to node C in the fusion time slot of CD for reception.

[0085] (7) Node C successfully accesses and obtains the resources allocated by subnet 1. Node C and node D become each other's official neighbors. Through the topology within the subnet, node C learns about its official neighbors. Node C then deletes nodes A / B / D in the same subnet from the potential neighbor list. At this point, subnet fusion is complete.

[0086] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A fast subnet fusion method based on directional mobile ad hoc network, characterized in that: include: A fixed set of dedicated fusion time slots is designed based on the subnet size, ensuring that any two nodes in each subnet have fixed fusion time slots available. Construct subnet convergence processes, including neighbor discovery, convergence notification, target selection, and access; Design the message content of the fusion notification so that the scope of the fusion notification is expanded to the two subnets participating in the fusion; When designing a fixed set of dedicated converged time slots based on the subnet size: The subnet size is N nodes. The number of nodes that can be parallelized in each fusion time slot is N / 2. The required number of fusion time slots is: 2(N-1), where N is an even number; or 2N, where N is an odd number. Each fusion time slot is divided into identical fusion time slot 1 and fusion time slot 2. Both fusion time slot 1 and fusion time slot 2 are divided into several sub-time slots. The fusion time slot of a group of parallel links occupies a pair of sub-time slots for access request and response, respectively, and their positions are fixed in advance. When accessing, the fusion time slot 1 or fusion time slot 2 is selected according to the target node selected by the user for access; if the access fails, the fusion time slot 2 or fusion time slot 1 is switched to access.

2. The method for rapid subnet fusion based on directional mobile ad hoc network according to claim 1, characterized in that: The subnet fusion process includes: (1) Neighbor discovery: Node Net2_B on the subnet to be merged, Net2_B, can discover node Net1_A on the target subnet Net1. Through handshake, Net1_A and Net2_B obtain each other's subnet member location information, timing difference, and the starting position of the fusion time slot of subnet Net1. (2) Fusion notification: Node Net2_B and node Net1_A send fusion notifications to other members of the subnet through their respective fusion notification processes; (3) Target selection: Members of subnet Net2 and subnet Net1 receive the fusion notification and use the newly added node as a potential neighbor. Members of subnet Net2 also use the node that sent the fusion notification as a potential neighbor and establish a potential neighbor list. They obtain the fusion time slots corresponding to the potential neighbors according to the fixed position of the fusion time slot and record them in the potential neighbor list, which includes the subnet ID, node ID, location, and fusion time slot. Nodes of subnet Net2 select the best access target node from the potential neighbor list. (4) Access: Each node in subnet Net2 adjusts the frame timing and system frame number before the arrival of the selected fusion time slot, completes coarse synchronization with subnet Net1, and sends an access request when the fusion time slot arrives; each node in subnet Net1 traverses its own potential neighbor list and points to the corresponding potential neighbor for reception when the associated fusion time slot arrives; the node in subnet Net1 receives the access request from the node in subnet Net2, removes the node from the potential neighbor list, adds it to the formal neighbor list, allocates resources of subnet Net1 to it, and replies to this node in the associated response time slot; the node that receives the reply removes the other party from the potential list and adds it to the formal neighbor list.

3. The method for rapid subnet fusion based on directional mobile ad hoc network according to claim 2, characterized in that: In step (3), the nodes of subnet Net2 select the best access target node in the potential neighbor list based on the distance.

4. The method for rapid subnet fusion based on a directional mobile ad hoc network according to any one of claims 1 to 3, characterized in that: The message content of the fusion notification includes: Subnet initiating fusion: timing difference between the two subnets, system frame difference, starting frame number of the fusion timeslot, member ID and location of the target subnet; Fusion target subnet: The member ID and location of the subnet that initiates the fusion.

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