A method for urban vehicle-mounted self-organizing network broadcasting based on preferred areas

Abstract

This invention discloses a broadcasting method for urban vehicular ad hoc networks based on preferred regions, comprising the following steps: When a vehicle node is ready to send a data packet, the following steps are executed: S1: Determine the location of the nearest intersection center point; S2: Determine the preferred region and record relevant information; S3: Add the preferred region information to the data packet to be sent and broadcast the data packet. When a vehicle node has no data packet to send and receives a data packet sent by another node, the following steps are executed: R1: Extract the preferred region information from the received data packet; R2: If it is the first time the data packet has been received, decode the data packet and broadcast it; otherwise, proceed to R3; R3: Determine whether the node is located within the preferred region of the data packet sending node; if so, decode the data packet and broadcast it; otherwise, discard it. This invention effectively alleviates the broadcast storm problem and improves broadcast efficiency, that is, it can deliver data packets to more vehicle nodes within a certain period of time.

Description

Technical Field

[0001] This invention relates to the field of routing technology for vehicular ad hoc networks in mobile communications, and in particular to a method for broadcasting urban vehicular ad hoc networks based on preferred regions. Background Technology

[0002] Broadcasting is a crucial routing strategy in vehicular ad hoc networks (VANs), particularly for delivering data packets related to safety. Broadcasting offers advantages such as simple network equipment, easy maintenance, and low deployment costs. However, broadcast storms caused by repeated data packet transmissions can be severe, leading to intense competition between nodes and limiting the efficiency of data packet broadcasting, especially in urban scenarios with dense traffic and high data volumes. Therefore, it is necessary to research broadcasting methods for VANs in urban road scenarios to mitigate broadcast storm problems and improve data packet broadcasting efficiency in urban environments. Summary of the Invention

[0003] The purpose of this invention is to provide a broadcasting method for urban vehicular ad hoc networks based on preferred regions. This method combines the road distribution characteristics of urban grid scenarios with the high mobility characteristics of vehicular ad hoc networks to determine preferred regions for data packet sending nodes. Only nodes within the preferred regions are allowed to broadcast and forward data packets, thereby effectively alleviating the broadcast storm problem and improving broadcasting efficiency in urban scenarios.

[0004] To achieve the above objectives, the present invention adopts the following solution:

[0005] A method for broadcasting in urban vehicle-mounted ad hoc networks based on preferred regions, the method comprising the following steps:

[0006] When the vehicle node is ready to send a data packet:

[0007] Step S1: Vehicle nodes obtain their own position and the center position of each intersection through the Global Navigation Satellite System (GNSS) and digital maps, and compare their own position with the center positions of each intersection to determine the nearest intersection center position. Determining the center position of this intersection in S1 is the basis for subsequently determining the center position of the preferred area. In this way, the center position of the preferred area can be set at the intersection center, allowing the preferred area to cover more roads, i.e., more nodes. Simulation results also verify that this setting significantly improves broadcast efficiency.

[0008] Step S2: Determine the preferred region and record relevant information:

[0009] Step S2.1: The vehicle node determines the set of its neighboring nodes that fall on the east, west, south, and north roads of the intersection determined in S1: Φ1, Φ2, Φ3, Φ4. Count the Φ...k The total number of one-hop neighbors of all nodes in (k = 1, 2, 3, 4) is denoted as Where k = 1, 2, 3, 4 represent the east, south, west, and north directions, respectively. Φ k The set of one-hop neighbors of all nodes in the set, where |·| is the cardinality of the set, i.e., the number of nodes in the set.

[0010] Step S2.2: Set the first preferred region PreZ1 and record relevant information. PreZ1 is a region with a radius of... The center of the circle is set at the center point of the first intersection in the direction of intersection k1 (k1 = 1, 2, 3, 4) determined in S1, where k1 = 1, 2, 3, 4 represent the east, south, west, and north directions, respectively. The value of k1 is preset. The value of k1 is determined according to the following formula:

[0011]

[0012] Formula (1) indicates that the number of one-hop neighbors of the vehicle node in the k1 direction is the maximum.

[0013] Step S2.3: Set the second preferred region PreZ2 and record the relevant information. PreZ2 is a region with a radius of... The center of the circle is set at the center point of the first intersection in the direction of intersection k2 (k2 = 1, 2, 3, 4) determined in S1, where k2 = 1, 2, 3, 4 represent the east, south, west, and north directions, respectively. The value of k is preset. The value of k2 is determined according to the following formula:

[0014]

[0015] in, Let PreZ1 be the set of neighboring nodes of the vehicle node that fall within the preferred region. Let PreZ1 be the set of one-hop neighbor nodes of all nodes in the preferred region. Equation (2) indicates that the number of one-hop neighbor nodes of the vehicle node in the k2 direction overlaps with the one-hop neighbor nodes of the vehicle node in the k1 direction is minimized.

[0016] Step S3: Add the preferred region information to the data packet to be sent and broadcast the data packet, wherein the preferred region information includes the center position of PreZ1 circle, the center position of PreZ2 circle, and...

[0017] When a vehicle node has no data packets to send and receives data packets from other nodes:

[0018] Step R1: The node extracts the preferred region information of the sending node from the received data packet, including the center position of PreZ1 circle, the center position of PreZ2 circle, and...

[0019] Step R2: If the vehicle node is receiving the data packet for the first time, it decodes the data packet and broadcasts it; otherwise, it proceeds to step R3.

[0020] Step R3: The vehicle node determines whether it is within the preferred area of ​​the data packet sending node, i.e., within PreZ1 or PreZ2, based on its current location; if so, it decodes the data packet and broadcasts it; otherwise, it discards the data packet.

[0021] The beneficial effects of this invention are:

[0022] This invention discloses a broadcasting method for urban vehicular ad hoc networks based on preferred regions. This method combines the road distribution characteristics of urban grid scenarios (the use of intersection center points) with the high mobility characteristics of vehicular ad hoc networks. Based on the two-hop neighbor node information of vehicle nodes (determining the k-value), a suitable intersection center point is selected to determine the preferred region for data packet sending nodes. By allowing only nodes within the preferred region to broadcast and forward data packets, the number of nodes forwarding data packets is limited, avoiding broadcast storms caused by a large number of nodes simultaneously forwarding the same data packet. This reduces the probability of data packet collisions at receiving nodes during broadcasting, allowing more nodes to successfully receive broadcast data packets and improving broadcast efficiency in urban scenarios. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a city grid road scene model according to a specific embodiment of the present invention.

[0024] Figure 2 This is a flowchart illustrating a method for broadcasting urban vehicle-mounted self-organizing networks based on preferred regions, provided in a specific embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] See Figures 1-2This embodiment provides a method for urban vehicle-mounted self-organizing network broadcasting based on preferred regions, applicable to scenarios with urban grid roads, such as... Figure 1 As shown.

[0028] like Figure 2 As shown, this method specifically includes the following steps:

[0029] When the vehicle node is ready to send a data packet:

[0030] Step S1: The vehicle node obtains its own position and the center position of each intersection through the Global Navigation Satellite System (GNSS) and digital map, and compares its own position with the center position of each intersection to determine the center position of the nearest intersection to itself;

[0031] Step S2: Determine the preferred region and record relevant information:

[0032] Step S2.1: The vehicle node determines the set of its neighboring nodes that fall on the east, west, south, and north roads of the intersection determined in S1: Φ1, Φ2, Φ3, Φ4. Count the Φ... k The total number of one-hop neighbors of all nodes in (k = 1, 2, 3, 4) is denoted as Where k = 1, 2, 3, 4 represent the east, south, west, and north directions, respectively. Φ k The set of one-hop neighbors of all nodes in the set, where |·| is the cardinality of the set, i.e., the number of nodes in the set.

[0033] Step S2.2: Set the first preferred region PreZ1 and record relevant information. PreZ1 is a region with a radius of... The center of the circle is set at the center point of the first intersection in the direction of intersection k1 (k1 = 1, 2, 3, 4) determined in S1, where k1 = 1, 2, 3, 4 represent the east, south, west, and north directions, respectively. The value of k1 is preset. The value of k1 is determined according to the following formula:

[0034]

[0035] Formula (1) indicates that the number of one-hop neighbors of the vehicle node in the k1 direction is the maximum.

[0036] Step S2.3: Set the second preferred region PreZ2 and record the relevant information. PreZ2 is a region with a radius of... The center of the circle is set at the center point of the first intersection in the direction of intersection k2 (k2 = 1, 2, 3, 4) determined in S1, where k2 = 1, 2, 3, 4 represent the east, south, west, and north directions, respectively. The value of k is preset. The value of k2 is determined according to the following formula:

[0037]

[0038] in, Let PreZ1 be the set of neighboring nodes of the vehicle node that fall within the preferred region. Let PreZ1 be the set of one-hop neighbor nodes of all nodes in the preferred region. Equation (2) indicates that the number of one-hop neighbor nodes of the vehicle node in the k2 direction overlaps with the number of one-hop neighbor nodes of the vehicle node in the k1 direction.

[0039] Step S3: Add the preferred region information to the data packet to be sent and broadcast the data packet, wherein the preferred region information includes the center position of PreZ1 circle, the center position of PreZ2 circle, and...

[0040] When a vehicle node has no data packets to send and receives data packets from other nodes:

[0041] Step R1: The node extracts the preferred region information of the sending node from the received data packet, including the center position of PreZ1 circle, the center position of PreZ2 circle, and...

[0042] Step R2: If the vehicle node is receiving the data packet for the first time, it decodes the data packet and broadcasts it; otherwise, it proceeds to step R3.

[0043] Step R3: The vehicle node determines whether it is within the preferred area of ​​the data packet sending node, i.e., within PreZ1 or PreZ2, based on its current location; if so, it decodes the data packet and broadcasts it; otherwise, it discards the data packet.

[0044] Any aspects of this invention not described in detail are well-known to those skilled in the art.

[0045] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method for broadcasting in urban vehicle-mounted ad hoc networks based on a preferred region, characterized in that, The broadcasting method includes the following steps: When the vehicle node is ready to send a data packet: S1: Determine the location of the nearest intersection center point based on the node's current location; S2: Determine the preferred area and record relevant information. Only nodes within the preferred area broadcast and forward data packets. S3: Add the preferred region information to the data packet to be sent, and broadcast the data packet; When a vehicle node has no data packets to send and receives data packets from other nodes: R1: Extract the preferred region information from the received data packet; R2: If this is the first time the data packet has been received, decode the data packet and broadcast it; otherwise, proceed to R3. R3: Determine whether the node is within the preferred area of ​​the node that sent the data packet based on its current location; if so, decode the data packet and broadcast it.

2. The method for urban vehicle-mounted ad hoc network broadcasting based on a preferred region according to claim 1, characterized in that, The broadcasting method is applicable to urban grid road scenarios, where roads and intersections are regularly distributed and the location of the center point of the intersection is known.

3. The method for urban vehicle-mounted self-organizing network broadcasting based on a preferred region according to claim 1, characterized in that, In step S1, the vehicle node obtains its own position and the center position of each intersection through the global satellite navigation system and digital map, and compares its own position with the center position of each intersection to determine the center position of the nearest intersection to itself.

4. The urban vehicle-mounted self-organizing network broadcasting method based on a preferred region according to claim 1, characterized in that, Step S2 specifically includes the following processes: S2.1: Determine the set of neighboring nodes of a vehicle node that fall on the east, west, south, and north roads of the intersection determined in S1: Φ1, Φ2, Φ3, Φ4; count Φ k The total number of one-hop neighbors of all nodes in the array is denoted as . Where k = 1, 2, 3, 4 represent the east, south, west, and north directions, respectively. Φ k The set of one-hop neighbors of all nodes in the set, where |·| is the cardinality of the set, i.e., the number of nodes in the set; S2.2: Set the first preferred region PreZ1 and record relevant information; PreZ1 is a region with a radius of... The center of the circle is set at the center point of the first intersection in the direction of intersection k1 as determined in S1, where k1 = 1, 2, 3, 4 represent the east, south, west, and north directions, respectively. The value is preset; S2.3: Set the second preferred region PreZ2 and record relevant information; PreZ2 is a region with a radius of... The center of the circle is set at the center point of the first intersection in the direction of intersection k2 as determined in S1, where k2 = 1, 2, 3, 4 represent the east, south, west, and north directions, respectively. The value is preset.

5. A method for broadcasting urban vehicle-mounted ad hoc networks based on a preferred region according to claim 4, characterized in that, In step S2.2, the value of k1 is determined according to the following formula: Formula (1) indicates that the number of one-hop neighbors of the vehicle node in the k1 direction is the maximum.

6. A method for broadcasting urban vehicle-mounted ad hoc networks based on a preferred region according to claim 4, characterized in that, In step S2.3, the value of k2 is determined according to the following formula: in, Let PreZ1 be the set of neighboring nodes of the vehicle node that fall within the preferred region. Let PreZ1 be the set of one-hop neighbor nodes of all nodes in the preferred region; Equation (2) indicates that the number of one-hop neighbor nodes of the vehicle node in the k2 direction overlaps with the one-hop neighbor nodes of the vehicle node in the k1 direction is minimized.

7. A method for broadcasting urban vehicle-mounted ad hoc networks based on a preferred region according to claim 4, characterized in that, In step S3, the preferred region information is added to the data packet to be sent, and the data packet is broadcast. The preferred region information includes the center positions of PreZ1 and PreZ2.

8. A method for broadcasting urban vehicle-mounted ad hoc networks based on a preferred region according to claim 4, characterized in that, In step R1, the vehicle node extracts the preferred region information of the sending node from the received data packet, including the center position of PreZ1 circle, the center position of PreZ2 circle, and...

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