Method and system for routing in hybrid wireless mesh networks based on node type and interference awareness

Abstract

The application discloses a mixed wireless mesh network routing method and system based on node type and interference perception, and the method comprises the following steps: nodes in a network periodically exchange Hello messages to maintain neighbor information and topology state, and the Hello messages carry queue length, residual energy, position and speed information of the nodes; according to the Hello messages, weight values of Mesh routers and Mesh clients in the network are respectively calculated; based on the weight values, routing metrics of gateway-oriented traffic and client-oriented traffic are respectively calculated; on-demand routing discovery is performed by using a route request and a route reply message, wherein an intermediate node updates the routing metrics based on the weight values, a destination node or a Mesh router which knows a path to the destination node replies to the route reply, and a source node selects a path for data transmission according to the routing metrics; when a link is broken or a network topology changes, a source node is informed by a route error message, and a new routing discovery process is triggered.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication network optimization technology, specifically relating to a routing method and system for hybrid wireless mesh networks based on node type and interference awareness. Background Technology

[0002] Wireless Mesh Networks (WMNs) evolved from Mobile Ad Hoc Networks (MANETs) and possess advantages such as self-organization, low cost, ease of deployment, and wide-area internet access, maintaining significant application prospects in 5G and next-generation wireless communication networks. Hybrid WMNs are the most common form of WMN, consisting of static mesh routers and mobile mesh clients. Static mesh routers typically have multiple radio interfaces and no energy limitations; mobile mesh clients usually have only one radio interface and limited energy. Everyday mobile devices such as laptops, PDAs, and sensors, as well as emergency communication networks formed by rescue teams in emergency scenarios, can all be considered application examples of hybrid WMNs.

[0003] In a hybrid WMN, there are two types of data traffic: gateway-directed traffic destined for the gateway and client-directed traffic destined for other clients. Routing is a crucial component of network design, aiming to find efficient paths from source nodes to destination nodes. Routing protocols mainly include active, reactive, and hybrid protocols. Static mesh routers are well-suited to active routing protocols (such as OLSR) because their routing tables can be pre-built; mobile mesh clients are better suited to reactive routing protocols (such as AODV), which can build routes on demand to save overhead. Therefore, hybrid routing protocols that combine the advantages of both are most suitable for hybrid WMNs. However, existing hybrid routing methods have significant shortcomings: firstly, they fail to fully consider the characteristic differences between different types of mesh nodes (routers and clients); secondly, they fail to deeply analyze the impact of different types of interference (physical interference and channel contention interference) on network latency; and thirdly, when handling both types of traffic, mesh routers closer to the gateway become overloaded due to the large amount of gateway-directed traffic, easily becoming network bottlenecks, lacking effective load balancing mechanisms. Interference is a key factor affecting network performance and can be divided into physical interference and channel contention interference. Physical interference, from the perspective of the receiving node, is caused by the superposition of physical layer signals and can be measured by the signal-to-interference-plus-noise ratio (SINR), affecting transmission rate and transmission delay (TD). Channel contention interference, from the perspective of the transmitting node, is caused by multiple nodes competing for the same channel. While CSMA / CA mechanisms are used to avoid collisions, this results in channel access waiting time, i.e., waiting delay (WD). Most existing studies do not provide joint, refined modeling of the delays caused by these two types of interference. Therefore, there is an urgent need in this field for a hybrid routing method that can distinguish node types, jointly perceive multiple types of interference, quantify their delay impact, and achieve load awareness, in order to comprehensively improve the performance of hybrid WMNs. Summary of the Invention

[0004] This invention aims to address the shortcomings of existing technologies and provides the following solutions:

[0005] A routing method for hybrid wireless mesh networks based on node type and interference awareness includes the following steps:

[0006] Nodes in the network periodically exchange Hello messages to maintain neighbor information and topology state, and also carry information such as the node's queue length, remaining energy, location, and speed.

[0007] Based on the information carried in the Hello message, calculate the first weight value of the Mesh router and the second weight value of the Mesh client in the network.

[0008] Based on the first weight value and the second weight value, calculate the first routing metric for gateway-directed traffic and the second routing metric for client-directed traffic, respectively.

[0009] On-demand route discovery is performed using route request and route reply messages, wherein intermediate nodes update the first route metric and the second route metric based on the first weight value and the second weight value, the destination node or a Mesh router that knows the path to the destination node replies with the route reply, and the source node selects a path for data transmission based on the first route metric and the second route metric.

[0010] When a link breaks or the network topology changes, the source node is notified via a routing error message, triggering a new route discovery process.

[0011] Preferably, the transmission and latency of the Mesh router are affected by network conditions, and the method for calculating the first weight value includes:

[0012]

[0013]

[0014]

[0015] in, This represents the first weight value. Indicates transmission delay. This indicates a delay. This represents the queue length of node i itself. This represents the expected queue load that may be transmitted from the neighboring nodes of node i. This indicates the number of bits contained in a single data packet. This represents the available bandwidth of the link after considering physical interference. Describes the set of interfering nodes of node i. This represents the queue length of the interfering node k. This represents the maximum number of data packets allowed to interfere with node k's transmission while node i is emptying its own queue.

[0016] Preferably, the Mesh client is energy-constrained and highly mobile, and the method for calculating the second weight value includes:

[0017]

[0018]

[0019] in, This represents the second weight value. It represents the ratio of energy consumed to energy remaining. This indicates the consumption of energy. Indicates the remaining energy. This represents the movement speed of client j. This indicates the maximum speed in the network.

[0020] Preferably, the destination node is the gateway. After the Mesh client connects to the Mesh router, it connects to the gateway along the path formed by the Mesh routers. The method for calculating the first routing metric includes:

[0021]

[0022] in, Indicates the first route metric. Represents a collection of Mesh clients. This indicates the path formed by the Mesh routers.

[0023] Preferably, the destination node is a Mesh client, and data transmission is completed through multiple Mesh clients and Mesh routers. The method for calculating the second routing metric includes:

[0024]

[0025] in, Indicates the second routing metric. This represents the set of Mesh client nodes that data forwarding passes through. This represents the set of Mesh router nodes that data forwarding passes through. This indicates the penalty weight.

[0026] The present invention also provides a hybrid wireless mesh network routing system based on node type and interference awareness. The system applies the above-mentioned method and is characterized by serving data transmission in multiple scenarios, including: a data acquisition module, a weight calculation module, a route metric calculation module, a path selection module, and a route discovery module.

[0027] The data acquisition module periodically exchanges Hello messages with nodes in the network to maintain neighbor information and topology status, and also carries the node's queue length, remaining energy, location and speed information.

[0028] The weight calculation module calculates the first weight value of the Mesh router and the second weight value of the Mesh client in the network based on the information carried in the Hello message.

[0029] The routing metric calculation module calculates the first routing metric for gateway-directed traffic and the second routing metric for client-directed traffic based on the first weight value and the second weight value, respectively.

[0030] The path selection module uses route request and route reply messages to perform on-demand route discovery, wherein intermediate nodes update the first route metric and the second route metric based on the first weight value and the second weight value, the destination node or a Mesh router that knows the path to the destination node replies with the route reply, and the source node selects a path for data transmission according to the first route metric and the second route metric.

[0031] When a link breaks or the network topology changes, the route discovery module notifies the source node via a route error message and triggers a new route discovery process.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) This invention is the first to jointly quantize the transmission delay (TD) caused by physical interference and the waiting delay (WD) caused by channel contention interference in hybrid WMN routing, making the routing more reflective of the real network conditions and effectively reducing end-to-end delay.

[0034] (2) This invention fully considers the essential differences between Mesh routers and Mesh clients in terms of energy, mobility, number of interfaces, etc., and designs different weight calculation models for them, making the routing selection more reasonable.

[0035] (4) By setting penalty weights for Mesh routers close to the gateway, the present invention guides client traffic to avoid these potentially heavily loaded nodes, effectively avoiding network bottlenecks and balancing network load.

[0036] (5) This invention combines the advantages of proactive and reactive routing, and adopts different path discovery and measurement strategies for different traffic types, thereby improving routing efficiency.

[0037] (6) The present invention has been verified by NS3 simulation and has significantly outperformed existing routing schemes such as LIB-HRP, LA-CHRP, and HMesh in key performance indicators such as average packet loss rate, average latency, network throughput, control overhead and remaining energy of the client. Attached Figure Description

[0038] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the method flow in an embodiment of the present invention;

[0040] Figure 2 This is an example diagram of gateway-directed traffic routing in an embodiment of the present invention;

[0041] Figure 3 This is an example diagram of client-directed traffic routing in an embodiment of the present invention;

[0042] Figure 4 This is a performance comparison chart of the average packet loss rate of the method described in this embodiment of the invention and other methods, wherein (a) is the change in packet loss rate with the increase of the number of data streams, (b) is the change in packet loss rate with the increase of the packet sending rate, and (c) is the change in packet loss rate with the increase of the Mesh client's moving speed.

[0043] Figure 5 This is a comparison chart of the average latency performance of the method described in this embodiment of the invention with other methods, where (a) is the change in packet loss rate with the increase of the number of data streams, (b) is the change in packet loss rate with the increase of the packet sending rate, and (c) is the change in packet loss rate with the increase of the Mesh client's moving speed.

[0044] Figure 6 This is a comparison chart of the average network throughput performance of the method described in this embodiment of the invention with other methods, wherein (a) is the change in average latency with the increase of the number of data streams, (b) is the change in average latency with the increase of the packet sending rate, and (c) is the change in average latency with the increase of the Mesh client's moving speed.

[0045] Figure 7 This is a comparison chart of the average network overhead performance of the method described in this embodiment of the invention with other methods, wherein (a) is the change in average overhead with the increase of the number of data streams, (b) is the change in average overhead with the increase of the packet sending rate, and (c) is the change in average overhead with the increase of the Mesh client's moving speed.

[0046] Figure 8 This is a comparison chart of the minimum remaining energy performance of the client with other methods in the embodiments of the present invention. Among them, (a) is the change of the minimum remaining energy of the client with the increase of the number of data streams, (b) is the change of the minimum remaining energy of the client with the increase of the packet sending rate, and (c) is the change of the minimum remaining energy of the client with the increase of the Mesh client movement speed. Detailed Implementation

[0047] 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 embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] Example 1

[0050] Performance was evaluated using the NS3 network simulator. Network devices were deployed within a 1000m × 1000m area. This included one gateway, 24 statically configured mesh routers (5 rows, 5 columns, with the gateway at the center), and 50 randomly moving mesh clients. Randomly generated gateway-directed and client-directed traffic coexisted within the network. Specific simulation parameters are shown in Table 1.

[0051] Table 1

[0052] .

[0053] In this embodiment, as Figure 1 As shown, the hybrid wireless mesh network routing method based on node type and interference awareness includes the following steps:

[0054] S1. Nodes in the network periodically exchange Hello messages to maintain neighbor information and topology state, and also carry information such as the node's queue length, remaining energy, location, and speed.

[0055] S2. Based on the information carried in the Hello message, calculate the first weight value of the Mesh router and the second weight value of the Mesh client in the network.

[0056] In this embodiment, based on the information carried by the Hello message, weight values ​​are defined and calculated for Mesh routers and Mesh clients in the network. The weight values ​​are used to evaluate the node status and serve as the basis for routing metrics. The lower the weight value, the higher the priority of the node being selected as a routing node.

[0057] For Mesh router i, its weight value Due to transmission delay With waiting delay The sum of these can be calculated as:

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064] in, This represents the queue length of node i itself. This represents the expected queue load that may be transmitted from the neighboring nodes of node i. This indicates the number of bits contained in a single data packet. This represents the available bandwidth of the link after considering physical interference. Describes the set of interfering nodes of node i. This represents the queue length of the interfering node k. This represents the maximum number of data packets allowed to interfere with node k's transmission while node i is emptying its own queue. Indicates the nominal bandwidth. This represents the ratio of signal-to-interference-plus-noise ratio (SIR) to signal-to-noise ratio (SNR) on link l. This represents the queue length of neighbor node a. Let i represent the set of neighboring nodes. This represents the probability that neighbor node a transmits data to node i. This indicates the number of neighboring Mesh routers of node a. This indicates the number of neighboring Mesh clients of node a.

[0065] Methods for calculating the second weight value include:

[0066]

[0067]

[0068] in, This represents the second weight value. It represents the ratio of energy consumed to energy remaining. This indicates the consumption of energy. Indicates the remaining energy. This represents the movement speed of client j. This indicates the maximum speed in the network.

[0069] S3. Based on the first weight value and the second weight value, calculate the first routing metric for gateway-directed traffic and the second routing metric for client-directed traffic, respectively.

[0070] In this embodiment, gateway-directed traffic and client-directed traffic are distinguished, and routing metrics are defined for them respectively.

[0071] For gateway-directed traffic, its routing metric The formula for calculating the weight of a Mesh router is: the sum of the weights of all Mesh clients on the path from the source client to the Mesh router, plus the sum of the weights of all Mesh routers on the active routing path from the Mesh router to the gateway.

[0072]

[0073] in, Indicates the first route metric. Represents a collection of Mesh clients. This indicates the path formed by the Mesh routers.

[0074] For client-directed traffic, its routing metric This is the sum of the weights of all Mesh clients along the path, plus the weights of all Mesh routers along the path and their penalty weights. The sum of the products of , and its formula is:

[0075]

[0076] in, Indicates the second routing metric. This represents the set of Mesh client nodes that data forwarding passes through. This represents the set of Mesh router nodes that data forwarding passes through.

[0077] S4. On-demand route discovery is performed using route request and route reply messages. Intermediate nodes update the first and second route metrics based on the first and second weight values. Destination nodes or Mesh routers that know the path to the destination node reply with a route reply. Source nodes select a path for data transmission based on the first and second route metrics.

[0078] S5. When a link breaks or the network topology changes, notify the source node via a routing error message and trigger a new route discovery process.

[0079] In this embodiment, with Figure 2 Taking gateway-directed traffic as an example: Mesh client S wants to send data to gateway G and broadcasts a route request (RREQ). Clients A and B forward the route request. After receiving the route request, Mesh routers C and D, because they maintain active routes to G, directly reply with a route reply (RREP). Source node S receives route replies for two paths, SACEG and SBDFG, and calculates their respective... It selects the path with the smaller value for communication.

[0080] by Figure 3Taking client-directed traffic as an example: from S to D, the Mesh routers (such as A and E) on each path are assigned penalty weights based on their distance from the gateway. Even if A and E have low latency weights, their contribution value may increase after being multiplied by the penalty weight. Therefore, unless their latency is extremely low, the path SAED may not be selected due to its large total metric value, and the path SBFD, which has a lighter load, is more likely to be chosen.

[0081] Example 2

[0082] In this embodiment, the hybrid wireless mesh network routing system based on node type and interference awareness includes: a data acquisition module, a weight calculation module, a route metric calculation module, a path selection module, and a route discovery module.

[0083] The data acquisition module periodically exchanges Hello messages with nodes in the network to maintain neighbor information and topology status, and also carries information such as the queue length, remaining energy, location, and speed of the nodes.

[0084] The weight calculation module calculates the first weight value of the Mesh router and the second weight value of the Mesh client in the network based on the information carried in the Hello message.

[0085] The routing metric calculation module calculates the first routing metric for gateway-directed traffic and the second routing metric for client-directed traffic based on the first weight value and the second weight value, respectively.

[0086] The path selection module uses route request and route reply messages to perform on-demand route discovery. Intermediate nodes update the first route metric and the second route metric based on the first weight value and the second weight value. The destination node or a Mesh router that knows the path to the destination node replies with a route reply. The source node selects a path for data transmission based on the first route metric and the second route metric.

[0087] When a link breaks or the network topology changes, the route discovery module notifies the source node via a route error message and triggers a new route discovery process.

[0088] Example 3

[0089] In this embodiment, the performance of the method proposed in this invention is evaluated.

[0090] This embodiment evaluates the routing methods for hybrid wireless mesh networks that are node type-aware and interference-aware. It compares the proposed NTRS method with other algorithms (LIB-HRP, LA-CHRP, HMesh) in five aspects: average packet loss rate, average latency, average throughput, average control overhead, and minimum remaining energy for the client.

[0091] a) Average packet loss rate: The ratio between the total number of data packets sent and the total number of data packets successfully received within a specific period of time.

[0092]

[0093] in, This represents the average packet loss rate. This indicates the number of lost packets. This indicates the total number of data packets sent by the source node.

[0094] b) Average delay: The average time required for a data packet to travel from the sender to the receiver and back to the sender.

[0095]

[0096] in, Indicates the average delay. This represents the time required to transmit data packet i from the source node to the destination node. This indicates the number of data packets successfully sent to the destination.

[0097] c) Average throughput: The average amount of data successfully transmitted by the network per unit of time.

[0098]

[0099] in, This represents the average throughput. This indicates the number of data packets received by the destination node. This indicates the number of bytes contained in each data packet. Indicates the time when the transmission is terminated. This indicates the time when packet sending begins.

[0100] d) Average control overhead: In network communication, the ratio between the resources (such as bandwidth and computing power) consumed for managing and controlling data transmission and the resources used to transmit valid user data.

[0101]

[0102] in, This represents the average control cost. This indicates the number of control packets transmitted in the network. This indicates the total number of data packets and control packets in the network.

[0103] e) Minimum remaining energy of a client: The energy value of the node with the lowest current remaining energy in a network consisting of multiple clients (nodes).

[0104]

[0105] in, This represents the minimum remaining energy of the client. This means taking the minimum value. This indicates the current remaining energy.

[0106] Simulation results are as follows Figures 4-8 As shown. Under different data stream quantities, transmission rates, and client mobility speeds, the NTRS method proposed in this invention achieves a lower average packet loss rate ( ). Figure 4 ), average delay ( Figure 5 ), average throughput ( Figure 6 Average control overhead ( Figure 7 ) and the client's minimum remaining energy ( Figure 8 In all aspects, NTRS consistently outperforms the comparison algorithms (LIB-HRP, LA-CHRP, HMesh). On average, NTRS improves performance by 18.61%, 31.45%, and 45.56% compared to LIB-HRP, LA-CHRP, and HMesh, respectively, fully demonstrating the effectiveness and superiority of the present invention.

[0107] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A routing method for hybrid wireless mesh networks based on node type and interference awareness, characterized in that, Includes the following steps: Nodes in the network periodically exchange Hello messages to maintain neighbor information and topology state, and also carry information such as the node's queue length, remaining energy, location, and speed. Based on the information carried in the Hello message, calculate the first weight value of the Mesh router and the second weight value of the Mesh client in the network. Based on the first weight value and the second weight value, calculate the first routing metric for gateway-directed traffic and the second routing metric for client-directed traffic, respectively. On-demand route discovery is performed using route request and route reply messages, wherein intermediate nodes update the first route metric and the second route metric based on the first weight value and the second weight value, the destination node or a Mesh router that knows the path to the destination node replies with the route reply, and the source node selects a path for data transmission based on the first route metric and the second route metric. When a link breaks or the network topology changes, the source node is notified via a routing error message, triggering a new route discovery process. The transmission and latency of a mesh router are affected by network conditions. The method for calculating the first weight value includes: in, This represents the first weight value. Indicates transmission delay. This indicates a delay. This represents the queue length of node i itself. This represents the expected queue load that may be transmitted from the neighboring nodes of node i. This indicates the number of bits contained in a single data packet. This represents the available bandwidth of the link after considering physical interference. Describes the set of interfering nodes of node i. This represents the queue length of the interfering node k. This represents the maximum number of data packets allowed to interfere with node k's transmission while node i is emptying its own queue. Indicates the nominal bandwidth. Indicates link l The ratio of signal-to-interference-plus-noise ratio to signal-to-noise ratio. This represents the queue length of neighbor node a. Let i represent the set of neighboring nodes. This represents the probability that neighbor node a transmits data to node i. This indicates the number of neighboring Mesh routers of node a. This represents the number of neighboring Mesh clients of node a; Mesh clients are energy-constrained and highly mobile; the method for calculating the second weight value includes: in, This represents the second weight value. It represents the ratio of energy consumed to energy remaining. This indicates the consumption of energy. Indicates the remaining energy. This represents the movement speed of client j. This indicates the maximum speed in the network.

2. The hybrid wireless mesh network routing method based on node type and interference awareness according to claim 1, characterized in that, The destination node is the gateway. After a Mesh client connects to a Mesh router, it connects to the gateway along the path formed by the Mesh routers. The method for calculating the first routing metric includes: in, Indicates the first route metric. Represents a collection of Mesh clients. This indicates the path formed by the Mesh routers.

3. The hybrid wireless mesh network routing method based on node type and interference awareness according to claim 1, characterized in that, The destination node is a Mesh client, and data transmission is completed through multiple Mesh clients and Mesh routers. The method for calculating the second routing metric includes: in, Indicates the second routing metric. This represents the set of Mesh client nodes that data forwarding passes through. This represents the set of Mesh router nodes that data forwarding passes through. This indicates the penalty weight.

4. A hybrid wireless mesh network routing system based on node type and interference awareness, wherein the system applies the method described in any one of claims 1-3, characterized in that, The service supports data transmission across multiple scenarios, including: data acquisition module, weight calculation module, route metric calculation module, path selection module, and route discovery module; The data acquisition module periodically exchanges Hello messages with nodes in the network to maintain neighbor information and topology status, and also carries the queue length, remaining energy, location and speed information of the nodes. The weight calculation module calculates the first weight value of the Mesh router and the second weight value of the Mesh client in the network based on the information carried in the Hello message. The routing metric calculation module calculates the first routing metric for gateway-directed traffic and the second routing metric for client-directed traffic based on the first weight value and the second weight value, respectively. The path selection module uses route request and route reply messages to perform on-demand route discovery, wherein intermediate nodes update the first route metric and the second route metric based on the first weight value and the second weight value, the destination node or a Mesh router that knows the path to the destination node replies with the route reply, and the source node selects a path for data transmission according to the first route metric and the second route metric. When a link breaks or the network topology changes, the route discovery module notifies the source node via a route error message and triggers a new route discovery process.

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