WO2017020619A1

WO2017020619A1 - Routing method and device

Info

Publication number: WO2017020619A1
Application number: PCT/CN2016/080917
Authority: WO
Inventors: 王海; 李智敏; 董超; 于卫波
Original assignee: 中兴通讯股份有限公司
Priority date: 2015-08-04
Filing date: 2016-05-03
Publication date: 2017-02-09
Also published as: CN106454984B; CN106454984A

Abstract

Provided are a routing method and device. The method is applicable to a heterogeneous wireless network and comprises: receiving, by a node, a hello message and a topology control (TC) message; and establishing a route according to the hello message and the TC message, wherein the hello message carries a unique IP address of each neighboring node, and a designated bit in the IP address indicates neighbor relationships between the node and a corresponding neighboring node in all channels. The above technical solution enables a routing message to be transmitted in a part of the channels, thereby reducing routing overheads of an entire network. Moreover, a low-speed channel can use a valuable bandwidth resource to transmit service data, thereby increasing use of the low-speed channel and throughput of the network.

Description

Method and device for routing

Technical field

This paper relates to the field of communications, and in particular to a method and apparatus for routing in a heterogeneous wireless network.

Background technique

Wireless Mesh (mesh) network is a new type of broadband wireless network structure. It inherits the main features of Ad Hoc (self-organizing) network multi-hop and self-organization. It consists of Mesh (mesh network) backbone network and Mesh access network. The goal of building a mesh network is to provide a high-capacity, high-rate, reliable, and self-organizing distributed network.

A wireless Mesh network can be seen as a combination of a traditional WLAN (Wireless Local Area Network) network and an Ad Hoc network. It combines the characteristics of both, while at the same time has its own characteristics. Its main features are as follows:

1) Mesh routers in wireless Mesh networks are usually static or slow moving. Terminal nodes are usually more mobile. Therefore, the topology of the backbone network of the wireless Mesh network changes relatively slowly, and the topology of the access network changes rapidly.

2) The wireless Mesh network is simple to set up and deployed quickly, which can support the free joining and evacuation of nodes.

3) The number of wireless channels is abundant. The communication node can simultaneously send and receive data using a plurality of different types of wireless interface devices, thereby greatly improving network throughput.

4) The mesh topology of the wireless Mesh network can expand the network coverage and application scenarios to achieve non-line-of-sight transmission.

5) Compared with Ad Hoc networks, wireless mesh networks have better scalability. It can support hundreds or even thousands of nodes to communicate, while a typical Ad Hoc network supports only a few dozen nodes.

6) Since the nodes in the wireless mesh network can be configured with multiple wireless interface devices, when the link of an interface is disconnected, the node can select other interfaces for data transmission and reception, and therefore, the redundancy of the network. Increase, reliability will also increase accordingly.

Wireless Mesh networks differ greatly from Ad Hoc networks in terms of topology and number of channels. These differences make the wireless mesh network have more and more complex requirements for routing protocols. If the traditional Ad Hoc routing protocol is directly applied to the wireless Mesh network, the network performance will be greatly reduced, and the network may not be used. Therefore, the Ad Hoc routing protocol needs to be improved. Multi-channel routing is one of the hotspots of wireless Mesh network routing protocols, as shown in Figure 1. Multi-channel transmission can make full use of network resources, thereby improving the overall performance of the network, such as throughput and delay. At present, the wireless Mesh network multi-channel routing protocol can be divided into a single interface multi-channel routing protocol and a multi-interface multi-channel routing protocol.

Single-interface multi-channel mode means that each node in the network has only one transceiver. The switching of the nodes through the channel causes the transceiver to work on different frequencies in a time-sharing manner, and both parties must ensure that they operate on the same frequency. The advantage of this method is that the spectrum utilization is improved and the inter-node interference is reduced. The disadvantage is that the channel switching time is relatively long, and the scheduling algorithm of the channel switching is also complicated.

The multi-interface multi-channel mode refers to that each node has multiple transceiver devices, and each transceiver device operates on a different channel, and can simultaneously transmit and receive data without interference. Although the multi-interface multi-channel approach can achieve higher system capacity, it is more complicated in the design of the protocol. The OLSR (Optimal Link State Routing) protocol uses the idea of multipoint relay. By reducing the number of repeated forwarding of the same control message in the same area, the number of broadcast messages in the network is significantly reduced, and it can also support multiple The integrated network of interfaces is applicable to networks with large network scales, dense node distribution, and frequent communication between nodes. The protocol also has the advantage of finding a small routing delay, and is currently a highly accepted wireless mesh network routing method. However, applying the multi-interface OLSR protocol directly to heterogeneous wireless networks will create the following problems:

1) Poor adaptability to heterogeneous networks

The multi-interface OLSR protocol sends the same control message size and transmission interval on each interface, treating all interfaces equally, without considering the bandwidth difference between different channels.

2) IP address is occupied more

In the multi-interface OLSR protocol, each node can have multiple interfaces. The OLSR protocol assigns an IP address to each interface, and each node will occupy multiple IP addresses. Assign multiple nodes to each node The practice of IP addresses is a great waste of limited IP address resources, creating obstacles for large-scale networking.

3) Channel selection is not supported

The multi-interface OLSR protocol does not support channel selection, and the dominant channel cannot be selected from multiple channels according to the difference in channel quality. In fact, choosing to use a high speed channel can achieve higher throughput.

4) Routing control message is repeatedly sent

The multi-interface OLSR protocol will repeatedly transmit the same TC (Topology Control) message in multiple subnets. Repeated transmission on a low bandwidth channel will increase the load of the low bandwidth channel and increase unnecessary routing overhead.

5) Use the minimum hop count as the routing criterion

The current multi-interface OLSR protocol uses a minimum hop as a routing criterion. The minimum hop count does not take into account the impact of the packet loss rate and channel bandwidth on the routing. The optimal routing cannot be selected, resulting in a decrease in network performance.

Summary of the invention

The following is an overview of the topics detailed in this document. This Summary is not intended to limit the scope of the claims.

The embodiment of the invention provides a method and a device for routing, which can provide energy-efficient routing for heterogeneous wireless network communication and improve communication efficiency of the heterogeneous wireless network.

The embodiment of the invention provides a routing method, which is applied to a heterogeneous wireless network, and includes:

The node receives the hello message and the topology control TC message;

The node establishes a route according to the Hello message and the TC message, where the Hello message carries a unique IP address of each neighbor node, and the designated bit on the IP address is used to indicate that the local node and the corresponding neighbor node are in all channels. Adjacency relationship on.

Optionally, the foregoing method further has the following feature: after receiving the Hello message, the node further includes:

The node periodically calculates an expected transmission time ETT of all channels between the local node and all neighbor nodes according to the Hello message, and the ETT is calculated according to the following formula:

Where p _f represents the forward transmission success rate, p _r represents the backward transmission success rate, Size is the size of the transmitted data packet, and B is the bandwidth of the transmission channel.

The forward transmission success rate p _f and the backward transmission success rate p _r are calculated according to the following formula:

When calculating p _f , recv_count(t-ω, t) represents the number of probe packets received by neighboring nodes from time t-ω to time t, and sent_count(t-ω, t) represents the time from t-ω time to time t. The number of probe packets sent by the node;

When calculating _{r r} , recv_count(t-ω, t) represents the number of probe packets actually received by the node from time t-ω to time t, and sent_count(t-ω, t) represents time from t-ω to time t. Number of probe packets sent by neighbor nodes,

If the node is selected as the multipoint relay node by the upstream node, the TC message is periodically generated and sent, and the TC message includes: a minimum value of the ETT values of all channels between the local node and the destination node, as a downstream The routing criteria of the node.

Optionally, the above method also has the following features:

The TC message further includes: an address of the destination node reachable by the node, and an address of a next hop node that needs to pass to reach the destination node address.

Optionally, the foregoing method further has the following feature: the sending, by the node, the TC message is implemented by:

The node uses a greedy algorithm to select a set of high rate channels to transmit the TC message.

The node establishes a link list of the node to the neighbor node according to the received Hello message;

A partial node is selected as a multipoint relay node from the one-hop neighbor node, and the multi-point relay node can send the Hello message sent by the local node to all the two-hop neighbor nodes.

Optionally, the foregoing method further has the following features:

The node periodically sends a Hello message, and the parameters in the Hello message include the local node. The number of probe packets received and the number of probe packets sent by the local node. The IP address of each neighbor node in the Hello message includes the number of Hello messages sent by the node to the neighbor node and the local node and the neighbor node on all channels. Link information.

Optionally, the foregoing method further has the following feature: the establishing, by the node, the routing according to the Hello message and the TC message is implemented by:

The node simultaneously uses a routing strategy combining proactive routing and reactive routing to establish a route.

The node establishes a route based on weak multipath coverage.

Optionally, the foregoing method further has the following feature: the node establishes a route based on the weak multipath coverage, including:

The node receives the homing response message, and records the upstream node, the path information, and the hop count according to the homing response message;

Listening for a request message;

Establishing a backup routing path different from the path in the request request message according to the path information recorded and the path information in the hunt request message that is detected;

The backup routing path is advertised to the upstream node by the seek request message.

The embodiment of the invention further provides a routing device, including:

a receiving module, configured to receive a hello message and a topology control TC message;

Establishing a module, configured to establish a route according to the Hello message and the TC message, where the Hello message carries a unique IP address of each neighbor node, and the specified bit on the IP address is used to indicate that the local node and the corresponding neighbor node are Adjacency on all channels.

Optionally, the routing device further has the following features:

And a calculating module, configured to periodically calculate, according to the Hello message, a desired transmission time ETT of all channels between the local node and all neighboring nodes, where the ETT is calculated according to the following formula:

Where p _f represents the forward transmission success rate, p _r represents the backward transmission success rate, Size is the size of the transmitted data packet, B is the bandwidth of the transmission channel, and the forward transmission success rate p _f and the backward transmission success rate p _r is calculated according to the following formula:

When calculating p _f , recv_count(t-ω, t) represents the number of probe packets received by neighboring nodes from time t-ω to time t, and sent_count(t-ω, t) represents the time from t-ω time to time t. The number of probe packets sent by the node. When calculating _{r r} , recv_count(t-ω, t) represents the number of probe packets actually received by the node from time t-ω to time t, and sent_count(t-ω, t) The number of probe packets sent by neighboring nodes from time t-ω to time t,

Generating a module, configured to periodically generate a TC message if the node is selected as a multipoint relay node by the upstream node, where the TC message includes: a minimum value of ETT values of all channels between the node and the destination node , as the routing criterion of the downstream node, and the address of the destination node reachable by the node and the address of the next hop node that needs to pass to reach the destination node address;

The sending module is configured to periodically send the TC message.

Optionally, the routing device further has the following feature: the sending module is configured to use the greedy algorithm to select a high rate channel set to send the TC message.

Optionally, the routing device further has the following features:

The establishing module is further configured to: establish a node-to-neighbor node list according to the received Hello message; select a partial node as a multi-point relay node from the one-hop neighbor node, and the multi-point relay node may send the node to send The Hello message arrives at all two-hop neighbor nodes.

Optionally, the routing device further has the following features:

The sending module is further configured to periodically send a Hello message, where the parameters in the Hello message include the number of probe packets received by the local node and the number of probe packets sent by the local node, and each neighbor node in the Hello message. The IP address includes the number of Hello messages sent by the node to the neighbor node and the link information of the local node and the neighbor node on all channels.

Optionally, the routing device further has the following features:

The establishing module is configured to establish a route by using a routing strategy combining proactive routing and reactive routing.

Optionally, the routing device further has the following features:

The establishing module is configured to establish a route based on the weak multipath coverage, including: receiving the seek And responding to the message, recording the upstream node, the path information, and the hop count according to the homing response message; and listening to the request message; and recording the path information and the intercepted request message in the request message The path information is used to establish a backup routing path different from the path in the request request message; the backup routing path is advertised to the upstream node by using the seek request message.

In summary, the embodiments of the present invention provide a method and apparatus for routing, aiming at channel differences in a heterogeneous wireless network, so that routing messages are transmitted on a high-speed channel as much as possible, and low-speed channels transmit or not transmit routes as little as possible. data pack. The transmission of routing messages on part of the channel reduces the routing overhead of the entire network, while the low-rate channels can use their valuable bandwidth resources for traffic data transmission, improving the utilization of low-rate channels and network throughput.

Other aspects will be apparent upon reading and understanding the drawings and detailed description.

BRIEF abstract

1 is a schematic diagram of multi-channel selection of the related art;

2 is a flowchart of a method for routing according to an embodiment of the present invention;

3 is a schematic diagram of a data structure of a TC message according to an embodiment of the present invention;

4 is a schematic diagram of a modified Hello message format according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an apparatus for routing according to an embodiment of the present invention.

Embodiments of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

FIG. 2 is a flowchart of a method for routing according to an embodiment of the present invention. As shown in FIG. 2, the method in this embodiment includes:

Step 11: The node receives a Hello message and a TC (Topology Control) message;

Step 12: The node establishes a route according to the Hello message and the TC message, where the Hello message carries a unique IP address of each neighbor node, and the specified bit on the IP address is used to indicate The adjacency relationship between this node and the corresponding neighbor node on all channels.

A method for routing according to the embodiment of the present invention uses a route advertisement mechanism based on joint metric coding to remove multi-interface description information and reduce routing overhead.

The method of this embodiment is based on the multi-interface OLSR protocol, by redesigning the routing criteria, optimizing the TC message broadcast channel, reducing the routing overhead, the routing strategy combining the proactive and reactive modes, and the multipath routing based on the weak multipath coverage. For the purpose of improving the efficiency of network communication, the method in this embodiment may specifically include the following steps:

Step 101: The node periodically sends a Hello message, and selects a set of its own MPR nodes according to the received Hello message.

The Hello message is sent out in the node period. The Hello message contains the IP address of the neighbor node obtained by itself, the number of Hello packets sent and received by the neighbor, and the number of Hello packets sent and received by itself.

At the same time, the node establishes its own to the neighbor node list according to the Hello information it receives, and selects some nodes from the one-hop neighbor node, so that the Hello message sent by itself can reach all the two-hop neighbor nodes. The selected part of the node A collection is called an MPR collection.

Step 102: The node periodically calculates the expected transmission time (ETT, Expected Transmission Time) of the neighbor node; after calculating the ETT, it is placed in the TC message, and is propagated outward by the node and the MPR node.

In this embodiment, the calculation criterion of the expected routing time ETT of the routing criterion adopted is:

In order to make the ETT routing criterion better adapt to the dynamic changes of the network topology, the calculation of the transmission success rate is:

Before calculating the success rate of p _f and the backward transmission to the transmission success rate of this formula can be used p _r.

When calculating p _f , recv_count(t-ω, t) represents the number of probe packets received by neighboring nodes from time t-ω to time t, and sent_count(t-ω, t) represents the time from t-ω time to time t. The number of probe packets sent by the node.

When calculating _{r r} , recv_count(t-ω, t) represents the number of probe packets actually received by the node from time t-ω to time t, and sent_count(t-ω, t) represents time from t-ω to time t. Number of probe packets sent by neighbor nodes.

In order to correctly calculate and use the ETT, the Hello message and the TC message of the OLSR protocol need to be modified, as follows:

1, the modification of the Hello message:

The Hello message is used as a probe packet to measure the packet loss rate between nodes. In order to correctly calculate the ETT between the neighboring nodes, the node adds two parameters "the number of probe packets received by the node" and "the number of probe packets sent by the node" in the Hello message.

The Hello message stores the adjacency relationship between the local node and all neighbor nodes. After the IP address of each neighbor node in the Hello message, the "number of Hello messages sent by the node to the neighbor" is stored, and then the link information of the node and the neighbor node on all channels is stored.

Because the number of Hello messages received by the node and the neighboring node on different interfaces is different, the number of probe packets received by the local node in the Hello message must be stored separately on the interface. After receiving the Hello message, the node takes the corresponding parameters and saves them in the neighbor table, and periodically calculates the ETTs of all interfaces of the node to all neighbor nodes. The calculation period ω set in this embodiment is 20 seconds.

2. Modification of TC message:

The OLSR protocol uses TC messages to provide network topology information. The node periodically broadcasts TC messages. The node that receives the TC message determines whether the network topology changes according to the message, thereby triggering the update of the routing table. The TC message includes, in addition to the source node address that generates the TC message, the destination node address reachable by the node and the address of the next hop node that needs to pass to reach the destination node address.

In order to enable other nodes in the network to use the ETT when updating the routing table, the node puts the minimum value of the ETT values of all channels between the destination node and the local node into the TC when generating the TC message. interest. After receiving the TC message, the node updates to the ETT of the destination node while updating its own topology table. The data format of the TC message is shown in Figure 3.

Using joint metric coding, a fixed bit channel identification is used in the Hello message to indicate the channel connection relationship between adjacent nodes. Each channel is represented by a fixed 2-bit binary number identifier, 00 indicates that it is not a neighbor on the channel, 01 indicates an asymmetric neighbor, 10 indicates a symmetric neighbor, and 11 indicates an MPR neighbor. If there are K channels connected between two nodes, 2K bits are used to indicate all channel connection relationships between the two neighbors. Sorted by channel bandwidth, the highest two bits represent the channel with the lowest bandwidth, and so on, with the lowest two bits representing the channel with the highest bandwidth.

In this embodiment, only one IP address is assigned to multiple interfaces of each node in the network. To indicate the link information between the node and the neighbor node, a 4-bit channel is added after the IP address of each neighbor node of the Hello message. The identifier is used to indicate the adjacency relationship between this node and the neighbor node on all channels. In FIG. 4, the channel identifier of the node transmitting the Hello message and the neighbor node 2 is 1100, indicating that the two nodes are not neighbors on channel one, and are MPR neighbors on channel two. Since the two nodes are not neighbors on the channel 1, the Hello message may not add the link information of the two nodes on the channel one. This also reduces the size of the Hello message and reduces the routing overhead.

The advantage of assigning a unique IP address to all interfaces of a node is that the MID (Multiple Interface Declaration) message is removed, which significantly reduces the routing overhead. Another benefit of this approach is that it reduces the use of IP addresses and saves limited IP address resources.

Step 103: The node selected as the MPR periodically generates a TC broadcast message, and selects a high rate channel set to send the TC message outward.

All nodes (MPR and non-MPR nodes) need to calculate the ETT of all interfaces of their own hop neighbor nodes, and only MPR nodes need to generate and forward TC messages. Each node will select the MPR node in its own one-hop neighbor, so the TC generated by the MPR can establish the route of the whole network node.

Optimize the sending policy of TC messages and narrow the scope of routing messages. Since the neighbor information of each node is stored in the neighbor table of each node in the network, that is, each node knows which node the node is adjacent to on which link.

In this embodiment, a greedy algorithm is used to optimize the sending policy of the TC message, so that the TC message is as far as possible. Broadcast on high bandwidth channels and minimize total number of broadcasts.

Before sending the TC message, the node will call the ChannelSelect() function to select the channel to be sent by the TC message. The formal algorithm is described as follows:

In the algorithm, NumberofChannel represents the number of channels in the network, NumberofNeighbor represents the number of all neighbor nodes of the node, and k represents the number of marked neighbor nodes.

In the ChannelSelect() function, all channels are first sorted according to the channel bandwidth from high to low (line 1); then all neighbors (3-6 lines) are checked in order from the high bandwidth channel to the low bandwidth channel, if one When the neighbor neighbor[j] and the local node are neighbors on the channel channel[i], the neighbor is marked, and the number k of the marked neighbor nodes is incremented by 1, and the channel channel[i] (9-17 lines) is recorded. For those neighbors that have already been marked, they are neighbors to the local node on the high-bandwidth channel, so these nodes are no longer checked on the low-bandwidth channel (lines 7-8). When the number of marked neighbors is equal to the total number of neighbors, the channel of the node and all neighbors has been recorded. At this time, the function exits and returns all recorded channels (lines 18-19). The return value of this function is the channel to be broadcast by the TC message. The method can control the TC message in a subnet with a high channel bandwidth, and reduce the broadcast of the TC message in the low bandwidth subnet, thereby reducing the load of the low bandwidth subnet.

The method in this embodiment selects a high-bandwidth channel according to the bandwidth of the channel and combines the MPR (multipoint relay) flooding method to propagate and diffuse the routing control message, and belongs to the proactive routing method. The method can effectively reduce the wireless network routing overhead and improve the utilization of the low bandwidth channel, thereby improving network throughput and energy efficiency performance.

Step 104: The intermediate node updates the topology information according to the TC message, and the MPR node needs to forward the TC message.

The TC message is flooded to the entire network through the MPR set. That is, only the MPR node is responsible for forwarding the received TC message. The non-MPR node only updates its own topology table according to the received TC message, and does not forward the TC message. The TC message carries the expected transmission time ETT sent to the corresponding neighbor node, and the intermediate node needs to store the routing criterion according to the IP address of the node. At the same time, when forwarding the TC message, the MPR node also uses the channel selection algorithm to select the high rate channel set to send the TC message.

Step 105: All nodes calculate routes to all possible destination nodes according to the topology information acquired by the nodes.

In this embodiment, the proactive route is used, and the node calculates the route to the possible destination node according to the topology information collected by the node. Each node can calculate the routes in the two ranges according to the Hello message received by the node. At the same time, according to the topology information table carried by the TC, the node can calculate the route to the node beyond the two hops. The node establishes a routing table to all nodes. When a new Hello or TC message arrives, the node needs to decide whether to recalculate the routing table according to the topology change.

This embodiment establishes a route based on weak multipath coverage: the weak multipath coverage method can establish a robust multi-route backup with low overhead in the route discovery process. Once the node moves, the node fails, etc., the route fails, and the node that finds the route is invalid can quickly switch to the backup route to continue communication. The weak multipath coverage method can largely avoid the route re-establishment process after route failure, and improve the urgency and availability of network routing. Moreover, the method allows the discovery of a route-failed node to locally switch routes without requiring the source node to participate in route switching, which further improves the flexibility of using multiple routing policies and the efficiency of route recovery.

At the same time, a routing strategy combining proactive routing and reactive routing is adopted. When the routing information is not routed or the route is incorrect because of the large interval, the local reactive route inquiry is used to establish the route as needed. “Weak multipath coverage” belongs to the proactive route. If multipath coverage is established, multiple lines will be established. Route backup, when a route fails, the node can quickly switch to the backup route without rerouting.

The weak multipath coverage of this embodiment is combined with the related mature Ad Hoc routing protocol DSR (Dynamic Source Routing) to improve on the basis of the protocol prototype.

Among them, the DSR algorithm belongs to the reactive routing algorithm (Reactive Routing), which utilizes the source point routing technology and has the monitoring capability, and can put the useful routing information into the local cache entry in time. The locating process of the DSR algorithm can be divided into two phases. The first is to find the request phase, and the request message RREQ (Routing Request) is broadcasted in the network in the form of broadcast, and the intermediate node forwards the RREQ message, and The node information is recorded; after receiving the RREP (Routing Reply) message, the destination node enters the response phase. The destination node sends the seek response message RREP to the source node in unicast form.

To implement the weak multipath coverage method, the following modifications need to be made on the basis of the original DSR protocol:

1) The RREP listening mechanism is added to the DSR. In weak multipath coverage, the node not only receives the RREP sent to itself, but also handles the RREP that the intercepted destination address is not its own. It is by analyzing and processing the path information of the detected RREP that the weak multipath coverage method establishes multiple different routing paths.

2) Process the received RREQ and the intercepted RREP, and generate a new route by path separation and path combination. The node records information such as the upstream node, path, and hop count when it receives the RREQ. When the node detects the RREP, it establishes a backup routing path different from the path in the RREP according to the recorded path information of the RREQ and the path information in the intercepted RREP, and advertises the backup routing path to its upstream node through the RREP.

Compared with the related art, the embodiments of the present invention have significant advantages in that:

(1) Using a route advertisement mechanism based on joint metric coding, the multi-interface description information is removed, and the routing overhead is reduced;

(2) The optimized TC message only propagates on the channel with high bandwidth, which reduces the load of the low bandwidth network and improves its communication efficiency;

(3) Method of proactive and reactive hybrid routing, increasing route advertisement interval and routing error Or reactively establishing a route without routing, which can reduce routing overhead and improve the sensitivity of the network to cope with topology changes;

(4) Based on the weak multipath routing recovery strategy, the route is improved in the harsh environment, the route convergence speed is improved, the network-wide route flapping caused by the local link fault is prevented, and the network routing maintenance overhead is reduced.

The embodiment of the invention further provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and the computer executable instructions are used to execute the above method.

FIG. 5 is a schematic diagram of an apparatus for routing according to an embodiment of the present invention. The apparatus for routing in this embodiment includes:

a receiving module, configured to receive a Hello message and a TC message;

In an optional embodiment, the routing device may further include:

Generating a module, configured to periodically generate a TC message if the node is selected as a multipoint relay node by the upstream node, where the TC message carries an ETT of all channels between the node and the destination node a minimum value of the value, as a routing criterion of the downstream node, the TC message further includes: an address of the destination node reachable by the node, and an address of a next hop node that needs to pass to reach the destination node address;

The sending module is configured to periodically send the TC message.

In an optional embodiment, the sending module is configured to select a high rate channel set to send the TC message using a greedy algorithm.

In an optional embodiment, the establishing module is further configured to: establish a local node to a neighbor node list according to the received Hello message; select a partial node as a multipoint relay node from the one hop neighbor node, the multiple point The relay node can send the Hello message sent by the local node to all the two-hop neighbor nodes.

In an optional embodiment, the sending module is further configured to periodically send a Hello message, where the parameters in the Hello message include the number of probe packets received by the node and the number of probe packets sent by the node, The IP address of each neighbor node in the Hello message includes the number of Hello messages sent by the node to the neighbor node and the link information of the local node and the neighbor node on all channels.

In an optional embodiment, the establishing module is configured to establish a route by using a routing policy combining proactive routing and reactive routing.

In an optional embodiment, the establishing module is configured to establish a route based on the weak multipath coverage, including: receiving a homing response message, recording the upstream node, the path information, and the hop according to the homing response message. And detecting a request message; and establishing a backup routing path different from the path in the request request message according to the path information recorded and the path information in the search request message being intercepted And advertise the backup routing path to the upstream node by using the seek request message.

One of ordinary skill in the art will appreciate that all or a portion of the steps described above can be accomplished by a program that instructs the associated hardware, such as a read-only memory, a magnetic or optical disk, and the like. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any What is the combination of specific forms of hardware and software.

The above is only an alternative embodiment of the present invention, and of course, the present invention may be embodied in various other embodiments without departing from the spirit and scope of the invention. Corresponding changes and modifications are intended to be included within the scope of the appended claims.

Industrial applicability

The above technical solution enables routing messages to be transmitted on the high speed channel as much as possible, while the low speed channel transmits or does not transmit routing data packets as little as possible, which reduces the routing overhead of the entire network, and the low rate channel can use their valuable bandwidth resources for the service. Data transmission improves the utilization of low-rate channels and network throughput.

Claims

A routing method applied to heterogeneous wireless networks, including:

The node receives the hello message and the topology control TC message;

The node establishes a route according to the Hello message and the TC message, where the Hello message carries a unique IP address of each neighbor node, and the designated bit on the IP address is used to indicate that the local node and the corresponding neighbor node are in all channels. Adjacency relationship on.
The method of claim 1 further comprising:

After the node receives the Hello message, the node periodically calculates the expected transmission time ETT of all channels between the local node and all neighboring nodes according to the Hello message, and the ETT is calculated according to the following formula:

Where p f represents the forward transmission success rate, p r represents the backward transmission success rate, Size is the size of the transmitted data packet, and B is the bandwidth of the transmission channel.

The forward transmission success rate p f and the backward transmission success rate p r are calculated according to the following formula:

When calculating p f , recv_count(t-ω, t) represents the number of probe packets received by neighboring nodes from time t-ω to time t, and sent_count(t-ω, t) represents the time from t-ω time to time t. The number of probe packets sent by the node;

When calculating r r , recv_count(t-ω, t) represents the number of probe packets actually received by the node from time t-ω to time t, and sent_count(t-ω, t) represents time from t-ω to time t. Number of probe packets sent by neighbor nodes,

If the node is selected as the multipoint relay node by the upstream node, the TC message is periodically generated and sent, and the TC message includes: a minimum value of the ETT values of all channels between the local node and the destination node, as a downstream The routing criteria of the node.
The method of claim 2,

The TC message further includes: an address of the destination node reachable by the node and reaching the destination The address of the next hop node that the node address needs to pass.
The method of claim 2 or 3, wherein: said node transmitting said TC message is implemented in the following manner:

The node uses a greedy algorithm to select a set of high rate channels to transmit the TC message.
The method of claim 1 further comprising:

After the node receives the Hello message, the node establishes a link list of the node to the neighbor node according to the received Hello message;

A partial node is selected as a multipoint relay node from the one-hop neighbor node, and the multi-point relay node can send the Hello message sent by the local node to all the two-hop neighbor nodes.
The method of claim 1 further comprising:

The node periodically sends a Hello message. The parameters in the Hello message include the number of probe packets received by the local node and the number of probe packets sent by the local node. The IP address of each neighbor node in the Hello message includes the local node. Sending the number of Hello messages to the neighbor node and the link information of the local node and the neighbor node on all channels.
The method of claim 1 wherein: said node establishing a route based on said Hello message and said TC message is implemented in the following manner:

The node simultaneously uses a routing strategy combining proactive routing and reactive routing to establish a route.
The method of claim 1 wherein: said node establishing a route based on said Hello message and said TC message is implemented in the following manner:

The node establishes a route based on weak multipath coverage.
The method of claim 8 wherein: said node establishes a route based on weak multipath coverage, comprising:

The node receives the homing response message, and records the upstream node, the path information, and the hop count according to the homing response message;

Listening for a request message;

According to the path information recorded and the path information in the homing request message that is detected, a backup routing path different from the path in the request request message;

The backup routing path is advertised to the upstream node by the seek request message.
A routing device comprising:

a receiving module, configured to receive a hello message and a topology control TC message;

Establishing a module, configured to establish a route according to the Hello message and the TC message, where the Hello message carries a unique IP address of each neighbor node, and the specified bit on the IP address is used to indicate that the local node and the corresponding neighbor node are Adjacency on all channels.
The routing device of claim 10, further comprising:

And a calculating module, configured to periodically calculate, according to the Hello message, a desired transmission time ETT of all channels between the local node and all neighboring nodes, where the ETT is calculated according to the following formula:
Where p f represents the forward transmission success rate, p r represents the backward transmission success rate, Size is the size of the transmitted data packet, B is the bandwidth of the transmission channel, and the forward transmission success rate p f and the backward transmission success rate p r is calculated according to the following formula:
When calculating p f , recv_count(t-ω, t) represents the number of probe packets received by neighboring nodes from time t-ω to time t, and sent_count(t-ω, t) represents the time from t-ω time to time t. The number of probe packets sent by the node. When calculating r r , recv_count(t-ω, t) represents the number of probe packets actually received by the node from time t-ω to time t, and sent_count(t-ω, t) The number of probe packets sent by neighboring nodes from time t-ω to time t;

Generating a module, configured to periodically generate a TC message if the node is selected as a multipoint relay node by the upstream node, where the TC message includes: a minimum value of ETT values of all channels between the node and the destination node , as the routing criterion of the downstream node; and the address of the destination node reachable by the node and the address of the next hop node that needs to pass to reach the destination node address;

The sending module is configured to periodically send the TC message.
The routing device of claim 11 wherein:

The sending module is configured to select a high rate channel set to send the TC message using a greedy algorithm.
The routing device of claim 10,

The establishing module is further configured to establish the local node to the neighbor node according to the received Hello message. A linked list is selected from a one-hop neighbor node as a multi-point relay node, and the multi-point relay node can send a Hello message sent by the local node to all two-hop neighbor nodes.
The routing device of claim 11

The sending module is further configured to periodically send a Hello message, where the parameters in the Hello message include the number of probe packets received by the local node and the number of probe packets sent by the local node, and each neighbor node in the Hello message. The IP address includes the number of Hello messages sent by the node to the neighbor node and the link information of the local node and the neighbor node on all channels.
A routing device according to any of claims 10-14, wherein:

The establishing module is configured to establish a route by using a routing strategy combining proactive routing and reactive routing.
A routing device according to any of claims 10-14, wherein:

The establishing module is configured to establish a route based on the weak multipath coverage, including: receiving a homing response message, recording an upstream node, a path information, and a hop count according to the homing response message; and listening for the homing request message Establishing a backup routing path different from the path in the request request message according to the path information and the path information in the hunted request message that is detected; The backup routing path is advertised to the upstream node.