A communication method based on low-power wireless sensor self-organizing network

Abstract

The invention discloses a communication method based on a low-power wireless sensor self-organizing network, and relates to the technical field of wireless sensor self-organizing networks. The low-power wireless sensor self-organizing network comprises a communication link, which is composed of a gateway, a convergence node and at least one sensor. The sensor, the convergence node and the gateway work in an orderly manner. Through the coordination of the convergence node, wireless silence is performed during the working period of the gateway downlink frame. After the gateway sends the frame, the communication with the sensor is started again to ensure that the wireless signals do not interfere with each other. The convergence node reports the registration information of the sensor in real time, and at the same time determines whether the sensor needs to be re-networked according to the sensor conditions under each convergence node of the gateway and the signal quality between the convergence node and the sensor. When the sensor receives the re-registration command of the convergence node, it automatically starts the re-scanning registration. This method simplifies the re-networking process when the communication signal between the sensor and the convergence node is not good.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless sensor ad hoc networks, and more particularly to a communication method for low-power wireless sensor ad hoc networks. Background Art

[0002] A wireless sensor ad hoc network refers to a wireless network composed of a large number of static or mobile sensors in a self-organizing manner. Its purpose is to collaboratively sense, collect, process and transmit monitoring information of sensed objects within the geographical area covered by the network. It is widely used in information systems for monitoring and controlling objects and the environment.

[0003] Most of the existing sensors use RS485 communication protocol, and a few use wireless communication. They need to be pre-configured by the management system at the installation site and sent to the sensors for normal communication. The configuration process is cumbersome and relies entirely on the experience of the configuration personnel to allocate the subordinate relationship between nodes and aggregation nodes. Once allocated, the subordinate relationship is difficult to change. If changes are required, manual adjustments are still required, and the networking efficiency is poor. Or they can have self-organizing network functions during the installation phase, but cannot be re-organized during use. Wireless signals have multipath effects and electromagnetic interference, and are highly correlated with the installation and use environment. The communication signal quality of nodes and aggregation nodes that are not close in a straight line is not the best. The management relationship between the two needs to be dynamically adjusted to meet the requirements of high-reliability wireless communication. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a communication method based on a low-power wireless sensor ad hoc network.

[0005] The present invention is implemented by the following technical solution: a communication method based on a low-power wireless sensor ad hoc network, wherein the low-power wireless sensor ad hoc network includes a communication link, and the communication link is composed of a gateway, a convergence node and at least one sensor, comprising the following steps:

[0006] A communication method based on a low-power wireless sensor ad hoc network, wherein the low-power wireless sensor ad hoc network includes a communication link, and the communication link is composed of a gateway, a convergence node and a sensor, and is characterized in that it includes the following steps:

[0007] S1: The gateway and the aggregation node use the same physical channel to communicate in the north, and the aggregation node uses another physical channel to communicate with the terminal in the south. The carrier communication frequency, bandwidth, spreading factor, and transmission power of the physical channel are configured through wireless communication. Among them, the access nodes are divided into master nodes and sub-nodes. The master node is the gateway, the sub-node is the aggregation node, and the terminal is the sensor.

[0008] S2: The communication cycle is divided into several frames, each of which is divided into several downlink communication frames and uplink communication frames; the downlink communication frames and uplink communication frames are divided into broadcast channels, downlink control channels, multicast channels, downlink shared channels, uplink random contention channels and uplink shared channels in the time domain according to the communication functions. Each channel is a time slot channel and occupies one or more time slots.

[0009] S3: The first downlink frame of each frame is a broadcast channel. The access node publishes the frame sequence number, cycle length, broadcast cycle, time slot length, number of uplink frame time slots, number of downlink frame time slots and the remaining time resource information of the current frame to the predetermined lower-level node through the broadcast channel;

[0010] S4: After receiving the broadcast frame, the predetermined lower-level node intercepts the frame sequence number, cycle length, broadcast cycle, time slot length, number of uplink frame time slots, number of downlink frame time slots and the remaining time resource information of the current frame, calculates the start time of the uplink contention channel, and sends a registration request to the upper-level node;

[0011] S5: After receiving the registration request, the upper node allocates reporting time slices to all predetermined lower nodes according to the preset reporting order, and completes the registration of the lower nodes;

[0012] S6: The lower-level node sends data to the upper-level node in the reporting time slice.

[0013] Specifically, the communication network uses the master node broadcast channel as the reference time, and the subordinate node time is automatically aligned;

[0014] When the sensor acts as a subnode, the connected master node is a sink node or gateway;

[0015] When the sink node acts as a child node, the connected master node is the gateway.

[0016] Specifically, there is time redundancy between adjacent reporting time slices, and the redundant time can be adjusted.

[0017] Preferably, the sensors report in a configured order after a predetermined time redundancy, and the reporting order matches the sensor address and the aggregation node address.

[0018] Preferably, the data transmission between the sensor, the aggregation node and the gateway adopts one of the following two transmission modes;

[0019] Y1: Serial timing is used for transmission. In this mode, during the downlink frame operation of the gateway, the aggregation node and the sensor are in wireless silence. After the gateway completes sending, the communication between the aggregation node and the sensor is started.

[0020] Y2: Parallel timing transmission is adopted. In this mode, during the downlink frame operation of the gateway, the southbound communication and data transmission of the aggregation node are carried out simultaneously, and are transmitted through physical channels with different carrier frequencies respectively;

[0021] Specifically, when there is no requirement on the communication distance between the sensor, the aggregation node and the gateway, parallel communication is adopted. During the downlink frame operation of the gateway, parallel communication is adopted between the aggregation node and the sensor.

[0022] Preferably, in a communication cycle, when the sensor fails in communication in a current frame, the sensor performs contention reporting in an idle period of the communication cycle.

[0023] Preferably, after the sensors are networked, the convergence node controls whether the sensors need to be re-networked according to the quality of information received from the sensors.

[0024] Specifically, when the broadcast frame signal monitored by the sensor is weak or the gateway sends the sensor to its blacklist, the sensor re-scans and registers.

[0025] Specifically, when the broadcast frame signal monitored by the sensor is good and / or the sensor is close to the sink node, the sensor communicates using a high baud rate.

[0026] Specifically, when the frequency scanning signal of the sensor is poor, the frequency is re-scanned at a low air baud rate and registered after receiving the aggregation node signal.

[0027] Preferably, each aggregation node reserves network configuration management time.

[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0029] 1. The working sequence of sensors, aggregation nodes and gateways is carried out in an orderly manner. Through the coordination of the aggregation node, wireless silence is performed during the downlink frame operation of the gateway. After the gateway has finished sending, communication with the sensor is started to ensure that the wireless signals do not interfere with each other.

[0030] 2. The sensor makes registration requests during the contention period to increase the registration success rate.

[0031] 3. The aggregation node reports the registration information of the sensor in real time, and decides whether the sensor needs to be re-networked based on the status of the sensors under the control of each aggregation node of the gateway and the signal quality between the aggregation node and the sensor. When the sensor receives the re-registration command from the aggregation node, it automatically starts the re-scanning registration. This method simplifies the re-networking process when the communication signal between the sensor and the aggregation node is poor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention.

[0033] Figure 1 is a registration flow chart of the sensor in the present invention;

[0034] Figure 2 It is a flowchart of the reporting timing of different sensors in the present invention;

[0035] Figure 3 It is a timing flow chart of data copying in the present invention. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0037] Embodiment 1:

[0038] like Figure 1 As shown, a communication method based on a low-power wireless sensor ad hoc network, wherein the low-power wireless sensor ad hoc network includes a communication link, wherein the communication link is composed of a gateway, a convergence node and at least one sensor, and comprises the following steps:

[0039] S1: The gateway and the aggregation node use the same physical channel to communicate in the north, and the aggregation node uses another physical channel to communicate with the terminal in the south. The carrier communication frequency, bandwidth, spreading factor, and transmission power of the physical channel are configured through wireless communication. Among them, the access nodes are divided into master nodes and sub-nodes. The master node is the gateway, the sub-node is the aggregation node, and the terminal is the sensor. The sensor can be multiple different types of sensors.

[0040] S2: The communication cycle is divided into several frames, each of which is divided into several downlink communication frames and uplink communication frames; the downlink communication frames and uplink communication frames are divided into broadcast channels, downlink control channels, multicast channels, downlink shared channels, uplink random contention channels and uplink shared channels in the time domain according to the communication functions. Each channel is a time slot channel and occupies one or more time slots;

[0041] S3: The first downlink frame of each frame is a broadcast channel. The access node publishes the frame sequence number, cycle length, broadcast cycle, time slot length, number of uplink frame time slots, number of downlink frame time slots and the remaining time resource information of the current frame to the predetermined lower-level node through the broadcast channel;

[0042] S4: After receiving the broadcast frame, the predetermined lower-level node intercepts the frame sequence number, cycle length, broadcast cycle, time slot length, number of uplink frame time slots, number of downlink frame time slots and the remaining time resource information of the current frame, calculates the start time of the uplink contention channel, and sends a registration request to the upper-level node;

[0043] S5: After receiving the registration request, the upper node allocates reporting time slices to all predetermined lower nodes according to the preset reporting order, and completes the registration of the lower nodes;

[0044] S6: The lower-level node sends data to the upper-level node in the reporting time slice.

[0045] Specifically, the communication network uses the master node broadcast channel as the reference time, and the subordinate node time is automatically aligned;

[0046] When the sensor acts as a subnode, the connected master node is a sink node or gateway;

[0047] When the sink node acts as a child node, the connected master node is the gateway.

[0048] Specifically, there is time redundancy between adjacent reporting time slices, and the redundant time can be adjusted.

[0049] Specifically, Figure 2 As shown, the sensors report in the configuration order after a predetermined time redundancy, and the reporting order matches the sensor address and the sink node address.

[0050] Preferably, the data transmission between the sensor, the aggregation node and the gateway adopts one of the following two transmission modes;

[0051] Y1: Serial timing is used for transmission. In this mode, during the downlink frame operation of the gateway, the aggregation node and the sensor are in wireless silence. After the gateway completes sending, the communication between the aggregation node and the sensor is started.

[0052] Y2: Parallel timing transmission is adopted. In this mode, during the downlink frame operation of the gateway, the southbound communication and data transmission of the aggregation node are carried out simultaneously, and are transmitted through physical channels with different carrier frequencies respectively;

[0053] Specifically, when there is no requirement on the communication distance between the sensor, the aggregation node and the gateway, parallel communication is adopted. During the downlink frame operation of the gateway, parallel communication is adopted between the aggregation node and the sensor.

[0054] The working sequence of sensors, aggregation nodes, and gateways is orderly. Through the coordination of the aggregation node, wireless silence is performed during the working period of the gateway downlink frame. After the gateway has finished sending, communication with the sensor is started to ensure that the wireless signals do not interfere with each other. In the specific implementation process, the aggregation node configures the reporting order of each sensor in advance. After the first sensor reports according to the reference time, the next sensor reports according to the configuration order after the specified time redundancy. The reporting order matches the node address;

[0055] The aggregation node publishes a broadcast frame to the predetermined sensor, which contains the current frame number, broadcast frame period, and the number of the remaining time slice in the current period. When the sensor finds a frame of data, it can calculate the contention gap and make a registration request during the contention period to increase the registration success rate.

[0056] Embodiment 2:

[0057] On the basis of Embodiment 1, after the sensors are networked, the sink node controls whether the sensors need to be re-networked according to the quality of the information received from the sensors;

[0058] The aggregation node reports the registration information of the sensor in real time, and decides whether the sensor needs to be re-networked based on the status of the sensors under the aggregation nodes of the gateway and the signal quality between the aggregation node and the sensor. During the implementation process, when the sensor receives the re-registration command from the aggregation node, it automatically starts the re-scanning registration. This method simplifies the re-networking process when the communication signal between the sensor and the aggregation node is poor.

[0059] Specifically, in a communication cycle, when the sensor fails to communicate in a current frame, the sensor performs contention reporting in an idle period of the communication cycle.

[0060] Specifically, when the broadcast frame signal monitored by the sensor is weak or the gateway sends the sensor to its blacklist, the sensor re-scans and registers.

[0061] Specifically, when the broadcast frame signal monitored by the sensor is good and / or the sensor is close to the sink node, the sensor communicates using a high baud rate.

[0062] Specifically, when the frequency scanning signal of the sensor is poor, the frequency is re-scanned at a low air baud rate and registered after receiving the aggregation node signal. The sensor is registered after receiving the aggregation node signal, thereby ensuring the stability of long-distance transmission to the greatest extent.

[0063] Embodiment 3:

[0064] On the basis of Example 2, each aggregation node reserves network configuration management time. Specifically, during this time period, the aggregation node can wake up the sensor to perform parameter configuration, time calibration, and data supplementation.

[0065] The specific steps for data supplement are as follows:

[0066] S1: The broadcast frame issued by the sink node wakes up the sensor;

[0067] S2: After being awakened, the sensor sends a wake-up response to the sink node;

[0068] S3: The aggregation node sends a meter reading command to the sensor;

[0069] S4: The sensor feeds back the collected data information to the sink node;

[0070] S5: After receiving the data information, the aggregation node sends an end communication instruction to the sensor.

[0071] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A communication method based on a low-power wireless sensor ad hoc network, wherein the low-power wireless sensor ad hoc network includes a communication link, and the communication link is composed of a gateway, a convergence node and at least one sensor, characterized in that: The steps include: S1: The gateway and the aggregation node use the same physical channel to communicate in the north, and the aggregation node uses another physical channel to communicate with the terminal in the south. The carrier communication frequency, bandwidth, spreading factor, and transmission power of the physical channel are configured through wireless communication. Among them, the access nodes are divided into master nodes and sub-nodes. The master node is the gateway, the sub-node is the aggregation node, and the terminal is the sensor. S2: The communication cycle is divided into several frames, each of which is divided into several downlink communication frames and uplink communication frames; the downlink communication frames and uplink communication frames are divided into broadcast channels, downlink control channels, multicast channels, downlink shared channels, uplink random contention channels and uplink shared channels in the time domain according to the communication functions. Each channel is a time slot channel and occupies one or more time slots; S3: The first downlink frame of each frame is a broadcast channel. The access node publishes the frame sequence number, cycle length, broadcast cycle, time slot length, number of uplink frame time slots, number of downlink frame time slots and the remaining time resource information of the current frame to the predetermined lower-level node through the broadcast channel; S4: After receiving the broadcast frame, the predetermined lower-level node intercepts the frame sequence number, cycle length, broadcast cycle, time slot length, number of uplink frame time slots, number of downlink frame time slots and the remaining time resource information of the current frame, calculates the start time of the uplink contention channel, and sends a registration request to the upper-level node; S5: After receiving the registration request, the upper node allocates reporting time slices to all predetermined lower nodes according to the preset reporting order, and completes the registration of the lower nodes; S6: The lower-level node sends data to the upper-level node in the reporting time slice.

2. A communication method based on low-power wireless sensor ad hoc network according to claim 1, characterized in that: The communication network uses the master node broadcast channel as the reference time, and the subordinate node time is automatically aligned; When the sensor acts as a subnode, the connected master node is a sink node or gateway; When the sink node acts as a child node, the connected master node is the gateway.

3. A communication method based on low-power wireless sensor ad hoc network according to claim 2, characterized in that: There is time redundancy between adjacent reporting time slices, and the redundancy time can be adjusted.

4. A communication method based on low-power wireless sensor ad hoc network according to claim 3, characterized in that: The sensors report in the configured order after a predetermined time redundancy, and the reporting order matches the sensor address and the aggregation node address.

5. A communication method based on low-power wireless sensor ad hoc network according to claim 4, characterized in that: The data transmission between the sensor, the aggregation node and the gateway adopts one of the following two transmission modes; Y1: Serial timing is used for transmission. In this mode, during the downlink frame operation of the gateway, the aggregation node and the sensor are in wireless silence. After the gateway has finished sending, the communication between the aggregation node and the sensor is started. Y2: Parallel timing transmission is adopted. In this mode, during the downlink frame operation of the gateway, the southbound communication and data transmission of the aggregation node are carried out simultaneously, and are transmitted through physical channels with different carrier frequencies respectively.

6. A communication method based on low-power wireless sensor ad hoc network according to claim 5, characterized in that: After the sensors are networked, the sink node controls whether the sensors need to be re-networked according to the quality of the information received from the sensors.

7. A communication method based on low-power wireless sensor ad hoc network according to claim 6, characterized in that: In a communication cycle, when the sensor fails to communicate in the current frame, the sensor performs contention reporting in an idle period of the communication cycle.

8. A communication method based on low-power wireless sensor ad hoc network according to claim 6, characterized in that: When the broadcast frame signal monitored by the sensor is weak or the gateway sends the sensor to its blacklist, the sensor re-scans and registers.

9. A communication method based on low-power wireless sensor ad hoc network according to claim 6, characterized in that: When the broadcast frame signal monitored by the sensor is good and / or the sensor is close to the sink node, the sensor communicates at a high baud rate.

10. A communication method based on a low-power wireless sensor ad hoc network according to any one of claims 8 or 9, characterized in that: When the sensor frequency scanning signal is poor, the frequency is re-scanned at a low air baud rate and registered after receiving the aggregation node signal.

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