CN103259632B - Based on the continuous reliable assemblage method of radio sensing network data adopting patrilineal line of descent with only one son in each generation model - Google Patents

Abstract

The invention discloses a reliable aggregation method of wireless sensor network data based on a continuous sampling single pass model. The method includes three processes of establishing data transmission mechanism connection, data transmission congestion control and data transmission selective retransmission. Establish a data transmission mechanism When the connection is initiated, the sensor node submits a data transmission request to the data sink node, and "piggyback" transmission of data transmission control information during the link establishment process reduces the control information overhead of the data source node. After the connection is established, enter the data transmission stage. The sensor nodes and the data aggregation nodes respectively control the network congestion through NACK to avoid a large amount of loss of transmitted data due to network congestion. When data loss or transmission errors occur during data transmission, sensor nodes perform selective and priority retransmission of data to ensure reliable and efficient data transmission without increasing network load too much.

Description

Reliable Data Aggregation Method for Wireless Sensor Networks Based on Continuous Collection Single Pass Model

technical field

The invention belongs to the data transmission communication technology, and in particular relates to a reliable aggregation method of wireless sensor network data based on a continuous sampling single transmission model.

Background technique

The wireless sensor network is composed of a large number of cheap micro sensor nodes deployed in the monitoring area, and forms a multi-hop self-organizing network system through wireless communication. Due to the limited resources of sensor nodes such as energy, storage, computing and communication bandwidth, the function of a single node is relatively weak. In the node design process, in order to prolong the life cycle of the entire network, energy consumption becomes the primary consideration.

The current mainstream wireless sensor network data transmission protocols include RMST (ReliableMulti-SegmentTransport, reliable multi-segmentation data transmission protocol), ESRT (Event-to-SinkReliableTransport, event-based data reliability transmission protocol), PSFQ (Pump-Slowly, Fetch-Quickly, a data transmission protocol based on slow injection and quick reply). The RMST protocol is mainly based on the flat routing protocol. The source sensor node divides larger data into smaller segments for transmission. The intermediate node ensures that the sink node successfully collects all segmented data as the receiving end, synthesizes data packets, and submits them to the terminal. Users, but the network congestion control mechanism is not introduced in the data transmission process, and the order and time limit of data transmission cannot be guaranteed. The ESRT protocol considers that a large number of nodes periodically report the occurrence of a certain type of event, which is mainly used to ensure that a sufficient amount of packet data reaches the sink node and minimize the number of redundant report packets. The design of PSFQ protocol solves the scalability problem of wireless sensor network data transmission well, but its usability is limited by the transmission bandwidth, and the effectiveness of the protocol requires high bandwidth support.

The design of wireless sensor network data transmission mechanism needs to consider various factors such as user requirements, network load, sensor node power consumption and processing capabilities, and design suitable mechanisms for different application requirements. Wireless sensor network nodes are generally battery-powered micro-nodes, limited energy and weak processing capabilities are the salient features of wireless sensor network nodes. The wireless sensor network continues to collect single-pass model, that is, each wireless sensor node in the sensor network wakes up at a fixed period, continuously performs data collection operations, and takes one day or longer as the transmission cycle to carry out the single transmission of collected data to the data aggregation center. Reliable aggregation. Traditional wireless sensor network data transmission protocols are relatively complex or limited to certain specific application environments, and some data transmission protocols do not have functions such as congestion control and reliable data transmission guarantee. It is not completely suitable for the wireless sensor network data transmission with low real-time requirements and high reliability requirements for the continuous sampling single-pass model.

Contents of the invention

The purpose of the present invention is to provide a reliable aggregation method for wireless sensor network data based on the continuous sampling single-pass model in order to solve the defects in the existing technology. In the environment where there are many sensor nodes and the network is unstable Efficient data transmission of data aggregation nodes, high reliability of data transmission, less control overhead, and prolonging the overall life of the wireless sensor network. In order to achieve the above purpose, the idea of the present invention is to invent the efficient and reliable data transmission between sensor nodes with limited energy and limited processing capacity and data sink nodes when the network is unreliable, and the invention introduces congestion control mechanism and data selection Sexual retransmission mechanism.

According to the above inventive concept, the present invention adopts the following technical solution: a reliable aggregation method for wireless sensor network data based on the continuous sampling single-pass model, which is characterized in that it includes data transmission mechanism connection establishment, data transmission congestion control and data transmission mechanism data selectivity Retransmit three processes:

a. The implementation steps of the connection establishment of the data transmission mechanism:

(a-1) In the initialization stage, all wireless sensor nodes are encoded, and each node is required to have an independent ID identification number, that is, an identity identification number. The wireless sensor node code can be automatically set by each sensor node Or pre-set manually according to actual application requirements;

(a-2), after the wireless sensor node completes initialization, it sends an ID number and a data transmission request to the data sink node;

(a-3), after the wireless sensor node sends the data transmission request, it starts to listen to the channel until it receives the confirmation frame sent back by the data sink node or exceeds the listening limit time;

(a-4). After receiving the data transmission request frame from the wireless sensor node, the data transmission convergence node parses the data transmission request, and inquires whether the sensor node has a data transmission history record according to the ID number;

(a-5), if the sensor node communicates with the data sink node for the first time, the data sink node sends T-ACK back to the sensor node, that is, transmits a confirmation message frame to confirm the data transmission request;

(a-6), if the wireless sensor node has previously communicated with the data sink node, the data sink node counts whether there is data loss or transmission error during the last data transmission, and sends back the packet sequence number of the lost data the wireless sensor node;

(a-7). After receiving the transmission confirmation frame from the data sink node, the wireless sensor node sends a link establishment success confirmation frame to the data sink node, and then enters the link connection state;

(a-8). After receiving the confirmation frame of successful connection establishment of the wireless sensor node, the data aggregation node enters the link connection state at the same time, waiting for the wireless sensor node to transmit subsequent data;

b. The data transmission congestion control includes data convergence node congestion control and wireless sensor node congestion control:

b-1. The implementation steps of the congestion control of the data aggregation node:

(b-1-1), after the data transmission convergence node receives a packet of data, the node records the sequence number of the packet;

(b-1-2), start the timer to start timing;

(b-1-3), if the data sink node receives the next packet of data within the time limit, clear the timer and start counting again;

(b-1-4), if the data sink node has not received the next packet of data after the timer expires, it will send a NACK signal back to the wireless sensor node, indicating that the data reception failed;

(b-1-5), the data aggregation node counts the number of NACKs sent back in a fixed period, and when it exceeds the preset threshold, it suspends receiving data from subsequent sensor nodes and enters the congestion control mode;

(b-1-6), the data sink node waits for a new data transmission request;

b-2. The implementation steps of the wireless sensor node congestion control:

(b-2-1), preprocessing the data to be sent, pre-dividing the large block of data to be sent into small blocks of data;

(b-2-2), assign continuous packet serial numbers to each small piece of data, and form a data packet with the packet serial number and small piece of data;

(b-2-3), the wireless sensor node determines the data packet transmission order according to the packet sequence number, and sends the data packet with a smaller packet sequence number first;

(b-2-4), the wireless sensor node starts the timer and listens to the channel for a short time;

(b-2-5). If the sensor node does not receive the NACK sent back by the data sink node within a fixed period, the default data transmission is successful; repeat the data transmission operation of step (b-2-3);

(b-2-6). If the sensor node receives the NACK sent back by the data sink node within a fixed period, it will start counting the NACK. When the number of NACKs received within the fixed period exceeds the preset threshold, the wireless transmission The sensing node suspends sending data and enters the congestion control mode;

(b-2-7), the wireless sensor node resubmits a data transmission connection establishment request to the data sink node after a random duration of congestion avoidance;

c. Implementation steps of data selection and retransmission of the data transmission mechanism:

(c-1), the wireless sensor node communicates with the data aggregation node, and the connection steps follow the steps of establishing a connection through the data transmission mechanism;

(c-2), the sensor node judges whether data retransmission is required according to the serial number information of the lost packet sent back by the data sink node;

(c-3) If data retransmission is required, reorder the data and arrange the data packets with smaller sequence numbers at the front of the transmission queue;

(c-4). The wireless sensor nodes send data packets in the reordered order.

Compared with the prior art, the present invention has the following obvious outstanding substantive features and significant technical progress: the method reduces the communication energy consumption of wireless sensor nodes as much as possible without losing the reliability of data transmission, which is different from the previous Compared with the wireless sensor network data transmission method, the method of the present invention introduces a congestion control mechanism, which ensures the efficient transmission of wireless sensor node data in the case of network instability; the method of the present invention has the advantages of small amount of calculation, low energy consumption, It is an effective data reliability aggregation method for wireless sensor networks due to the characteristics of high data transmission reliability.

Description of drawings

Figure 1 is a structural diagram of wireless sensor network data transmission;

Fig. 2 is the flowchart of wireless sensor node data transmission of the present invention;

Fig. 3 is the flowchart of the data reception of the data sink node of the present invention;

Fig. 4 is a flow chart of data pre-segmentation processing in the present invention;

Fig. 5 is a data packet sequencing diagram in the data retransmission stage of the present invention;

FIG. 6 shows various data packet structures used for data transmission control in the present invention.

detailed description

Preferred embodiments of the present invention are described in detail as follows in conjunction with accompanying drawings:

The reliable aggregation method of wireless sensor network data based on the continuous sampling single pass model includes three processes of data transmission mechanism connection establishment, data transmission congestion control and data transmission mechanism data selective retransmission.

In the actual system design process, several wireless sensor nodes are usually deployed in the data collection area. In the selection of node locations, wireless sensor nodes should be distributed in open areas as much as possible to ensure that the data collection area has wireless network coverage. The structure diagram of wireless sensor network data transmission is shown in Fig.1. The data source node collects data regularly, and takes 1 day or longer as the data transmission cycle, and transmits the collected sensor data to the data sink node through WIFI or GPRS, and the data sink node shares the collected and aggregated data with the Internet through the Internet. Users or transfer to the data server for subsequent sharing of data.

In the connection establishment phase, wireless sensor nodes and data sink nodes perform different processes.

The flow chart of wireless sensor node data transmission is shown in Figure 2. The wireless sensor node first performs initialization coding and assigns an independent ID number. The ID number of the wireless sensor node can be manually set in advance or according to actual application requirements. Automatic setting, the range of ID number is: OX0000～OXFFFF. After the wireless sensor node completes the initialization, it sends the ID number and data transmission request to the data sink node. After the wireless sensor node sends the data transmission request, it starts to listen to the channel, and receives the connection confirmation information T-ACK sent back by the data sink node or the RT containing the sequence number of the data packet lost in the last communication process within the listening limit time. -ACK, send confirmation information to the data sink node and enter the connection success state. Failure to receive the confirmation message sent back by the data aggregation node within the time limit or the serial number of the lost data packet often indicates that the connection establishment fails, and the wireless sensor node backs off for a short time to make the next connection establishment request.

The flow chart of data reception by the data sink node is shown in Figure 3. After receiving the data transmission request from the wireless sensor node, the data transmission sink node inquires whether the sensor node has a data transmission history record according to the ID number. If the historical data record corresponding to the ID number is not found in the historical records, it indicates that this is the first time the sensor node communicates with the data sink node, and the data sink node sends back a T-ACK to confirm the data transmission request. If the wireless sensor node has previously communicated with the data sink node, the data sink node counts whether there is data loss or transmission error between the wireless sensor node and the wireless sensor node during the last communication according to the packet sequence number. Or the data is lost, and the packet sequence number of the lost data is sent back to the wireless sensor node for retransmission of the lost packet. After the data aggregation node receives the confirmation information from the wireless sensor node, it enters the connection success state at the same time, waiting for the wireless sensor node to transmit subsequent data.

When the network is congested, the wireless sensor node and the data sink node implement the congestion control mechanism respectively.

After the data transmission aggregation node receives a packet of data, the node records the packet sequence number of this data packet, and starts the timer to start counting. If the data aggregation node receives the next packet of data within the time limit, the timer will be cleared and restarted; if the data aggregation node has not received the next packet of data after the timer expires, it will send a NACK signal back to the wireless sensor node , indicating that data reception failed; the data sink node counts the number of NACKs sent back within a fixed period, and when it exceeds the preset value, it suspends receiving subsequent data and enters the congestion control mode.

The wireless sensor node preprocesses the data to be sent, pre-segments large blocks of data into small pieces of data, and assigns continuous packet sequence numbers to each small piece of data. The block diagram of data preprocessing is shown in Figure 4. Assuming that the length of data to be sent by a wireless sensor node is n*m Byte, and m Byte is used as the division length, n data packets can be obtained. In the range of 1-n, assign a packet sequence number to each data packet according to the data sequence, and sort the data according to the packet sequence number. After completing the preprocessing of the data, the wireless sensor node sends a data packet according to the sequence number of the packet. After the wireless sensor node sends a packet of data, it starts the timer and listens to the channel for a short time. If the sensor node does not receive the NACK sent back by the data sink node within a fixed period, the data is sent successfully by default and continues to send subsequent data pack. If the sensor node receives the NACK sent back by the data sink node within a fixed period, it will start counting the NACK. When the number of NACKs received within the fixed period exceeds the preset value, the wireless sensor node will stop sending data and enter congestion control model. After the wireless sensor node enters the short-term backoff, it re-submits a data transmission request to the data sink node, and reconnects with the data sink node. The backoff time is k*T, T is the time for the sensor node to send a data packet, and k is a random number from 0X00 to OXFF.

Due to network congestion and interruption, wireless sensor nodes need to selectively retransmit erroneous data. In the data retransmission stage, the wireless sensor node communicates with the data sink node, and the connection steps follow the steps of the data transmission mechanism to establish a connection. During the connection process, the data sink node returns the serial number of the data loss packet. The wireless sensor node judges whether data retransmission is required according to the sequence number information of the lost packet sent back by the data sink node. If a data transmission error occurs, data retransmission is required. The packet sequence number in the data retransmission stage is shown in Figure 5. The normal data transmission of the wireless sensor node transmits data packets in sequence according to the packet sequence number 1-n. sort the data. If the packet sequence numbers of the lost data packets are 2 and 4, the wireless sensor node will arrange the data packets 2 and 4 with smaller packet sequence numbers at the front of the transmission queue, and retransmit the data to ensure that the earliest data can Priority transmission.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (1)

1., based on the continuous reliable assemblage method of radio sensing network data adopting patrilineal line of descent with only one son in each generation model, it is characterized in that, comprise data transmission mechanism connection establishment, transfer of data congestion control and data transmission mechanism data selection and retransmit three processes:

A. the performing step of described data transmission mechanism connection establishment:

(a-1), initial phase, all wireless sensing nodes are encoded, require that each node has independently ID identification number, i.e. an identify label number, wireless sensing node coding can automatically be set by each sensing node or manually set in advance according to practical application request;

(a-2), after wireless sensing node completes initialization, ID identification number and data transfer request is sent to convergence node;

(a-3), wireless sensing node sends after data transfer request and starts to intercept channel, intercepts binding hours until receive acknowledgement frame that convergence node beams back or exceed;

(a-4), after transfer of data aggregation node receives the data transfer request frame of wireless sensing node, resolution data transmission request, and inquire about this sensing node according to ID mark number and whether have transfer of data historical record;

(a-5) if this sensing node first time and convergence node communication, convergence node postbacks T-ACK to this sensing node, i.e. acknowledge information frame, confirms data transfer request;

(a-6) if this wireless sensing node previously carried out communication with convergence node, whether there are loss of data, error of transmission in the last data transmission procedure of convergence node statistics, and the packet number of obliterated data is postbacked this wireless sensing node;

(a-7), after wireless sensing node receives the acknowledge information frame of convergence node, send link to convergence node and be successfully established acknowledgement frame, then enter link connection state;

(a-8), convergence node receive wireless sensing node connection establishment success acknowledgement frame after, enter link connection state simultaneously, wait for wireless sensing node transmission follow-up data;

B. described transfer of data congestion control comprises the control of convergence node congestion and wireless sensing node congestion control:

B-1. the performing step of described convergence node congestion control:

(b-1-1), after transfer of data aggregation node receives bag data, the packet number of this packet of nodes records;

(b-1-2), start timer and start timing;

(b-1-3) if convergence node receives next bag data in binding hours, then empty timer and restart timing;

(b-1-4) if convergence node timer time-out does not receive next bag data yet, then postback a NACK signal to wireless sensing node, show data receiver failure;

(b-1-5), NACK number postbacking in the convergence node statistics fixed cycle, after exceeding pre-set threshold value, suspend the data receiving follow-up sensing node, enter congestion control mode;

(b-1-6), convergence node waits for new data transfer request;

B-2. the performing step of described wireless sensing node congestion control:

(b-2-1), to data to be sent carry out preliminary treatment, chunk data to be sent is pre-segmented into small block data;

(b-2-2), be that every small block data distributes continuous print packet number, and packet number and small block data are formed a packet;

(b-2-3), wireless sensing node according to bag sequence number determination Packet Generation order, preferential send the less packet of bag sequence number;

(b-2-4), wireless sensing node starts timer, and intercepts in short-term channel;

(b-2-5) if sensing node does not receive the NACK that convergence node postbacks within the fixed cycle, default data sends successfully; Repeat the data transmit operation of step (b-2-3);

(b-2-6) if sensing node receives the NACK that convergence node postbacks within the fixed cycle, then counting is started to NACK, after the NACK quantity received in length when clamped exceedes pre-set threshold value, wireless sensing node suspends transmission data, enters congestion control mode;

(b-2-7), wireless sensing node carry out random duration congested keep out of the way after again submit the request of transfer of data connection establishment to convergence node;

C. the performing step of described data transmission mechanism data selection re-transmission:

(c-1), wireless sensing node and convergence node communicate to connect, and Connection Step follows the step that data transmission mechanism connects;

(c-2) the lost package sequence number information that, sensing node postbacks according to convergence node judges whether to need data re-transmitting;

(c-3) if need to carry out data re-transmitting, data are resequenced, and packet less for packet number is come transmit queue foremost;

(c-4), wireless sensing node sends packet according to the order after rearrangement.