CN102883370B - Distributed data transmission method for power line monitoring system on basis of wireless sensor network - Google Patents

Abstract

A distributed data transmission method for a power line monitoring system based on a wireless sensor network, comprising the following steps: 1) The sensor node takes T as the working cycle, and the initial stage of each cycle is time-synchronized by capturing the beacon and the sink node; 2) ) Sensor nodes exchange node information with neighbors by broadcasting to determine the nodes that need to send data in this cycle; 3) Through the communication reachability between sending nodes and local network energy load balancing, distributed selection of relay nodes as data transmission 4) The relay node selection stage is initiated by the sending node, and the sensor node that has no data to send in this cycle is selected as the relay node; 4) Distributed for the nodes that need to be woken up at the data transmission node; 5) Using a ladder-like The data upload link performs wake-up/sleep scheduling on the nodes. The invention is applicable to the chain multi-hop network and energy load balancing based on the wireless sensor network power line monitoring system.

Description

Distributed data transmission method of power line monitoring system based on wireless sensor network

technical field

The invention relates to a data transmission method of a power line monitoring system, in particular to a distributed data transmission method of a power line monitoring system based on a wireless sensor network.

Background technique

The power line transmission system is an important part of the power system, and its stable operation directly affects the country's economic development and people's lives. At the same time, there are many distribution points and wide areas of power line transmission lines. Most of them are far away from cities and towns. The terrain is complex and the natural environment is harsh. It is easy to cause power lines to break due to natural disasters or fatigue accumulation, resulting in serious power outages. Therefore, it is necessary to establish a power line monitoring system to monitor the environmental factors and tension of the power line in real time, and to be able to warn of dangerous situations in time. The current emerging wireless sensor network technology has data transmission characteristics of low power consumption, which is especially suitable for applications. in the power line detection system. For the special requirements of the power line network, such as chain, multi-hop, event-driven, etc., it is necessary to design a data transmission method specifically for the power line monitoring system based on wireless sensor networks.

At present, the patents for the power line monitoring system based on wireless sensors are [1] Wu Jianguo. Power line safety monitor with ZIGBEE wireless communication function [P]. Chinese patent: 201020204953.7, 2010-05-27. [2] Sensor Networks For MonitoringPipelines And Power Lines. US2007041333A1, 2007-02-22. Among them [1] proposed the use of ZIGBEE technology for power line detection and data transmission. However, ZIGBEE is a general data transmission protocol and does not propose data for the special needs of power line networks. transfer method. [2] proposed the use of wireless sensor networks to detect power lines, and did not involve specific data transmission methods. Patent [3] Remote Monitoring of Pipelines using Wireless Sensor Network. US7526944B2, 2009-05-05. It proposes a method for monitoring chained networks using wireless sensor networks, but its focus is on the design of the network organizational structure. Literature [4] I. Jawhar, N. Mohamed and K. Shuaib. A framework for pipeline infrastructure monitoring using wireless sensor networks. The Sixth Annual Wireless Telecommunications Symposium (WTS2007), IEEE Communication Society/ACM Sigmobile.A Calif.2, Pomona, 0 . Document [5] Imad Jawhar, Nader Mohamed, Khaled Shuaiband Nader Kesserwan. An Efficient Framework and Networking Protocol for Linear Wireless Sensor Networks. Ad Hoc&Sensor Wireless Networks01/2009, 7:3-21. The characteristics and design of the sensor network, but its focus is on the design of the overall framework of the network. Literature [6] Marco Zimmerling, Waltenegus Dargie, Johnathan M. Reason, Localized power-aware routing in linear wireless sensor networks, Proceedings of the 2nd ACMinternational conference on Context-awareness for self-managing systems, p.24-33, May 19- 19,2008,Sydney,Australia. Designed a routing protocol for chained multi-hop wireless sensor networks, but it did not consider the more important MAC layer design. Literature [7] S.U.Hashmi, J.H.Sarker, H.T.Mouftah, N.D.Georganas, AnEffcient TDMA Scheme with Dynamic Slot Assignment in Clustered Wireless Sensor Networks, GLOBECOM 2010, 2010IEEE.6-10Dec.2010. Proposed event-driven MAC in wireless sensor networks Protocol idea, but it is limited to single-hop network and has not been extended to multi-hop chain network.

Contents of the invention

In order to overcome the shortcomings of the existing data transmission mode based on wireless sensor network power line monitoring system, which is limited to single-hop network and unbalanced energy load, the present invention proposes a chain-like system suitable for wireless sensor network based power line monitoring system A distributed data transmission method for a wireless sensor network based power line monitoring system with multi-hop network and energy load balancing.

The technical scheme that adopts in order to solve the above-mentioned technical problem is:

A distributed data transmission method of a power line monitoring system based on a wireless sensor network, the power line monitoring system includes a convergence node and a sensor node, and the convergence node periodically broadcasts beacons for time synchronization with the sensor nodes; the sensor node transmits data through The multi-hop mode is sent to the sink node, and the data transmission method includes the following steps:

1) The sensor node takes T as the working cycle, and the initial stage of each cycle synchronizes time with the sink node by capturing the beacon;

2) Random access: the sensor node exchanges node information with its neighbors through broadcasting to determine the node that needs to send data in this cycle, that is, the sending node;

3) Distributed selection of relay nodes as relays for data transmission through communication accessibility between sending nodes and local network energy load balancing;

The relay node selection phase is initiated by the sending node, and a sensor node that has no data to send in this cycle is selected as a relay node, and the steps are as follows:

3.1) Check the neighbor information table to determine whether there is data sent to the forward N-hop neighbor; if yes, exit; if not, execute 3.2);

3.2) Select the sensor node with the largest remaining energy among the forward N-hop neighbors as the relay node, and send the request packet;

3.3) The target sensor node receives the request packet, sets itself as a relay node, and executes 3.1);

4) Distributedly allocate time slices for the nodes that need to be woken up at the data transmission node, that is, the sending node and the relay node, and the rest of the nodes are in a dormant state;

The sending node and the relay node perform distributed time slice allocation by broadcasting time slice data packets, the steps are as follows:

4.1) The sending node and the relay node initialize the local time slice as S ₀ ;

4.2) Broadcast the time slice data packet, which contains the current time slice value S ₀ of the sensor node;

4.3) If the sensor node receives the time slice data packet broadcast to the neighbor node, record the time slice in the data packet as S _c , judge S ₀ and S _c , if S _c is greater than or equal to S ₀ , execute 4.4); S ₀ =S _c ; Execute 4.2);

4.4) If the time slice data packet is not received within T _a time, the time slice allocation ends;

5) Use a ladder-shaped data upload link to schedule wake-up/sleep of nodes.

Further, the convergence node broadcasts a beacon frame at the beginning of the working period T, and the beacon frame includes time synchronization information.

Furthermore, the working cycle T includes four stages: random access, relay node selection, time slice allocation, and data upload. The length of the random access phase is T _r , the length of the relay node selection phase is T _s , and the time slice allocation The length of the stage is T _a , the length of the data uploading stage is T _u , and T=T _r +T _s +T _a +T _u is satisfied.

The random access phase is used for sensor nodes to exchange information. The sensor nodes broadcast HELLO data packets, which include node ID, node power, and whether to send data indications; meanwhile, nodes maintain N-hop neighbor information tables locally, which include Neighbor node ID, node power, data transmission indicator bit.

When the sensor node receives the HELLO data packet from the neighbor sensor node, it writes the relevant node information in the data packet into the neighbor information table.

In the data upload stage, a ladder-like data upload method is adopted. The sending node and the relay node wake up within the allocated time slice to send and receive data, and enter a dormant state during the rest of the time; the rest of the nodes remain dormant.

Set the size of the time slice S _i as T _slot , which is divided into the receiving stage RX _i and the sending stage TX _i , for the adjacent nodes i and i+1 on the link, the corresponding sending stage of the time slice S _i and S The receiving stages of _i+1 overlap, that is, TX _i =RX _i+1 , so as to realize the link-like data upload method.

The technical idea of the present invention is: mainly for the characteristics of the chain multi-hop network of the power line monitoring system, and according to the event-driven nature, a targeted data transmission method is proposed. Two types of nodes are set up: sink nodes and sensor nodes. The sink nodes periodically broadcast beacons for time synchronization with the sensor nodes; the sensor nodes send data to the sink nodes in a multi-hop manner.

The network takes T as the working cycle. In each network cycle, the information is sent by broadcasting the energy and data of the switching nodes, and a reasonable relay node is selected according to the principle of energy load balancing to extend the network life cycle. After that, time slices are assigned to the sending node and the relay node to perform ladder-like data uploading to reduce data transmission delays, while controlling the rest of the nodes to remain dormant to reduce node energy consumption.

The beneficial effects of the present invention are:

Description of drawings

Fig. 1 is a schematic diagram of a network duty cycle based on wireless sensor network power line monitoring according to the present invention;

Fig. 2 is a HELLO broadcast frame structure diagram of the present invention;

Fig. 3 is a structural diagram of a beacon frame according to the present invention;

Fig. 4 is a flowchart of the relay selection algorithm of the present invention;

Fig. 5 is a structural diagram of a relay request frame according to the present invention;

Fig. 6 is a time slice allocation algorithm flow chart of the present invention;

Fig. 7 is a time slice data frame structural diagram of the present invention;

Fig. 8 is a schematic diagram of node data upload time slice scheduling according to the present invention.

specific implementation plan

The present invention will be described in detail below in conjunction with the accompanying drawings.

Referring to Figures 1 to 8, a distributed data transmission method of a power line monitoring system based on a wireless sensor network, the power line monitoring system includes a convergence node and a sensor node, and the convergence node periodically broadcasts beacons to communicate with the sensor node time Synchronization; the sensor node sends data to the sink node in a multi-hop mode, and the data transmission method includes the following steps:

6), the sensor node takes T as the working cycle, and the initial stage of each cycle synchronizes time with the sink node by capturing the beacon;

7) Random access: The sensor node exchanges node information with neighbors through broadcasting to determine the node that needs to send data in this cycle, that is, the sending node;

8) Distributed selection of relay nodes as relays for data transmission through communication accessibility between sending nodes and local network energy load balancing;

The relay node selection phase is initiated by the sending node, and a sensor node that has no data to send in this cycle is selected as a relay node, and the steps are as follows:

3.1) Check the neighbor information table to determine whether there is data sent to the forward N-hop neighbor; if yes, exit; if not, execute 3.2);

3.2) Select the sensor node with the largest remaining energy among the forward N-hop neighbors as the relay node, and send the request packet;

3.3) The target sensor node receives the request packet, sets itself as a relay node, and executes 3.1);

9) Distributedly allocate time slices for the nodes that need to be woken up at the data transmission node, that is, the sending node and the relay node, and the rest of the nodes are in a dormant state;

The sending node and the relay node perform distributed time slice allocation by broadcasting time slice data packets, the steps are as follows:

4.1) The sending node and the relay node initialize the local time slice as S ₀ ;

4.2) Broadcast the time slice data packet, which contains the current time slice value S ₀ of the sensor node;

4.3) If the sensor node receives the time slice data packet broadcast to the neighbor node, record the time slice in the data packet as S _c , judge S ₀ and S _c , if S _c is greater than or equal to S ₀ , execute 4.4); S ₀ =S _c ; Execute 4.2);

4.4) If the time slice data packet is not received within T _a time, the time slice allocation ends;

10) Use a ladder-shaped data upload link to schedule wake-up/sleep of nodes.

Further, the convergence node broadcasts a beacon frame at the beginning of the working period T, and the beacon frame includes time synchronization information.

Furthermore, the working cycle T includes four stages: random access, relay node selection, time slice allocation, and data upload. The length of the random access phase is T _r , the length of the relay node selection phase is T _s , and the time slice allocation The length of the stage is T _a , the length of the data uploading stage is T _u , and T=T _r +T _s +T _a +T _u is satisfied.

The random access phase is used for sensor nodes to exchange information. The sensor nodes broadcast HELLO data packets, which include node ID, node power, and whether to send data indications; meanwhile, nodes maintain N-hop neighbor information tables locally, which include Neighbor node ID, node power, data transmission indicator bit.

When the sensor node receives the HELLO data packet from the neighbor sensor node, it writes the relevant node information in the data packet into the neighbor information table.

In the data upload stage, a ladder-like data upload method is adopted. The sending node and the relay node wake up within the allocated time slice to send and receive data, and enter a dormant state during the rest of the time; the rest of the nodes remain dormant.

Set the size of the time slice S _i as T _slot , which is divided into the receiving stage RX _i and the sending stage TX _i , for the adjacent nodes i and i+1 on the link, the corresponding sending stage of the time slice S _i and S The receiving stages of _i+1 overlap, that is, TX _i =RX _i+1 , so as to realize the link-like data upload method.

The specific working cycle is shown in Figure 1. The sink node broadcasts the beacon frame with T (1 minute) as the working cycle. The beacon frame contains time synchronization information for time synchronization between the sensor node and the sink node. The structure of the beacon frame is shown in Figure 3. The time T is organized into four stages: random access, relay node selection, time slice allocation, and data upload. The length of the random access stage is T _r (5 seconds), and the length of the relay node selection stage is T _s (5 seconds). The length of the time slice allocation phase is T _a (10 seconds), the length of the data upload phase is T _u (40 seconds), and T=T _r +T _s +T _a +T _u is satisfied.

The random access stage is used for sensor nodes to exchange information, and the sensor nodes broadcast HELLO data frames, and the specific frame format is shown in Figure 2. The HELLO data frame includes node ID, node power, and whether to send data indication. At the same time, the node maintains an N (typically 3) hop neighbor information table locally, which contains the neighbor node ID, node power, and data transmission instructions. The information exchange process is:

1. The node records the local ID, node power, and whether to send data indication into the HELLO data packet, and broadcasts the data packet.

2. When the node receives the HELLO data packet from the neighbor node, it puts the corresponding node ID, node power, and whether it needs to send data into the locally maintained N-hop neighbor information table.

The relay node selection phase is initiated by the sending node. According to the local network energy load balance, the corresponding sensor node that has no data to send in this cycle is selected as the relay node, as shown in Figure 4. The corresponding steps are as follows:

1. Check the neighbor information table to determine whether the forward N (typical value is 3) hop neighbors have data to send. If yes, exit; if not, execute 2).

2. Select the sensor node with the largest remaining energy in the forward N-hop neighbors as the relay node, and send a relay request frame. The frame format is shown in Figure 5.

3. If the target sensor node receives the relay request frame, set itself as a relay node and execute 1).

In the time slice allocation stage, the time slice allocation is performed by the sending node and the relay node, and the remaining nodes are in a dormant state. The sending node and the relay node perform distributed time slice allocation by broadcasting time slice packets, as shown in Figure 6, and the corresponding steps are as follows:

1. The sending node and the relay node initialize the local time slice as S ₀ =1;

2. The broadcast time slice data frame has a format as shown in FIG. 7 . The time slice data frame contains the current time slice value S ₀ of the sensor node;

3. If the sensor node receives the time slice data frame broadcast to the neighbor nodes, record the time slice in the data packet as S _c , and judge S ₀ and S _c . If S _c is greater than or equal to S ₀ , execute 4);

4. S ₀ =S _c ; execute 2);

If the time slice data packet is not received within the Ta time, the time slice allocation ends.

In the data upload stage, a stepped data upload method is adopted, as shown in Figure 8. The sending node and the relay node wake up within the allocated time slice to send and receive data, and enter a sleep state for the rest of the time. The rest of the nodes have been kept dormant. The size of the time slice S _i is T _slot (typically 200 milliseconds), which is divided into a receiving phase RX _i (100 milliseconds) and a transmitting phase TX _i (100 milliseconds). For adjacent nodes i and i+1 on the link, the sending phase of the corresponding time slice S _i coincides with the receiving phase of S _i+1 , that is, TX _i =RX _i+1 , so as to realize the link ladder Data upload method.

Claims (5)

1. the distributed data transport method based on the power line monitoring system of wireless sensor network, it is characterized in that: described power line monitoring system comprises aggregation node and sensor node, the periodic broadcast beacon of aggregation node is used for and sensor node time synchronized; Data are sent to aggregation node by the mode of multi-hop by sensor node, and described data transmission method comprises the following steps:

1), sensor node take T as the work period, and the initial period in each cycle is by catching beacon and aggregation node carries out time synchronized; Described aggregation node, in the initial period broadcast beacon frame of work period T, comprises time synchronization information in beacon frame; Described work period T is Stochastic accessing, trunk node selection, timeslice are distributed, data upload four-stage, and accidental access stage length is T _r, trunk node selection stage length is T _s, timeslice allocated phase length is T _a, data upload stage length is T _u, and meet T=T _r+ T _s+ T _a+ T _u;

2), Stochastic accessing: sensor node is by broadcasting with neighbours' switching node information to determine that this cycle has data to need the node sent, i.e. sending node;

3), by the communication accessibility between sending node and the equilibrium of localized network energy load, distributed selection via node is as the relaying of transfer of data;

The described trunk node selection stage is initiated by sending node, and select at this cycle countless sensor node according to sending as via node, step is as follows:

3.1) check neighbor information table, judge that forward direction N hop neighbor sends with or without data; If have, then exit; If nothing, perform 3.2);

3.2) sensor node that in selection forward direction N hop neighbor, dump energy is maximum, as via node, sends request bag;

3.3) objective sensor node receives request bag, and self is set to via node, performs 3.1);

4), in a distributed manner for needing the node waken up at data transmission nodal, namely sending node and via node distribute timeslice, and all the other nodes are in resting state;

Sending node and via node carry out distributed timeslice distribution by airtime sheet packet, and step is as follows:

4.1) sending node and via node initialization local zone time sheet are S ₀;

4.2) airtime sheet packet, comprises the time chip value S of this sensor node at present in packet ₀;

4.3) if sensor node receives the timeslice packet of backward neighbor node broadcast, recording timeslice in this packet is S _c, judge S ₀with S _cif, S _cbe more than or equal to S ₀, perform 4.4); S ₀=S _c; Perform 4.2);

4.4) if at T _ado not have time of receipt (T of R) sheet packet in time, timeslice distributes end;

5), stair-stepping data upload link is adopted to carry out wake/sleep scheduling to node.

2. as claimed in claim 1 based on the distributed data transport method of the power line monitoring system of wireless sensor network, it is characterized in that: described accidental access stage is used for sensor node and carries out information exchange, sensor node broadcasts HELLO packet, comprising node ID, node electricity, indicates the need of transmission data; Meanwhile, node, at local maintenance N hop neighbor information table, comprises neighbor node ID, node electricity, data transmission indicating bit in table.

3. as claimed in claim 2 based on the distributed data transport method of the power line monitoring system of wireless sensor network, it is characterized in that: when sensor node receives the HELLO packet of neighbours' sensor node, by nodal information relevant in packet write neighbor information table.

4. as claimed in claim 3 based on the distributed data transport method of the power line monitoring system of wireless sensor network, it is characterized in that: in the data upload stage, adopt stair-stepping data upload mode, sending node and via node wake up in the timeslice of distributing, carry out data transmit-receive, in all the other times, enter resting state; All the other nodes keep resting state always.

5., as claimed in claim 4 based on the distributed data transport method of the power line monitoring system of wireless sensor network, it is characterized in that: described timeslice S is set _isize is T _slot, be divided into reception stage RX _iwith transmission phase TX _i, for adjacent node i and i+1 on link, the timeslice S of its correspondence _itransmission phase and S _i+1the reception stage overlap, i.e. TX _i=RX _i+1, realize the stair-stepping data upload mode of link with this.