CN102291302B - Local routing reconstruction method in power line carrier communication network of low-voltage electric distribution network - Google Patents

Abstract

The invention relates to a local routing reconfiguration method in a power line carrier communication network of a low-voltage distribution network, which relates to the field of power line communication. It solves the problems of reconstruction efficiency, poor accuracy of meter reading and low channel utilization in the existing automatic meter reading system for node routing reconstruction methods. The present invention analyzes and studies the network layer and the MAC layer of the automatic meter reading system, and utilizes this special network structure of the artificial spider web. All nodes in the network are reconfigured to save routing time and improve communication efficiency and reliability. The invention is suitable for routing reconfiguration in the low-voltage power distribution network power line carrier communication network.

Description

Local Routing Reconfiguration Method in Power Line Carrier Communication Network of Low-Voltage Distribution Network

technical field

The invention relates to the field of power line communication, in particular to a route reconfiguration method.

Background technique

After the artificial cobweb networking of the MAC layer of the electric power automatic meter reading system is completed, due to serious channel interference, the terminal nodes in each subnet may still fail to communicate with the central node. In this case, a reliable and efficient blind spot rerouting method is very important to ensure the service quality of the entire automatic meter reading system. Currently, there are mainly the following two routing reconfiguration technologies for nodes.

The first is the power line communication routing algorithm based on the idea of clustering. The power line communication clustering algorithm mainly includes the network initialization algorithm and the network reconfiguration algorithm, which can effectively expand the communication radius of the power line communication network. The problem with this method is that once the network terminal node cannot communicate with the cluster head due to channel environment changes, all nodes in the entire network need to be re-clustered and route reconstructed. This situation greatly increases the data acquisition cycle and time delay of the system, and reduces the efficiency and accuracy of the automatic meter reading system.

The second is based on artificial intelligence algorithms, such as the routing optimization algorithm of the power line communication network based on the idea of ant colony optimization. These algorithms are based on the connectivity of the network. The optimal path to the target node. Similarly, if the ant colony optimization algorithm is applied, if there is a communication blind spot caused by the change of the channel environment, it is still necessary to re-search for routes and select relay nodes for all nodes in the network. Although the automatic meter reading system does not have high requirements on time, due to frequent changes in the channel environment, the frequency of blind spots after the completion of the network is still relatively high. It is necessary to reconfigure the routes of all nodes in the system frequently, which increases the calculation of nodes. It is easy to cause data conflicts in bus-type channels and reduce channel utilization.

Qi Jiajin disclosed a dynamic networking method of low-voltage distribution network power line carrier communication in "Research on Dynamic Networking Method of Low-Voltage Distribution Network Power Line Carrier Communication" published in 2010, but the communication efficiency and reliability of this dynamic networking method lower.

Contents of the invention

In order to improve the communication efficiency and reliability in the existing automatic meter reading system, the present invention provides a local route reconstruction method in the power line carrier communication network of the low-voltage distribution network.

A local route reconstruction method in a power line carrier communication network of a low-voltage distribution network, which is realized by the following steps:

Step 1: The base station in the power line carrier communication network of the low-voltage distribution network initiates data broadcasting, m G nodes in the MAC layer of the power line carrier communication network of the low-voltage distribution network receive the data broadcasting of the base station, and form m-1 edges in the MAC layer The n-th layer subnet of the single-layer cobweb logic topology, m is an integer greater than 1, n=1;

Step 2, select a node h _n as the center node in the nth layer subnetwork of the m-1 edge single-layer cobweb logical topology structure described in step one, and the nth layer of the single-layer cobweb logical topology structure between the central node and the single-layer cobweb logical topology structure Any other node in the subnet can directly perform data communication;

Step 3, the central node h _n assigns a logical ID to each node in the nth layer subnetwork of the m-1 edge single-layer cobweb logical topology structure;

Step 4, the central node h _n of the n-th layer subnet initiates data broadcasting again;

Step 5. The k nodes in the MAC layer of the low-voltage distribution network power line carrier communication network receive the data broadcast by the central node h _n , and then remove all the nodes that have obtained the logical ID, and form the remaining km nodes into the n+1th layer subnetwork, select a node in the n+1th layer subnetwork as the central node h _n+1 of this layer subnetwork, the said central node _hn+1 and any other A node can directly perform data communication, and the central node h _n+1 assigns a logical ID to each node in the n+1th layer subnet; set n=n+1, m=km, return to step 4, and The remaining B nodes search until all nodes realize direct communication or relay communication with the base station, and complete the establishment of the communication network in the MAC layer of the low-voltage distribution network power line carrier communication network; k is an integer greater than m;

Step 6. Update the channel environment. For each layer of subnet: the central node judges whether it has received data from each peripheral node in the layer of subnet through the logical ID. If the judgment result is yes, then end the routing of the layer of subnet Reconstruction; if the judgment result is no, the subnet of this layer needs to be reconfigured; for each subnet that needs reconfiguration, perform steps 7 and 8 to reconfigure the subnet;

Step 7, judge one by one whether each peripheral node that cannot communicate with the central node of the subnet in the layer subnet can communicate with the adjacent nodes of the peripheral node in the layer subnet, if the judgment result of all the peripheral nodes is If not, go back to step 1 and re-establish the network; otherwise, go to step 8;

Step 8. The central node of the subnet of this layer sends an instruction to each neighboring node in the subnet of the subnet that has not received the data, and initiates a route reconstruction broadcast to each of the surrounding nodes that has not received the data. , establish a handshake mechanism between each peripheral node that has not received data and the adjacent nodes of the peripheral node in the subnet of this layer, and then realize the communication between all peripheral nodes that have not received data and the central node of the subnet of the layer relay communication, and end the local routing reconstruction of the layer subnet;

Step 9. After all subnets of all layers complete the local routing reconstruction, realize the local routing reconstruction of the automatic meter reading system;

The G node is a node that can directly communicate with the base station in point-to-point communication;

Node B is a node that cannot directly communicate with the base station due to the influence of the channel state, but can communicate with its adjacent nodes.

Beneficial effects: the present invention analyzes and studies the low-voltage distribution network power line carrier communication network layer and the MAC layer, and utilizes the special network structure of the artificial spider web to make the central node of the subnet responsible for local blind spots of the subnet after the networking is completed. Rerouting does not need to rerouting all nodes in the network, saving routing time, improving communication efficiency and reliability, improving meter reading accuracy, and high channel utilization.

Description of drawings

Fig. 1 is a schematic diagram of the principle of the bus-type physical topology described in Embodiment 1 of the present invention, where G is marked as a G node, and B is marked as a B node; Fig. 2 is a schematic diagram of the logical topology of artificial cobweb communication; Fig. 3 is a specific embodiment 1 In the schematic diagram of the networking results, mark G as node G, and mark B as node B; FIG. 4 is a schematic diagram of the principle of blind spot routing reconstruction in the first embodiment, mark G as node G, and mark B as node B; FIG. 5 is a specific embodiment The blind spot rerouting sequence diagram described in 1.

Detailed ways

Embodiment 1. A local routing reconfiguration method in a low-voltage power distribution network power line carrier communication network, which is implemented by the following steps:

Step 1: The base station in the power line carrier communication network of the low-voltage distribution network initiates data broadcasting, m G nodes in the MAC layer of the power line carrier communication network of the low-voltage distribution network receive the data broadcasting of the base station, and form m-1 edges in the MAC layer The n-th layer subnet of the single-layer cobweb logic topology, m is an integer greater than 1, n=1;

Step 2, select a node h _n as the center node in the nth layer subnetwork of the m-1 edge single-layer cobweb logical topology structure described in step one, and the nth layer of the single-layer cobweb logical topology structure between the central node and the single-layer cobweb logical topology structure Any other node in the subnet can directly perform data communication;

Step 3, the central node h _n assigns a logical ID to each node in the nth layer subnetwork of the m-1 edge single-layer cobweb logical topology structure;

Step 4, the central node h _n of the n-th layer subnet initiates data broadcasting again;

Step 5. The k nodes in the MAC layer of the low-voltage distribution network power line carrier communication network receive the data broadcast by the central node h _n , and then remove all the nodes that have obtained the logical ID, and form the remaining km nodes into the n+1th layer subnetwork, select a node in the n+1th layer subnetwork as the central node h _n+1 of this layer subnetwork, the said central node _hn+1 and any other A node can directly perform data communication, and the central node h _n+1 assigns a logical ID to each node in the n+1th layer subnet; set n=n+1, m=km, return to step 4, and The remaining B nodes search until all nodes realize direct communication or relay communication with the base station, and complete the establishment of the communication network in the MAC layer of the low-voltage distribution network power line carrier communication network; k is an integer greater than m;

Step 6. Update the channel environment. For each layer of subnet: the central node judges whether it has received data from each peripheral node in the layer of subnet through the logical ID. If the judgment result is yes, then end the routing of the layer of subnet Reconstruction; if the judgment result is no, the subnet of this layer needs to be reconfigured; for each subnet that needs reconfiguration, perform steps 7 and 8 to reconfigure the subnet;

Step 7, judge one by one whether each peripheral node that cannot communicate with the central node of the subnet in the layer subnet can communicate with the adjacent nodes of the peripheral node in the layer subnet, if the judgment result of all the peripheral nodes is If not, go back to step 1 and re-establish the network; otherwise, go to step 8;

Step 8. The central node of the subnet of this layer sends an instruction to each neighboring node in the subnet of the subnet that has not received the data, and initiates a route reconstruction broadcast to each of the surrounding nodes that has not received the data. , establish a handshake mechanism between each peripheral node that has not received data and the adjacent nodes of the peripheral node in the subnet of this layer, and then realize the communication between all peripheral nodes that have not received data and the central node of the subnet of the layer relay communication, and end the local routing reconstruction of the layer subnet;

Step 9. After all subnets of all layers complete the local routing reconstruction, realize the local routing reconstruction of the automatic meter reading system;

The G node is a node that can directly communicate with the base station in point-to-point communication;

Node B is a node that cannot directly communicate with the base station due to the influence of the channel state, but can communicate with its adjacent nodes.

Principle: Figure 1 shows the bus-type physical topology of the automatic meter reading system in a unit building. The base station initiates data collection and broadcasting. Since the broadcast signal attenuates with the transmission distance, only terminal nodes that are relatively close to the base station can communicate directly and reliably with the base station, which are G nodes. Other nodes cannot receive the broadcast information of the base station and cannot send data to the base station, but point-to-point communication between adjacent nodes is possible, which is a B node.

In Figure 1, all nodes in the first layer subnet can communicate directly with the base station, and the nodes can communicate directly point-to-point or through relay nodes. According to this feature, each node in the first layer subnet can be equivalent to the logical topology of the single-layer artificial cobweb shown in Figure 2 at the MAC layer. As shown in Figure 2, m terminal nodes form a single-layer spider web with m-1 edges, h is any one of the m nodes, node h can communicate directly with all nodes in the subnet, and point-to-point communication between adjacent nodes , the non-adjacent nodes communicate with the central node h as the relay.

The central node h allocates logical IDs to the remaining m-1 terminal nodes in the subnet until all nodes obtain logical IDs.

The broadcast is sent again by node h. Compared with the base station, node h is physically closer to node B, and the number of nodes receiving the broadcast information of node h is k (k>m). One node is selected as the central node among k-m nodes without logical ID, and Assign logical IDs to these k-m nodes.

The central node of the second subnet sends a broadcast again to explore the B node. If there are still new nodes, repeat step 5, select the central node, and assign logical IDs until there are no new blind spots; information. The final networking result of the MAC layer is shown in Figure 3, taking 3 subnets to search for all blind spots as an example.

After the networking is completed, all nodes in the network maintain communication with the base station using the central node of each subnet as a relay. However, due to changes in the channel environment, there are still peripheral nodes in the subnet that cannot communicate with the central node, as shown in Figure 3.

Taking the second layer subnet as an example, when the central node n receives data from peripheral nodes, it confirms that no data from node r is received by judging the logical ID, and waits for a period of time to confirm the status of node r.

The nodes p and q adjacent to the node r can still maintain communication with the central node n. After the data processing time PT (Process Time), the node n sends the request data packet RP (Request Packet) to the node p, q. The node initiates a rerouting broadcast to node r.

After receiving the request packet RP, node p sends a request packet RP to node r after time PT, and q sends a request packet RP to node r after time WT (Wait Time) (WT>PT).

Node r processes RPs from nodes p and q after time PT, waits for time WT, sends response data packets AP (Answer Packet) to nodes p, q, nodes p, q receive the response data packets AP from node r, and complete node r Communication handshake mechanism with nodes p, q.

Nodes p and q wait for the time 2WT respectively, and WT sends the received response data packet AP to the central node n, so far, node r uses nodes p and q as the relay to regain data communication with central node n, and node n completes the blind point r routing refactoring.

The specific process of the above nodes p and q being relay nodes at the same time, the timing of individually selecting one of them as a relay node is similar to this, remove the timing of node p or node q in Figure 5, and modify the waiting time accordingly. In order to avoid data conflicts caused by routing reconstruction, the present invention defines a data processing time PT (Process Time) and a waiting time WT (Wait Time). Data packets are received and forwarded according to the set timing.

The present invention analyzes and studies the network layer and the MAC layer of the automatic meter reading system, and uses the special network structure of the artificial spider web to make the central node of the subnet responsible for rerouting the local blind spots of the subnet after the completion of the network, without All nodes in the network are rerouted to save routing time and improve communication efficiency and reliability.

Claims (1)

1. localized routing reconstructing method in low-voltage network power line carrier communication network, is characterized in that: it is realized by following steps:

Data broadcast is initiated in base station in step 1, low-voltage network power line carrier communication network, m G node in the MAC layer of low-voltage network power line carrier communication network receives the data broadcast of base station, and at MAC layer, form the n straton net of m-1 limit individual layer spider web logical topological structure, m is greater than 1 integer, n=1;

Step 2, in the n straton net of the m-1 limit individual layer spider web logical topological structure described in step 1, select a node h _nas Centroid, in the n straton net of described Centroid and individual layer spider web logical topological structure, all the other any one nodes all can directly carry out data communication;

Step 3, Centroid h _nto each the node assignment logic ID in the n straton net of m-1 limit individual layer spider web logical topological structure;

The Centroid h of step 4, n straton net _nagain initiate data broadcast;

K node receiving center node h in the MAC layer of step 5, low-voltage network power line carrier communication network _nthe data of broadcast, then, by obtaining all node revocations of logic ID, form n+1 straton net by a remaining k-m node, in described n+1 straton net, select a node as the Centroid h of this straton net _n+1, described Centroid h _n+1all can directly carry out data communication with all the other any one nodes in n+1 straton net, this Centroid h _n+1to each the node assignment logic ID in n+1 straton net; Make n=n+1, m=k-m, returns to execution step four, and remaining B node is searched for, until all nodes are all realized direct communication or trunking traffic with base station, completes the foundation of communication network in the MAC layer of low-voltage network power line carrier communication network; K is the integer that is greater than m;

Step 6, upgrade channel circumstance, for every straton net: Centroid judges whether the data from each week mid-side node in this straton net of receiving by logic ID, if judgment result is that it is to finish the routing reconfigurability of this straton net; If the determination result is NO, this straton net need to carry out routing reconfigurability; For each, need the subnet of routing reconfigurability, execution step seven and eight, carries out routing reconfigurability to this subnet;

Step 7, judge that whether each week mid-side node can not communicating by letter with the Centroid of this subnet in this straton net can communicate by the adjacent node in this straton net with this week mid-side node one by one, if the determination result is NO for all mid-side nodes, return to step 1, re-start networking; Otherwise, execution step eight;

The Centroid of step 8, this straton net sends instruction to the adjacent node of each all mid-side node of not receiving data in this straton net, initiation is to described routing reconfigurability broadcast of not receiving each week mid-side node of data, set up and not receive each week mid-side node of data and the handshake mechanism between this week mid-side node adjacent node in this straton net, and then realize all trunking traffics of not receiving between all mid-side nodes of data and the Centroid of this straton net, and finish the localized routing reconstruct to this straton net;

Step 9, all complete after localized routing reconstruct when all straton nets, realize the localized routing reconstruct to Automatic meter reading system;

G node for can be directly and base station carry out the node of point-to-point communication;

B node is that the impact that is subject to channel status can not directly communicate with base station, but can be adjacent the node that node communicates;

In above-mentioned communication process, be set with data processing time PT and stand-by period WT, the reception of packet and forwarding are carried out according to the sequential of setting.

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