CN101938418A

CN101938418A - Relaying method of power line communication network

Info

Publication number: CN101938418A
Application number: CN2010102707080A
Authority: CN
Inventors: 李智
Original assignee: SHENZHEN YESTUNED INDUSTRY Co Ltd
Current assignee: SHENZHEN YESTUNED INDUSTRY Co Ltd
Priority date: 2010-09-01
Filing date: 2010-09-01
Publication date: 2011-01-05

Abstract

The invention provides a relaying method of a power line communication network, which can extend the communication distance of a power line network in a hop-by-hop mode by selecting and using relay nodes. The method does not need any relay equipment but only one software module among nodes, and the software module is used for obtaining the relay nodes from a central node to a destination node. The method can realize the reliable transmission of data in the long-distance condition, thereby improving the efficiency of the network.

Description

The trunking method of power line communication network

[technical field]

The present invention relates to the method for relaying in an electric line communication system, that is to say, under the situation about how when the powerline systems channel circumstance, to become, realize the long-distance transmissions of data, improve the reliability of system.

[background technology]

Power line communication is meant by carrier system and will simulates or digital signal is carried out transmission manner on power line, is the peculiar communication mode of electric power system.In the last few years, both at home and abroad Utilities Electric Co. and related scientific research mechanism all actively developing with power line as transmission medium, realized the high-speed transfer of information, thereby the research of service were provided for the electric power enterprise informationization.The key property of power line communication is by the carrier chip decision, and this is the progress of semiconductor technology, comprise reduce transmitting power, improve receiving ability (sensitivity), improve communication bandwidth, increase network function, the aspect such as reduce cost.And at present in order to make power line can transmit information effectively reliably, main by increasing transmitting power, optimize Coupling device, adopt relaying; The direction that wherein increases the development of transmitting power and power line communication runs in the opposite direction, and should not adopt; Optimizing Coupling device is the basic skills of improving the passage attenuation, is useful measure.In order to increase transmission range, in implementation process,, carrier signal is amplified, thereby make distance node far away can correctly receive data by installing repeater additional.But repeater can reduce the available bandwidth of power circuit to the amplification that sends signal, makes data bump and the probability that conflicts increases.

[summary of the invention]

The purpose of this invention is to provide a kind of power line data relay method, can satisfy the remote transmission of power distribution network high speed data message.This method can be obtained routing iinformation automatically very soon under the blind state of network topology, and the greatest difficulty that relaying is realized is how to eliminate a certain node to repeat the same packets of receiving that Centroid and via node are sent, and this method has added next hop address in grouping, if certain node discovery next-hop node is not oneself then abandons this grouping, can avoid the transmission that repeats of same packets like this.

Power line communication network generally by a Centroid, a plurality ofly form from node.Centroid has the control and the function of supervising the network, and main in the service of general power line communication network also be Centroid and from the information interchange between the node.After Centroid and each node module all started, Centroid can search out the path of each child node in the present networks, is established to the route of all child nodes, is kept in the route table items.So after each node module started, Centroid had just been set up the route table items of each node.If send data to certain node (destination node), Centroid can be searched the next hop address of destination node in local routing table, if do not have to the next hop address of this destination node or to the link down of this node, then Centroid will get access to the route of destination node again, and the node that participates in the route relaying has also obtained to arrive the route of destination node, and the routing table form is as shown in table 1.The method is characterized in that: need not be by increasing physical hardware, such as repeater, improve communication distance, can reach the effect that improves transmission range and just add a little software modules from one's body at node, this method can not know to obtain routing iinformation automatically under the situation of network topology structure in addition, and if certain network node since fault can not communicate, this method can be obtained routing iinformation again, obtains via node.

Table 1 route table items form

Type

Hop?count

Origin?id

Next?hop?ID

Destination?ID

Sequence?number

[description of drawings]

Fig. 1 is a power line communication network topological diagram.

Fig. 2 is the flow chart of route acquisition

Fig. 3 is the link repair flow chart

Main symbol description:

In Fig. 1: 0 is power line, and 1 is Centroid, and 2 to 10 is from node, and 11 is power line coupler.

[embodiment]

This method is in obtaining the path process, use three kinds of routing packets: route requests grouping (RRQ), as shown in table 2,＜Centroid IP, REQ ID〉identified a REQ message uniquely, the hop count of REQ equals 0 during beginning, and jumping figure can increase in route finding process, arrives the jumping figure that can draw from the Centroid to the destination node after the destination node at last what are.Route response grouping (REP), the form of REP grouping is as shown in table 3.Centroid, is broadcasted the REQ grouping to its neighbours and is used for route discovery when certain destination node sends data (path does not exist or be invalid) at needs.Receive the node of " route requests " grouping when certain node, the reverse path list item be set point to source node that when destination node was received the REQ grouping, it just sent the REP grouping in routing table.The REP grouping is got back to Centroid along reverse path (the REQ grouping is through the opposite direction in the path of out-of-date formation).Here to note in the REQ grouping, Source ID is last one node ID of jumping, and Origin ID is the NC node, Destination ID is for obtaining the destination node of route, but in the REP grouping, Origin ID is the destination node in the REQ grouping, and Destination ID is the Origin ID in the REQ grouping, that is to say that Destination ID is the ID of NC node.Route repair grouping (RER) is shown in the RER packet format table 4.

Table 2REQ packet format

Type

Hop?count

Destination?ID

Source?ID

Origin?ID

REQ?ID

Table 3REP packet format

Type

Hop?count

Origin?ID

Destination?ID

Next?hop?ID

Lifetime

Route repair grouping (RER), the RER packet format:

Table 4RER packet format

Type

Unreachable?Destination?ID

Lifetime

This method specifically comprises three steps:

The first step, route finding process, Centroid at needs when certain destination node sends data, can in routing table, inquire about the next hop address that arrives this destination node, via node just will be if the routing iinformation of this destination node not will carry out route discovery, Centroid can send route requests grouping (REQ), and is as shown in table 2.Wherein: the type of REQ message is set to 1, represents that this message is the REQ grouping;＜Centroid address, REQ ID〉to the only REQ grouping of having determined, when the center node was initiated a new REQ, REQ ID counter just increased by 1.Route or this node that whether the neighbor node judging of receiving REQ arrives destination node are exactly destination node, if below either way be not, then broadcast this REQ grouping to oneself neighbours again, a node may be received a plurality of copies of same broadcasting from different neighbours, if when intermediate node is received a REQ grouping, its can judge to the grouping of receiving: if when node has been received the REQ of identical broadcasts sign and Centroid address, it will lose this grouping; If node was not received such REQ grouping in the past, it will be preserved some information and be used to set up reverse path, and then this REQ grouping is broadcasted away.

In second step, oppositely route is set up, when the REQ grouping when a Centroid is forwarded to certain destination node, on the way the node of process to be established to the reverse route of Centroid automatically.Node is set up reverse route by the neighbours address of first REQ grouping that record is received, these reverse routes will be kept certain hour, and enough REQ of this section period are grouped in the REP grouping of transmitting in the net and producing and return Centroid.When REQ grouping has arrived destination node or has to the node of destination node route, this node will produce the REP grouping, and utilizes the reverse route of setting up to transmit REP.The REP grouping is as shown in table 3.

In the 3rd step, the forward route is set up, and the REQ grouping arrives a node the most at last, and this node may be exactly a destination node, and perhaps this node has the route that arrives destination node.If this intermediate node has the route that arrives destination node, will produce the REP grouping and return Centroid, otherwise can only be to continue this REQ grouping of broadcasting.Transmit back in the process of Centroid at REP, each node on this paths all will be established to the route in the same way of destination node, and just noting REP is the address of coming from which neighbor node.Set up reverse route for those, but the REP grouping does not have the node of process, it is invalid that the reverse route of setting up in them will become behind certain hour automatically.Receive that the node of REP grouping will go out to the REP packet forward, and jump the address, be established to the route of destination node according to last one in the REP grouping, just the last jumping address assignment of REP in the routing table in the next hop address of destination node.Centroid will just be set up the route of Centroid to destination node after receiving the REP grouping.The route acquisition flow chart as shown in Figure 2.

Route repair process: when the center node will be when destination node sends grouping, can in local routing table, inquire about the next hop address that arrives destination node, to divide into groups then to send, the node that the receives grouping hop node that will make progress returns the ACK grouping, if certain node is not received the ACK grouping of next-hop node, then continue to send grouping to next-hop node, triplicate like this, if all there is not ACK to return in three times, then this node produces the RER grouping and reports this situation to Centroid, the RER grouping transmits by broadcast mode, after the node of maintaining routing list item is received this RER grouping, jumping figure to destination node in the route table items is set to infinity, represents that the route of this node is invalid, can't arrive.After RER arrives Centroid, wait for that RER lost efficacy, send route requests then again, get access to the route of destination address.The route repair flow chart as shown in Figure 3.

Embodiment 1:

General power line network comprises tree-like, annular, and chain is illustrated in figure 1 as a power line network topological diagram.In the figure, suppose that each node power module just starts, so Centroid is without any the routing iinformation of node.1 is Centroid, and 2 to 10 all is from node, and we obtain the via node of destination node 5 with this method now.Here node 1 and

node

2,3,6,10 can direct communications, and node 3 can direct communication with node 4,5.2 with, 3,4 can direct communication, 4 and 5 can direct communication.As scheme us and do not take relaying, Centroid can't be passed to information node 5.At this we with the inventive method make Centroid 1 with can communicate by letter from node 5, and guarantee that the relaying jumping figure is the shortest.

Step 1: Centroid at first finds not arrive the routing iinformation of destination node, then broadcast the REQ grouping, then

node

2,3,6,10 is received this REQ information, and be established to the reverse route of Centroid according to the address information among the REQ, judge the routing iinformation that whether arrives destination node 5 then, because 2,3,6,10 do not arrive the routing iinformation of destination node 5, continue broadcasting REQ.

Step 2: in the loop network on Fig. 1 the right, if

node

6,10 continues broadcasting REQ grouping, Centroid also can be received the REQ grouping that it sends itself so, then abandons this REQ grouping.And in loop network, the REQ grouping has all passed to 6 at last, 7,8,9, several nodes of 10, and the repeated packets that the broadcasting between the node is received all abandons at last, and

node

6,7,, 8,9,10 have also all set up the reverse route of Centroid, and oppositely route can keep a period of time, at last deletion.

Step 3: in the recurrent network of on the left side,

node

2,3 have set up the reverse route of Centroid, the next-hop node of having preserved Centroid in this reverse routing table is 1 continuation broadcasting REQ grouping then, after 2 broadcasting,

node

3,4 has all been received the REQ grouping, and node 3 just received should the sign grouping, be left intact so abandon this grouping.And node 4 is received this REQ grouping, sets up reverse path, and the next-hop node that node 4 has been preserved Centroid is 2. node 4 continuation broadcasting then, and node 5 is received this REQ grouping, has then set up the reverse path of article one to Centroid, is 5 → 4 → 2 → 1.

And node 3 also will be broadcasted the REQ grouping, finds to have received this REQ grouping after node 4 is received, and oneself is not node 5, then abandons this grouping.Node 5 is received this grouping, and the reverse route of then having set up Centroid is 5 → 3 → 1.Because 5 → 3 → 1 jumping figure is shorter, the ability double bounce, then destination node is abandoned 5 → 4 → 2 → 1 this 3 path of jumping.Last REP grouping sends the REP grouping to Centroid by reverse route, and in the process that transmits,

node

3,1 has all been set up the routing iinformation of destination node, and the reverse routing iinformation that each node is set up has arrived certain hour and deletes automatically.

Therefore can communicate by letter with node 5 by the last Centroid of this method, via node is 3.Therefore take length that the power line communication network of the method can guarantee data apart from reliable transmission, can guarantee the service quality that voice and video is used, other some common application have also obtained good service simultaneously.

It should be noted that protection scope of the present invention only is subjected to the restriction of claims, is not to be the restriction of specification disclosed method.

Claims

1. power line communication network is generally by a Centroid with a plurality ofly form from node.The invention provides a kind of under the network topology structure condition of unknown Centroid search out the method for destination node route.If certain bar link disconnects, then from node notice Centroid, Centroid obtains route again.

2. as right 1 said power line network trunking method, this trunking method is characterised in that: this trunking scheme does not need to increase any repeater, just increases a software module.Centroid is initiated route discovery, if certain node has the route to destination node, then returns route replies, has so just set up the route of Centroid to destination node, has just known all via nodes.

3. as right 1 described power line network trunking method, it is characterized in that the via node that participates in route discovery will be set up reverse routing iinformation, can arrive Centroid smoothly to make things convenient for the route replies grouping.Arrive in the process of Centroid in the route replies grouping, set up the forward route, obtain via node.

4. as right 1 described power line network trunking method, it is characterized in that, if certain node send information to the next-hop node failure, then retransmit twice again, if Centroid is then notified in still failure, the fracture of this section link, Centroid is then initiated route discovery again, obtains via node.