CN104348659A

CN104348659A - Fault detection method and node for multi-hop network

Info

Publication number: CN104348659A
Application number: CN201310343977.9A
Authority: CN
Inventors: 奥琛; 底欣; 田军
Original assignee: Fujitsu Ltd
Current assignee: Fujitsu Ltd
Priority date: 2013-08-08
Filing date: 2013-08-08
Publication date: 2015-02-11
Anticipated expiration: 2033-08-08
Also published as: CN104348659B; JP2015035807A; JP6354434B2

Abstract

The embodiment of the invention provides a fault detection method and a node for a multi-hop network. The method comprises the following steps of according to a first preset strategy, selecting a preset number of links among all links from the node to a gateway as effective detection links, and using the node corresponding to the selected link as the effective detection parent node; according to the effective detection links and the effective detection parent node, updating the fault detection information in a neighborhood list of the nodes; according to the received HELLO packet, detecting the faults of the effective detection links and the effective detection parent node. The method and the node provided by the embodiment have the advantages that a control terminal (Gateway) is guaranteed to timely and accurately know the states of the network, the overhigh expense of the network system is reduced, and the integral service property of the network is improved.

Description

The fault detection method of multihop network and node

Technical field

The present invention relates to communication technical field, particularly relate to a kind of fault detection method and node of multihop network.

Background technology

Wireless multi-hop network is the network morphology that the tiny node of the modules such as integrated data process, network service is consisted of the organizational form of wireless link.Due to the complexity of wireless transmission environments and changeable, what can often cause wireless link to show under many circumstances be very fragile.In addition; limited node capacity (powered battery etc.), such as node energy exhausts the node failure, module failure etc. that cause also can cause communication disruption often, and the problems such as information reception error occur; thus cause control centre to make false judgment, and then reduce the service quality of network.

As the method for fault detect, often utilize monitoring around the approach of HELLO bag that sends of all neighbor node cycles judge around each node whether normally work and and surroundings nodes between link connection state whether normal.

Fig. 1 is the schematic diagram sent in the current HELLO cycle of wrapping.As shown in Figure 1, node N1, N2 are the neighbor node of node P, in the whole process of the network operation, all nodes are outwards periodically broadcasted (Broadcast) HELLO all at a certain time interval as transmitting terminal and are wrapped, in order to notify the state of surroundings nodes self.Simultaneously all nodes (as node P) HELLO bag of being received again all neighbor nodes around as receiving terminal (or neighbor state monitoring side) by continuous print to around all nodes and and link circuit condition around between all neighbor nodes monitor.But due to the unsteadiness of wireless transmission environments, in network some node can according to the situation of transmission link frequently from the neighbor node of oneself, select new father node, and then the up link switching self is to ensure and the stable transfer of data between network control end (Gateway).And the path switched only concentrates on and on link between several surrounding neighbours, not around all neighbours.

Fig. 2 is the schematic diagram of multi-path selecting solution.As shown in Figure 2, node N1 ~ N6 is the neighbor node of node P.Due to the impact of transmission environment, the up path of node P is at link (P-N1), link (P-N2), switch between link (P-N3), ensure the data of node P with this and network control end (Gateway) can be arrived normally by the data that node P forwards, and the link between all the other neighbor nodes is as link (P-N4), link (P-N5), link (P-N6) is never selected as the up link that node P transmits data.In conventional node method for diagnosing faults, each node relies on periodic HELLO to wrap monitoring link circuit condition between all neighbours around, but there is part of links choice very little (or never being selected) in these links, if detect the Link State that these Path selection chances are very little simultaneously, the communication overhead for fault detect can be caused excessive.With regard to network performance, the process fault detection brought out due to the generation of fault in network also can form larger impact to the transmission of normal data in network, causes problems such as increasing network traffic, data-bag lost, increase node energy consumption.

Above it should be noted that, just conveniently to technical scheme of the present invention, clear, complete explanation is carried out to the introduction of technical background, and facilitate the understanding of those skilled in the art to set forth.Only can not think that technique scheme is conventionally known to one of skill in the art because these schemes have carried out setting forth in background technology part of the present invention.

Summary of the invention

Embodiments provide a kind of fault detection method and node of multihop network, to ensure that network control end (Gateway) can awareness network state accurately in real time, reduce the excessive expense of network system, thus improve overall network service performance.

The above-mentioned purpose of the embodiment of the present invention is achieved by the following technical solution:

A kind of fault detection method, described method is applied to the node in multihop network, and wherein, described method comprises:

According to the first predetermined policy, arrive all links of gateway from described node and select the link of predetermined quantity as effectively detecting link, using node corresponding for the link of selection as effectively detecting father node;

According to described effective detection link and described effective detection father node, upgrade the fault detection information in the neighbor list of described node;

According to the HELLO bag received, fault detect is carried out to described effective detection link and described effective detection father node.

A node in multihop network, wherein, described node comprises:

First selected cell, described first selected cell is used for according to the first predetermined policy, arrives all links of gateway select the link of predetermined quantity as effectively detecting link, using node corresponding for the link of selection as effectively detecting father node from described node;

First updating block, described first updating block, for the described effective detection link selected by described first selected cell and described effective detection father node, upgrades the fault detection information in the neighbor list of described node;

First receiving element, described first receiving element wraps for the HELLO received from neighbor node;

First detecting unit, the HELLO bag that described first detecting unit is used for receiving according to described first receiving element carries out fault detect to described effective detection link and described effective detection father node.

The beneficial effect of the embodiment of the present invention is, by fault detection method and the node of the multihop network of the embodiment of the present invention, ensure that network control end (Gateway) can awareness network state accurately in real time, decrease the excessive expense of network system, thus improve overall network service performance.

With reference to explanation hereinafter and accompanying drawing, disclose in detail particular implementation of the present invention, specifying principle of the present invention can adopted mode.Should be appreciated that, thus embodiments of the present invention are not restricted in scope.In the spirit of claims and the scope of clause, embodiments of the present invention comprise many changes, amendment and are equal to.

The feature described for a kind of execution mode and/or illustrate can use in one or more other execution mode in same or similar mode, combined with the feature in other execution mode, or substitutes the feature in other execution mode.

Should emphasize, term " comprises/comprises " existence referring to feature, one integral piece, step or assembly when using herein, but does not get rid of the existence or additional of one or more further feature, one integral piece, step or assembly.

Accompanying drawing explanation

With reference to following accompanying drawing a lot of aspects that the present invention may be better understood.Parts in accompanying drawing are not proportional draftings, and just in order to illustrate principle of the present invention.For the ease of illustrating and describing some parts of the present invention, in accompanying drawing, corresponding part may be exaggerated or reduce.The element described in an accompanying drawing of the present invention or a kind of execution mode and feature can combine with the element shown in one or more other accompanying drawing or execution mode and feature.In addition, in the accompanying drawings, similar label represents parts corresponding in several accompanying drawing, and can be used for instruction more than the corresponding component used in a kind of execution mode.

In the accompanying drawings:

Fig. 1 is that between a multihop network node, HELLO wraps cycle transmission schematic diagram;

Fig. 2 is a multihop network multi-path selecting solution schematic diagram;

Fig. 3 is the fault detection method flow chart of the embodiment of the present invention 1;

Fig. 4 is the implementation method flow chart of step 303 in the embodiment of the present invention 1;

Fig. 5 effectively detects link to select schematic diagram in the embodiment of the present invention 1;

Fig. 6 is the fault detection method flow chart of the embodiment of the present invention 2;

Fig. 7 is the schematic diagram of the frame structure of state-detection request bag in the embodiment of the present invention 2;

Fig. 8 is that the status request in the embodiment of the present invention 2 detects schematic diagram;

Fig. 9 is the detected state schematic diagram of instantiation in the embodiment of the present invention 2;

Figure 10 A is a kind of execution mode flow chart of the fault detection method of the embodiment of the present invention 3;

Figure 10 B is the another kind of execution mode flow chart of the fault detection method of the embodiment of the present invention 3;

Figure 11 is the schematic diagram of the reply frame structure in the embodiment of the present invention 3;

Figure 12 is the schematic diagram that the state-detection in the embodiment of the present invention 3 asks the frame structure wrapped by force;

Figure 13 effectively detects formation schematic diagram in the embodiment of the present invention 3;

Figure 14 is that effective detection of another kind of mode in the embodiment of the present invention 3 is to schematic diagram;

Figure 15 is the formation schematic diagram of the node in the multihop network in the embodiment of the present invention 4;

Figure 16 is the formation schematic diagram of the first detecting unit 1504 in the embodiment of the present invention 4;

Embodiment

With reference to accompanying drawing, by specification below, the aforementioned and further feature of the embodiment of the present invention will become obvious.These execution modes are exemplary, are not limitations of the present invention.In order to enable those skilled in the art to easily to understand principle of the present invention and execution mode, be wireless sensor network below with multihop network for example is described the method for the embodiment of the present invention and node.Wherein, suppose that in network, all nodes have set up up route, namely all nodes have all obtained the required parent information that to communicate with Gateway.

With reference to the accompanying drawings the preferred embodiment of the present invention is described.

Embodiment 1

Fig. 3 is the fault detection method flow chart of the embodiment of the present invention, and the method is applied to the node in sensor network.Please refer to Fig. 3, the method comprises:

Step 301, according to the first predetermined policy, arrives all links of gateway from described node and selects the link of predetermined quantity as effectively detecting link, using node corresponding for the link of selection as effectively detecting father node;

Step 302, according to described effective detection link and described effective detection father node, upgrades the fault detection information in the neighbor list of described node;

Step 303, according to the HELLO bag received, carries out fault detect to described effective detection link and described effective detection father node.

In step 301, this first predetermined policy can be set as the strategy arriving route least cost each bar link of gateway from described node, and described first predetermined policy also can be set as the strategy etc. arriving shortest path each bar link of gateway from described node in addition; But the present embodiment is not in this, as restriction.

In the present embodiment, each node has safeguarded a neighbor list, the fault detection information of all neighbor nodes of this node is have recorded in this neighbor list, can store in the mode of data entries, the corresponding neighbor node of each data entries, comprises the statistical value, Linktype, Link State, node type, node state etc. of the ID of this neighbor node, latest update time, HELLO bag.Wherein, the latest update time refers to the up-to-date time receiving the HELLO bag that this neighbor node sends; The statistical value of HELLO bag refers to the number of the HELLO bag that this neighbor node received in the timing time of the timer of this neighbor node sends; Linktype refers to whether the link between this locality and this neighbor node is selected as effectively detecting link, such as, can not be selected as effectively detecting link by " 0 " instruction initial value or instruction, be selected as effectively detecting link by " 1 " instruction, by " 2 " instruction special circumstances, such as, form the situation of diagnosis to (in the following examples will to diagnosis to being described in detail); Link State refers to that whether link that local node arrives this neighbor node is the state of fault, such as, and can by " 0 " instruction initial value, by "-1 " instruction suspected malfunctions, by "-2 " indication fault, by " 1 " instruction fault-free; Node type refers to whether this neighbor node is selected as effectively detecting father node and (comprises and effectively detect father node and detect in process as being formed, be reversed the child node (i.e. special circumstances corresponding node) of detection), such as, can not be selected as effectively detecting link by " 0 " instruction initial value or instruction, be selected as effectively detecting father node by " 1 " instruction, by " 2 " instruction special circumstances, the situation that such as preceding diagnosis is right; Node state refers to the state of this neighbor node whether fault, such as, can by " 0 " instruction initial value, by "-1 " indication fault, by " 1 " instruction fault-free.

Table 1 is the signal of an execution mode of neighbor list, as shown in table 1,

Table 1

In the present embodiment, for Node configuration, each node needs to safeguard such neighbor list, and the Hello bag sent according to the neighbor node received, in this neighbor list to the data entries (being called fault detection information in the present embodiment) of sending node of HELLO bag carrying out real-time renewal.

Wherein, in order to set up such neighbor list, in the present embodiment, this fault detection method also comprises the step upgrading neighbor list according to the HELLO bag received.Such as, when a node receives the HELLO bag sent from another node (being called neighbor node), if the information of this neighbor node is in neighbor list, then this node directly upgrades the corresponding information of sending node that this HELLO wraps (also i.e. this neighbor node) according to the HELLO bag received; If the information of this neighbor node is not in neighbor list, then the information of this neighbor node is inserted neighbor list by this node, also namely in neighbor list newly-increased one to should the data entries of neighbor node, comprise the statistical value etc. of number of this neighbor node ID, latest update time, HELLO bag, and the Linktype of data entries corresponding to this neighbor node of initialization and/or state, both candidate nodes type and/or state, such as, the type of aforementioned link and/or node and/or state are all labeled as " 0 ", to represent initial value.

Wherein, the example of table 1 just illustrates, the embodiment of the present invention is not in this, as restriction, and such as, the latest update time can omit, and Linktype and node type can merge, specifically depending on actual enforcement demand.

In step 302, after determining effective detection link and effectively detecting father node, the fault detection information in the neighbor list of described node can be upgraded accordingly, such as, by in described neighbor list, the type of corresponding described effective detection link and effectively detection father node is revised as the value of instruction " effectively ".Such as, the Link Type/status of the entry of correspondence is revised as " 1 " by initial markers value " 0 ", marks this link for effectively to detect link with this; The Candidate node Type/status of the entry of correspondence is revised as " 1 " by initial markers value " 0 " simultaneously, marks this node for effectively to detect father node with this.

In step 303, determine effective detection link and effectively detect father node, fault detect can be carried out to this effective link that detects with effective father node that detects according to the HELLO bag received.

Fig. 4 is the method flow diagram that step 303 carries out an execution mode of fault detect, and please refer to Fig. 4, the method comprises:

Step 401, adds up the number of the HELLO bag received;

Step 402, if in the timing time of the predetermined timer of the sending node wrapped at described HELLO, the number of the HELLO bag of the sending node transmission of the described HELLO bag received is less than first threshold, then determine that described node arrives the link suspected malfunctions of the sending node that described HELLO wraps.

Wherein, if in the timing time of the predetermined timer of the sending node wrapped at described HELLO, the number of the HELLO bag of the sending node transmission of the described HELLO bag received is more than or equal to described first threshold, then upgrade described neighbor list, the statistics number that HELLO corresponding for described sending node wraps is reset to 0, and resets the predetermined timer (step 407) of described sending node.Again add up.

Wherein, to should each data entries in the neighbor list of node, this node can also arrange a timer (Timer) for each neighbor node in neighbor list, determines whether to arrive setting-up time T.Before not arriving T, the Hello intercepted from this neighbor node wraps, and calculates the number having received Hello bag, inserts neighbor table Hello count hurdle.When arriving T, if receive Hello bag number continuously to reach threshold value M(first threshold), just Hello count column number word corresponding for this neighbor node is reset to 0, restart the status monitoring process of carrying out next round, namely reset timer.If receive Hello bag number continuously not reach threshold value M, just regard this link as suspected malfunctions link.

In one embodiment, after determining that described node arrives the link suspected malfunctions of described neighbor node, described method also comprises:

Step 403, determines by inquiring about described neighbor list whether the link of described suspected malfunctions is effectively detect link, if so, then performs step 404, otherwise performs step 405;

Step 404, upgrades described neighbor list, and the Link State of described link is revised as suspected malfunctions, and startup detects to the node failure of effective detection father node that effectively should detect link;

Wherein, owing to determining that the link that suspected malfunctions occurs is for effectively to detect link, also, need to carry out fault detect to it, then in the present embodiment, further starter node fault detect, so that localizing faults reason (link failure or node failure).Wherein, the method that node failure detects is not limited in the present embodiment, such as, existing node failure detection method can be adopted to carry out node failure detection to the node (node link-attached with this suspected malfunctions) corresponding to the link of this suspected malfunctions.

Wherein, if determine it is node failure, then can upgrade neighbor list accordingly, such as by neighbor list to should the status modifier of node of link be the state (step 406) of instruction " fault ".Wherein, for the state (being modified to the state of " suspected malfunctions ") of this link in neighbor list, can revise or not revise, reason is, due to node failure, the link be then connected with this node is also down state, even if so be not link failure, also its state need not be revised as " fault-free " from " suspected malfunctions ".

Such as, after determining suspected malfunctions, the Link Type/status hurdle that this entry is corresponding can be checked, if be labeled as 1(and current ink is active link), just the Link Type entry of correspondence is revised as-1 by mark value 1, mark current active link for suspected malfunctions link with this, thus start the node failure testing mechanism (or status enquiry mechanism) for effective father node, collect fault message.When node failure testing result is effective father node fault, Candidate parent status entry is revised as-1, identification nodes fault.

Step 405, upgrades described neighbor list, and the Link State of described link is revised as suspected malfunctions.

Wherein, owing to determining that the link that suspected malfunctions occurs is not effectively detect link, also be, do not need to carry out fault detect to it, then in the present embodiment, just upgrade neighbor list, such as by neighbor list to should the status modifier of link be the value of instruction " suspected malfunctions ", and not starter node fault detect.

Such as, if the Link Type/status entry of this link is 0(and current ink is non-effective link), just Link Type/status entry is revised as-1 by mark value 0, marking this link is suspected malfunctions link, but not starter node fault detection mechanism.

In the present embodiment, each node in network periodically sends Hello bag to notify surroundings nodes oneself state, and surroundings nodes passes through received periodic Hello bag and monitors the state of its surroundings nodes and the link circuit condition between itself and surroundings nodes.The data transmitted to Gateway due to some node only can switch on a few paths, therefore each node only needs to be concerned about that upstream data can a few paths situations of normal transmission, without the need to the path from non-selected mistake of monitoring and between all the other neighbor nodes.Therefore, in the present embodiment, each node is only monitored the state of the highest K bar link of utilance in around link, this K bar link is also the link of the predetermined quantity that step 301 is selected according to the first predetermined policy, here the utilance that the first predetermined policy is link is the highest, but as previously mentioned, the present embodiment is not in this, as restriction, such as, also this K bar link to be measured can be selected (in the present embodiment also referred to as tested link based on other strategies, effective detection link etc.), such as, arrive the minimum K paths of Gateway routing cost (route cost) after only monitoring routing update.In the present embodiment, selected for K bar link is called active link (Effective links), K the father node that K bar link is connected therewith is referred to as effective father node (Effective parent) of present node.

Fig. 5 effectively detects link to select schematic diagram in the present embodiment, as shown in Figure 5, link (P1-N1), link (P1-N2), link (P1-N3) is the selected effective detection link (Effective links) of node P1, node N1, N2, N3 are the selected effective detection father node (Candidate parent) of node P1.Link (P2-N4), link (P2-P1), effective detection link (Effective links) that link (P2-N5) is selected for node P2, node N4, P1, N5 are effective detection father node (Candidate parent) that node P2 selectes.

By the fault detection method of the present embodiment, a part of link is only selected to carry out fault detect, ensure that control end (Gateway) can awareness network state accurately in real time, decrease the excessive expense of network system, thus improve overall network service performance.

In a special applications scene of the embodiment of the present invention, the number of the child node of some node is little, be even zero, now, according to the scheme of embodiment 1, fault detect may be carried out without any node to these nodes, in order to address this problem, the embodiment of the present invention additionally provides a kind of fault detection method, is described in detail to this below by embodiment 2.

Embodiment 2

The embodiment of the present invention 2 additionally provides a kind of fault detection method, and the method is applied to the node in multihop network.Fig. 6 is the method flow chart.Please refer to Fig. 6, the method comprises:

Step 601, according to the first predetermined policy, arrives all links of gateway from described node and selects the link of predetermined quantity as effectively detecting link, using node corresponding for the link of selection as effectively detecting father node;

Step 602, according to described effective detection link and described effective detection father node, upgrades the fault detection information in the neighbor list of described node;

Step 603, according to the HELLO bag received, carries out fault detect to described effective detection link and described effective detection father node.Wherein, the execution mode of step 601 ~ 603 is identical with the execution mode of step 301 ~ 303 in embodiment 1, and its content is incorporated in this, repeats no more herein.

Wherein, described method also comprises:

Step 604, described node is according to the HELLO bag received, add up himself as effective number detecting the child node of father node, and when the result of adding up is less than Second Threshold, effectively detect father node to it and send state-detection request bag, so that it effectively detects father node detect its state accordingly.

In the present embodiment, in order to the quantity of the child node solving certain node is very few, and cause the problem of without any neighbor node, described node being carried out to fault detect, when this node is selected after active link (Effective links) process completes, add and effectively detect father node (Candidate parent) id information to Hello bag, and broadcast (Broadcast) towards periphery thereupon.

In the present embodiment, as the neighbor node that the HELLO receiving the above-mentioned type wraps, check Candidate parent information in bag whether with oneself information match, if information is consistent, determine effective detection father node that the source node (sending node) of oneself Hello bag is for this reason selected.

In one embodiment, this neighbor node is according to the HELLO package informatin received, statistics is selected oneself is the child node number (namely statistics has how many child nodes to detect oneself state) effectively detecting father node, if child node quantity is less than threshold value L(Second Threshold), show that this neighbor node oneself state current can not obtain sufficient detection.For this category node, after selected good active link (after also namely performing step 601), detect request bag (Monitoring Request) to effective father node broadcast state, ask its effective father node to be responsible for the fault detect of this node.After effective detection father node of this neighbor node receives this state-detection request bag, namely the state of this neighbor node is detected, and, effective detection father node of this neighbor node can revise its neighbor list simultaneously, such as, the Link Type and the Node Type that revise corresponding entry in neighbor table are particular value, such as " 2 ", to show that needs detect this neighbor node, but this neighbor node is not its father node but its child node.

Fig. 7 is the schematic diagram of the frame structure of the state-detection request bag of the embodiment of the present invention, as shown in Figure 7, this state-detection request handbag contains broadcast head (Broadcast header), effectively detects father node ID(Candidate parent ID1, Candidate parent ID2 etc.).Wherein, broadcast head and comprise again sequence (Preamble), control frame (Control Frame), transport address (Transmitter ID), Frame Check Sequence (FCS, Frame Check Sequence).

Fig. 8 is state-detection request schematic diagram, and as shown in Figure 8, node P1 sends state-detection request bag respectively to its father node N1, N2 and N3, carries out fault detect to ask its father node N1, N2, N3 to it.

In order to make the method for the present embodiment clearly understandable, be described below in conjunction with the method for instantiation to the present embodiment.In this instantiation, that effectively detects link with each node according to the routing cost to Gateway is chosen as example, but the present embodiment is not in this, as restriction, specifically as described in Example 1, do not repeat them here.

Fig. 9 is the detected state schematic diagram of this instantiation, as shown in Figure 9, each node is by receiving the child node number of HELLO bag statistics to self formation testing mechanism, because all nodes carry out active link selection according to Gateway routing cost, therefore can find that oneself is not elected to be effective father node by any child node at some nodes of statistic processes.Such as, node N12 selectes node N1, N2, N3 and is effective father node and detects its state.But node N12 finds by checking the HELLO package informatin that receives, in active link selection course, being not effective father node by any sensor selection problem, making do not have child node to carry out detection correct in real time to the state of node N12.According to the method for the present embodiment, node N12 broadcasts the state-detection request bag effectively detecting parent information with it, asks it effectively to detect the reverse state testing mechanism of father node shape paired node N12.

By the method for the present embodiment, even if some node does not have child node, also can set up and effectively detect path, avoid this category node to can not get the problem effectively detected, and decrease the excessive expense of network system, thus improve overall network service performance.

In a special applications scene of the present embodiment; as effectively detecting father node one end; usually multiple child node is had; therefore effective detection father node of multiple child node can usually be become; its HELLO bag simultaneously received from multiple child node asks the effective detection of formation with it right; if but select too much child node to carry out state-detection; excessive network overhead can be caused; in order to address this problem; the embodiment of the present invention additionally provides a kind of fault detection method, is described in detail to this below by embodiment 3.

Embodiment 3

The embodiment of the present invention 3 additionally provides a kind of fault detection method, and the method is applied to the node in multihop network.

Figure 10 A is the flow chart of a kind of execution mode of the method, and please refer to Figure 10 A, the method comprises:

Step 1001, according to the first predetermined policy, arrives all links of gateway from described node and selects the link of predetermined quantity as effectively detecting link, using node corresponding for the link of selection as effectively detecting father node;

Step 1002, according to described effective detection link and described effective detection father node, upgrades the fault detection information in the neighbor list of described node;

Step 1003, according to the HELLO bag received, carries out fault detect to described effective detection link and described effective detection father node;

Step 1004, described node wraps according to receiving described HELLO, adds up using himself as effective number detecting the child node of father node, and when the result of adding up is greater than the 3rd threshold value, select a part of child node to form diagnosis right, and send a reply information to the parton node of described selection.

Figure 10 B is the another kind of execution mode flow chart of the method.Please refer to Figure 10 B, the method comprises:

Step 1004 ', it is effectively detected parent information and adds in HELLO bag by described node, and broadcast described HELLO and wrap, so that the effective detection father node receiving this HELLO bag is added up himself as effective number detecting the child node of father node, and when the result of adding up is greater than the 3rd threshold value, select a part of child node to form diagnosis right, and send a reply information (step 1004) to the parton node of described selection.

In the method shown in Figure 10 A and Figure 10 B, the execution mode of step 1001 ~ 1003 is identical with the execution mode of step 301 ~ 303 in embodiment 1, and its content is incorporated in this, repeats no more herein.

And wherein, step 1004 ' be set forth from the angle of broadcast HELLO bag, step 1004 sets forth from the angle receiving HELLO bag.Below describe in detail.

In the present embodiment, for certain node while quilt sensor selection problem is effectively detect father node, also can add oneself selected effective detection father node (Candidate parent) id information to wrap to Hello, and broadcast (Broadcast) towards periphery thereupon, and wait for that it effectively detects the reply of father node, ask effectively to detect with it father node with this and form the effective status that can carry out mutually state-detection for a pair and detect (Detection pair).(step 1004 ').

In the present embodiment, for the node receiving this HELLO bag, when the result of adding up is greater than Y (the 3rd threshold value), for the effective detection father node one end receiving the HELLO bag that certain node sends, can according to the second predetermined policy, a part of child node is selected to transmit a reply message, formed to represent effectively detect (step 1004) with these child nodes, in addition, in order to show the special circumstances that this detection is right, it is particular value that this node can also revise the Link Type of respective entries in its neighbor list and Node Type, such as " 2 ".Wherein, second predetermined policy can be " arriving first " principle, such as HELLO bag is selected to arrive C child node of present node (being also effective father node) at first according to arriving first principle, may also be the principle of " according to reception RSSI(Received Signal Strength Indication; received signal power intensity indicates) value ", such as choose C maximum child node of present node reception RSSI value according to receiving RSSI value principle, but embodiment is not limited in this.

In the present embodiment, Figure 11 is for replying the schematic diagram of (Reply) message frame structure, as shown in figure 11, this Reply frame contains clean culture head (Unicast header), effectively detects father node ID(Candidate parent ID), requesting node ID (Request node ID).Wherein, clean culture head comprises again sequence (Preamble), control frame (Control Frame), transport address (Transmitter ID), receiver address (Receiver ID), Frame Check Sequence (FCS, Frame Check Sequence).

In the present embodiment, as the node sending this HELLO bag, refer to Figure 10 B, if receive the reply that its selected effective detection father node is replied, then selected with it effective detection father node formed detect right, if do not receive the reply that its selected effective detection father node is replied, then illustrate that its selected effective detection father node cannot detect detecting its state with its formation, then in this case, this node needs to select other node to detect its state in addition, then described method also comprises:

Step 1005, described node adds in its HELLO bag at the parent information that detects that it is effective, and after the described HELLO bag of broadcast, judge whether to receive its effective return information detecting father node and return, if so, perform step 1006, otherwise perform step 1007;

Step 1006, described node with send effective detection father node of this return information formed diagnose right;

Step 1007, judge to select described node whether to be less than the 4th threshold value as the number of the child node effectively detecting father node with the number sum of the effective detection father node returning return information, if, then broadcast packet asks bag by force containing the state-detection of the effective detection parent information not receiving return information, forces this effective detection father node not returning return information to detect described node; Otherwise end process.

Wherein, suppose that certain node has A _childindividual sub-sensor selection problem its be effective father node and state-detection is carried out to it, receive A in addition _parentthe Reply of individual effective father node replys, and namely there is A _parentindividual effective father node also carries out state-detection to it simultaneously.If form total node number (A of state-detection to it _parent+ A _child) be equal to or greater than threshold value N(the 4th threshold value, the minimum node number detecting certain node state can be represented), show that existing enough nodes form state-detection mechanism to it, do not carry out any operation, otherwise sum of the two does not reach the number requirement of threshold value N, illustrate the state-detection number of nodes of present node not enough, then broadcast state detects and asks bag by force, add the effective parent information not receiving Reply in bag, force the effective father node in this request bag to carry out state-detection to it.Receive effective father node that state-detection asks to wrap by force, reply Reply to it, formed with these child nodes and effectively detect (detection pair), and the Link Type of respective entries in neighbor table and Node Type is revised as particular value, such as " 2 ", indicate this special circumstances.

Wherein, if select described node to be still less than described 4th threshold value as the number of the child node effectively detecting father node with the number of effective detection father node and the described number sum not returning effective detection father node of return information returning return information, then described method also comprises:

Step 1008, described node selects a part of neighbor node according to the 3rd predetermined policy from neighbor list;

Step 1009, and ask bag by force to the neighbor node transmission state-detection selected, the neighbor node forcing this to select carries out fault detect to described node.

In one embodiment, if A _parent+ A _child+ do not return the number of effective detection father node of replying message and be still less than N, then from its neighbor list, select a part of neighbor node according to the 3rd predetermined policy, to selected go out neighbor node broadcast state detect ask by force bag, the neighbor node forcing this to select carries out fault detect to described node, if the state-detection that the neighbor node selected receives described node broadcasts asks bag by force, the then state of node described in this neighbor discovery, and, revise its neighbor list, the Link Type and the Node Type that revise the entry of corresponding described node are particular value, such as " 2 ".Wherein, the 3rd predetermined policy can be set as until described A _parent+ A _child+ do not return the number of effective detection father node of replying message and be more than or equal to threshold value N, or until the neighbor node in described neighbor list is all selected, but be not limited in this.

Wherein, Figure 12 is the schematic diagram of state-detection claim frame structure by force, and as shown in figure 12, this frame contains broadcast head (Broadcast header), effectively detects father node ID(Candidate parent ID1, Candidate parent ID2 etc.).Wherein, broadcast head and comprise again sequence (Preamble), control frame (Control Frame), transport address (Transmitter ID), Frame Check Sequence (FCS, Frame Check Sequence).

Figure 13 effectively detects formation example schematic, and as shown in figure 13, node N1 is respectively by child node P1, P2, effective father node is done in P3, P4, P5 choosing, and node N1 have received from P1 simultaneously, the interpolation N1 of P2, P3, P4, P5 is that the request Hello of effective parent information wraps.But for node N1, select too much child node to carry out state-detection, excessive network overhead can be caused.Therefore, according to " arriving first " principle, namely select Hello bag to arrive the parton node (P1, P2, P5) of current effective father node at first, effective father node N1 replys Reply to it, with these child nodes formed effectively detect right.

Figure 14 is another kind of effectively detection formation example schematic, and as shown in figure 14, node N2 is chosen as effective father node by child node P6, P7, P8, and carries out state to N2 and detect in real time.Simultaneously node N2 is in selection active link process, and by node P1, P2, P3, P4, P5 elect self effective father node as.Node N2 adds node P1, P2, P3, P4, P5 information to oneself Hello bag and neighbours' broadcast towards periphery, with ask these father nodes and N2 formed effective detect right.But based on aforementioned " arriving first " principle, the Reply that node N2 does not receive all effective nodes replys, and only receives the Reply from the effective father node of part, and effectively detects N2 state.N2 statistics forms effective father node number (A of state-detection to it _parent) and number of child nodes (A _child), and its sum of the two and threshold value N are compared, if be less than threshold value N, N2 broadcast state detects request bag, and request is not replied the effective father node of Reply and detected its state.If form effective father node number (A of state-detection to it _parent) and number of child nodes (A _child) be still less than threshold value N with the number sum not returning effective detection father node of replying message, then from its neighbor node Q1, Q2, part neighbor node (meeting the 3rd predetermined policy) is selected in Q3 (non-effective detection father node), broadcast state detects asks bag by force, and the neighbor node selected by pressure carries out state-detection to it.

By the method for the present embodiment, solve effectively detection father node reception and ask to form with it effective detection to problem from the HELLO bag of too much child node, and decrease the excessive expense of network system, thus improve overall network service performance.

Embodiment 4

The embodiment of the present invention 4 additionally provides the node in a kind of multihop network, and the method for the principle of dealing with problems due to this node and embodiment 1 ~ 3 is similar, and therefore its concrete enforcement with reference to the enforcement of the method for embodiment 1 ~ 3, can repeat part and repeat no more.

Figure 15 is the node 1500 in a kind of multihop network, and wherein, this node 1500 comprises: the first selected cell 1501, first updating block 1502, first receiving element 1503, first detecting unit 1504, wherein

First selected cell 1501, it, for according to the first predetermined policy, arrives all links of gateway from described node and selects the link of predetermined quantity as effectively detecting link, using node corresponding for the link of selection as effectively detecting father node;

First updating block 1502, it, for the described effective detection link selected by this first selected cell 1101 and described effective detection father node, upgrades the fault detection information in the neighbor list of described node;

First receiving element 1503, it wraps for the HELLO received from neighbor node;

First detecting unit 1504, it carries out fault detect for the HELLO bag received according to this first receiving element 1103 to described effective detection link and described effective detection father node.

In the present embodiment, this first updating block 1502 is also for by described neighbor list, and corresponding described effective detection link and the type effectively detecting father node are revised as effectively.

Figure 16 is the formation schematic diagram of the present invention first detecting unit 1504, and as shown in figure 16, the first detecting unit 1504 also comprises:

First statistic unit 1601, its number of HELLO bag for adding up described first receiving element and receiving;

First determining unit 1602, it is in the timing time of the predetermined timer of sending node that wraps at described HELLO, when the number of the HELLO the received bag of this first statistic unit 1601 statistics is less than first threshold, determine that described node arrives the link suspected malfunctions of described neighbor node.

In an execution mode of the present embodiment, this first detecting unit 1504 also comprises:

Second determining unit 1603, by the described neighbor list of inquiry, it is for determining whether the link of described suspected malfunctions is effectively detect link;

Second updating block 1604, the Link State of described link for determining that in this second determining unit 1603 link of described suspected malfunctions, when effectively detecting link, upgrades described neighbor list, and is revised as suspected malfunctions by it;

Second detecting unit 1605, it is for after this second updating block 1604 upgrades described neighbor list, starts and detects to the node failure of effective detection father node that effectively should detect link;

3rd updating block 1606, it, for when this second determining unit 1603 determines that the link of described suspected malfunctions is non-effective detection link, upgrades described neighbor list, and the Link State of described link is revised as suspected malfunctions.

In the another one execution mode of the present embodiment, this first detecting unit 1504 also comprises:

4th updating block 1607, it, for when the testing result of described second detecting unit 1605 is described effective detection father node fault, upgrades described neighbor list, and is fault by the status modifier of described effective detection father node.

In the present embodiment, first detecting unit 1504 also comprises replacement updating block 1608, it is in the timing time of the predetermined timer of sending node that wraps at described HELLO, described first statistic unit adds up the number of the HELLO bag received when being more than or equal to described first threshold, upgrade described neighbor list, the statistics number that HELLO corresponding for described sending node wraps is reset to 0, and resets the predetermined timer of described sending node.

In an execution mode of the present embodiment, the information that it also effectively can be detected father node by some nodes add to its HELLO wrap in and broadcast this HELLO and wrap, so that the node receiving this HELLO bag adds up the number that it can be used as the child node effectively detecting father node accordingly, and carry out subsequent treatment according to statistics, such as, when the result of adding up is less than Second Threshold, effectively detects father node to it and send state-detection request bag, so that it effectively detects father node detect its state accordingly; Or when the result of adding up is greater than the 3rd threshold value, select a part of child node to form diagnosis according to the second predetermined policy right.

In this embodiment, as the node receiving this HELLO bag, this node 1500 can also comprise:

Second statistic unit 1506, it, for the HELLO bag comprising effective detection parent information of these other nodes sent according to other nodes received, is added up described node as effective number detecting the child node of father node;

Second transmitting element 1507, its in the statistics of this second statistic unit 1506 be described number be less than Second Threshold time, effective detection father node to described node sends state-detection request bag, carries out fault detect to ask effective detection father node of described node to described node;

This second transmitting element 1507 also in the statistics of this second statistic unit 1506 be described number be more than or equal to the 3rd threshold value time, from described child node, select a part of child node to form diagnosis according to the second predetermined policy right, send a reply information to the child node selected.

In the present embodiment, to should the receiving node of execution mode, first receiving element 1503 of the present embodiment also may receive the state-detection request bag of other nodes transmission, first detecting unit 1504 of the present embodiment is also for receiving state-detection request bag that other nodes send during at this first receiving element 1503, detect the state of other nodes described, first updating block 1502 of the present embodiment also for upgrading neighbor list in this case, by the node type of other nodes being revised as particular value.

In this embodiment, as the node sending this HELLO bag, this node 1500 can also comprise:

First transmitting element 1505, it for being added to by effective detection parent information of described node in the HELLO bag of described node, and is broadcasted described HELLO and wrap, so that the effective detection father node receiving described HELLO bag carries out subsequent treatment, as previously mentioned.

In this embodiment, this node may receive the effective return information detecting father node and return of a part, and therefore in the present embodiment, this node can also comprise:

Second receiving element 1508, its return information returned for the effective detection father node receiving described node;

Second selected cell 1509, during the return information that it returns for the effective detection father node receiving described node at this second receiving element 1508, with send effective detection father node of this return information formed diagnose right;

3rd statistic unit 1510, it selects described node as effectively detecting the number of child node of father node and the number sum of effective detection father node returning return information for adding up;

3rd transmitting element 1511, its for when the statistics of the 3rd statistic unit 1510 be described number sum be less than the 4th threshold value time, send the state-detection comprising the effective detection parent information not receiving return information and ask bag by force, force this effective detection father node not returning return information to detect described node, otherwise end process.

In this embodiment, this node 1500 can also comprise:

3rd selected cell 1512, it, for when the statistics of the 3rd statistic unit 1510 is still less than described 4th threshold value with the number sum not returning effective detection father node of replying message, selects a part of neighbor node according to the 3rd predetermined policy from neighbor list;

4th transmitting element 1513, it asks bag by force for sending state-detection to the neighbor node selected, and the neighbor node forcing this to select carries out fault detect to described node.

In the present embodiment, as receive such state-detection ask by force wrap node, this node 1500 can also comprise:

3rd receiving element 1514, it asks bag by force for the state-detection comprising the information of described node receiving the transmission of other nodes, and returns return information to other nodes described;

5th updating block 1515, it is for upgrading neighbor list, by the node type of other nodes being revised as particular value.

The function of each part of the node of the present embodiment is identical with each step of the method for embodiment 1 ~ 3, and its content is incorporated in this, does not repeat them here.

By the fault detection method of the present embodiment, a part of link is only selected to carry out fault detect, ensure that control end (Gateway) can awareness network state accurately in real time, even if solve some node there is no child node simultaneously, also can set up and effectively detect path, avoid this category node to can not get effectively detecting and effectively detect the father node HELLO received from too much child node and wrap to ask to be formed with it and effectively detect right problem, decrease the excessive expense of network system, thus improve overall network service performance.

More than describe the preferred embodiment of the present invention with reference to the accompanying drawings.Many feature and advantage of these execution modes are clearly according to this detailed description book, and therefore claims are intended to all these feature and advantage fallen in its true spirit and scope covering these execution modes.In addition, owing to those skilled in the art will find apparent that a lot of amendment and changing, therefore not embodiments of the present invention to be limited to precision architecture that is illustrated and that describe and operation, but can contain and fall into all suitable modifications within the scope of it and equivalent.

Should be appreciated that each several part of the present invention can realize with hardware, software, firmware or their combination.In the above-described embodiment, multiple step or method can with to store in memory and the software performed by suitable instruction execution system or firmware realize.Such as, if realized with hardware, the same in another embodiment, any one in the following technology can known altogether with this area or their combination realize: the discrete logic with the logic gates for realizing logic function to data-signal, there is the application-specific integrated circuit (ASIC) of suitable combinational logic gate circuit, programmable gate array (PGA), field programmable gate array (FPGA) etc.

About the execution mode comprising above multiple embodiment, following remarks is also disclosed.

Remarks 1, a kind of fault detection method, described method is applied to the node in multihop network, and wherein, described method comprises:

Remarks 2, method according to remarks 1, wherein, the step upgrading the fault detection information in the neighbor list of described node comprises:

By in described neighbor list, the type of corresponding described effective detection link and effectively detection father node is revised as effectively.

Remarks 3, method according to remarks 1, wherein, the HELLO bag according to receiving comprises the step that described effective detection link and described effective detection father node carry out fault detect:

Add up the number of the HELLO bag received;

If in the timing time of the predetermined timer of the sending node wrapped at described HELLO, the number of described HELLO bag is less than first threshold, then determine that described node arrives the link suspected malfunctions of described neighbor node.

Remarks 4, method according to remarks 3, wherein, after determining that described node arrives the link suspected malfunctions of described neighbor node, described method also comprises:

Inquire about described neighbor list and determine whether the link of described suspected malfunctions is effectively detect link;

If effectively detect link, then upgrade described neighbor list, the Link State of described link is revised as suspected malfunctions, and startup detects to the node failure of effective detection father node that effectively should detect link;

If non-effective detection link, then upgrade described neighbor list, the Link State of described link is revised as suspected malfunctions.

Remarks 5, method according to remarks 3, wherein, after starting and detecting the node failure of described effective detection father node, described method also comprises:

If node failure testing result is described effective detection father node fault, then upgrading described neighbor list, is fault by the status modifier of described effective detection father node.

Remarks 6, method according to remarks 3, wherein, described method also comprises:

If in the timing time of the predetermined timer of the sending node wrapped at described HELLO, the number of described HELLO bag is more than or equal to described first threshold, then upgrade described neighbor list, the statistics number that HELLO corresponding for described sending node wraps is reset to 0, and resets the predetermined timer of described sending node.

Remarks 7, method according to remarks 1, wherein said method also comprises:

It is effectively detected parent information and adds in its HELLO bag by described node, and broadcast described HELLO and wrap, so that the effective detection father node receiving described HELLO bag is added up himself accordingly as effective number detecting the child node of father node, and when the result of adding up is less than Second Threshold, effectively detect father node first determining unit 1602 to it and send state-detection request bag, so that it effectively detects father node detect its state accordingly; Or when the result of adding up is greater than the 3rd threshold value, select a part of child node to form diagnosis according to the second predetermined policy right.

Remarks 8, method according to remarks 1, wherein, described method also comprises:

Described node is added up himself as effective number detecting the child node of father node according to the HELLO bag received;

If the number of described child node is less than Second Threshold, then described node effectively detects father node to it and sends state-detection request bag, effectively detects father node carry out fault detect to it to ask it;

If the number of described child node is more than or equal to the 3rd threshold value, then described node selects a part of child node formation diagnosis right according to the second predetermined policy from described child node, sends a reply information to the child node selected.

Remarks 9, method according to remarks 1, wherein, if described node receives the state-detection request bag that other nodes send, then described method also comprises:

The state of other nodes described in described nodal test, and upgrade neighbor list, by the node type of other nodes being revised as particular value.

Remarks 10, method according to remarks 7, wherein, described method also comprises:

If described node receives it effectively detect the return information that father node returns, then described node and the effective detection father node sending this return information formed diagnose right;

If described node does not receive its effective return information detecting father node and return, and select described node to be less than the 4th threshold value as the number of the child node effectively detecting father node with the number sum of the effective detection father node returning return information, then send the state-detection comprising the effective detection parent information not receiving return information and ask bag by force, force this effective detection father node not returning return information to detect described node, otherwise end process.

Remarks 11, method according to remarks 10, wherein, if select described node to be still less than described 4th threshold value as the number of the child node effectively detecting father node with the number of effective detection father node and the described number sum not returning effective detection father node of return information returning return information, then described method also comprises:

Described node selects a part of neighbor node according to the 3rd predetermined policy from neighbor list;

Described node sends state-detection to the neighbor node selected and asks bag by force, and the neighbor node forcing this to select carries out fault detect to described node.

Remarks 12, method according to remarks 10, wherein,

If the state-detection comprising the information of described node that described node receives the transmission of other nodes asks bag by force, then described node returns return information to other nodes described, and upgrade its neighbor list, by the node type of other nodes being revised as particular value.

Node in remarks 13, a kind of multihop network, wherein, described node comprises:

Remarks 14, node according to remarks 13, wherein, described first updating block is also for by described neighbor list, and corresponding described effective detection link and the type effectively detecting father node are revised as effectively.

Remarks 15, node according to remarks 13, wherein, described first detecting unit also comprises:

First statistic unit, the number of HELLO bag of described first statistic unit for adding up described first receiving element and receiving;

First determining unit, described first determining unit is used in the timing time of the predetermined timer of the sending node wrapped at described HELLO, when the number of the HELLO the received bag of described first statistic unit statistics is less than Second Threshold, determine that described node arrives the link suspected malfunctions of described neighbor node.

Remarks 16, node according to remarks 15, wherein, described first detecting unit also comprises:

Second determining unit, described second determining unit is used for determining by inquiring about described neighbor list whether the link of described suspected malfunctions is effectively detect link;

Second updating block, described second updating block is used for determining that the link of described suspected malfunctions, when effectively detecting link, upgrades described neighbor list in described second determining unit, and the Link State of described link is revised as suspected malfunctions;

Second detecting unit, described second detecting unit is used for after described second updating block upgrades described neighbor list, starts and detects to the node failure of effective detection father node that effectively should detect link;

3rd updating block, described 3rd updating block is used for when described second determining unit determines that the link of described suspected malfunctions is non-effective detection link, upgrades described neighbor list, and the Link State of described link is revised as suspected malfunctions.

Remarks 17, node according to remarks 15, wherein, described first detecting unit also comprises:

4th updating block, described 4th updating block is used for when the testing result of described second detecting unit is described effective detection father node fault, upgrades described neighbor list, and is fault by the status modifier of described effective detection father node.

Remarks 18, node according to remarks 15, wherein, described first detecting unit also comprises replacement updating block, described replacement updating block is used in the timing time of the predetermined timer of the sending node wrapped at described HELLO, described first statistic unit adds up the number of the HELLO bag received when being more than or equal to described first threshold, upgrade described neighbor list, the statistics number that HELLO corresponding for described sending node wraps is reset to 0, and resets the predetermined timer of described sending node.

Remarks 19, node according to remarks 13, wherein, described node also comprises:

First transmitting element, described first transmitting element is used for effective detection parent information of described node to add in the HELLO bag of described node, and broadcast described HELLO and wrap, so that the effective detection father node receiving described HELLO bag is added up himself accordingly as effective number detecting the child node of father node, and when the result of adding up is less than Second Threshold, effectively detect father node to it and send state-detection request bag, so that it effectively detects father node detect its state accordingly; Or when the result of adding up is greater than the 3rd threshold value, select a part of child node to form diagnosis according to the second predetermined policy right.

Remarks 20, node according to remarks 13, wherein, described node also comprises:

Second statistic unit, described second statistic unit is used for the HELLO bag comprising effective detection parent information of these other nodes sent according to other nodes received, and adds up described node as effective number detecting the child node of father node;

Second transmitting element, described second transmitting element be used for the statistics of described second statistic unit be described number be less than Second Threshold time, effective detection father node to described node sends state-detection request bag, carries out fault detect to ask effective detection father node of described node to described node;

Described second transmitting element also in the statistics of described second statistic unit be described number be more than or equal to the 3rd threshold value time, from described child node, select a part of child node to form diagnosis according to the second predetermined policy right, send a reply information to the child node selected.

Remarks 21, node according to remarks 13, wherein, described first detecting unit also for receive at described first receiving element other nodes send state-detection request bag time, detect the state of other nodes described, described first updating block also for upgrading neighbor list, by the node type of other nodes being revised as particular value.

Remarks 22, node according to remarks 19, wherein, described node also comprises:

Second receiving element, the return information that described second receiving element returns for the effective detection father node receiving described node;

Second selected cell, described second selected cell is used for when the return information that effective detection father node that described second receiving element receives described node returns, with send effective detection father node of this return information formed diagnose right;

3rd statistic unit, described 3rd statistic unit selects described node as effectively detecting the number of child node of father node and the number sum of effective detection father node returning return information for adding up;

3rd transmitting element, described 3rd transmitting element be used for when the statistics of described 3rd statistic unit be described number sum be less than the 4th threshold value time, send the state-detection comprising the effective detection parent information not receiving return information and ask bag by force, force this effective detection father node not returning return information to detect described node, otherwise end process.

Remarks 23, node according to remarks 22, wherein, described node also comprises:

3rd selected cell, described 3rd selected cell is used for, when the statistics of described 3rd statistic unit is still less than described 4th threshold value with the number sum not returning effective detection father node of replying message, selecting a part of neighbor node according to the 3rd predetermined policy from neighbor list;

4th transmitting element, described 4th transmitting element is used for sending state-detection to the neighbor node selected asks bag by force, and the neighbor node forcing this to select carries out fault detect to described node.

Remarks 24, node according to remarks 22, wherein said node also comprises:

3rd receiving element, described 3rd receiving element asks bag by force for the state-detection comprising the information of described node receiving the transmission of other nodes, and returns return information to other nodes described;

5th updating block, described 5th updating block for upgrading neighbor list, by the node type of other nodes being revised as particular value.

Claims

1. a fault detection method, described method is applied to the node in multihop network, and wherein, described method comprises:

2. method according to claim 1, wherein, the HELLO bag according to receiving comprises the step that described effective detection link and described effective detection father node carry out fault detect:

Add up the number of the HELLO bag received;

If in the timing time of the predetermined timer of the sending node wrapped at described HELLO, the number of described HELLO bag is less than first threshold, then determine that described node arrives the link suspected malfunctions of described neighbor node;

If determine that described node arrives the link suspected malfunctions of described neighbor node, then inquire about described neighbor list and determine whether the link of described suspected malfunctions is effectively detect link;

3. method according to claim 1, wherein said method also comprises:

It is effectively detected parent information and adds in its HELLO bag by described node, and broadcast described HELLO and wrap, so that the effective detection father node receiving described HELLO bag is added up himself accordingly as effective number detecting the child node of father node, and when the result of adding up is less than Second Threshold, effectively detect father node to it and send state-detection request bag, so that it effectively detects father node detect its state accordingly; Or when the result of adding up is greater than the 3rd threshold value, select a part of child node to form diagnosis according to the second predetermined policy right.

4. method according to claim 1, wherein, described method also comprises:

5. method according to claim 3, wherein, described method also comprises:

6. method according to claim 5, wherein, if select described node to be still less than described 4th threshold value as the number of the child node effectively detecting father node with the number of effective detection father node and the described number sum not returning effective detection father node of return information returning return information, then described method also comprises:

7. the node in multihop network, wherein, described node comprises:

8. node according to claim 7, wherein, described first detecting unit also comprises:

First determining unit, described first determining unit is used in the timing time of the predetermined timer of the sending node wrapped at described HELLO, when the number of the HELLO the received bag of described first statistic unit statistics is less than first threshold, determine that described node arrives the link suspected malfunctions of described neighbor node.

9. node according to claim 8, wherein, described first detecting unit also comprises:

10. node according to claim 7, wherein, described node also comprises:

11. nodes according to claim 7, wherein, described node also comprises:

12. nodes according to claim 10, wherein, described node also comprises:

13. nodes according to claim 12, wherein, described node also comprises:

14. nodes according to claim 12, wherein said node also comprises: