CN101146336A

CN101146336A - Method and device for selecting marking message broadcasting device

Info

Publication number: CN101146336A
Application number: CNA2006101533333A
Authority: CN
Inventors: 单娜; 杨凯
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2006-09-14
Filing date: 2006-09-14
Publication date: 2008-03-19

Abstract

The invention discloses two methods and devices for selecting BB in the process of BB shift in two kinds of wireless networks. The node device in the wireless network adds the following to the sent circular of information: BB capability information that indicates whether the identity has BB capability itself, and the information about its own status of BB coverage; BB capability information that the identity of neighboring node device firstly acquired by the current BB has BB capability and BB induction information indicating the number of BB that cover the neighboring node device; when BB shift is conducted, new BB is selected according to the BB capability information of the neighboring node device and BB induction information and/or information about the time when the neighboring node became BB for the last time, and further completes BB shifting. It can be seen that with the invention, the current BB selects new BB according to the BB capability information of the neighboring node as well as the BB induction information, so that the BB selection is reasonable and it's less likely to cause BB competition thus reducing beacon conflicts. To select BB with reference made to the time of neighboring node becoming BB for the last time thus making the distribution of BB more reasonable to facilitate Mesh network topological extension.

Description

Select the method and the device of marking message broadcasting device

Technical field

The present invention relates to marking message broadcasting device in the wireless network (Beacon Broadcaster, handoff technique BB), particularly method and the device of selection BB in the wireless network BB handoff procedure.

Background technology

At present, the node in the wireless network passes through to come other node advertised network information in wireless network in beacon (Beacon) message usually, thereby realizes the synchronous and parameter synchronization of time in the network.Simultaneously, add the node deposited network, get access to information in the network by receiving beacon message, thereby join in the network for desire.

Beacon message is the beacon message that the node cycle sends in the wireless network, and the parameter information that wherein carries network comprises: information such as timestamp and time slot division information equal time parameter, physical parameter and logic parameter information.

In WLAN grid (Mesh) network, can adopt and specify the mode of BB to send Beacon, the node that is designated as BB sends Beacon at its TBTT race channel, and the mode of this competitive channel does not need avoidance mechanism.The node that becomes BB shows certainly as BB by the beacon information that transmission has the BB sign.WLAN Mesh network as shown in Figure 1 comprises node A～node I totally 9 nodes in this network, each node all might be designated as BB.

The BB competitive Principle: send when having BB sign beacon information when intention sends node M P2 that the MP1 have BB sign beacon information receives same mesh network, this MP1 abandons the transmission of self beacon, promptly abandons becoming BB.

Define in the draft of IEEE 802.11s, BB role must cyclomorphosis.Mesh DTIM interval when the time of BB operation arrival given number) time, current BB carries the information of specifying next BB by transmission Beacon and initiates the BB switching.

Comprised information such as time parameter, physical parameter and logic parameter in the beacon message as previously mentioned, neighbor node tabulation (neighborlist) parameter that only is useful on transmission BB state information wherein related to the present invention, this argument structure is as shown in table 1:

Used byte number: 1	1	1	6	6	…	6	k
Used byte number: 1	1	1	6	6	…	6	k	Node identification (ID)	Parameter length (Length)	MP controls (MP control)	Terminal 1 MAC Address (MAC Address of terminal 1)	Terminal 2 MAC Address (MAC Address of terminal 2)	…	Terminal n MAC Address (MAC Address of terminal n)	Neighbor node power managed modes (Neighbor power management mode)

Table 1

Wherein, the MAC Address of " MAC Address ofterminal " expression neighbor node; The power managed modes of the corresponding front of " Neighborpower management mode " step-by-step neighbor node, 1 expression is in power management (PS) pattern, and 0 is expressed as the active pattern; The structure of " MP control " is as shown in table 2:

Used position: 0-4	5	6	7
Used position: 0-4	5	6	7	Keep position (Reserved)	BB indicates (Designated BB)	BB switches indication (BB switch)	BB node power management mode (BB power management mode)

Table 2

Whether the node that " Designated BB " expression sends this beacon is to specify BB, and it is to specify BB for 1 expression, and 0 expression is not for specifying BB; Whether " BB switch " expression BB will switch, and 1 indicates carries out BB role's switching, and " MAC Address of terminal1 " corresponding neighbor node is the new BB that selects; 0 expression is not carried out BB role and is switched.

When switching, current BB is provided with BB switching mark position in the DTIM beacon that sends, i.e. BB switch, the new BB that switches appointment are first node in the neighbor list of beacon.The method that BB role's node is taken in selection is the arbitrarily synchronous neighbor node that has the BB ability and support the PS operation.

When the BB of appointment neighbor node sent the beacon failure, other MPs with BB ability can adopt the principle of BB competition to obtain the BB operational rights.Other have BB ability MPs and compete the Rule of judgment that obtains the BB operation and be: do not receive beacons continuous 3 times from original BB, it adopts and has yieldings (backoff) process access mechanism and send and have the beacon that BB identifies.

((Power Save Capability field) obtains power management information in the power hold capacity territory of Capabilityelement by the WLAN Mesh ability cell among the Beacon; Specify the ability of BB operation in message parameter, not have, be defaulted as and support the node of power management operation just to have the BB ability.Select a suitable node as BB in the neighbor node of PS operation as for how having the BB ability and support, do not provide in the agreement.

Because prior art selects the method for BB very random in the BB handoff procedure, cause the new BB that selects to lose efficacy because in the neighbor node existence of BB is arranged, also may cause the BB of neighbor node to lose efficacy.In addition, each node in the Mesh network all is reciprocity, acentric, in the BB selection course, wishes to allow each node can both share the role of BB as far as possible, thereby avoids being difficult for expanding because of the BB role in the network concentrates on the network topology that causes on several nodes.This method that chooses at random BB of prior art can not reach the purpose that each node can both be shared the role of BB.

In a word, select the method BB selection of BB unreasonable in the prior art, cause the BB competition easily, cause beacon conflict aggravation.

Summary of the invention

In view of this, main purpose of the present invention is to provide the method for selecting BB in a kind of wireless network BB handoff procedure, reduces the BB competition.

Second main purpose of the present invention is to provide the device of a kind of BB of selection, makes can reduce the BB competition by the wireless network of using this device in the BB handoff procedure.

The 3rd main purpose of the present invention is to provide the method for selecting BB in the another kind of wireless network BB handoff procedure, allows each node can both share the role of BB as far as possible.

The 4th main purpose of the present invention is to provide the device of the another kind of BB of selection, allows each node can both share the role of BB as far as possible.

Be first aspect that achieves the above object, the invention provides the method for selecting BB in a kind of wireless network BB handoff procedure, may further comprise the steps;

The node device of A, wireless network increases in the advertised information that sends: whether indicating self has the BB ability information of BB ability and the situation information that self is covered by BB;

The current described advertised information of BB in B, the wireless network from receiving, obtain the BB ability information of each neighbor node equipment, and the situation information that is covered by BB according to neighbor node equipment self, the indicating self of determining each neighbor node is by the BB induction information of what BB covering, and when carrying out the BB switching, according to the BB ability information and the BB induction information of neighbor node equipment, from neighbor node equipment, select the BB that conduct is new.

Wherein, describedly self can be the BB induction information by the situation information that BB covers;

Described steps A comprises: node device increases the BB ability information in beacon message and/or association messages, and increases the BB induction information in beacon message;

Among the described step B, current BB obtains the BB ability information of neighbor node from the beacon message that receives and/or association messages, and obtains the BB induction information of neighbor node from the beacon message that receives.

Describedly self can be the BB induction information by the situation information that BB covers;

Described steps A comprises: node device increases the BB ability information in beacon message and/or association messages, and increases the BB induction information in BB management frames message;

Among the described step B, current BB obtains the BB ability information of neighbor node from the beacon message that receives and/or association messages, and obtains the BB induction information of neighbor node from the BB management frames message that receives.

Described steps A comprises: node device increases the BB ability information of self in the scanning response message of returning after the scanning BB capability information message that receives current BB transmission; After the scanning BB induction information message that receives current BB transmission, in the scanning response message of returning, increase the BB induction information of self; Or node device increases BB ability information and the induction information of self in the scanning response message of returning after the scanning BB ability information and BB induction information message that receive current BB transmission;

Among the described step B, current BB scans BB ability information and the BB induction information that obtains neighbor node the response message from BB ability information and the BB induction information that receives.

Described steps A comprises: node device increases the BB ability information in beacon message and/or association messages, and, in the induction information request response of returning, increase the BB induction information of self receiving current BB after triggering BB switches the request BB induction information message of back transmission;

Among the described step B, current BB obtains the BB ability information of neighbor node from the beacon message and/or association messages that receive, and obtains the BB induction information of neighbor node from the induction information request response that receives.

Described node device know self BB induction information method can for: record comprises the BB information of BB sign and fresh-keeping duration;

The beacon message of every reception neighbor node determines according to message content whether this neighbor node is BB earlier, if the beacon message that BB sends, then judge whether it is the BB information that has write down, if then upgrade the fresh-keeping duration of this BB information, otherwise write down the BB information of this BB; According to the quantity of the BB information that writes down, determine self BB induction information;

If the beacon message that non-BB sends, the identification record of this non-BB is then deleted this BB information in BB information.

This method may further include: at the fresh-keeping duration of a BB then, delete this BB information;

If receive what the neighbor node that is recorded in the BB information sent: carry and show oneself the beacon message of the information of right and wrong BB, then delete this BB information;

Or according to the transmission self of neighbor node by the situation information that BB covers, determine to have in the BB information of this node record right and wrong BB state, then delete this BB information.

This method can further include: when node device changes at self BB induction information, send in network and comprise the BB induction information notification message that changes back BB induction information.

Whether described self can be the information of BB for each neighbor node by the situation information that BB covers;

Among the described step B, current BB is according to the notice message that receives, and it is BB that definite earlier node device that sends this notice message has several neighbor nodes.

Described steps A can comprise: node device increases the BB ability information in beacon message and/or association messages, and increases whether each neighbor node is the neighbor node BB state information of BB in beacon message;

Among the described step B, current BB is according to the neighbor node BB state information in the beacon message that receives, and it is BB that definite node device that sends this beacon message has several neighbor nodes.

Described step C may further include: BB current in the wireless network is behind selected new BB, and the node device in the network is given in announcement.

This method may further include: if new BB does not receive the announcement that step C sends, adopt competitive way to select new BB.

Step B described BB ability information and BB induction information according to neighbor node equipment, from neighbor node equipment, select the new BB of conduct method can for:

The node device of selecting to have the BB ability and covered by minimum BB from neighbor node equipment is as new BB.

This method may further include:

If the node device that has the BB ability and covered by minimum BB is a plurality of, then further according to whether having the PS ability and/or current power supply state selects one of them as new BB.

This method can further include: node device starts the timing to this BB after showing of receiving at every turn that neighbor node sends self is the advertised information of BB;

Among the described step B,, then from these node devices, select one to show it self is that time of advertised information of BB is to the longest node device of current time, as new BB for the last time if having the BB ability and the node device that covered by minimum BB is a plurality of.

Be second aspect that achieves the above object, the invention provides the device of a kind of BB of selection, comprise: message sink module, neighbor node BB ability information and BB induction information acquisition module, BB select module;

Wherein, message sink module receiving node device forwards comprise the BB ability information whether indicating self has the BB ability, with the advertised information of the situation information that self is covered by BB, and message content sent to neighbor node BB ability information and BB induction information acquisition module;

Neighbor node BB ability information and BB induction information acquisition module, from the described advertised information that receives, obtain the BB ability information of neighbor node equipment, and, determine that the BB induction information that the sign neighbor node equipment by what BB is covered sends to BB selection module according to the situation information that wherein self is covered by BB;

The select command that BB selects module receiving node equipment to send, according to BB ability information and the BB induction information of this select command according to neighbor node equipment, from neighbor node equipment, select the BB that conduct is new, generate the selection result that comprises new BB information and send to node device.

This device can also comprise the message generating module of obtaining neighbor node BB ability information and BB induction information;

Described neighbor node BB ability information and BB induction information acquisition module, further timing or not timing send to the message generating module of obtaining neighbor node BB ability information and BB induction information and obtain message command;

The described message generating module of obtaining neighbor node BB ability information and BB induction information according to obtaining message command, generates the message of obtaining the BB ability information and/or obtaining the BB induction information, sends to node device.

This device can also comprise timing module;

Described message sink module further shows neighbor node it self is that the advertised information of BB sends to timing module;

Timing module shows it self is the advertised information of BB according to the each transmission of each neighbor node, and each neighbor node is carried out timing, and clocking information is sent to BB selection module;

Described BB select module from neighbor node equipment, selects to have the BB ability and by the node device of minimum BB covering as new BB, if the node device that has the BB ability and covered by minimum BB is a plurality of, then from these node devices, select one to show it self is that time of advertised information of BB is to the longest node device of current time, as new BB for the last time.

This device can be arranged in the node device.

Be the 3rd aspect that achieves the above object, the invention provides the method for selecting BB in the another kind of wireless network BB handoff procedure, may further comprise the steps:

The node device of A, wireless network increases in the advertised information that sends: whether indicating self has the BB ability information of BB ability, and the record neighbor node equipment shows it self is the duration of BB to the current time;

The current described advertised information of BB in B, the wireless network from receiving, obtain the BB ability information of each neighbor node equipment, and when carrying out the BB switching, show self to be BB according to the BB ability information of neighbor node equipment and record neighbor node equipment, from neighbor node equipment, select the BB that conduct is new to the duration of current time.

Wherein, the described record neighbor node equipment of steps A shows that self to be BB to the method for the duration of current time be:

Node device starts the timing to this BB after showing of receiving at every turn that current BB sends self is the advertised information of BB, and record.

To receiving that not neighbor node shows the neighbor node of the notice message that self is BB, duration can be recorded as maximum sign;

Among the described step B,, then select to have the BB ability information, and the record duration is that the maximum neighbor node equipment that identifies is as new BB if the maximum sign is arranged in the duration of neighbor node.

Described steps A may further include: the node device of wireless network increases in the advertised information that sends: the situation information that self is covered by BB;

Among the described step B,, then from these node devices, select a node device that is covered by minimum BB as new BB if the longest node device of duration is a plurality of.

In the described steps A: node device can increase the BB ability information in beacon message and/or association messages;

Described show self be BB advertised information can for: show it self is the beacon message of BB.

Be the 4th aspect that achieves the above object, the invention provides the device of the another kind of BB of selection, comprise: message sink module, neighbor node BB ability information acquisition module, BB select module and timing module;

Wherein, message sink module receiving node device forwards comprise the notice message whether indicating self has the BB ability information of BB ability, message content is sent to neighbor node BB ability information acquisition module, and neighbor node is shown it self is that the advertised information of BB sends to timing module;

Neighbor node BB ability information acquisition module from the described advertised information that receives, obtains the BB ability information of neighbor node equipment, sends to BB and selects module;

BB selects module to receive the clocking information that timing module sends, select command with the node device transmission, according to this select command, from neighbor node equipment, select to have the BB ability, and show it self is that time of advertised information of BB is to the longest node device of current time for the last time, as new BB, generate the selection result that comprises new BB information and send to node device.

This device can be arranged in the node device.

As seen from the above technical solutions, select method and the device of BB in first kind of wireless network BB handoff procedure provided by the invention, at first the node device of wireless network increases in the advertised information that sends: whether indicating self has the BB ability information of BB ability and the situation information that self is covered by BB; The sign that current then BB obtains neighbor node equipment earlier has the BB ability information of BB ability and the BB induction information that the sign neighbor node equipment by what BB is covered, and when carrying out the BB switching, according to the BB ability information and the BB induction information of neighbor node equipment, select new BB.

As seen, after using the method and device of first kind of selection BB, current BB selects new BB according to the BB ability information and the BB induction information of neighbor node, two adjacent nodes can not be designated as BB simultaneously in the basic assurance WLAN Mesh network, it is more reasonable to make that BB selects, be not easy to cause the BB competition, can reduce the beacon conflict.

Select method and the device of BB in second kind of wireless network BB handoff procedure provided by the invention, at first the node device of wireless network increases in the advertised information that sends: whether indicating self has the BB ability information of BB ability, and the record neighbor node last send show it oneself is the duration of the notice message of BB to the current time; When carrying out the BB switching,, select new BB according to the BB ability information and the described duration of neighbor node equipment.

As seen, use second kind of method and device of selecting BB after, current BB as the duration of BB, selects new BB according to the BB ability information of neighbor node and neighbor node, guarantees the role that allows each node can both share BB substantially, it is more reasonable to make that BB selects.

Description of drawings

Fig. 1 is the topology diagram that Mesh network typical case uses;

Fig. 2 carries out the flow chart that BB switches for the present invention's first preferred embodiment;

Fig. 3 is a kind of simple Mesh network topology structure figure;

Fig. 4 is the flow chart that is applied to network shown in Figure 3 embodiment illustrated in fig. 2;

Fig. 5 carries out the flow chart that BB switches for the present invention's second preferred embodiment;

Fig. 6 is the flow chart that is applied to network shown in Figure 3 embodiment illustrated in fig. 5;

Fig. 7 carries out the flow chart that BB switches for the present invention's the 3rd preferred embodiment;

Fig. 8 is the flow chart that is applied to network shown in Figure 3 embodiment illustrated in fig. 5;

Fig. 9 is applied to the flow chart of network shown in Figure 3 for the present invention's the 4th preferred embodiment;

Figure 10 is the structural representation of the device of the selection BB of the present invention's the 5th preferred embodiment;

Figure 11 is the structural representation of the device of the selection BB of the present invention's the 8th preferred embodiment.

Embodiment

For making purpose of the present invention, technical scheme and advantage clearer, below with reference to the accompanying drawing embodiment that develops simultaneously, the present invention is described in more detail.

Select method and the device of BB in this wireless network BB handoff procedure provided by the invention, first kind: at first the node device of wireless network increases in the advertised information that sends: whether indicating self has the BB ability information of BB ability and the situation information that self is covered by BB; The sign that current then BB obtains neighbor node equipment earlier has the BB ability information of BB ability and the BB induction information that identification nodes equipment by what BB is covered, and when carrying out the BB switching, according to the BB ability information and the BB induction information of neighbor node equipment, select new BB.Second kind: at first the node device of wireless network increases in the advertised information that sends: whether indicating self has the BB ability information of BB ability,

Following elder generation is elaborated to selecting method and the device of BB in first kind of wireless network BB handoff procedure.

Obtain the BB ability information of neighbor node equipment and the different modes of BB induction information according to current BB among the present invention, numerous embodiments can be arranged:

Because whether node device has the BB ability in existing technical scheme, it is a kind of ability information of acquiescence, be that synchronization node in the mesh network all has the BB ability, all not mentioned BB ability information in the what is the need breath in office, can not obtain the BB ability information according to the content of any message, therefore the BB ability information must provide in notice message and transmit by explicit way, just directly increases the BB ability information in notice message.For instance, can or set up in the association messages that network connects use in Beacon message and directly increase the BB ability information.Like this, Beacon message that just can receive from neighbor node equipment of the current BB in the network or the association messages BB ability information that directly obtain this node.

The BB induction information of node device then both can provide in notice message and transmit by explicit way, just in notice message, directly increase the BB induction information, can in notice message, transmit by the implicit expression mode again, just in notice message, increase the situation information that this node device is covered by BB, like this, current BB by the situation information that BB covers, obtains the BB induction information of this node device according to this node device.For instance, can pass through Beacon message or BB management frames message, transmit with explicit way or implicit expression mode.Wherein, BB management frames message can be the management frames message that being exclusively used in of redetermination obtained the BB induction information, also can increase above-mentioned information in the already used management frames of prior art.

The present invention is described in detail below to lift five preferred embodiments.

First preferred embodiment:

In the present embodiment, node device increases the BB ability information in beacon message and/or association messages, and directly increases the BB induction information in beacon message.

The structure such as the table 3 of BB ability information (BB Capability information):

Used byte number: 1	1	1
Used byte number: 1	1	1	Component identification (Element ID)	Parameter length (Length)	BB ability BB Capability

Table 3

Wherein, BB Capability form is as shown in table 4:

Figure place: 0-6	7
Figure place: 0-6	7	Keep position (Reserved)	Support BB ability (Supporting BB)

Table 4

Whether " Supporting BB " expression supports the BB ability, and 1 expresses support for, and 0 expression is not supported.The structure of BB induction information (BB sense information) is as shown in table 5:

Used byte number: 1	1	1
Used byte number: 1	1	1	Component identification (Element ID)	Parameter length (Length)	BB sensed data (BB sense number)

Table 5

Wherein, " BB sense information " is the number of node perceived to BB.

Referring to Fig. 2, Fig. 2 carries out the flow chart that BB switches for the present invention's first preferred embodiment.This flow process may further comprise the steps:

Step 201, the non-BB node device of current BB node device cycle to its covering sends Beacon message.

Step 202, non-BB node device send Beacon message to comprising current BB node device at each interior neighbor node.Comprise BB ability information and BB induction information in the Beacon message that each non-BB node device sends.

In fact, ordinal relation before and after step 201 and step 202 do not have, the Beacon that carries BB situation information and ability information that the node in the Mesh network sends according to its neighbor node upgrades the BB situation information of the neighbor node that oneself writes down.So the execution of which step elder generation can, just simple here in order to illustrate.

Here be not limited to the BB record,, all write down the BB situation information of its neighbor node, the information that BB can write down according to this node when selecting new BB so advise each node because might can become BB at certain follow-up time by other nodes.

Obtain the BB ability information of neighbor node the association messages that step 203, current BB node device are used from the beacon message that receives and/or when connecting, and from the beacon message that receives, obtain the BB induction information of neighbor node.

Step 204, the cycle is triggered the BB switching, just arrives predetermined switching cycle triggering and switches.

Because regulation BB will switch in the cycle in the existing protocol, so present embodiment has adopted cycle triggering BB to switch.In fact, also can be that Event triggered BB switches.The BB switching by which kind of mode is triggered, and the present invention is suitable for.

Step 205 according to the BB ability information and the BB induction information of neighbor node, selects to have the BB ability, and the neighbor node of BB induction information minimum is as new BB.

Because the BB induction information is used for identification nodes equipment and by what BB is covered, therefore common BB induction information is exactly the quantity that is covered by BB.

BB has many more BB around covering the big more explanation present node of quantity, if select this node as BB, certainly will cause BB conflict aggravation so, so must select the neighbor node of BB induction information minimum.

Step 206, current BB node device sends the broadcasting handoff notification message that has new BB sign to the non-BB node device of its covering, finishes BB and switches.

In the present embodiment, can also be in the BB ability information, increase BB power supply capacity information, carry out in the BB handoff procedure at current BB, can also be when selecting new BB with reference to the BB power supply capacity.

For instance, BB ability information (BB Capability) form can be revised as shown in table 6 on the basis of table 4:

Figure place: 0-5	6	7
Figure place: 0-5	6	7	Keep position (Reserved)	Support BB ability (Supporting BB)	BB power supply capacity (BB Power)

Table 6

In this case, in the above-mentioned steps 205, if neighbor node has the induction information of BB of a plurality of nodes identical and be minimum value, then neighbor node selects power supply capacity to possess the node of PS ability as new BB for the node of normal power supply as new BB and/or selection according to from these nodes.

In the present embodiment, be directly to increase the BB induction information in beacon message, during practical application, the BB induction information also can pass through management frame transmission.For example: adopt special-purpose BB management frames (BBAnnouncement frame) to carry, its form is as shown in table 6:

Used byte number: 1	1	1
Used byte number: 1	1	1	Kind	Behavior	The BB induction information

(Category)

(Action)

(BB?sense?information)

Table 6

In this case, each non-BB node sends the BB management frames message that comprises the BB induction information to the BB node after receiving the beacon message of BB node, and BB obtains the BB induction information from the BB management frames message that receives.Certainly, among the described embodiment in present embodiment and back, each non-BB node all can also directly send the BB management frames message that comprises the BB induction information to the BB node after knowing the autonomous induction information change.

What node device was known self BB induction information can method be: the BB information that nodes records the is sensed: (MAC Address of BB, the fresh-keeping duration of BB), how long also remain the effective time that the fresh-keeping duration of BB refers to current its survival of BB of sensing, and this value is along with the time successively decreases, until being 0.

Node is whenever receiving Beacon message, determines whether to send into BB according to its content, from BB, at first judges whether this BB is to be the BB that senses of record if find this Beacon message.If the fresh-keeping duration that then upgrades BB is the fresh-keeping cycle of BB.Otherwise, increasing the BB information record of sensing, the fresh-keeping duration of BB is initialized as the fresh-keeping cycle of BB, and this fresh-keeping cycle refers to the effective time of the survival of the BB that senses.

The node that node receives Beacon and find to send Beacon is not BB, can be 0 to judge by the BB indicating bit, but this node has been recorded in the BB information of induction, then deletes this record.

When the fresh-keeping duration counting of certain BB of record is 0, then can be understood as node and for a long time do not received Beacon from this BB, think that then this BB lost efficacy.Delete this record according to the MAC Address of this BB.

By the situation information that BB covers, determine to have in the BB information of this node record right and wrong BB state according to the transmission self of neighbor node, then delete this BB information.

Node device can be with the quantity of BB information of record, is defined as current self BB induction information.

In addition, in the present embodiment, each node device can start the timing to this BB after showing of receiving at every turn that neighbor node sends self is the advertised information of BB.In step 205, when selecting BB, be a plurality of as if the node device that has the BB ability and covered, then from these node devices by minimum BB, select one to show it self is that time of advertised information of BB is to the longest node device of current time, as new BB for the last time.

Referring to Fig. 3, Fig. 3 is a kind of simple Mesh network topology structure figure.In this wireless network, each node all has the BB ability, and node A and node D are current BB, and Node B and node E are arranged in the coverage of node D, and Node B and node C are arranged in the coverage of node A.Wherein, Node B had both been covered by node D and had also been covered by node A.

Referring to Fig. 4, Fig. 4 is the flow chart that is applied to network shown in Figure 3 embodiment illustrated in fig. 2.This flow process may further comprise the steps:

Step 401 and step 401a, the BB node A cycle, Node B and the node C to its covering sent Beacon message; The BB node D cycle, Node B and the node E to its covering sent Beacon message.

Step 402 and step 402a, non-BB Node B, node C, node E send Beacon message.Comprise BB ability information and BB induction information in the Beacon message that each non-BB node device sends.

Identical with Fig. 2, step 401 and step 402 do not have sequencing.

Below to carry out BB with node D and switch to example and be elaborated, the process of node A is identical with it, no longer repeats:

Step 403 obtains the BB ability information of neighbor node E and Node B the association messages that node D uses from the beacon message that receives and/or when connecting, and obtain the BB induction information of neighbor node E and Node B from the beacon message that receives.

Step 404, the node D cycle triggers BB and switches the switching cycle triggering switching that arrival just is predetermined.

Step 405, node D selects to have the BB ability according to the BB ability information and the BB induction information of neighbor node E and Node B, and the neighbor node E of BB induction information minimum is as new BB.

Step 406, node D sends the broadcasting handoff notification message that has new BB sign to Node B, the node E of its covering.

Step 407, node E switches to BB with self after receiving the broadcasting handoff notification message, and execution in step 408.

In this step,, then adopt competitive way to carry out BB and switch if node E does not receive the broadcasting handoff notification message.Be that each node self is the broadcasting handoff notification message of BB to other nodes transmission indications all, wherein the competition that sends at first becomes new BB.

Step 408, node E sends beacon message as the BB cycle to the node D and the Node B of its covering.Node D switching is finished.

Second preferred embodiment:

In the present embodiment, node device increases the BB ability information of self in the scanning response message of returning after the scanning BB capability information message that receives current BB transmission; After the scanning BB induction information message that receives current BB transmission, in the scanning response message of returning, increase the BB induction information of self.

Among present embodiment and the follow-up embodiment, the structure of BB ability information is identical with first preferred embodiment, no longer repeats later on.

Referring to Fig. 5, Fig. 5 carries out the flow chart that BB switches for the present invention's second preferred embodiment.This flow process may further comprise the steps:

Step 501, current BB node send the active scan request message of BB ability information and BB induction information to the non-BB node of its covering.

Step 502, non-BB node are returned the scanning response message that comprises BB ability information and BB induction information to current BB node.

In the present embodiment, request BB ability information and induction information can certainly pass through 2 request messages in a piece of news, ask BB ability information and BB induction information respectively, but have increased interacting message like that.

In the present embodiment, the method for non-BB node acquisition self BB induction information can be identical with first preferred embodiment.

Step 503, current BB node obtain the BB ability information and the BB induction information of neighbor node from above-mentioned two kinds of scanning response messages that non-BB node returns.

Step 504～step 506, current BB node trigger BB to be switched, and selects new BB, finishes BB and switches.These 3 steps and step 204 shown in Figure 2～step 206 are identical, no longer repeat here.

Referring to Fig. 6, Fig. 6 is the flow chart that is applied to network shown in Figure 3 embodiment illustrated in fig. 5.This flow process may further comprise the steps:

Step 601 and step 601a, BB node A is to the node C of its covering and the active scan request message of Node B transmission BB ability information and BB induction information; BB node D is to the node E of its covering and the active scan request message of Node B transmission BB ability information and induction information.

Step 602 and step 602a, node C and Node B are returned the scanning response message that comprises BB ability information and BB induction information to node A; Node E and Node B are returned the scanning response message that comprises BB ability information and BB induction information to node D.

Same, BB ability information and BB induction information can obtain by 2 request message requests.

Step 603, node D obtains the BB ability information and the BB induction information of node E and Node B from above-mentioned two kinds of scanning response messages that node E and Node B are returned.

Step 604～step 608, node D triggers BB and switches, and selects new BB, finishes BB and switches.These 5 steps and step 404 shown in Figure 4～step 408 are identical, no longer repeat here.

The 3rd preferred embodiment:

In the present embodiment, node device increases the BB ability information in beacon message and/or association messages, and, in the induction information request response of returning, increase the BB induction information of self receiving current BB after triggering BB switches the request induction information message of back transmission.

In the present embodiment, BB induction information request (BB sense Request frame) form is as shown in table 7:

Used byte number: 1	1
Used byte number: 1	1	Category	Action

Table 7

BB induction information response (BB sense Response frame) form is as shown in table 8:

Used byte number: 1	1	1
Used byte number: 1	1	1	Category	Action	BB induction information (BB sense information)

Table 8

Referring to Fig. 7, Fig. 7 carries out the flow chart that BB switches for the present invention's the 3rd preferred embodiment.This flow process may further comprise the steps:

Step 701, the non-BB node device of current BB node device cycle to its covering sends Beacon message.

Step 702, non-BB node device send Beacon message to comprising current BB node device at each interior neighbor node.Comprise the BB ability information in the Beacon message that each non-BB node device sends.

Identical with Fig. 2, step 701 and step 702 do not have sequencing.

Obtain the BB ability information of neighbor node the association messages that step 703, current BB node device are used from the beacon message that receives and/or when connecting.

Step 704, the current BB node device cycle is triggered the BB switching, just arrives predetermined switching cycle triggering and switches.

Step 705, the non-BB node device of its covering of current BB node device sends the induction information request message.

Step 706, non-BB node device are returned the induction information request response that comprises self BB induction information to current BB node device.

Step 707, current BB node device select to have the BB ability according to the BB ability information and the BB induction information of neighbor node, and the neighbor node of BB induction information minimum is as new BB.

Step 708, current BB node device sends the broadcasting handoff notification message that has new BB sign to the non-BB node device of its covering, finishes BB and switches.

Referring to Fig. 8, Fig. 8 is the flow chart that is applied to network shown in Figure 3 embodiment illustrated in fig. 5.This flow process may further comprise the steps:

Step 801 and step 801a, the BB node A cycle, Node B and the node C to its covering sent Beacon message; The BB node D cycle, Node B and the node E to its covering sent Beacon message.

Step 802 and step 802a, non-BB Node B, node C, node E send Beacon message.Comprise the BB ability information in the Beacon message that each non-BB node device sends.

Identical with Fig. 2, step 401 and step 402 do not have sequencing.

Step 803 obtains the BB ability information of neighbor node E and Node B the association messages that node D uses from the beacon message that receives and/or when connecting.

Step 804, the node D cycle triggers BB and switches the switching cycle triggering switching that arrival just is predetermined.

Step 805, node D sends the induction information request message to the Node B and the node E of its covering.

Step 806, Node B and node E return the induction information request response that comprises self BB induction information to node D.

Step 807, node D selects to have the BB ability according to the BB ability information and the BB induction information of neighbor node E and Node B, and the neighbor node E of BB induction information minimum is as new BB.

Step 808, node D sends the broadcasting handoff notification message that has new BB sign to Node B, the node E of its covering.

Step 809, node E switches to BB with self after receiving the broadcasting handoff notification message, and execution in step 810.

Step 810, node E sends beacon message as the BB cycle to the node D and the Node B of its covering.Node D switching is finished.

The 4th preferred embodiment:

In the present embodiment, still by the explicit way transmission, the BB induction information transmits by the implicit expression mode BB ability information.Specifically, in the present embodiment: node device increases the BB ability information in beacon message and/or association messages, and increases whether each neighbor node is the neighbor node BB state information list parameter of BB in beacon message.

The neighbor list argument structure that is used to send the BB state information among the Beacon is as shown in table 9:

Octets：1	1	1	6	6	…	6	k	k
Octets：1	1	1	6	6	…	6	k	k	ID	Length	MP control	MAC Address of terminal?1	MAC Address of terminal?2	…	MAC Address of terminal?n	Neighbor power management mode	BB StateS

Table 9

Wherein, the MAC Address of " MAC Address of terminal " expression neighbor node; The power managed modes of the corresponding front of " Neighborpower management mode " step-by-step neighbor node, 1 expression is in the PS pattern, and 0 is expressed as the active pattern; The current BB state of " BB states " positional representation neighbor node, 1 expression neighbor node is BB, 0 expression neighbor node is not BB.The structure of " MP control " is as shown in table 10:

Bits：0-4	5	6	7
Bits：0-4	5	6	7	Reserved	Designated?BB	BB?switch	BB?power?management?mode

Table 10

Whether the node that " Designated BB " expression sends this beacon is to specify BB, and it is to specify BB for 1 expression, and 0 expression is not for specifying BB; Whether " BB switch " expression BB will switch, and 1 indicates carries out BB role's switching, and " MAC Address ofterminal1 " corresponding neighbor node is the new BB that selects; 0 expression is not carried out BB role and is switched.

Set Mesh DTIM Interval=1s, the fresh-keeping cycle of BB induction information is 2s.Array (a, b, c, d) in a represent the MAC Address of neighbor node, b represents the BB induction information value of neighbor node, c indicates whether this neighbor node is BB, 1 expression is, 0 expression not, d represents the fresh-keeping duration of this node as BB, if the c value is 0, d is meaningless.

Referring to Fig. 9, Fig. 9 is applied to the flow chart of network shown in Figure 3 for the present invention's the 4th preferred embodiment.This flow process may further comprise the steps:

Step 901, node A sends Beacon message constantly at T, and specifying this node at Beacon is BB, and its neighbor node B and node C are non-BB node.

Neighbor list information is as shown in table 11 in the beacon message that node A sends:

Octets：1	1	1	6	6	1	1
Octets：1	1	1	6	6	1	1	ID	Length	00000100	Node B	Node C	00000000	00000000

Table 11

Step 902a and step 902b, Node B and node C receive this DTIM Beacon message, find that node A is BB, then writing down node A is the BB that senses, and the fresh-keeping duration of initialization BB induction information is its fresh-keeping cycle: (MAC Address of node A, 0,1,2s).

Step 903, node D sends Beacon message at T+0.1ms, and specifying this section point in Beacon message is BB, and its neighbor node B and node E are non-BB node.

Neighbor list information is as shown in table 12 in the beacon message that node D sends:

Octets：1	1	1	6	6	1	1
Octets：1	1	1	6	6	1	1	ID	Length	00000100	Node B	Node E	00000000	00000000

Table 12

Step 904a and step 904b, Node B and node E receive this Beacon message, find that node D is BB, and then writing down node D is the BB that senses, and the fresh-keeping duration of initialization BB induction information is its fresh-keeping cycle: (MAC Address of node D, 0,1,2s).

Step 905, Node B sends Beacon message constantly at T+0.2s, and specifying this section point in Beacon message is non-BB node, and its neighbor node E and node C are non-BB, and its neighbor node A and node D are BB.

Neighbor list information is as shown in table 13 in the beacon message that MP-B sends:

Octets：1	1	1	6	6	6	6	1	1
Octets：1	1	1	6	6	6	6	1	1	ID	Length	00000000	Node A	Node C	Node D	Node E	00000000	10100000

Table 13

Step 906a/906b/906c/906d, node A, node C, node D, node E receive this Beacon message, then are recorded as (MAC Address of Node B, 2,0,0).The value of b is 2 to be that node A and node D are BB in the neighbor node of B according to getting access to from Beacon in the array, is 2 thereby obtain the BB quantity that Node B senses.And from this Beacon message, obtain the BB ability information of Node B.

Step 907, node E sends Beacon message constantly at T+0.3s, and specifying this section point in beacon message is non-BB, and its neighbor node B is non-BB, and its neighbor node A is BB.

Neighbor list information is as shown in table 14 in the beacon message that MP-E sends:

Octets：1	1	1	6	6	1	1
Octets：1	1	1	6	6	1	1	ID	Length	00000000	Node B	Node D	00000000	01000000

Table 14

Step 908a/908b/, Node B and node D receive this Beacon message, then are recorded as (MAC Address of node E, 1,0,0).And from this Beacon message, obtain the BB ability information of node E.

Step 909, node D switches at T+0.4 time trigger BB.

Step 910, node D is according to its recorded information (MAC Address of Node B, 2,0,0), and (MAC Address of node E, 1,0,0) selects the little node E of the value of b as specifying new BB node.

Step 911, node D sends the broadcasting switching message that has node E address information to Node B and node E.

At this moment, neighborlist information is as shown in Table 15 in the beacon message of node D transmission:

Octets：1	1	1	6	6	1	1
Octets：1	1	1	6	6	1	1	ID	Length	00000110	Node E	Node B	00000000	00000000

Table 15

Step 912a, Node B is received broadcasting switching message, node D is set to non-BB.After Node B received that node D sends beacon, it was shown in table 16 to revise neighbor list information:

Octets：1	1	1	6	6	6	6	1	1
Octets：1	1	1	6	6	6	6	1	1	ID	Length	00000000	Node A	Node C	Node D	Node E	00000000	10000000

Table 16

Step 912b, node E receive broadcasting switching message, and oneself is switched to BB.Step 913, the node E cycle, Node B and the node D to its covering sent beacon message.MP-E sends beacon at next DTIM interval after receiving that MP-D sends beacon, and neighbor list information is shown in 16 among the beacon:

Octets：1	1	1	6	6	1	1
Octets：1	1	1	6	6	1	1	ID	Length	00000100	Node B	Node D	00000000	00000000

Table 16

Step 914, Node B are received the beacon message that the node E cycle sends, and node E is set to BB, and the fresh-keeping duration of its correspondence of initialization.

This moment, the neighbor list information of Node B was shown in table 17:

Octets：1	1	1	6	6	6	6	1	1
Octets：1	1	1	6	6	6	6	1	1	ID	Length	00000000	Node A	Node C	Node D	Node E	00000000	10010000

Table 17

In the present embodiment, node device knows that the method for autonomous induction information can be identical with first preferred embodiment.In addition, node device can be according to the neighbor list that receives in the present embodiment, determines to have in the BB information of this node record right and wrong BB state, then deletes this BB information.Suppose: Node B record node A and node D are BB, and receive the neighbor list of node A this moment, and wherein the state of node D is non-BB, can determine that then node D has become non-BB, deletes this BB information.

The 5th preferred embodiment:

Referring to Figure 10, Figure 10 is the structural representation of the device of the selection BB of the present invention's the 5th preferred embodiment.This device comprises: message sink module 1001, neighbor node BB ability information and BB induction information acquisition module 1002, BB select module 1003, optional timing module 1005 and optionally obtain neighbor node BB ability information and the message generating module 1004 of BB induction information.

Wherein, message sink module 1001 receiving node device forwards comprise the BB ability information whether indicating self has the BB ability, advertised information with the situation information that self is covered by BB, and message content sent to neighbor node BB ability information and BB induction information acquisition module 1002, or further neighbor node is shown it self is that the advertised information of BB sends to timing module 1005.

Neighbor node BB ability information and BB induction information acquisition module 1002, from the described advertised information that receives, obtain the BB ability information of neighbor node equipment, and, determine that the BB induction information that the sign neighbor node equipment by what BB is covered sends to BB selection module 1003 according to the situation information that wherein self is covered by BB.

Timing module 1005 shows it self is the advertised information of BB according to the each transmission of each neighbor node, and each neighbor node is carried out timing, and clocking information is sent to BB selection module.

The select command that BB selects module 1003 receiving node equipment to send, can also receive the clocking information that timing module sends, according to BB ability information and the BB induction information of this select command according to neighbor node equipment, from neighbor node equipment, select the BB that conduct is new, generate the selection result that comprises new BB information and send to node device.BB in the present embodiment selects module 1003 can select to have the BB ability, and the neighbor node of BB induction information minimum is as new BB.If the node device that has the BB ability and covered by minimum BB is a plurality of, then from these node devices, select one to show it self is that time of advertised information of BB is to the longest node device of current time, as new BB for the last time.

Described neighbor node BB ability information and BB induction information acquisition module, further timing or not timing send and obtain message command to the message generating module 1004 of obtaining neighbor node BB ability information and BB induction information.

The described message generating module 1004 of obtaining neighbor node BB ability information and BB induction information according to obtaining message command, generates the message of obtaining the BB ability information and/or obtaining the BB induction information, sends to node device.

The BB choice device of present embodiment can be arranged in the node device, carries out alternately with the main control unit of node device, realizes that BB selects.

And then to selecting method and the device of BB to be elaborated in second kind of wireless network BB handoff procedure.

The 6th preferred embodiment:

In the present embodiment, node device writes down the information of its neighbor node, and (c), a represents the neighbor node sign for a, b, and b represents the BB sign, and 0 expression is not as tlv triple; 1 expression is, on behalf of this node, c receive the last time offset value of time gap current time that shows the Beacon that oneself is BB that sends of neighbor node, and it participates in the selection of BB as the time fairness factor.Selection course can may further comprise the steps:

Node in the step 1.Mesh network receives the Beacon message from neighbor node, if the information of carrying shows that this node is BB in this Beacon message, neighbor node should be revised c=0 according to the Beacon of this node, otherwise the c value is along with the time increases progressively.

Step 2.BB node triggers and switches, and the information of the neighbor node of BB basis oneself self nodes records selects the maximum node of c value as the BB that switches from have the BB capable nodes.

The current BB node device of step 3. sends the broadcasting handoff notification message that has new BB sign to the non-BB node device of its covering, finishes BB and switches.

Specific to network shown in Figure 3, suppose that Node B sends Beacon and the information of carrying shows that this section point is BB constantly at T, node A, C, D, the information of E record neighbor node B (MAC Address of B, 1,0ms).

Node B has been initiated the BB switching at T+10ms, and think does not have reference information herein, and then Node B is specified at random, might as well suppose that node C is next BB.This moment, Node B still carried to show it oneself is the information of BB in Beacon.Node A then, C, D, the information of E record neighbor node B (MAC Address of Node B, 1,0ms).Wherein, d is modified again and is 0ms.

Node C has sent to carry at T+11ms and has shown that this node is the Beacon of BB information.Neighbor node A be recorded as (MAC Address of Node B, 0,1ms), (MAC Address of node C, 1,0ms); Node B be recorded as (MAC Address of node A, 0 ,-ms), (MAC Address of node C, 1,0ms).Node C be recorded as (MAC Address of node A, 0 ,-ms), (MAC Address of Node B, 0,1ms).Here " ms " expression does not receive showing from the message as BB of node A transmission as yet, sign duration maximum.

Node C has initiated the BB switching at T+21ms, the neighbor node that C writes down at this moment for (MAC Address of node A, 0 ,-ms), (MAC Address of Node B, 0,11ms).Because " ms " expression does not receive showing from the message as BB of node A transmission as yet, therefore determines the d maximum of node A, thereby node C selects node A as next BB.This moment, node C still carried to show it oneself is the information of BB in Beacon.Node A then, and the information of B record neighbor node C (MAC Address of node C, 1,0ms).Wherein, d is modified again and is 0ms.

Node A has sent to carry at T+22ms and has shown that this node is the Beacon of BB information.Node A record information of neighbor nodes (MAC Address of Node B, 0,12ms), (MAC Address of node C, 0,22ms).

After this, switch, select Node B as next BB when node A initiates BB.Steps in sequence is analogized.

The 7th preferred embodiment:

In the present embodiment, time fairness factor and BB induction information are combined into BB and select the factor.In the present embodiment, the information of its neighbor node of nodes records, as four-tuple (a, b, c, d), a represents the neighbor node sign, b represents BB sign (0 not 1 be), and on behalf of this node, c receive the last time offset value of time gap current time that shows the Beacon that oneself is BB that sends of neighbor node.D represents the BB induction information of this node.

The variation of step 1.d value and embodiment illustrated in fig. 9 identical, the c value changes: the node in the Mesh network receives the Beacon from neighbor node, if the information of carrying shows that this node is BB among this Beacon, neighbor node should be revised c=0 according to the Beacon of this node, otherwise the c value is along with the time increases progressively.

Step 2.BB node triggers and switches, the information of the neighbor node of BB basis oneself self nodes records, select the minimum node of d value as the BB that switches from have the BB capable nodes, if there is the d value of a plurality of nodes identical and all be minimum, the node of then therefrom selecting c value maximum is as BB.

Also can select the maximum node of c value as the BB that switches from have the BB capable nodes, if there is the c value of a plurality of nodes identical and all be minimum, the node of then therefrom selecting d value maximum is as BB.

Current BB node device sends the broadcasting handoff notification message that has new BB sign to the non-BB node device of its covering, finishes BB and switches.

The 8th preferred embodiment:

Referring to Figure 11, Figure 11 is the structural representation of the device of the selection BB of the present invention's the 8th preferred embodiment.This device comprises: message sink module 1101, neighbor node BB ability information acquisition module 1103, BB select module 1104 and timing module 1102;

Wherein, message sink module 1101 receiving node device forwards comprise the notice message whether indicating self has the BB ability information of BB ability, message content is sent to neighbor node BB ability information acquisition module 1103, and neighbor node is shown it self is that the advertised information of BB sends to timing module 1102;

Neighbor node BB ability information acquisition module 1103 from the described advertised information that receives, obtains the BB ability information of neighbor node equipment, sends to BB and selects module 1104;

Timing module 1102 shows it self is the advertised information of BB according to the each transmission of each neighbor node, and each neighbor node is carried out timing, and clocking information is sent to BB selection module 1104;

BB selects module 1104 to receive the clocking information that timing module sends, select command with the node device transmission, according to this select command, from neighbor node equipment, select to have the BB ability, and show it self is that time of advertised information of BB is to the longest node device of current time for the last time, as new BB, generate the selection result that comprises new BB information and send to node device.

By the above embodiments as seen, select method and device and the BB changing method of BB in these two kinds of wireless network BB handoff procedures of the present invention, it is more reasonable to make that BB selects, and is not easy to cause the BB competition, can reduce the beacon conflict, and it is more reasonable to make that BB selects.The temporal information that became BB by the reference neighbor node last time is selected BB, make the distribution of BB disperse more, embodies Mesh network distributivity, acentric characteristics more.

Claims

1. select the method for BB in the wireless network marking message broadcasting device BB handoff procedure, it is characterized in that, may further comprise the steps:

2. the method for selection BB as claimed in claim 1 is characterized in that the described situation information that self is covered by BB is the BB induction information;

3. the method for selection BB as claimed in claim 1 is characterized in that the described situation information that self is covered by BB is the BB induction information;

4. the method for selection BB as claimed in claim 1 is characterized in that the described situation information that self is covered by BB is the BB induction information;

5. the method for selection BB as claimed in claim 1 is characterized in that the described situation information that self is covered by BB is the BB induction information;

6. as the method for the described selection of the arbitrary claim of claim 1～5 BB, it is characterized in that described node device knows that the method for self BB induction information is: record comprises the BB information of BB sign and fresh-keeping duration;

The beacon message of every reception neighbor node determines according to message content whether this neighbor node is BB earlier, if the beacon message that BB sends, then judge whether it is the BB information that has write down, if then upgrade the fresh-keeping duration of this BB information, otherwise write down the BB information of this BB;

Or according to the transmission self of neighbor node by the situation information that BB covers, the neighbor node of determining this node be the BB state and be not increased in the BB information of record, then write down the BB information of this BB;

According to the quantity of the BB information that writes down, determine self BB induction information;

7. the method for selection as claimed in claim 6 BB is characterized in that this method further comprises: at the fresh-keeping duration of a BB then, delete this BB information;

8. the method for selection as claimed in claim 6 BB is characterized in that this method further comprises: node device sends in network and comprises the BB induction information notification message that changes back BB induction information when self BB induction information changes.

9. the method for selection BB as claimed in claim 1 is characterized in that, whether described self be the information of BB by the situation information that BB covers for each neighbor node;

10. the method for selection BB as claimed in claim 9, it is characterized in that, described steps A comprises: node device increases the BB ability information in beacon message and/or association messages, and increases whether each neighbor node is the neighbor node BB state information of BB in beacon message;

11. the method as claim 1～5 or the described selection of 9 arbitrary claims BB is characterized in that described step C further comprises: BB current in the wireless network is behind selected new BB, and the node device in the network is given in announcement.

12. the method for selection BB as claimed in claim 11 is characterized in that this method further comprises:, adopt competitive way to select new BB if new BB does not receive the announcement that step C sends.

13. the method for selection as claimed in claim 1 BB is characterized in that, step B described BB ability information and BB induction information according to neighbor node equipment select the method for the new BB of conduct to be from neighbor node equipment:

14. the method for selection BB as claimed in claim 13 is characterized in that this method further comprises:

15. the method for selection as claimed in claim 13 BB is characterized in that this method further comprises: node device starts the timing to this BB after showing of receiving at every turn that neighbor node sends self is the advertised information of BB;

16. a device of selecting BB is characterized in that, comprises: message sink module, neighbor node BB ability information and BB induction information acquisition module, BB select module;

17. the device of selection BB as claimed in claim 16, it is characterized in that: this device also comprises the message generating module of obtaining neighbor node BB ability information and BB induction information;

18. the device of selection BB as claimed in claim 16, it is characterized in that: this device also comprises timing module;

19. as the device of claim 16 or 17 or 18 described selection BB, it is characterized in that: this device is arranged in the node device.

20. select the method for BB in the wireless network BB handoff procedure, it is characterized in that, may further comprise the steps:

The current described advertised information of BB in B, the wireless network from receiving, obtain the BB ability information of each neighbor node equipment, and when carrying out the BB switching, show self to be BB according to the BB ability information of neighbor node equipment and record neighbor node equipment, from neighbor node equipment, select the node device that duration is the longest as new BB to the duration of current time.

21. the method for selection as claimed in claim 20 BB is characterized in that, the described record neighbor node equipment of steps A shows, and self to be BB to the method for the duration of current time be:

22. the method for selection BB as claimed in claim 21 is characterized in that, shows the neighbor node of the notice message that self is BB to not receiving neighbor node, duration is recorded as maximum sign;

23. the method for selection BB as claimed in claim 20 is characterized in that described steps A further comprises: the node device of wireless network increases in the advertised information that sends: the situation information that self is covered by BB;

24. the method as claim 22 or 22 or 23 described selection BB is characterized in that, in the described steps A: node device increases the BB ability information in beacon message and/or association messages;

Described showing self is that the advertised information of BB is: show it self is the beacon message of BB.

25. a device of selecting BB is characterized in that, comprises: message sink module, neighbor node BB ability information acquisition module, BB select module and timing module;

26. the device of selection BB as claimed in claim 25 is characterized in that this device is arranged in the node device.