The method that the wireless sensing network topology of oriented mission is set up
Technical field
The topology that the present invention relates to the static backbone network of a kind of wireless sense network is set up the network topology management method that combines with the self adaptation sub-clustering of oriented mission, belongs to wireless sense network Topology Management field.
Background technology
(wireless sensor network WSN) is current emerging forward position research hot fields that receive much concern in the world, that intersected by multidisciplinary height to wireless sensor network.Wireless sensor network has very wide application prospect, in military and national defense, industrial or agricultural, city management, biologic medical, environmental monitoring, rescue and relief work, anti-probably anti-terrorism, many fields such as deathtrap Long-distance Control all have important scientific research to be worth and huge practical value, world many countries military circles have been caused, the great attention of academia and industrial quarters, and become the hot research field, emerging forward position of generally acknowledging that entered since 2000, be considered to one of the technology of power that will have an immense impact on to 21st century, it will exert far reaching influence to the human following life style.
The otherness of applied environment and task has proposed great challenge to the design of wireless sense network system, simultaneously, because the energy constraint characteristic of wireless sensing net node, how organization network is with effective conserve energy, and prolonging network lifetime also is one of very important important subject.In order to satisfy the complicated and diversified demand of wireless sense network task, domestic and international research concentrates on the methods such as adaptation function reconstruct of the self adaptation dynamic topology tissue that adopts oriented mission and node, as the Cougar system of Cornell University and the TinyDB system of University of California Berkeley etc.The Cougar system proposes the method for network local nodes dynamic clustering, at different cluster structured of the formation of the different node self-adapting of different application choices, can support the mission requirements that change preferably, but be difficult to the topology control functions such as dormancy management of network enabled.
For the wireless sensor network that has great deal of nodes, the topological structure of sub-clustering has more advantage on network topology management and extensibility.Leader cluster node (Cluster Head, the CH) backbone of formation network, the sleeping/waking of node and data route in the laod network, can reduce the network energy consumption preferably, prolong network lifetime, but the cluster structured of its formation is static relatively, variation with mission requirements is difficult to conform.And if be the heavily sub-clustering of center self adaptation with the task, one comes the gained topology to be difficult to network enabled node distribution formula management preferably and network connectivty requirement, the load balance of network is difficult to reach, and two variations at task need frequent full mesh topology to rebuild, and network overhead is too big.
Summary of the invention
The method that the purpose of this invention is to provide a kind of wireless sensing network topology foundation of oriented mission.
At existing problem, the method that the wireless sensing network topology of oriented mission of the present invention is set up may further comprise the steps:
A. set up overall static backbone network topology, node administration mode and assurance network connectivty preferably are provided;
B. keeping under the constant prerequisite of static topology, localized network node oriented mission dynamic clustering to support different mission requirements, after finishing the work, is removed internodal logical relation based on task.
As a kind of optimal way of the present invention, steps A can adopt the topological structure of sub-clustering, may further comprise the steps:
A1, channel are intercepted; After the node initializing, continue to intercept the channel certain hour,, then change step a3 over to,, then upgrade self neighbor table if receive the information (as: Hello message) of other nodes if receive a bunch message;
A2, information interaction: pass through periodic Hello interacting message self information between node, and compete bunch head on this basis;
A3, node network: the node that competition is successful is not sent into the net application to finish the section networking process to its neighbours bunch hair.
As another optimal way of the present invention, competition among a step a2 bunch method can adopt bunch competitive way based on multiple weighing value, node is according to the weighted average competition bunch head of self attributes (as: node energy, node degree etc.), the successful node of the competition bunch member node that becomes to be as the criterion is waited for networking.
As another optimal way of the present invention, bunch periodic superframe structure of head maintenance, in comprising bunch the communication period with bunch between communicate by letter the period, bunch in communication period broadcasting Beacon frame finish functions such as bunch inter-sync, bunch member node is deferred to the periodic scheduling of leader cluster node, changes resting state when sending out on free of data over to.
As a kind of improvement of the present invention, step B specifically describes as follows;
B1, task analysis and node Task Distribution, after node detection requires to target or the data query that receives the upper strata, task to required execution is analyzed, this step is carried out by bunch head of physical cluster, and according to the suitable Logic Cluster head of mission requirements selection, and wake bunch member node that needs the work of participation task up;
B2, Logic Cluster head node are carried out corresponding processing capacity at task, and carry out Logic Cluster member's selection, the work such as appointment of next Logic Cluster head;
B3, bunch member node temporary adandonment handled of executing the task after task is complete, are then deferred to the dispatching cycle of physical cluster to the deferring to of physical cluster dispatching cycle again;
B4, results of task execution, are then carried out with the routing policy of backbone network not in the direct communications range of Logic Cluster head as if the node that need be uploaded to the upper strata or reach;
The present invention when mission requirements are arranged, then in the localized network zone according to mission requirements dynamic clustering (Logic Cluster), after task is finished, remove internodal logical communication link based on task.The present invention provides network topology management preferably when supporting the dynamic task conversion, effectively prolong network lifetime.
Description of drawings
Fig. 1 is the network topology schematic diagram of the dynamic clustering of the static backbone network of network and oriented mission.
Fig. 2 is the flow chart of network topology management step of the present invention.
Fig. 3 is the establishment step flow chart of the static backbone network of network (physics sub-clustering).
Fig. 4 is the foundation and dismission flow chart of the dynamic clustering (Logic Cluster) of oriented mission.
Specific implementation method
The invention will be further described below in conjunction with accompanying drawing.
The invention provides a kind of local dynamic clustering and the topological topological management method of setting up the physical cluster+Logic Cluster that combines of overall static backbone network of oriented mission, the connectedness of static backbone network (physical cluster) maintaining network and the scheduling of the sleeping/waking of node, when mission requirements are arranged, then in the localized network zone according to mission requirements dynamic clustering (Logic Cluster), after finishing, task removes internodal logical communication link based on task, its work schematic diagram as shown in Figure 1, implementation step is as shown in Figure 2.
Step 101: set up overall static backbone network topology, node administration mode and assurance network connectivty preferably are provided; A kind of distributed clustering method based on weights is provided among the present invention.In the network topology structure of sub-clustering, have two kinds of nodes: bunch head (ClusterHead, CH) with bunch member (ClusterMember, CM).During node initializing, identity is that uncertain (Undefined UN), in the networking process, comprises that channel is intercepted, interacting message and node network three threads, can adopt any distributed bunch of competing method.In the present invention, provide a kind of election of cluster head method of optimizing based on multiple weighing value as an example, its concrete steps are as follows:
Step 201: neighbours find
1) node is intercepted 1 super frame period of channel, if receive the Beacon frame of CH, then putting own state is PreCM, changes step 202 over to;
2) node periodic broadcast Hello message (periodicity generally is no more than 10) comprises node ID, current ENERGY E
i, weights W
i(initial value is 0), present node state information such as (being initially UN);
3) node is set up neighbor table according to the Hello information that receives, and upgrades bunch head competition weights W of oneself
i
Step 202: election of cluster head
1), still needs periodic Hello broadcasting in this stage;
2) if the weights W of node
iMinimum in its neighbours, put oneself and be CH;
3) if there be the CH of weights among the node neighbours, put the own PreCM of being less than self weights;
Step 203: cluster
1) CH broadcasts the Beacon frame, comprises the schedule information of CH;
2) PreCM intercepts 1 super frame period of channel, receives Beacon, sets up the CH table;
3) PreCM begins by the best CH in the xxx principle selection CH table at the 2nd superframe, sends to it to add application MSG_JOIN_REQ message, the WaitACK timer is set, wait MSG_JOIN_ACK message;
4) CH receives MSG_JOIN_REQ, if bunch less than, send MSG_JOIN_ACK message, otherwise, send MSG_JOIN_DENY message;
5) PreCM then puts oneself for CM if receive MSG_JOIN_ACK message, finishes sub-clustering, if receive MSG_JOIN_DENY message or WaitACK timer expiry, then changes 3 over to);
6) as if no available CH in the CH table of PreCM node, then put oneself and be CH, the Beacon that goes on the air finishes sub-clustering.
Its flow chart as shown in Figure 3.Bunch periodic superframe structure of head maintenance, in comprising bunch the communication period with bunch between communicate by letter the period, bunch in communication period broadcasting Beacon frame finish functions such as bunch inter-sync, bunch member node is deferred to the periodic scheduling of leader cluster node, changes resting state when sending out on free of data over to.
Step 102: task is obtained, and comprises two kinds of situations: one, and upper network layer is initiated mission requirements; Its two, node detection is to object variations;
Step 103: task analysis and Task Distribution, what start this process for the first time is the physical cluster head node, one, the mission requirements that initiate on the upper strata are passed to the physical cluster head, do Task Distribution by the physical cluster head; Its two, node detection is uploaded to the physical cluster head to object variations, the physical cluster head judges that mission requirements also do Task Distribution.Specify suitable Logic Cluster head by the physical cluster head according to mission requirements, i.e. " Leader " node of carrying out of task, and wake bunch member node of the task that may participate in up, the node that is waken up temporarily abandons observing the dispatching cycle of physical cluster;
Step 104: the Leader (Logic Cluster head) that task is carried out is provided with the condition (as surpassing a certain threshold value etc. apart from the distance of self, the information of obtaining) that adds Logic Cluster, broadcasting Logic Cluster cluster message, enable logic bunch cluster process according to mission requirements; Receive the node of Logic Cluster cluster message, judge whether oneself satisfies the cluster requirement,, then add Logic Cluster, carry out the task of distributing, and after task is finished, the result is sent to Leader if satisfy;
Step 105:Leader collects required result, (as: as if task is data clusters after respective handling is done in this locality, then carry out the data fusion function) at the leader place, if data need be uploaded or in next step operation of other bunches continuation, then be uploaded to the physical cluster head, start network routing function by the physical cluster head and carry out corresponding data/request transmitting function;
Step 106: the Logic Cluster of finishing the work is dismissed, and each node re-executes the dispatching cycle of physical cluster.
The generation of Logic Cluster and dismission process are as shown in Figure 4.
Described above only is a most preferred embodiment of the present invention, and protection scope of the present invention is not limited to above-mentioned specific embodiment, and the conspicuous change that all those skilled in the art are made according to the present invention all drops in protection scope of the present invention.