Background technology
Wireless sensor network can detect collaboratively in real time, tracking and collection network are laid various environment in region or the information of monitoring target, and to these information work in coordination with, fusion treatment, obtain conclusion comparatively accurately, be then sent to user.Sensing node generally adopts powered battery, and its a large feature is energy constraint.Another important feature of sensor network is application specificity.In order to improve uploading data comentropy and event accuracy rate, between network node, often need sensor, multi-node collaborative information processing, and require to realize the seamless coverage of area to be monitored.Therefore, it is high that sensor network has node layout density, and node perceived information has the features such as redundancy.In addition, wireless sensor network does not rely on fixing infrastructure, and network node requires to have self organization ability.
Most simple datas are collected application scenarios as environment measuring, industrial detection etc., the network organization form of the single aggregation node of more employing (Sink), the reliability of whole network, extensibility are subject to the restriction of this Sink node, and network cannot treatment S ink node failure problem.Therefore, in actual sensor network application, mostly adopt many Sink pattern.
In wireless sensor network, the feature of data traffic is a large amount of sensor node perception data, then to aggregation node (being Sink node) aggregate transmission.Performance of route protocol in transmitting procedure is the key factor that affects network performance.In the application of many Sink sensor network, the load of whole network is assigned to many Sink node by Routing Protocol, generally adopt nearest Sink strategy (nearest Sink scheme, NS mechanism), be the destination node of the nearest Sink node of sensor node chosen distance oneself as data packet transmission, guarantee the minimum hop count of sensor node to Sink node, minimize the energy consumption of network.Because the data of wireless sensor network sensing node perception have the features such as continuous, uncertain, because of the sensing node perception task difference of zones of different, on diverse geographic location, node produces data volume difference, it is the disequilibrium of sensor network data, and NS mechanism load area is divided inhomogeneous, cause some Sink load overweight, the node of close Sink, because transmitting too much data depleted of energy, has a strong impact on the useful life of network.Visible, a key issue of the sensor network based on many Sink is the load assignment problem between each Sink during the network operation.Therefore how the fractional load of overload Sink is adjusted to other idle Sink, avoiding indivedual Sink loads overweight is a problem of needing solution badly.
Summary of the invention
Technical problem to be solved by this invention is: a kind of load balancing between multiple sink nodes method for routing of wireless sense network is provided, and the method expense is little, and efficiency is high.
For solving the problems of the technologies described above, the present invention adopts following technical scheme.
A kind of load balancing between multiple sink nodes method for routing of wireless sense network comprises the following steps:
Step 1, aggregation node broadcast transmission is in order to set up the RINIT broadcasting command bag of convergence gradient;
Step 2, the sensing node that receives described RINIT broadcasting command bag is resolved the content of RINIT broadcasting command bag, and according to the content setting of described RINIT broadcasting command bag or upgrade the distance/jumping figure of sensing node self to aggregation node; The specific implementation process of described step 2 is:
After A1, sensing node electrifying startup, if receive for the first time described RINIT broadcasting command bag, sensing node is set self to the distance of aggregation node of sending described RINIT broadcasting command bag;
If the described sensing node of A2 had been received described RINIT broadcasting command bag, sensing node is set or is upgraded self to the distance of aggregation node of sending described RINIT broadcasting command bag;
A3, judge whether the aggregation node that sends described RINIT broadcasting command bag is the aggregation node nearest from described sensing node, if stop forwarding described RINIT broadcasting command bag, if not continue to forward described RINIT broadcasting command bag.
Step 3, described aggregation node is transferred to the data volume of described aggregation node according to adjacent aggregation node subordinate's sensing node, determine the zoning of described adjacent aggregation node; Described aggregation node sends the RCTL order bag that adjustment region is divided as required; In step 3, described aggregation node periodically judges that adjacent aggregation node subordinate's sensing node is transferred to the data volume of described aggregation node, determines the zoning of described adjacent aggregation node.
Step 4, the sensing node that receives described RCTL order bag is resolved the content of RCTL order bag, obtain and need the address of the adjacent aggregation node of adjusting and need the area size of adjusting, and according to the object aggregation node of the content setting of described RCTL order bag or renewal sensing node self, feasible region is adjusted; The implementation procedure of step 4 is: described sensing node receives after RCTL order bag, first judges that whether self node was processed after described RCTL order bag, if so, stopped forwarding described RCTL order and wrapped; Otherwise judge whether self node is in the regional extent that described aggregation node need to adjust, if adjust the object Sink node of self, continues to forward described RCTL order bag, wraps otherwise abandon described RCTL order.
Step 5, repeating step four, until the adjusted region of sensing node meets the requirement of described RCTL order bag.
As a preferred embodiment of the present invention, described RINIT broadcasting command bag comprises that type, source address, the maximum of the Sink node that sends RINIT broadcasting command bag spread jumping figure, receive the sensing node of RINIT broadcasting command bag to the jumping figure/distance of Sink node.
As another kind of preferred version of the present invention, described RCTL order comprises type, source address, the source sequence number of the Sink node that sends RCTL order, the object Sink address of node of adjustable range, adjusting jumping figure/distance, life cycle.
Beneficial effect of the present invention is: due to the always state in having set up of the route in the method for the invention, in the time having data to send, can send immediately, greatly reduce the control overhead of wireless sensor network system, computing cost is little, efficiency is high, has effectively extended network life.
Embodiment
The feature that when the present invention is evenly distributed according to information, event amount of information is directly proportional to event area size, for prolong network lifetime, reduce computing cost as far as possible, in poly concourse nodes situation, for the feature of wireless sensor network, a kind of adaptive wireless sense network load balancing between multiple sink nodes method for routing is proposed.The main thought of load balancing method for routing of the present invention is: in radio sensing network, according to the feature of Sensor Network data flow, the control frame self adaptation that sensing node sends according to the Sink node receiving regulates the object Sink node of transfer of data.
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.
Embodiment mono-
The present embodiment provides a kind of load balancing between multiple sink nodes method for routing of wireless sense network, and the method realizes based on nearest Sink strategy, mainly comprises following two parts content:
One, the load balancing method for routing in aggregation node (Sink node) compass of competency:
1), when initialization, each aggregation node (Sink node) sends Route establishment frame RINIT, the sensing node that receives RINIT obtains the own minimum hop count that arrives each Sink node by the broadcast of this frame;
2), sensing node selects the aggregation node of jumping figure minimum as the object Sink node of transfer of data;
3), sensing node is according to the Energy Expenditure Levels of self some father node, selects the slowest father node of energy consumption speed as next-hop node.
Two, load balancing method for routing between aggregation node (Sink node):
1), a certain Sink node is to detect the rate of received data of each Sink node compared with large period TS, if the ratio of the rate of received data of adjacent S ink node exceedes thresholding α, the slow Sink node of inbound pacing sends RCTL (control) frame, regulates the quantity of the sensing node that is transferred to the fast Sink node of inbound pacing; Wherein thresholding α is the sensing node that is transferred to adjacent S ink node for fear of re-adjustments, and its effect is to guarantee to be transferred to when the data volume of adjacent S ink node is more or less the same not regulate, wherein α > 1.
2), sensing node changes former object Sink node according to the RCTL frame receiving, or selects the aggregation node of jumping figure minimum as the new object Sink node of transfer of data.
Embodiment bis-
The present embodiment, take following supposing the system as example, describes the specific implementation process of the load balancing between multiple sink nodes method for routing of wireless sense network of the present invention in detail.
First the supposition that system meets the following conditions:
1, in network, be laid with N sensing node, and N sensing node has identical primary power;
2, in network, there is M aggregation node (Sink node), between Sink node, intercom mutually by wired or other wireless channels;
3, the whole aggregation nodes in network and sensing node have identical wireless coverage radius, and channel is symmetrical.
Describe the implementation procedure of the method for the invention in detail below in conjunction with accompanying drawing.
[the route initialization procedure of aggregation node]
With reference to Fig. 1, when initialization, aggregation node (Sink node) sends Route establishment frame RINIT, the frame format of RINIT as shown in Figure 6, wherein comprise the maximum radius of this frame diffusion and the jumping figure to aggregation node, type refers to the type of the Sink node that sends RINIT broadcasting command bag, source address refers to the source address of the Sink node that sends RINIT broadcasting command bag, maximum diffusion jumping figure/distance refers to the size of the existence radius TTL in RINIT broadcast packet, refer to that to the jumping figure/distance of aggregation node the sensing node that receives RINIT broadcasting command bag is to the jumping figure/distance of Sink node.The maximum diffusion radius that described Route establishment frame RINIT sets up can be along with the change of application flexible configuration, the flow process that aggregation node is broadcasted this frame is as follows:
S1-1Sink node powers on;
S1-2 arranges timer, waits for that it is overtime;
S1-3 timer expiry, aggregation node (Sink node) sends Route establishment frame RINIT broadcast packet.
[processing of Route establishment frame RINIT]
With reference to Fig. 2, the handling process of Route establishment frame RINIT is:
S2-1 sensing node receives described Route establishment frame RINIT broadcast packet;
S2-2 sensing node judges in described Route establishment frame RINIT broadcast packet, whether self is greater than in routing table and self, to the jumping figure of Sink node, forwards if not S2-3 to, if forward S2-4 to the jumping figure of Sink node;
S2-3 sensing node is revised and is added routing table, and the life span of route is set, and life span is deleted this route to after date;
S2-4 sensing node reduces the existence radius TTL in Route establishment frame RINIT broadcast packet, increases self jumping figure to Sink node, then judges whether TTL is greater than zero, if forward S2-5 to, otherwise forwards S2-6 to;
S2-5 forwards this Route establishment frame RINIT broadcast packet;
S2-6 abandons this Route establishment frame RINIT broadcast packet.
[the resource adjustments process between aggregation node]
With reference to Fig. 3, aggregation node (Sink node) periodically detects data receiver speed between adjacent S ink node, if the ratio of the data receiver speed of adjacent S ink node exceedes thresholding α, send RCTL frame, its frame format is as Fig. 7, in RCTL frame, comprise the broadband length that will regulate, the width value of adjusting can be along with the change flexible configuration of application.Type in Fig. 7 refers to the type of the Sink node that sends RCTL order, source address refers to the source address of the Sink node that sends RCTL order, source sequence number refers to the sequence number of the Sink node that sends RCTL order, destination address refers to the object Sink address of node of wanting the sensing node of adjustable range to be about to be adjusted to, and refers to the term of validity of the routing table after adjusting life cycle.
Adjusting flow process is as follows:
S3-1Sink node powers on;
S3-2 arranges timer, waits for that it is overtime;
S3-3 timer expiry, judges whether the ratio of the data receiver speed of adjacent S ink node exceedes thresholding α, turns S3-4 if exceed; Otherwise turn S3-5;
S3-4 calculates the jumping figure that regulates sensing node to change object Sink node, and in adjacent S ink node, the slower Sink node of rate of received data sends RCTL frame;
S3-5 finishes.
[processing of RCRL frame]
With reference to Fig. 4, the handling process of RCRL frame is:
S4-1 sensing node is received RCRL frame;
S4-2 sensing node judges whether oneself processed this frame, if turn S4-5, otherwise turns S4-3;
S4-3 sensing node judges and oneself whether in the adjustable range of this frame, if turn S4-4, otherwise turns S4-5;
S4-4 sensing node is adjusted the object Sink node of self, broadcasts this RCRL frame;
S4-5 abandons this frame.
[transmitting procedures of data]
With reference to Fig. 5, data source nodes is according to the object Sink node of the RCTL frame receiving or nearest Sink (NS) policy selection transfer of data, and intermediate data handling process is:
S5-1 sensing node is received data;
S5-2 sensing node judges whether oneself is the destination node of transfer of data, if finish; Otherwise turn S5-3;
S5-3 sensing node records route, and the life span of route is set;
S5-4 sensing node, according to the routing table of self node, continues forwarding data.
The sensing node energy, the computing capability etc. that the present invention is directed to wireless sensor network are limited, the random intensive laying of node, aggregation node be than the resourceful feature of sensing node, according to sensing node perception task difference, consider emphatically load balancing between different aggregation nodes, effectively extend the network system life-span, improve the extensibility of network.In large-scale wireless sensing network, aggregation node is determined behind the zoning of adjacent aggregation node, make the sensing node in adjacent aggregation node region can change the object aggregation node that node perceived transfer of data arrives by the method for the invention, sensing node can one be jumped or multi-hop arrives object aggregation node after changing.
Here description of the invention and application is illustrative, not wants scope of the present invention to limit in the above-described embodiments.Here the distortion of disclosed embodiment and change is possible, and for those those of ordinary skill in the art, the various parts of the replacement of embodiment and equivalence are known.Those skilled in the art are noted that in the situation that not departing from spirit of the present invention or substantive characteristics, and the present invention can be with other forms, structure, layout, ratio, and realize with other elements, material and parts.