CN103780364A - Sending end selecting method considering link correlation in wireless sensor network - Google Patents

Abstract

The invention discloses a sending end selecting method considering link correlation in a wireless sensor network. The method provided by the invention comprises the steps that request vectors heard by each node are merged on the node; effective receiving quantity of each data packet to be sent is calculated; the total effective receiving quantity of all data packets to be sent is calculated; the ratio of the total effective receiving quantity to the total number of the data packets to be sent is the average effective receiving quantity; according to the average effective receiving quantity, each node starts to send a request data packet after waiting for a period of time; and the greater the average effective receiving quantity is, the shorter the waiting time is. Compared with the existing sending end selecting method, the method provided by the invention considers the effect of link correlation, and selects a more accurate sending end.

Description

In a kind of radio sensing network, consider the method for the selection transmitting terminal of link correlation

Technical field

The invention belongs to wireless network and sensing network field, relate to a kind of selecting properly method of data sending terminal, for reducing the conflict in radio sensing network Data dissemination process, reduce transport overhead, reduce the deadline, improve the efficiency of Data dissemination.

Background technology

Along with the development of modern information technologies, massive wireless sensor technology develops and is widely applied to the numerous areas such as military surveillance, public safety, intelligent transportation, environment measuring, health care rapidly.Typical wireless sensor network is made up of a large amount of microsensor nodes, they are deployed in nobody or need in the frequent environment participating in of the mankind, and by the wireless net of composition certainly, automatically form multihop network system by topology control and procotol, be not subject to the restriction of existing cable network infrastructure.Wireless sensor network make people at any time and place with environmental condition under a large amount of accurate and reliable information of Real-time Obtaining, the mankind have been stretched to long-range nerve endings all things on earth in the world seemingly.Just because of the large coverage of wireless sense network scale is wide, make the code update of institute's working procedure on sensor node run into a lot of challenges, the process of code update is the process of a Data dissemination, selects correct transmitting terminal to can be good at reducing data collision, transport overhead and deadline.Though existing transmitting terminal selection algorithm can be worked, ignore the objective fact that link correlation exists, it not is better making the transmitting terminal of selecting.

Summary of the invention

The object of this invention is to provide a kind of consider link correlation selection transmitting terminal in radio sensing network method, upgrade for the speed code that realizes radio sensing network node.

For achieving the above object, the technical solution used in the present invention comprises the steps:

Step 1: the receiving terminal node in radio sensing network, receiving when after previous round data, in radio sensing network, broadcast REQ message, the ID that described REQ message comprises the node that sends this REQ message, sequence number and the request vector of data page;

Step 2: sender node is listened to REQ message and obtained the sending node ID in current REQ message, sequence number and the request vector of data page, and the ID of the sending node in current REQ message and request vector are stored in structure array;

Step 3: sender node continues to listen to REQ message and obtains the sending node ID in current REQ message, sequence number and the request vector of data page;

Step 4: the sequence number of the data page in the more up-to-date REQ message of obtaining of sender node and the sequence number of the data page that current structure body array has been stored:

If the sequence number of the data page in the REQ message of obtaining up-to-date is larger, directly abandons the up-to-date REQ message of obtaining; If now also have REQ message to listen to, return to execution step three, otherwise execution step five;

If the sequence number of the data page in the REQ message of obtaining up-to-date is less, empties all elements in current structure body array, then the sending node ID in the up-to-date REQ message of obtaining and request vector are stored in current structure body array; If now also have REQ message to listen to, return to execution step three, otherwise execution step five;

If the sequence number of the data page that the sequence number of the data page in the REQ message of obtaining up-to-date and current structure body array have been stored equates, judge whether the sending node ID in the up-to-date REQ message of obtaining has been stored in current structure body array, if, directly the request vector in the corresponding request vector of this sending node ID in current structure body array and the up-to-date REQ message of obtaining is carried out to step-by-step exclusive disjunction, re-use the corresponding request vector of this sending node ID that the request vector obtaining after step-by-step exclusive disjunction goes to replace current structure body array, if now also having REQ message need to listen to, return to execution step three, otherwise execution step five,

If sending node ID in the REQ message of obtaining up-to-date is not stored in current structure body array, directly the request vector in this sending node ID and the up-to-date REQ message of obtaining is stored in current structure body array, if now also having REQ message need to listen to, return to execution step three, otherwise execution step five;

Step 5: after REQ message sink process finishes, corresponding each sending node ID storing in current structure body array request vector is carried out step-by-step exclusive disjunction by sender node, obtains joint-request vector;

Sender node is calculated effective quantities received of corresponding each packet of the corresponding request vector of each node ID of storing in current structure body array according to formula (1); Draw the sum of the corresponding packet to be sent of joint-request vector according to formula (2); And then calculate the average effective quantities received of the corresponding packet to be sent of joint-request vector according to formula (3), and calculate the element in structure array after average effective quantities received and lost efficacy, need to empty all elements in structure array.Then start a timer, as the formula (4), in the time that timer triggers, sender node sends the corresponding packet to be sent of joint-request vector at the timing interval of described timer;

$\mathrm{\μ}\left[i\right]={\mathrm{\Σ}}_{v\∈N_u}\left(R_{\mathrm{vu}}\right[i]\×q_{\mathrm{uv}})---\left(1\right)$

$M={\mathrm{\Σ}}_{i=1}^{\left|R_u\right|}{R}_u\left[i\right]---\left(2\right)$

${\mathrm{\γ}}_u=\frac{{\mathrm{\Σ}}_{i=1}^{\left|R_u\right|}{R}_u\left[i\right]\×\mathrm{\μ}\left[i\right]}{M}---\left(3\right)$

In formula (1), (2) and (3):

I represents the i position of request vector, i >=1,

μ [i] represents effective quantities received of the corresponding packet in request vector i position,

V represents to send request vectorial receiving terminal node,

U represents to receive the sender node of request vector,

N _urepresent to send request the set of vectorial receiving terminal node,

R _vurepresent that receiving terminal node v issues the request vector of sender node u,

R _vu[i] represents R _vuthe value of i position,

Q _uvrepresent the link-quality of link u → v,

M represents the sum of the corresponding packet to be sent of joint-request vector,

R _urepresent the joint-request vector that sender node u calculates,

R _u[i] represents joint-request vector R _uthe value of i position,

| R _u| represent joint-request vector R _umould,

γ _urepresent the average effective quantities received that sender node u calculates;

$\mathrm{\Δt}=\frac{C}{{\mathrm{\γ}}_u}+T_r---\left(4\right)$

In formula (4), C is not less than 100 integer; γ _urepresent average effective quantities received, T _rrepresent the random number in 0 to 8 scope.

In the present invention, average effective quantities received is larger, and timing interval is shorter, timer more early triggers, and just more early sends data, after the corresponding packet to be sent of joint-request vector has all been sent out, sender node stops sending, and waits for and listen to the REQ message in radio sensing network.

The present invention is compared with background technology, its beneficial effect is: consider the impact of the accuracy of link correlation on transmitting terminal selection, when link-quality constant, link correlation is larger, the average effective quantities received calculating in step 5 is just larger, and the interval of timer is also just shorter, and corresponding sender node just more early starts to send packet, thereby can select more accurately transmitting terminal, reduce the transport overhead of radio sensing network.

Accompanying drawing explanation

Fig. 1 is a part topological diagram in data distribution procedure, and A and B are two sender node, and C, D and E are 3 receiving terminal nodes, and the other percentage of each oriented arrow represents link-quality.

Embodiment

Below with specific embodiment explanation the inventive method.

Realized radio sensing network of the present invention in Embedded Network Operating System TinyOS version 2 .1.1 in, consider the method for the selection transmitting terminal of link correlation, TinyOS is the open source code operating system of University of California Berkeley's exploitation, aims at embedded type wireless sensing network design.If what transmitting current is that the sequence number of data page is p, and the size of data page is 10, and each data page comprises 10 packets.

In Fig. 1, the link-quality of link A->C is 60%, and the link-quality of link A->D is 70%, and the link-quality of link B->D is 60%, and the link-quality of link B->E is 50%.Link correlation between link A->C and A->D is 100%, if represent the bust this of packet on link A->C, also failure of the transmission of packet on link A->D, and link correlation between link B->D and B->E is 0, representing the bust this of packet on link B->D, is but successful in the transmission of B->E.The rectangle of receiving terminal node C, D, E below represents respectively the accepting state of each node, and the little rectangle of grey has represented corresponding data-bag lost, and the little rectangle of white represents that corresponding packet has successfully received.Dotted arrow represents to carry out the selection of transmitting terminal.

The method of selection transmitting terminal of considering link correlation in radio sensing network of the present invention is specific as follows:

Step 1: the receiving terminal node in radio sensing network, receiving when after previous round data, the accepting state of the data page n of receiving terminal node C, D, E is respectively as shown in rectangle in Fig. 1, now data page n does not receive, in network, broadcast REQ message, sequence number, the request vector that described REQ message comprises sending node ID, data page to arrange in request vector be 1 bit representation corresponding data packet loss is that 0 bit representation corresponding data is bundled into merit and receives.In the present invention, receive and refer generally to following two kinds of situations when previous round data: the first situation is, if what sender node sent is first data page, sender node sends each packet in first data page successively, after the each Packet Generation in first data page completes, sender node stops sending, and waits for and receives REQ message, and this process is called takes turns DRP data reception process; The second situation is that sender node receives the REQ message in network, and sends the packet of disappearance according to request vector, when the packet of the corresponding disappearance of request vector all sends, sender node stops sending, and waits for REQ message, and this process also represents to take turns the receiving course of data.

If receiving terminal node C, D, the node ID of E is respectively 8, 9, 10, and successfully receiving the data page sequence number that is over is 0, 1 data page, what now ask is that data page sequence number is 2 data page (being denoted as below data page 2), the sequence number of data page is since 0 number consecutively, data page is made up of 10 packets, the sequence number of packet is since 0, the REQ message table of receiving terminal node C is shown <8, 2, { 0000011111}>, the REQ message table of receiving terminal node D is shown <9, 2, { 0000011111}>, the REQ message table of receiving terminal node E is shown <10, 2, 1000000000>.In vector, being data-bag lost that 1 bit representation is corresponding, is that 0 packet corresponding to bit representation successfully receives, and such as the 9th of the request vector of node C is 1, represents the 9th data-bag lost of data page 2.If at this moment also have in a receiving terminal node F(figure and do not mark), ID is 12, has received data page 2, prepares to receive data page 3, the REQ message table of receiving terminal node F is shown <12, and 3, { 1111111111}>.

Step 2: sender node A, B listen to REQ message and obtain the sending node ID in current REQ message, sequence number and the request vector of data page, the ID of the sending node in current REQ message and request vector are stored in structure array, the size of structure array represents the number of the neighbor node that node can record, such as 10;

Step 3: sender node continues to listen to REQ message and obtains the sending node ID in current REQ message, sequence number and the request vector of data page, symbol N, V represent respectively sequence number and the request vector of data page, and the sender node A in Fig. 1 hears the REQ message of receiving terminal node D, E;

Step 4: the sequence number of the data page that relatively N and current structure body array have been stored, with symbol, P represents, in the current structure body array of sender node A, the sequence number P of recorded data page is 2, now sender node A hears the REQ message <9 of receiving terminal node D, 2, and 0000011111}>, the up-to-date sending node ID obtaining is 9, the sequence number N of the up-to-date data page obtaining is 2, and the up-to-date request vector V obtaining is { 0000011111}.

If N>P, directly abandons the up-to-date REQ message of obtaining; If now also have REQ message to listen to, return to execution step three, otherwise execution step five, sender node A has heard the REQ message <12 of receiving terminal node F for data page 3,3, { 1111111111}>, because 3>2, directly abandons this REQ message;

If N<P, empties all elements in current structure body array, the more up-to-date sending node ID getting and request vector V are stored in current structure body array; If now also have REQ message to listen to, return to execution step three, otherwise execution step five;

Obviously, for the REQ message of receiving terminal node D, N=P=2, judge that the up-to-date sending node ID(obtaining is 9) whether be stored in current structure body array: if find, 9 have been stored in structure array, and with 9 corresponding request vector V2 be { 0000000011}, directly V2 and V are carried out to step-by-step exclusive disjunction, obtain new request vector { 0000011111}, replace 9 corresponding request vectors in current structure body array with this, if now also having REQ message need to listen to, return to execution step three, otherwise execution step five;

If the sending node ID obtaining up-to-date is not stored in current structure body array, directly this sending node ID and the up-to-date request vector obtaining are stored in current structure body array, if now also have REQ message to listen to, return to execution step three, otherwise execution step five;

Step 5: after REQ message sink process finishes, corresponding each sending node ID storing in current structure body array request vector is carried out step-by-step exclusive disjunction by sender node, obtain joint-request vector, sender node A only hears the request vector of receiving terminal node C and D, carries out the joint-request vector R obtaining after step-by-step exclusive disjunction _a={ 0000011111};

Take sender node A as example, sender node A calculates according to formula (1) ID that each sender node ID(storing in current structure body array refers to receiving terminal node C, D here) effective quantities received of corresponding each packet of corresponding request vector, such as effective quantities received of the 6th packet is

$\mathrm{\&mu;}\left[6\right]=\underset{v\&Element;N_u}{\mathrm{\&Sigma;}}\left(R_{\mathrm{vu}}\right[6]\&times;q_{\mathrm{uv}})=R_{\mathrm{CA}}\left[6\right]\&times;q_{\mathrm{AC}}+R_{\mathrm{DA}}\left[6\right]\&times;q_{\mathrm{AD}}$

$=1\&times;0.5+1\&times;0.5=1$

In like manner, μ [7]～μ [10] equals 1.

Draw the sum of the corresponding packet to be sent of joint-request vector according to formula (2);

$M={\mathrm{\&Sigma;}}_{i=1}^{\left|R_A\right|}{R}_A\left[i\right]=5$

And then sender node A calculates the average effective quantities received of the corresponding packet to be sent of joint-request vector according to formula (3)

${\mathrm{\&gamma;}}_A=\frac{{\mathrm{\&Sigma;}}_{i=1}^{\left|R_A\right|}{R}_A\left[i\right]\&times;\mathrm{\&mu;}\left[i\right]}{M}=\frac{1+1+1+1+1}{5}=1,$ The average effective quantities received that in like manner sender node B calculates is ${\mathrm{\&gamma;}}_B=\frac{0.9+0.5\&times;5}{6}\&ap;0.57.$

Sender node A, B are calculating after average effective quantities received, and the element of storing in structure array lost efficacy, and emptied all elements in structure array; Then start a timer, the packet that timer sends request while triggering, sender node A, B are as follows according to formula (4) calculating timing interval, and the C in formula (4) gets 128:

$\mathrm{\&Delta;t}\left(A\right)=\frac{C}{{\mathrm{\&gamma;}}_A}+T_r=\frac{128}{1}+6=134\left(\mathrm{ms}\right)$

$\mathrm{\&Delta;t}\left(B\right)=\frac{C}{{\mathrm{\&gamma;}}_B}+T_r=\frac{128}{0.57}+4=228\left(\mathrm{ms}\right)$

Because the timing interval of A is shorter, thus the morning that timer triggers, the packet preferentially sending request.Because receiving terminal node C, D request is identical packet, the expectation transmission value that sender node A will cover receiving terminal node C, D is 5/0.5=10, next sender node B just can as long as cover receiving terminal node E, expectation transmission value is 1/0.9=1.1, so total expectation transmission value is 11.1.And background technology selection is that sender node B first sends out, the expectation transmission value that sender node B covers receiving terminal node D, E is 1/0.9+5/0.5=11.1, receiving terminal node C is covered by sender node A, and expectation transmission value is 5/0.5=10, so total expectation transmission value is 21.1.

To sum up, the inventive method can be selected transmitting terminal more accurately than prior art, reduces better the transport overhead of node, the energy consumption of node, thereby reduces the time that whole Data dissemination process completes.

Claims (3)

1. a method of considering the selection transmitting terminal of link correlation in radio sensing network, is characterized in that, comprises the steps:

Step 1: the receiving terminal node in radio sensing network, receiving when after previous round data, in radio sensing network, broadcast REQ message, the ID that described REQ message comprises the node that sends this REQ message, sequence number and the request vector of data page;

Step 2: sender node is listened to REQ message and obtained the sending node ID in current REQ message, sequence number and the request vector of data page, and the sending node ID in current REQ message and request vector are stored in structure array;

Step 3: sender node continues to listen to REQ message and obtains the sending node ID in current REQ message, sequence number and the request vector of data page;

Step 4: the sequence number of the data page in the more up-to-date REQ message of obtaining of sender node and the sequence number of the data page that current structure body array has been stored:

If the sequence number of the data page in the REQ message of obtaining up-to-date is larger, directly abandons the up-to-date REQ message of obtaining; If now also have REQ message to listen to, return to execution step three, otherwise execution step five;

If the sequence number of the data page in the REQ message of obtaining up-to-date is less, empties all elements in current structure body array, then the sending node ID in the up-to-date REQ message of obtaining and request vector are stored in current structure body array; If now also have REQ message to listen to, return to execution step three, otherwise execution step five;

If the sequence number of the data page that the sequence number of the data page in the REQ message of obtaining up-to-date and current structure body array have been stored equates, judge whether the sending node ID in the up-to-date REQ message of obtaining has been stored in current structure body array, if, directly the request vector in the corresponding request vector of this sending node ID in current structure body array and the up-to-date REQ message of obtaining is carried out to step-by-step exclusive disjunction, re-use the request vector obtaining after step-by-step exclusive disjunction and remove to replace the corresponding request vector of this sending node ID in current structure body array, if now also having REQ message need to listen to, return to execution step three, otherwise execution step five,

If sending node ID in the REQ message of obtaining up-to-date is not stored in current structure body array, directly the request vector in this sending node ID and the up-to-date REQ message of obtaining is stored in current structure body array, if now also having REQ message need to listen to, return to execution step three, otherwise execution step five;

Step 5: after REQ message sink process finishes, corresponding each sending node ID storing in current structure body array request vector is carried out step-by-step exclusive disjunction by sender node, obtains joint-request vector;

Sender node is calculated effective quantities received of corresponding each packet of the corresponding request vector of each node ID of storing in current structure body array according to formula (1); Draw the sum of the corresponding packet to be sent of joint-request vector according to formula (2); And then according to the average effective quantities received of the corresponding packet to be sent of formula (3) calculating joint-request vector, then start timer, the timing interval of described timer as the formula (4), in the time that timer triggers, sender node sends the corresponding packet to be sent of joint-request vector;

$\mathrm{\&mu;}\left[i\right]={\mathrm{\&Sigma;}}_{v\&Element;N_u}\left(R_{\mathrm{vu}}\right[i]\&times;q_{\mathrm{uv}})---\left(1\right)$

$M={\mathrm{\&Sigma;}}_{i=1}^{\left|R_u\right|}{R}_u\left[i\right]---\left(2\right)$

${\mathrm{\&gamma;}}_u=\frac{{\mathrm{\&Sigma;}}_{i=1}^{\left|R_u\right|}{R}_u\left[i\right]\&times;\mathrm{\&mu;}\left[i\right]}{M}---\left(3\right)$

In formula (1), (2) and (3):

I represents the i position of request vector, i >=1,

μ [i] represents effective quantities received of the corresponding packet in request vector i position,

V represents to send request vectorial receiving terminal node,

U represents to receive the sender node of request vector,

N _urepresent to send request the set of vectorial receiving terminal node,

R _vurepresent that receiving terminal node v issues the request vector of sender node u,

R _vu[i] represents R _vuthe value of i position,

Q _uvrepresent the link-quality of link u → v,

M represents the sum of the corresponding packet to be sent of joint-request vector,

R _urepresent the joint-request vector that sender node u calculates,

R _u[i] represents joint-request vector R _uthe value of i position,

| R _u| represent joint-request vector R _umould,

γ _urepresent the average effective quantities received that sender node u calculates;

$\mathrm{\&Delta;t}=\frac{C}{{\mathrm{\&gamma;}}_u}+T_r---\left(4\right)$

In formula (4), C is not less than 100 integer; γ _urepresent the average effective quantities received that sender node u calculates, T _rrepresent the random number in 0 to 8 scope.

2. method according to claim 1, is characterized in that: described REQ message is made up of the ID of sending node, sequence number and the request vector of data page.

3. method according to claim 1 and 2, is characterized in that: in step 5, calculate after the average effective quantities received of the corresponding packet to be sent of joint-request vector, before starting timer, empty all elements in current structure body array.