CN107786660A

CN107786660A - A kind of radio sensing network code distribution method based on umbrella multipath

Info

Publication number: CN107786660A
Application number: CN201711034222.5A
Authority: CN
Inventors: 黄晓; 洪诗钢; 保延翔
Original assignee: National Sun Yat Sen University
Current assignee: National Sun Yat Sen University
Priority date: 2017-10-30
Filing date: 2017-10-30
Publication date: 2018-03-09
Anticipated expiration: 2037-10-30
Also published as: CN107786660B

Abstract

The present invention provides a kind of radio sensing network code distribution method based on umbrella multipath, and it has advantages below：1. building umbrella multirouting path, spatial multiplex ratio is improved, is distributed beneficial to the quick mirror image of follow-up phase, improves distribution efficiency；2. " receive single-turn hair " pseudo- route transmission mode equipped with retransmission mechanism expands mirror image range of receiving more, and ensure that the reliability in path；3. being explored based on neighbours, the local transmission relation that competition subscription thought formation is not influenceed by concealed terminal, the generation of message transition collision is avoided, effectively shortens the code distribution time.

Description

Wireless sensor network code distribution method based on umbrella-shaped multipath

Technical Field

The invention relates to the technical field of wireless sensor networks, in particular to a wireless sensor network code distribution method based on umbrella-shaped multipath.

Background

In a wireless sensor network, node deployment has the characteristics of large quantity and wide spatial position dispersion, partial application scene environments are severe, after the node deployment, a user needs to update a software code mirror image after proposing a new network function requirement, and a traditional manual wired burning mode is adopted, so that the wireless sensor network has the defects of high labor cost and difficulty in realizing meeting the requirement. Under the background, a wireless channel is used as a medium, and a code image is distributed and upgraded in a single-hop and multi-hop mode, namely, a code distribution protocol for updating by using the image can effectively solve the problems.

The traditional code distribution protocol is divided into a pure broadcast routing protocol and a protocol of a routing and broadcasting framework; the pure broadcast routing protocol mainly carries out mirror image updating on all nodes in the WSN in a multi-hop mode, a source node can complete mirror image distribution of surrounding nodes through one-time broadcasting without sequentially carrying out interactive updating on the source node and the surrounding nodes, so that the time is saved, but the nodes need to be subjected to interception management before forwarding, and a large amount of time delay is caused by accumulation; the routing and broadcasting frame protocol greatly shortens the code distribution time by utilizing the characteristic of rapid routing transmission on one hand, and the broadcasting can cover all corners of the whole network on the other hand.

Whether the pure broadcast routing protocol or the protocol of the routing and broadcast framework exists, the aliasing of the control message and the mirror image data message in space and time exists, so that the message collision is generated, and the reliability of the mirror image transmission is influenced. The traditional method for suppressing the problems is to add a certain time delay before sending the message to avoid the generation of message collision, but the accumulated time delay is larger for the whole code distribution, and the mirror image transmission efficiency is influenced.

Disclosure of Invention

The invention provides a wireless sensor network code distribution method based on umbrella-shaped multipath, aiming at solving the technical defect of low mirror image transmission efficiency in the prior art.

In order to realize the purpose, the technical scheme is as follows:

a wireless sensor network code distribution method based on umbrella-shaped multipath comprises the following steps:

s1, determining nodes positioned at source node corners in a network edge as first-level seed nodes, and respectively determining two nodes positioned at two adjacent corners of the source node in the network edge as second-level seed nodes and third-level seed nodes;

s2, broadcasting the RREQ message by the source node through the whole network, reversely replying the RREQ message to the source node after the first-stage seed node receives the RREQ message, and constructing a main path after the source node receives the RREQ message;

s3, enabling a node at the midpoint of a main path between the source node and the primary seed node to be a super node, and constructing the main path; the source node broadcasts a notifyTarget message to the main path, after receiving the notifyTarget message, the super node confirms that the identity is the super node and broadcasts an RREQ message, and initiates path search to the secondary seed node, after receiving the RREQ message, the secondary node replies the RREP message along a reverse path, and after receiving the RREP message, the super node successfully establishes a path between the super node and the secondary seed node; establishing a path between the super node and the third-level seed node according to the method; after the path between the super node and the secondary seed node and the path between the super node and the tertiary seed node are established, the super node reversely sends a notifyTarget message along the main path to inform the source node of the completion of the establishment of the umbrella-shaped multi-path;

s4, after receiving the notifyTarget message, the source node circularly sends all mirror image pages of the code mirror image file to the super node through the main path, and the super node respectively transmits the received mirror image pages to the primary seed node, the secondary seed node and the tertiary seed node through the established paths; in the transmission process of the mirror image page, the path nodes between the source node and the super node, the super node and the first-level seed node, and the path nodes between the second-level seed node and the third-level seed node are stored after receiving the mirror image page, and then the mirror image page is transmitted to the next hop node; after receiving and storing all the mirror image pages, the nodes perform code distribution updating of the steps S5 to S9 on the nodes to be updated around the nodes;

s5, enabling the nodes which store all the image pages and have nodes to be updated around the image pages to be GREY nodes, enabling the nodes to be updated to be WHITE nodes, enabling the GREY nodes to enter a MAINTAIN state after all the image pages are received by the GREY nodes, starting a random timer TM, broadcasting an adv message and transitioning to a HALFINKING state when the timing time is up; when the WHITE node receives the adv message in the SILENT state, the node transits to the HALFINKING state, and the ID number of the GREY node which enables the GREY node to enter the HALFINKING state is recorded;

s6, after the WHITE node enters a HALFINKING state, a half-connection timer T is started _Half2 And at a timer T _Half2 Replying an advReply message to the GREY node at a random time before expiration, timer T _Half2 The duration of (d) is λ × neighbours count; after the GREY node enters a HALFINKING state, a half-connection timer T is started _Half1 ，T _Half1 With a duration of λ x N _{WhiteNeighbours} Where λ is a constant, GREY node is at timer T _Half1 Counting the ID numbers of the WHITE nodes replying the advRely message before expiration, and recording the ID numbers in a local receiving set;

s7. GREY node in HALFINKING state is in timer T _Half1 After the period expires, judging whether the local neighbor set and the local receiving set are the same, if so, immediately broadcasting the sub message; if not, the GREY node returns to MAINTAIN state, and executes S5 again;

s8, after receiving the sub message, the WHITE node sends a sub reply message to the GREY node within a short random time, and simultaneously enters an RX stable state; the GREY node receiving the sub reply message judges whether the message is sent to the GREY node, if so, the GREY node transitions to a TX stable state; if not, the stable state of SILENT is transited;

and S9, after the WHITE node and the GREY node enter a TX stable state, carrying out code distribution.

Compared with the prior art, the invention has the beneficial effects that:

(1) an umbrella-shaped multi-routing path is constructed, so that the space reuse rate is improved, the rapid mirror image distribution in the subsequent stage is facilitated, and the distribution efficiency is improved; (2) the 'multi-receiving single-forwarding' pseudo-route transmission mode with the retransmission mechanism enlarges the mirror image receiving range and ensures the reliability of the path; (3) and a local transmission relation which is not influenced by a hidden terminal is formed based on the ideas of neighbor exploration and subscription signing, so that the occurrence of message collision is avoided, and the code distribution time is effectively shortened.

Drawings

Fig. 1 a Umbrella protocol code distribution framework

FIG. 2 example of seed node selection by the Umbrella protocol under different network architectures

FIG. 3 the UMBRELLA PROTOCOL establishes an interactive map of Umbrella-like multipath messages (routing phase)

Fig. 4 Umbrella-shaped multi-path effect diagram of the urea protocol

FIG. 5 is a comparison between the conventional pure route transmission method and the dummy route transmission method based on the Umbrella protocol

FIG. 6 message interactive process of the UMBRELLA PROTOCOL MULTI-PAGE TRANSMISSION MECHANISM

Fig. 7 is an example of retransmission opportunity of node packet loss in the routing stage of the urea protocol

FIG. 8 Special handling of last mirror page by the Umbrella protocol

FIG. 9 is a flow chart of the timing control of the source node of the Umbrella protocol to the whole network (broadcast phase)

FIG. 10 is a table of states associated with different node types

FIG. 11 state machine of a contention subscription period GREY node

FIG. 12 State machine for a Contention subscription period WHITE node

In particular to

Detailed Description

The drawings are for illustrative purposes only and are not to be construed as limiting the patent;

the invention is further illustrated below with reference to the figures and examples.

Example 1

The technical scheme of the invention is as follows: the wireless sensor network code distribution method based on umbrella-shaped multipath interference-free multi-local transmission comprises two stage strategies, namely an umbrella-shaped multipath establishment stage strategy and an interference-free multi-local transmission mechanism strategy, which are shown in figure 1 and are explained below.

1. Umbrella-shaped multi-path establishment phase strategy

1. An umbrella-shaped multi-path establishment phase strategy, comprising: and selecting seed nodes, and establishing paths through information interaction.

In the stage, seed nodes are selected firstly according to the principle: a certain network edge node at a source node diagonal in the network is selected as a first-level seed node, and second-level and third-level seed nodes should be selected from network edge nodes at two neighboring corners of the source node, respectively, and fig. 2 (a), (b), and (c) are examples of seed node selection for a circular network, a lattice network, and an irregular network, respectively.

After the node is selected, a path is established through interaction of three types of messages, namely RREQ message, RREP message and notifyTarget, as shown in fig. 3, a specific interaction process is described as follows:

1) And broadcasting the RREQ message by the source node in the whole network, and initiating path searching for the first-level seed nodes.

2) After receiving the RREQ message, the first-level seed node replies the RREP message to the source node along the reverse path.

3) Once the RREP message sent by the primary seed node is forwarded to the source node, the primary path setup is complete.

And then, the source node sends a notifyTarget message to the super node at the midpoint of the main path, so as to inform the super node to initiate path finding to the secondary seed node.

4) And the super node broadcasts the RREQ message and initiates path searching for the secondary seed nodes.

5) And after receiving the RREQ message trying to find the secondary seed node, the secondary seed node immediately replies the RREP message along a reverse path leading to the super node.

6) And when the super node receives the RREP message replied by the secondary seed node, successfully establishing a second bidirectional path between the source node and the secondary seed node. And then the super node initiates a third RREQ path search to the third-level seed node.

7) And after receiving the third RREQ message, the third-level seed node replies a RREP message to the super node along a reverse path to form a forward path from the super node to the third-level seed node.

8) And at the moment that the super node receives the RREP message sent by the three-level seed node, all three bidirectional paths of the network are established. And finally, the super node reversely sends a notifyTarget message along the main path to inform the source node that the umbrella-shaped multi-path is established. As shown in fig. 4.

After receiving the notifyTarget message, the source node circularly sends all mirror image pages of the code mirror image file to the super node through the main path, and the super node respectively transmits the received mirror image pages to the primary seed node, the secondary seed node and the tertiary seed node through the established paths; in the transmission process of the mirror image page, the path nodes between the source node and the super node, the super node and the first-level seed node, and the path nodes between the second-level seed node and the third-level seed node are stored after receiving the mirror image page, and then the mirror image page is transmitted to the next hop node; after receiving and storing all the mirror image pages, the node performs code distribution and update on the nodes to be updated around the node, and a non-interference multi-local transmission mechanism policy in the second part of the specific distribution process will be described in detail, as shown in fig. 5.

2. Information exchange of consecutive multi-page transmission as shown in fig. 6, the pseudo code can be described as follows:

while(currentPage<PAGE_SUM){

if (currentPage and mirror block not sent out) front page

Starting a timer with the timing duration of T _ Block, and sending the next mirror when the timer is up

A block;

}else{

currentPage++；

starting a timer, wherein the timing duration is T _ Page, and sending the next mirror image Page when the timing is up

// the next mirror page is also the currentPage;

}

when constructing the second and third transmission paths, the super node records the ID numbers of the next hop nodes in the forward path to the second and third seed nodes, and knows the ID number of the next hop node in the forward main path, so that the super node has three next hop nodes in the forward path. After receiving the mirror image data, the common path node firstly queries the ID number of the next hop node in the forward routing table, and then forwards the mirror image data to the next hop node. And before the super node forwards the data message, three forward path next-hop nodes are set in the message, and after receiving the data message, the three next-hop nodes continue to forward the message along respective forward paths until the data message is transmitted to the seed nodes of the respective paths.

As shown in fig. 7, tc is the duration of the retransmission timer, and when the path node and the path one-hop node receive discontinuous mirror pages, the retransmission timer is started, and the duration of Tc can ensure that retransmission is always initiated between page and page intervals, thereby avoiding collision with mirror page messages. Because the nodes receive the mirror pages in order, when all the mirror blocks in one mirror page are received, the mirror page can be used. The path node and the path one-hop node can only receive the adjacent next mirror image page data which is 1 more than the current mirror image page number of the node, but cannot receive the data across the page numbers. When a path node or a path hop node receives a cross-page mirror image block, a retransmission timer is started, and after the timing time is up, the path node or the path hop node sends a retransmission request message, namely a speciarreq message, to a source node along a reverse path. After receiving the retransmission request message, the source node sequentially transmits each mirror block of the requested mirror page at the next transmission time.

Because packet loss detection is based on continuous mirror pages and cannot ensure correct reception of the last page, special processing of the last mirror page is required to be introduced to ensure correct transmission, and the method carries out verification by introducing srcdata complete messages. As shown in fig. 8, the protocol causes the source node to forward the srcdata completed message once again along the umbrella multipath after completing the consecutive multi-page transmission. And the source node immediately starts a timer after sending the srcDataCompleted message, the timing duration is the size of a mirror page transmission time interval Tpage, and if no retransmission application message is received before the timer expires, the last page of the path node and the path one-hop node is considered to be correctly received. At this time, the routing transmission phase task is completed, and the source node can inform the whole network to enter the broadcast transmission phase. If a retransmission request message requesting the last page is received before the timer expires, the source node retransmits the last mirror page and repeats the above process.

2. Interference-free multi-local transmission mechanism strategy

In order to implement the strategy of the interference-free multi-local transmission mechanism, a mechanism for exploring neighbors and competing subscriptions is mainly adopted, and the specific flow is shown in fig. 9. The three states of a node are referred to herein as GREY, WHITE, and BLACK, respectively, where the WHITE node represents the node to be updated and the BLACK and GREY nodes are the nodes with the new images. The difference is that the BLACK node has no WHITE node, and GREY nodes are surrounded by WHITE nodes, namely potential sending nodes of the GREY nodes.

And in the neighbor exploration stage, the GREY node ascertains whether a WHITE node exists around the GREY node, if no WHITE node exists, the GREY node becomes a BLACK node, if the WHITE node exists, the total number of the WHITE nodes is recorded, and then the GREY node enters a competition subscription stage. In a competitive subscription period, a BLACK node does not operate, a GREY node communicates with a WHITE node, the WHITE node possibly receives subscription signals of a plurality of GREY nodes at the stage, a GREY node is selected to perform subscription response by adopting a node optimization selection strategy, after the GREY node sends a subscription request, the subscription response signals are continuously collected and the total number is counted, if the total number is equal to the total number of the WHITE explored by a neighbor, namely, all the peripheral WHITE nodes subscribe with the GREY node, namely, under a collision-free transmission condition, the subscription is successful; if the total numbers are different, the collision-free transmission relation is not satisfied, the subscription fails, and the neighbor exploration stage needs to be entered again.

In order to ensure that the messages in the neighbor exploration and competition subscription stages do not lose the subscription messages due to message collision, the method adopts a random delay message sending technology, and the time magnitude of random delay is very small. The random time delay for sending the information can greatly reduce the phenomenon of collision and packet loss caused by the fact that the nodes receive the information at the same time.

Meanwhile, each node starts a timer with fixed time in a competition stage, the use of the timer can ensure that the node can receive messages in the stage, and simultaneously, the problem of small probability message collision and packet loss still generated by a random delay message sending technology can be solved, and the timer does not wait for a subscription response and reenters a neighbor exploration and competition subscription stage if the subscription fails.

In the competitive subscription phase, the three types of nodes respectively go through various intermediate states from respective default states and finally are converted into stable states. The situation is shown in fig. 10.

1. The behavior state of a GREY node for a contention subscription period can be described as follows, as shown in fig. 11:

and (3) starting a random timer TM when the G.1GREY node enters a MAINTAIN state, broadcasting an adv message as soon as the timing time is up, and transitioning to a HALFINKING state.

G.2 if the GREY node in MAINTAIN state monitors that there is an adv message to send, it shows that there is a GREY neighbor around trying to initiate a request for establishing a relationship. Then defer sending of its adv message and defer μ x N _{WhiteNeighbours} +τ _rand Where μ is a constant, τ _rand Is a short random delay time. The goal is to provide a quieter environment for GREY neighbor nodes that attempt to initiate an establishment relationship.

After the G.3GREY node enters a HALFINKING state, a half-connection timer T is started _Half1 ，T _Half1 With a duration of λ x N _{WhiteNeighbours} Where λ is a constant. T is _Half1 Before the timer expires, the ID number of the WHTIE node of the current GREY node advRely message is counted and repliedThey are recorded in the local reception set.

GREY node in G.4HALFINKING state at T _Half1 After expiration, it is determined whether the local neighbor set and the local receive set are the same. (1) If it is the same, it indicates that all its WHITE neighbors have made a recovery to it. A subscription message (sub message) is immediately broadcast with the aim of immediately initiating its subscription request to all WHITE nodes. (2) If the current node is different from the WHITE neighbor node, the current node indicates that a certain node preferentially participates in the transmission relationship of other GREY nodes, and the current node gives up being a sending node of the transmission relationship. The GREY node returns to MAINTAIN state and G.1 step is executed again.

G.5 whether in MAINTAIN state or HALFINKING state, as long as the GREY node has monitored the sub-message, indicating that its surrounding GREY neighbors have established a transmission relationship, it will not have a chance to participate in the transmission relationship. All timers are immediately turned off and the steady state of SILENT is entered.

G.6 the GREY node receiving the sub reply message will judge whether the message is sent to itself. (1) If so, transitioning to a TX steady state; (2) if not, a transition is made to the stable state of SILENT.

2. The behavior state of the contention subscription period WHITE node can be described as the following points, as shown in fig. 12:

w.1 when the WHITE node receives the adv message in the SILENT state, the state is transited to the halt state, and the ID number of the GREY node which enables the current WHITE node to enter the halt state is recorded, namely the ID number of the sender of the adv message. Half-connection timer T is started while entering HALFINKING state _Half2 ，T _Half2 The duration of (c) is λ × neighbours count. Since the neighbors count field is from the received adv message (the neighbors count field is the number of WHITE neighbors of the GREY node), T is actually T _Half1 And T _Half2 Are equal in duration.

After the W.2WHITE node enters a halt state, a timer T is started _Half2 An advReply message is returned at a random time prior to expiration. And after entering a HALFINKING state, the WHITE node does not reply to the received adv message.

W.3WHITE node is at timer T _Half2 After expiration, the previously recorded half-link GREY node ID number is cleared and the SILENT state is restored, so that the WHITE node has an opportunity to participate in the establishment of other transmission relationships.

After receiving the sub message, the W.4WHITE node sends a sub reply message after a short random time, and simultaneously enters an RX stable state.

3. The optimization selection strategy of the sending node is to enable the GREY node to start a random timer TM in the MAINTAIN state, and the following formula is followed:

wherein T is _low And T _high Is the lower and upper limit of the expected value range of TM, N _{AverageNeighbours} Is the average number of neighbors, N, of a network node _{WhiteNeighbours} Is the number of neighbor nodes to be updated, τ _rand Is a short delay. The goal is to allow more WHITE neighbor GREY nodes to have a larger sending node that is likely to be a transmitting relationship.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A wireless sensor network code distribution method based on umbrella-shaped multipath is characterized in that: the method comprises the following steps:

s1, determining nodes positioned at a source node diagonal in a network edge as primary seed nodes, and respectively determining two nodes positioned at two adjacent corners of the source node in the network edge as secondary seed nodes and tertiary seed nodes;

s6, after the WHITE node enters a HALFINKING state, a half-connection timer T is started _Half2 And at the timer T _Half2 Replying an advReply message to the GREY node at a random time before expiration, timer T _Half2 The duration of (d) is λ × neighbours count; after the GREY node enters a HALFINKING state, a half-connection timer T is started _Half1 ，T _Half1 With a duration of λ x N _{WhiteNeighbours} Where λ is a constant, GREY node is at timer T _Half1 Counting the ID numbers of the WHITE nodes replying the advRely message before expiration, and recording the ID numbers in a local receiving set;

s7, the GREY node in HALFLINKING state is in the timer T _Half1 After the period expires, judging whether the local neighbor set and the local receiving set are the same, if so, immediately broadcasting the sub message; if not, the GREY node returns to MAINTAIN state, and executes S5 again;

s8, after receiving the sub message, the WHITE node sends a sub reply message to the GREY node within a short random time, and simultaneously enters an RX stable state; the GREY node receiving the sub reply message judges whether the message is sent to the GREY node, and if yes, the GREY node transits to a TX stable state; if not, the stable state of SILENT is transited;

2. The umbrella multipath-based wireless sensor network code distribution method of claim 1, wherein: in step S5, if the GREY node in MAINTAIN state monitors that there is an adv message sent around, the GREY node delays sending of its own adv message for a time μ × N _{WhiteNeighbours} +τ _rand Where μ is a constant, τ _rand Is a short random delay time.

3. The umbrella multipath-based wireless sensor network code distribution method of claim 1, wherein: in step S5, if the GREY node in the maintarget state or the suspend state monitors the sub message, the GREY node enters the stable state of SILENT.

4. The umbrella multipath-based wireless sensor network code distribution method of claim 1, wherein: in the step S6, the WHITE node is at a timer T _Half2 Upon expiration, the ID number of the GREY node of the previous record of half-connection is cleared and the SILENT stable state is resumed.

5. The umbrella multipath-based wireless sensor network code distribution method of claim 1, wherein: the timing duration of the random timer TM is as follows:

wherein T is _low And T _high Is the lower and upper limit of the expected value range of TM, N _{AverageNeighbours} Is the average number of neighbors of the network node, N _{WhiteNeighbours} Number of WHITE nodes, τ, of GREY nodes _rand Is a short delay.

6. The umbrella multipath-based wireless sensor network code distribution method according to any one of claims 1 to 5, wherein: in step S4, when the first-level seed node, the second-level seed node, the third-level seed node, the super node, or the node on the path receives the discontinuous mirror image page, the retransmission timer is started, and a retransmission application message is sent to the source node after the time of the retransmission timer expires, and after the source node receives the retransmission application message, each mirror image block of the requested mirror image page is sequentially sent at the next sending time.

7. The umbrella multipath-based wireless sensor network code distribution method of claim 6, wherein: in step S4, after the source node finishes sending all the mirror pages, it sends srcdata completed messages to the first-level seed node, the second-level seed node, the third-level seed node, and the super node along the path, the source node immediately starts a timer after sending the srcdata completed messages, the timing duration is the mirror page transmission time interval Tpage, and if no retransmission application message is received before the timer expires, it considers that the last mirror page is correctly received.