CN105246123B - A kind of improved CARP Routing Protocols - Google Patents

Abstract

The invention discloses an improved CARP routing protocol, which is characterized in that the specific steps of selecting the optimal data transmission relay node are as follows: Step 1: Whenever the sensor node nv _sn broadcasts a PING control information packet, calculate and node nv The channel quality parameter g(nv _sn ) value of the sensor node adjacent to _sn ; step 2: last data transmission relay node and all adjacent nodes whose g(nv _sn ) values are in the range (β×g(ω), ∞) reply PONG packets, where the threshold β is a floating-point number ranging from 0‑1; step 3: in Among the adjacent nodes whose values of g(nv _sn ) are in the range (β×g(ω), ∞), select the upper layer node uv _z with the largest value of g(nv _sn ), if Then select uv _z as the relay node for the current data transmission, otherwise, continue to use the last relay node When selecting the optimal data transmission relay node, reduce PING‑PONG redundant control information packets; further, a data packet upload algorithm is proposed to use the data collected by the sensor in an efficient and energy-saving manner.

Description

An Improved CARP Routing Protocol

technical field

The invention relates to an improved CARP routing protocol.

Background technique

The ocean covers more than 70% of the earth's surface area, the earth's environment is deeply affected by the ocean, and human life is heavily dependent on the ocean. Underwater sensor networks (a network established by deploying underwater sensor nodes with low energy consumption and short-distance communication in designated sea areas) are considered to be a reliable choice for exploring the underwater environment. Among them, the vast majority of sensor nodes are powered by batteries. Therefore, improving energy efficiency is the most basic principle when designing routing protocols that collect detection data and upload these data to surface base stations.

CARP (Common Access Redundancy Protocol: Common Address Redundancy Protocol) is a location-independent and layer-by-layer greedy routing protocol. It uses the hop count of sensor nodes to represent the network topology, which can effectively avoid connectivity holes and shadow areas. CARP continuously monitors the link quality between adjacent sensor nodes and takes it into consideration as an important factor in the selection process of data transmission relay nodes. During the data packet upload process, CARP adopts layer-by-layer greedy and full-packet upload methods.

The performance and applicability of CARP have been evaluated in the actual marine environment. When the network topology is relatively stable, CARP's optimal data transmission relay node selection strategy, that is, the PING-PONG strategy, will generate a large amount of redundant control information packets, causing network congestion and reducing the efficiency of data transmission. In addition, CARP does not consider reusing previously collected probe data to support certain domain-specific applications (some applications can still work well when the value of the probe data changes within a certain threshold range).

Contents of the invention

In view of the above problems, the present invention provides an improved CARP routing protocol, which reduces PING-PONG redundant control information packets when selecting the optimal data transmission relay node; collected data.

In order to achieve the above-mentioned technical purpose and achieve the above-mentioned technical effect, the present invention is realized through the following technical solutions:

An improved CARP routing protocol is characterized in that the specific steps of selecting the optimal data transmission relay node are as follows:

Step 1: Whenever the sensor node nv _sn broadcasts a PING control information packet, calculate the channel quality parameter g(nv _sn ) value of the sensor node adjacent to the node nv _sn ;

Step 2: Last data transmission relay node and all adjacent nodes whose g(nv _sn ) values are in the range (β×g(ω), ∞) reply PONG packets, where the threshold β is a floating-point number ranging from 0-1, and g(ω) is the channel quality parameter value of the last optimal node;

Step 3: Among all adjacent nodes whose g(nv _sn ) value is in the range (β×g(ω), ∞), select the upper layer node uv _z with the largest g(nv _sn ) value, if Then select uv _z as the relay node for the current data transmission, otherwise, continue to use the last relay node

Preferably, the specific steps of uploading the information package are as follows:

Step a: When the sensor node uv _sn collects new data packets After that, with the last collected data stored on the local node Compare;

Step b: If the change amount is less than the set threshold α _atr , send to the relay node Send an INFORM control packet; if the change is greater than the set threshold α _atr , upload the data packet and update the data stored in the local node to the newly collected data

Among them, the INFORM control package is defined as:

Indicates the ID identification number of the sensor node uv _sn , indicates the ID identification number of the relay node, HC(uv _sn ) indicates the hop count of the sensor node uv _sn , pid indicates the last uploaded data packet id, L _pkt indicates the data packet identification set , including the node that generates the data packet and the node that forwards the data packet.

Among them, the calculation formula of the channel quality parameter g(nv _sn ) is as follows:

g(nv _sn )＝goodness(nv _sn )+1/HC(nv _sn )

In the formula: g(nv _sn ) represents the communication quality between node uv _x and node nv _sn , HC(nv _sn ) represents the hop count of sensor node nv _sn , goodness(nv _sn )=lq(uv _x ,nv _sn )×lq (nv _sn ,uv _z ), lq(uv _x ,nv _sn ) represents the link quality of node uv _x and node nv _sn , lq(nv _sn ,uv _z ) represents the link quality of node nv _sn and node uv _z , uv _z is the sensor node with the best link quality among the adjacent nodes of nv _sn .

The beneficial effects of the present invention are: on the basis of the CARP routing protocol, an optimized routing protocol E-CARP is proposed, from the perspective of high efficiency and energy saving, the CARP routing protocol is optimized, and a more efficient and energy-saving routing protocol E-CARP is proposed. Among them, the E-CARP routing protocol follows the idea of CARP in network initialization, and improves on relay node selection and data packet transmission:

First, when selecting the optimal data transmission relay node, reduce PING-PONG redundant control information packets, the last data transmission relay node And all adjacent nodes whose g(nv _sn ) values are in the range (β×g(ω), ∞) reply PONG packets, and adjacent nodes outside the range do not need to reply PONG packets, reducing the redundancy of some PONG packets. Moreover, the selection procedure of the data transmission relay node does not have to be updated every time, and it may be more appropriate to use the data transmission relay node used some time ago. This strategy will significantly reduce the number of PONG control packets in the network, thereby reducing the energy consumption of underwater sensor networks.

Second, data packet reuse: In two adjacent time segments, when the environmental changes in the monitored sea area are relatively stable, when the detection data changes within a certain threshold range, some applications in specific fields can still work well. In most cases, the detection data will only change in a small range, and slight changes in the detection data are of little value to some applications that do not require high-precision data. Use INFORM packets to replace part of the data packets whose change range is within the threshold, so as to reduce the transmission of data packets in the entire network and reduce the energy consumption of the sensor network.

Description of drawings

Fig. 1 is the deployment figure of underwater sensor node of the present invention;

Fig. 2 is a working flow diagram of the improved CARP routing protocol of the present invention.

Detailed ways

The technical scheme of the present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and implement it, but the examples given are not intended to limit the present invention.

An improved CARP routing protocol, from the perspective of energy efficiency, optimizes the CARP routing protocol, and proposes a more efficient and energy-saving routing protocol E-CARP. The E-CARP routing protocol follows the idea of CARP in network initialization. Two improvements are made on relay node selection and data packet transmission, and the improvements will be described in detail below.

The specific steps for selecting the optimal data transmission relay node are as follows:

Step 1: Whenever the sensor node nv _sn broadcasts a PING control information packet, calculate the channel quality parameter g(nv _sn ) value of the sensor node adjacent to the node nv _sn ;

The calculation formula of the channel quality parameter g(nv _sn ) value (i.e. g value) is as follows:

g(nv _sn )＝goodness(nv _sn )+1/HC(nv _sn )

In the formula: g(nv _sn ) represents the communication quality between node uv _x and node nv _sn , HC(nv _sn ) represents the hop count of sensor node nv _sn , goodness(nv _sn )=lq(uv _x ,nv _sn )×lq (nv _sn ,uv _z ), lq(uv _x ,nv _sn ) represents the link quality of node uv _x and node nv _sn , lq(nv _sn ,uv _z ) represents the link quality of node nv _sn and node uv _z , uv _z is the sensor node with the best link quality among the adjacent nodes of nv _sn . Obviously, among all adjacent sensor nodes, the sensor node with the largest g(nv _sn ) value is the most suitable to be selected as a data transmission relay node.

Step 2: Last data transmission relay node and all adjacent nodes whose g(nv _sn ) values are in the range (β×g(ω), ∞) reply PONG packets, where the threshold β is a floating-point number ranging from 0-1, and g(ω) is the channel quality parameter value of the last optimal node;

Node positions change with water flow. Therefore, according to the turbulence and slowness of the water flow in a specific area and a specific season, the threshold β is updated appropriately to better reduce the energy consumption of the underwater wireless sensor network.

Step 3: Among all adjacent nodes whose g(nv _sn ) value is in the range (β×g(ω), ∞), select the upper layer node uv _z with the largest g(nv _sn ) value, if Then select uv _z as the relay node for the current data transmission, otherwise, continue to use the last relay node

In the algorithm of selecting the relay node, use the algorithm based on the received EPING packet to reply the PONG packet. In this process, the selection procedure of the data transmission relay node does not have to be updated every time, and it may be more appropriate to use the data transmission relay node used some time ago. This strategy will significantly reduce the number of PONG control packets in the network, thereby reducing the energy consumption of underwater sensor networks.

The specific steps of uploading the information package are as follows:

Step a: When the sensor node uv _sn collects new data packets After that, with the last collected data stored in the local node Compare;

Step b: If the change amount is less than the set threshold α _atr , send to the relay node Send an INFORM control packet; if the change is greater than the set threshold α _atr , upload the data packet and update the data stored in the local node to the newly collected data In order to compare the next new detection data and determine the amount of change;

Among them, α _atr is a change factor, which specifies the data change range of reused data: (0,α _atr ), and the INFORM control package is defined as:

Indicates the ID identification number of the sensor node uv _sn , indicates the ID identification number of the relay node, HC(uv _sn ) indicates the hop count of the sensor node uv _sn , pid indicates the last uploaded data packet id, L _pkt indicates the data packet identification set , including the node that generates the data packet and the node that forwards the data packet.

Use the INFORM control packet to notify the base station that if the change between the newly collected data and the last data uploaded to the base station is within the threshold _αatr , the application program can continue to use the last data. relay node Receiving an INFORM packet and replying with an ACK packet indicates that the INFORM packet is received correctly. A data packet upload algorithm is proposed to allow the application to determine the required data accuracy to use the data collected by the sensor in an energy-efficient manner.

When the monitoring sea area is in a relatively stable environment, the change of the detection data is likely to be within the range of the threshold _αatr . At this time, the INFORM control information packet should be sent to the surface base station instead of the data information packet. Therefore, the total amount of data transmitted in the network is significantly reduced, and the energy consumption of the network is greatly reduced.

An embodiment is fully introduced below:

1) In the monitoring sea area, a number of wireless sensor nodes are randomly and evenly deployed. The density and detection properties of sensor nodes can be controlled by themselves according to specific scenarios and specific applications. The node deployment method is shown in Figure 1. Sensor represents sensor nodes , deployed at different depths, and Sink represents the base station, deployed on the water surface.

The working principle described in this routing protocol is to deploy the sensors of the wireless sensor network in the actual underwater detection area, and the application program requests the underwater sensors to collect and upload data of a certain attribute according to the requirements. In the base station, set the collective cache CAH storage node to transmit data, and set the threshold β, cache Data change factor α _atr . The complete flow chart is shown in Figure 2.

Set cache CAH in the base station to store the data uploaded by the node, CAH is defined as Defined as a vector, namely:

in, Indicates the property of interest of the sensor node uv _sn , a sensor node can be equipped with one or more devices to detect one or more properties of interest; parameter records identified as The latest detection data uploaded to the surface base station by the sensor node uv _sn . parameter It is also stored in the memory of the sensor node uv _sn , and is used to compare with the newly detected data to see whether the newly detected data changes significantly.

2) After the nodes are deployed, initialize the entire underwater wireless sensor network: broadcast the HELLO packet from the base station downward, the hop count HC(SN) of the base station is initialized to 0, and the node receiving the HELLO packet is the adjacent node of the base station, that is, the next layer node , whose HC is 1, and so on, initialize the hops of all nodes. At the time of initialization, no data packet is transmitted, therefore, both the CAH in the base station and the cache in the node are emptied at the time of initialization.

3) After the node receives the request from the base station, the sensor node collects the data required by the application.

4) According to the specific application program's data accuracy requirements or real-time data requirements, set the application data change factor threshold α _atr to determine whether the information package to be uploaded is a data package or an INFORM package.

5) Select the relay node after confirming the information package. Set the threshold β in the node according to the flow model or empirical value of the specific water area. According to the relay node selection algorithm, if a node with a g value (that is, a channel quality parameter) in the range of (β×g, ∞) is selected as a candidate relay node, the node with the highest g value in the upper layer is selected from the candidate relay nodes. Compared with the relay node of the second data transmission, the relay node with the larger g value is selected as the relay node of this data transmission.

6) Upload the information package.

7) If the relay node is the base station, the uploading of the information packet is completed; otherwise, continue to select the relay node until the information packet is uploaded to the base station node.

After the base station receives the data collected by the sensor nodes, it uploads it to the service through radio, and the application program can obtain the data information through the specific service.

In order to facilitate the further understanding of the present invention, the pseudo codes of each algorithm are introduced respectively below.

Algorithm 1 is the pseudocode of relay node selection algorithm:

Algorithm 1 relay node selection pseudocode:

In the relay node selection algorithm, the input is the set Contains all reply PONG packet nodes and the corresponding g value, the output is the relay node selected as this data transmission When the sensor node detects new data and needs to upload it, it is selected by Algorithm 1 to obtain the next hop relay node.

Algorithm 2 is based on the received EPING algorithm pseudocode:

Algorithm 2 is based on receiving EPING algorithm pseudocode:

In Algorithm 2, the input is an EPING packet, and the output is a PONG packet. Based on the received EPING algorithm, it is determined whether a sensor node needs to reply a PONG packet after receiving the EPING. If the value of g is not in the range (β×g, ∞), there is no need to reply the PONG packet, otherwise, reply the PONG packet.

Algorithm 3 is the pseudocode of the packet upload algorithm:

Algorithm 3 packet upload pseudocode:

In Algorithm 3, the input is the data detected by the current sensor node Node cache data The change factor α _atr is preset, and the output is an INFORM packet or data packet. According to the change factor α _atr set in the node and the change amount of the data packet, use Algorithm 3 to determine whether the data packet or the INFORM packet needs to be uploaded. When the relay node receives the INFROM packet or data packet, it will reply ACK to the sending node to confirm that it has been received. Upload data packets or INFORM packets to the base station in a layer-by-layer greedy manner.

The beneficial effects of the present invention are: on the basis of the CARP routing protocol, an optimized routing protocol E-CARP is proposed, from the perspective of high efficiency and energy saving, the CARP routing protocol is optimized, and a more efficient and energy-saving routing protocol E-CARP is proposed. Among them, the E-CARP routing protocol follows the idea of CARP in network initialization, and improves on relay node selection and data packet transmission:

First, when selecting the optimal data transmission relay node, reduce PING-PONG redundant control information packets, the last data transmission relay node And all adjacent nodes whose g(nv _sn ) values are in the range (β×g(ω), ∞) reply PONG packets, and adjacent nodes outside the range do not need to reply PONG packets, reducing the redundancy of some PONG packets. Moreover, the selection procedure of the data transmission relay node does not have to be updated every time, and it may be more appropriate to use the data transmission relay node used some time ago. This strategy will significantly reduce the number of PONG control packets in the network, thereby reducing the energy consumption of underwater sensor networks.

Second, data packet reuse: In two adjacent time segments, when the environmental changes in the monitored sea area are relatively stable, when the detection data changes within a certain threshold range, some applications in specific fields can still work well. In most cases, the detection data will only change in a small range, and slight changes in the detection data are of little value to some applications that do not require high-precision data. Use INFORM packets to replace part of the data packets whose change range is within the threshold, so as to reduce the transmission of data packets in the entire network and reduce the energy consumption of the sensor network.

Third, by reducing redundant PING-PONG control packets and increasing the reuse rate of data packets, the energy consumption in data collection and data transmission of underwater wireless sensor networks is greatly reduced, and the life cycle of the entire underwater wireless sensor network is extended. . An energy-efficient routing protocol is provided for underwater wireless sensor networks. So that humans can better explore the ocean.

The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technical fields , are all included in the scope of patent protection of the present invention in the same way.

Claims (5)

1. an improved CARP routing protocol is characterized in that, the concrete steps of selecting optimal data transmission relay node are as follows: Step 1: Whenever the sensor node nv _sn broadcasts a PING control information packet, calculate the channel quality parameter g(nv _sn ) value of the sensor node adjacent to the node nv _sn ; Step 2: Last data transmission relay node and all adjacent nodes whose g(nv _sn ) values are in the range (β×g(ω), ∞) reply PONG packets, where the threshold β is a floating-point number ranging from 0-1, and g(ω) is the channel quality parameter value of the last optimal node; Step 3: Among all adjacent nodes whose g(nv _sn ) value is in the range (β×g(ω), ∞), select the upper layer node nv _z with the largest g(nv _sn ) value, if Then select nv _z as the relay node for the current data transmission, otherwise, continue to use the last relay node The specific steps of uploading the information package are as follows: Step a: When the sensor node nv _sn collects a new data packet After that, with the last collected data stored on the local node Compare; Step b: If the change amount is less than the set threshold α _atr , send to the relay node Send an INFORM control packet; if the change is greater than the set threshold α _atr , upload the data packet and update the data stored in the local node to the newly collected data Among them, the INFORM control package is defined as: Indicates the ID identification number of the sensor node uv _sn , Represents a relay node HC(uv _sn ) represents the hop count of the sensor node uv _sn , pid represents the last uploaded data packet id, L _pkt represents the data packet identification set, including the node that generates the data packet and the node that forwards the data packet. 2. a kind of improved CARP routing protocol according to claim 1, is characterized in that, the calculation formula of channel quality parameter g (nv _sn ) value is as follows: g(nv _sn )＝goodness(nv _sn )+1/HC(nv _sn ) In the formula: g(nv _sn ) represents the communication quality between node uv _x and node nv _sn , HC(nv _sn ) represents the hop count of sensor node nv _sn , goodness(nv _sn )=lq(uv _x ,nv _sn )×lq (nv _sn ,uv _z ), lq(uv _x ,nv _sn ) represents the link quality of node uv _x and node nv _sn , lq(nv _sn ,uv _z ) represents the link quality of node nv _sn and node uv _z , uv _z is the sensor node with the best link quality among the adjacent nodes of nv _sn . 3. a kind of improved CARP routing protocol according to claim 1, is characterized in that, relay node Receiving an INFORM packet and replying with an ACK packet indicates that the INFORM packet is received correctly. 4. A kind of improved CARP routing protocol according to claim 1, characterized in that, the size of the threshold β is updated according to the rapidity and slowness of the region and season water flow. 5. a kind of improved CARP routing protocol according to claim 1, is characterized in that, cache CAH is set at base station and is used for storing the data that node uploads, and CAH is defined as Defined as a vector, namely: in, Indicates the property of interest of the sensor node uv _sn , a sensor node can be equipped with one or more devices to detect one or more properties of interest; parameter records identified as The latest detection data uploaded to the surface base station by the sensor node uv _sn .