CN103415065B - Transmission power control method of mobile nodes in sensor network and node apparatus - Google Patents

Abstract

The invention provides a transmission power control method of mobile nodes in a sensor network. In the transmission power control method, a transmission node obtains link attenuation via a beacon signal; uplink transmission power is determined according to the link attenuation and receiving sensitivity of a receiving node; and a protocol data packet is transmitted to the receiving node by the uplink transmission power. The invention also provides a wireless sensor network node apparatus including a transmission unit, a link attenuation acquisition unit, an uplink transmission power acquisition unit and a receiving unit. According to the invention, the transmission power control method of the mobile nodes in the sensor network and the node apparatus can achieve more accurate control of transmission power and ensure reliable data transmission between mobile nodes, are particularly suitable for transmission environment of a wireless sensor network, reduce average power loss in each node, that is, increase service life of electric quantity of the nodes so that the overall transmission reliability and link performance of the wireless sensor network are improved, and reduce the interference to networking neighboring cells.

Description

The transmission power control method and node apparatus of mobile node in sensor network

Technical field

The present invention relates in wireless sensor network field, more particularly to sensor network mobile node through-put power control Method processed and node.

Background technology

Wireless sensor network (wireless sensor network, WSN) is by substantial amounts of static or mobile sensing The wireless network that device node is constituted in the way of self-organizing and multi-hop.In the geographic area that wireless-transmission network is covered, each Sensor node is perceived cooperatively, gathered, processing the perceived object information covered in geographic area, and finally handle These information are sent to the setting user of network.Each sensor node in wireless sensor network may include polytype Sensor, therefore be capable of achieving earthquake, electromagnetism, temperature and noise, the detection of pressure and other parameters, realize to the size of mobile object, Diversified phenomenon is perceived in the surrounding enviroment such as speed and direction.So as to be widely used in ECOLOGICAL ENVIRONMENTAL MONITORING, gloomy In the field such as woods fire monitoring and natural calamity rescue.

In the application process of wireless sensor network, each sensor node is deployed in wide detection range.Often The most of individual sensor node is powered using battery.But when actually used, because battery electric quantity is limited, need in use Regularly replace.Affected by environment and geographical position and construction, be often difficult to change battery in time.Therefore, section how is realized The key issue in application of higher wireless sensor network can be become.Meanwhile, the energy consumption being wirelessly transferred occupies sensor node The major part of power consumption, therefore the transmitting power control of sensor network how is carried out, ensure that network data is passed with low energy consumption Defeated performance, just becomes the key that energy-conservation is realized in sensor network.

Transmitting power control in prior art in wireless sensor network it is many with the initial layout of network, channel distribution and Regional area decays to main consideration aspect, makes the path of transmission efficiently by centralized Control and implements adaptation zone decay, So as to reach the effect of energy-conservation.But the problem of above-mentioned transmission power control method is, when sensor node occurs mobile, pass Regional decay in defeated network can be increased instantaneously, by therewith using ensureing each node by the way of raising through-put power in network Effective transmission.But the power consumption of node is at the same time also just improve, and it is interior to increase the competition intensity and net of sensor network Interference.Thus the rising of caused average packet loss ratio also creates longer queue time delay, so that wireless sensor network Overall performance is deteriorated.Said method another problem is that：Due to network decay adjustment be to node in receiving data Detection afterwards is carried out, therefore the Adjustment effect of its decay relatively lags behind, for the sensing node in movement it cannot be guaranteed that reliable Data transfer.It follows that transmission power control method of the prior art is unable to the Power Control of effectively solving mobile node Problem.

The content of the invention

In view of situation present in prior art, according to an aspect of the invention, there is provided moving in sensor network The transmission power control method of node, including：

Sending node obtains link attenuation by the beacon signal that receiving node is sent；

Up-link transmit power is determined by the receiving sensitivity of the link attenuation and the receiving node；

Protocol data bag is sent to the receiving node with the up-link transmit power.

In some embodiments, the sending node obtains link attenuation by the beacon signal that receiving node is sent The step of include：

The down transmitting power included in the beacon signal that the sending node is sent according to the receiving node P_{DL_Beacon}And receive receiving end signal intensity P of the beacon signal_{DL_RSSI}Link attenuation A (i) is obtained by following formula：

A(i)=P_{DL_Beacon}-P_{DL_RSSI}。

In some embodiments, uplink is determined by the receiving sensitivity of the link attenuation and the receiving node Road transmit power P_{UL_Node}The step of include：

If the sending node has differences with the RF schemes of the receiving node, corresponding connecing is obtained according to the difference Receive incremental sensitivity Δ；According to the reception of the receiving sensitivity increment Delta, link attenuation A (i) and the receiving node Sensitivity P_SenUp-link transmit power P is obtained by following formula_{UL_Node}：

P_{UL_Node}=A(i)–Δ+P_Sen。

In some embodiments, if the sending node has differences with the RF schemes of the receiving node, The step of obtaining corresponding receiving sensitivity increment Delta according to the difference includes：

If the receiving node be using the enhanced RF schemes of external low-noise amplifier LNA, sending node be basic RF During scheme, receiving sensitivity increment Delta is 10dB；

If the receiving node be using the enhanced RF schemes of itself chip, sending node be basic RF schemes when, receive Incremental sensitivity Δ is 20dB.

In some embodiments, the sending node obtains link attenuation by the beacon signal that receiving node is sent The step of include：

For the M link that the beacon signal that the receiving node received for M time from the sending node is sent is obtained Decay, obtains in the following manner link attenuation sliding average

By the link attenuation sliding averageIt is defined as link attenuation A (i).

In some embodiments, it is described according to the receiving sensitivity increment Delta, link attenuation A (i) and described Receiving sensitivity P of receiving node_SenObtain up-link transmit power P_{UL_Node}The step of include：For from the transmission section The M link attenuation that the beacon signal that the receiving node that point is received for M time is sent is obtained, obtains in the following manner link Decay sliding average

By the M link attenuation, the link attenuation sliding averageAnd current link attenuation A (i), and In the following manner obtains attenuation standard difference σ_AI () is：

According to attenuation standard difference σ_A(i) setting wireless link power surplus L_adj；

According to the receiving sensitivity increment Delta, link attenuation A (i), the receiving node receiving sensitivity P_Sen And radio link power surplus L_adjUp-link transmit power P is obtained in the following manner_{UL_Node}：

In some embodiments, it is described according to attenuation standard difference σ_A(i), setting wireless link power surplus L_adj The step of include：

The attenuation standard difference is σ_ADuring (i)=4dB, L is set_adj=2dB；

The attenuation standard difference is σ_ADuring (i)=8dB, L is set_adj=4dB；

The attenuation standard difference is σ_ADuring (i)=12～15dB, L is set_adj=10dB。

In some embodiments, it is described that protocol data bag is sent to the reception section with the up-link transmit power The step of point, includes：With up-link transmit power P_{UL_Node}Protocol data bag is sent to the receiving node, or with institute State link attenuation A (i) or link attenuation sliding averageTo the receiving node.

In some embodiments, it is described that protocol data bag is sent to the reception section with the up-link transmit power Also include after the step of point：Receiving node is with up-link transmit power P_{UL_Node}Lower line number is carried out to the sending node According to transmission.

In some embodiments, it is described with up-link transmit power P_{UL_Node}Send protocol data bag and described Link attenuation A (i) also includes to after the step of the receiving node：Receiving node declines according to link attenuation A (i) or link Subtract sliding averageObtain downlink transmit power；Carried out to the sending node with the downlink transmit power Downlink data sends.

Meanwhile, present invention also offers a kind of wireless sensor network node device, including：

Including：Transmitting element, link attenuation A (i) acquiring unit, up-link transmit power P_{UL_Node}Acquiring unit, with And receiving unit, the receiving unit is configured to receive the beacon signal that sent of receiving node；Or reception protocol data bag；Institute State link attenuation A (i) acquiring unit and be configured to pass beacon signal acquisition link attenuation A (i) that receiving node is sent；It is described Up-link transmit power P_{UL_Node}Acquiring unit is configured to pass the reception of link attenuation A (i) and the receiving node Sensitivity P_SenDetermine up-link transmit power P_{UL_Node}；The transmitting element is configured to the up-link transmit power P_{UL_Node}Protocol data bag is sent to the receiving node；Or transmission broadcast beacon signal.

In some embodiments, link attenuation A (i) acquiring unit is additionally configured to：According in the beacon signal Down transmitting power P_{DL_Beacon}And receiving end signal intensity P of the reception beacon signal_{DL_RSSI}Link is obtained by following formula Decay A (i)：

A(i)=P_{DL_Beacon}-P_{DL_RSSI}；

Or, link attenuation A (i) acquiring unit also includes link attenuation sliding averageModule, the module It is configured to：For the M link that the beacon signal that the receiving node received for M time from the sending node is sent is obtained declines Subtract, link attenuation sliding average is obtained in the following manner

By the link attenuation sliding averageIt is defined as link attenuation A (i)；

Up-link transmit power P_{UL_Node}Acquiring unit also includes：

Receiving sensitivity increment Delta module is configured to：If it is poor that the sending node exists with the RF schemes of the receiving node It is different, then corresponding receiving sensitivity increment Delta is obtained according to the difference；If the receiving node is using external low noise When the enhanced RF schemes of amplifier LNA, sending node are basic RF schemes, receiving sensitivity increment Delta is 10dB；If described connect Receive node be using the enhanced RF schemes of itself chip, sending node be basic RF schemes when, receiving sensitivity increment Delta is 20dB；

Up-link transmit power P_{UL_Node}Acquiring unit is additionally configured to：According to the receiving sensitivity increment Delta, Link attenuation A (i) and receiving sensitivity P of the receiving node_SenUp-link transmit power is obtained by following formula P_{UL_Node}For：

P_{UL_Node}=A(i)–Δ+P_Sen；

Up-link transmit power P_{UL_Node}Acquiring unit also includes：

Radio link power surplus acquisition module is configured to for the receiving node institute received for M time from the sending node The M link attenuation that the beacon signal of transmission is obtained, obtains in the following manner link attenuation sliding average

By the M link attenuation, link attenuation sliding averageAnd current link attenuation A (i), and below Mode obtains attenuation standard difference σ_AI () is：

According to attenuation standard difference σ_A(i) setting wireless link power surplus P_adj；The attenuation standard difference is σ_A(i)= During 4dB, L is set_adj=2dB；The attenuation standard difference is σ_ADuring (i)=8dB, L is set_adj=4dB；The attenuation standard difference is σ_A During (i)=12～15dB, L is set_adj=10dB；

Up-link transmit power P_{UL_Node}Acquiring unit is additionally configured to：According to the receiving sensitivity increment Delta, Link attenuation A (i), receiving sensitivity P of the receiving node_SenAnd radio link power surplus L_adjBy following Formula obtains up-link transmit power P_{UL_Node}For：

The transmitting element is additionally configured to：With up-link transmit power P_{UL_Node}Transmission protocol data bag, or with Link attenuation A (i) or link attenuation sliding averageTo the receiving node

By above-mentioned technical proposal, the present invention has compared with prior art advantages below：Mobile node in the present invention Between transmission power control method, link attenuation A (i) and receiving sensitivity P of receiving node by receiving node_Sen, it is determined that Up-link transmit power P of sending node_{UL_Node}, so as to work as sending node in the case of in real time mobile, can be from reception Node obtains dynamic link quality parameter, i.e., different link attenuations A (i), and with reference to receiving node sensitivity P_SenAs up The important evidence of link transmit power, so that while transmitting power control is more accurate, it is ensured that data between mobile node Transmitting, be particularly well-suited to the uncertain situation of transmission link in wireless sensor network, and reduce equipment investment, carry High effective transmission rate, makes the overall transfer performance boost of wireless sensor network.

Description of the drawings

Fig. 1 is the structure composition figure of the sensor network of an embodiment of the present invention；

Fig. 2 is the node composition figure in the sensor network of another embodiment of the present invention；

Fig. 3 for one embodiment of the present invention sensor network in beacon signal superframe structure schematic diagram；

Fig. 4 adds the schematic flow sheet of network for the wireless sensor network interior joint of one embodiment of the present invention；

Fig. 5 is the uplink Poewr control method of mobile node in the sensor network of one embodiment of the present invention Schematic process flow diagram；

Fig. 6 is the uplink Poewr control method of mobile node in the sensor network of one embodiment of the present invention Data link schematic diagram；

Fig. 7 is the structure composition figure of another kind of sensor network in an embodiment of the present invention.

Specific embodiment

Embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

Fig. 1 is a kind of structure composition figure of the sensor network that can implement the present invention.The wireless sensor network is, in nothing Arrange multiple sensor nodes in the D01 of line overlay area, such as Node1, Node2, Node3, Node4, Node5, Node6 and Node7）Form wireless sensor network W1.As shown in Fig. 2 each sensor node includes data acquisition unit 101, data Processing unit 102, data transmission unit 103 and power supply 104.The form of monitored physical signalling determines data acquisition unit The type of the sensor in 101, such as may include in this element：Sound transducer 1011, shock sensor 1012 ....Pass through Protocol data bag signal generating unit 1013, by the transducing signal of collection data signal is converted to.

Data processing unit 102 is mainly used to carry out scheduling and the pipe of agreement carrying and allotment, task and each functional unit Reason, can adopt the operating system of embedded miniaturization, such as：The TinyOS systems of UC Berkeley, uCOS-II systems and embedded The systems such as Linux are realized.The processor of hardware generally selects MCU, such as Mega16/128, and MSP430, Cortex-M3, SoC are such as CC2530, nRF9E5 etc..Data transmission unit 103 is mainly made up of wireless communication module, such as CC1100, CC2520, NRF905, Si4432 etc. are so as to realizing the communication between node.Power supply 104 is above-mentioned data acquisition unit 101, data processing Unit 102 and data transmission unit 103 provide electric power.

In embodiments of the present invention, the protocol stack of wireless sensor network includes five layers of basic agreement：Application layer, transmission Layer, Internet, MAC layer, physical layer.Wherein, the basic function of each layer and known publicly-owned protocol function and it has been known Proprietary protocol function phase is same, and here is omitted.

Beacon signal used in this sensor network is superframe structure, wireless under mobile environment in this embodiment The up and down power control of sensor network node device is using synchronous superframe structure（As shown in Figure 3）, the frame structure uses Ensuring mechanism time slot, can be dynamically the equipment distribution time slot of application.Using ensuring mechanism time slot need between equipment when Between it is synchronous.In superframes, comprising three major parts：The contention access period (CAP--connection access period)；Nothing Contention access period (CFP--connection free period) and inactive period（inactive period）. In CFP, there is a part GTS（Guaranteed time slot), can be certain specific node distribution, consequently facilitating Management to node, and after into the inactive period, Coordinator stops communication, this means that Node can be entered Sleep pattern.The active part of superframe is divided into 16 isometric time slots, and the length of each time slot, contention access period include The parameter such as timeslot number, all set by telegon, and the beacon frames broadcast sent when being started by superframe is to whole network.In thing Reason layer is that in MAC layer, synchronous superframe structure is by beacon frame Beacon Frame（As in Fig. 3 1. shown in）, communication frame Traffic Frame（As in Fig. 3 2. and 4. shown in, wherein 2. for it is descending, 4. for up）, Stochastic accessing frame Random Access Frame（As in Fig. 3 5. shown in）And protective time slot Guard Period（As in Fig. 3 3. shown in）Composition.Beacon frame The same Zigbee of effect of Beacon Frame（Low-power consumption Personal Area Network agreement based on IEEE802.15.4 standards）Effect it is similar, Difference is the broadcast message that with the addition of more performance enhancements；The effect of communication frame Traffic frame is to carry Payload（Net load, can transmit for upstream or downstream）, carry signaling（MAC orders）Can also be divided into less short frame simultaneously, use In real-time response ACK；The effect of Stochastic accessing frame Random Access Frame is by accessing evenly distributing for chance To realize the Stochastic accessing of node, it is fixedly installed as up, that is receive or routing node may be configured as Transmit-Receive Unit.Protection Time Guard Period（It is reduced to GP）, effect be for the handoff reservation of the Transmit-Receive Unit TX/RX enough execution time （The transmitting-receiving switching time of some wireless sets is longer, and some acquiescences need calibration, and what is had is controlled by internal state machine, is had Be limited to TX buffer wait）.The introducing of superframe structure and beacon frame greatly facilitates network management, in the present embodiment From with superframe as cycle, the communication of equipment room in organizing transmission network LR-WPAN.Each superframe is sent with network coordinator Beacon frame contains superframe by information such as duration and distribution to this period to begin in this beacon frame.Net Conventional equipment in network is received after beacon frame when superframe starts, it is possible to according to the content arrangement therein task of oneself, For example into resting state until this superframe terminates.Wireless sensor network interior joint adds the flow process of network as shown in Figure 4. Therefore, the routing node in the present embodiment can be operated in the working conditions such as dormancy, work, and can be by carrying to superframe signal The instruction of node working condition, makes node enter resting state from working condition, and from resting state working condition is entered.

In practical application, include in above-mentioned data transmission unit 103：Transmitting element 1031 and receiving unit 1032. Receiving unit 1032 is used to from receiving node receive to be broadcasted by receiving node under local node is operated in the pattern of sending node The beacon signal of transmission, transmitting element 1031 is used for up-link transmit power P_{UL_Node}Protocol data bag is sent to connecing Receive node.The receiving unit 1032 is used to receive the agreement sent from sending node under node is operated in the pattern of receiving node Packet；Transmitting element 1031 is used to send broadcast beacon signal to sending node.

When local node is operated in sending node pattern, include in data processing unit 102：Link attenuation A (i) is obtained Take unit 1021 and up-link transmit power P_{UL_Node}Acquiring unit 1022.Link attenuation A (i) acquiring unit 1021 be used for from The broadcast beacon signal received in receiving unit 1032, parses, from the superframe to the superframe structure of this broadcast beacon signal Beacon frame in extract transmission power configured information P_{DL_Beacon}, and extraction reception should from the receiver module 1032 of sending node Received signal strength P during broadcast beacon signal_{DL_RSSI}Value, obtaining link attenuation A (i) by following formula 1-1 is：

A(i)=P_{DL_Beaco}-P_{DL_RSSI}（Formula 1-1）；

Wherein, the unit of A (i) is：dB.

After repeatedly carrying out data transmission between local node and node to be transmitted, can be right in data processing unit 102 Link attenuation A (i) per data transfer is recorded, so as to also slide including link attenuation in link attenuation A (i) acquiring unit Dynamic mean valueModule 1023；It is sending node that the module is used for local node, and M time by i.e. receiving node institute to be transmitted The beacon signal of transmission obtains link attenuation sliding average by below equationFor：

Wherein,Unit be：dB.

And according to the obtained link attenuation sliding average of this calculatingIt is defined as link attenuation A (i).

Up-link transmit power P_{UL_Node}Acquiring unit 1022 is used for according to obtaining in link attenuation A (i) acquiring unit Link attenuation A (i) and receiving node receiving sensitivity P_SenTwo parameters and P_{UL_Node}=A(i)+P_SenObtain up-link Transmit power P_{UL_Node}。

Wherein " receiving sensitivity P of receiving node_Sen", can be joined by being stored in the local equipment of data processing unit 102 Number information or physical layer carry gain of parameter.

Up-link transmit power P is being obtained in this embodiment_{UL_Node}Acquiring unit 1022 in, it is contemplated that different nodes The difference that RF equipment is present, therefore also include in this element：Receiving sensitivity increment Delta module 10221, the module, for root When having differences according to the RF schemes of equipment between transmission and receiving node, i.e., it sends and the transceiver performance of receiving node is inconsistent When, then corresponding receiving sensitivity increment Delta is obtained according to the difference；Specifically, when receiving node Node2 is using external Enhanced RF schemes, on original enhancement mode chip basis external LNA is increased（Low-noise amplifier）When, Δ is 10dB, is received Node Node2 sensitivity is -105～-108dBm；When receiving node Node2 strengthens the RF schemes of cake core reinforcement using itself, That is receiving node Node2 uses the enhanced chip of itself sensitivity（Such as ADF7021 chips）It is that sending node Node5 uses general Obturator piece（Typical chip CC2530）When, Δ is 20dB, and receiving node Node2 receiving sensitivities are -120dBm（The number of support According to speed：1kbps, 2FSK pattern）.So as to up-link transmit power P_{UL_Node}Acquiring unit is according to the receiving sensitivity Receiving sensitivity P of increment Delta, link attenuation A (i) and the receiving node_SenUp-link is obtained by following formula to send Power P_{UL_Node}For：P_{UL_Node}=A(i)–Δ+P_Sen。

Up-link transmit power P is being obtained in this embodiment_{UL_Node}Acquiring unit 1022 in, it is contemplated that radio node The impact brought to link after movement, therefore also include in this element：Radio link power surplus acquisition module 10222, uses It is flat link attenuation slip to be obtained in the M beacon signal and below equation sent by receiving node for M time according to sending node AverageFor：

Wherein,Unit be：dB.

By described M time, link attenuation sliding averageAnd current link attenuation A (i) and below equation are obtained Attenuation standard difference σ_AI () is：

Wherein, σ_AI the unit of () is：dB

According to attenuation standard difference σ_A(i) setting wireless link power surplus L_adj；The attenuation standard difference is σ_A(i)= During 4dB, L is set_adj=2dB；The attenuation standard difference is σ_ADuring (i)=8dB, L is set_adj=4dB；The attenuation standard difference is σ_A During (i)=12～15dB, L is set_adj=10dB；

So as to up-link transmit power P_{UL_Node}The reception that acquiring unit is obtained according to receiving sensitivity increment Delta module Incremental sensitivity Δ；Link attenuation A (i) acquiring unit or link attenuation moving averageThe link attenuation that acquiring unit is obtained A(i)；Receiving sensitivity P of the receiving node that radio link power surplus acquisition module is obtained_SenAnd the radio link power Surplus P_adjUp-link transmit power P is obtained by below equation_{UL_Node}For：

Transmitting element 1031 is additionally operable to up-link transmit power P_{UL_Node}Protocol data bag is sent or, with described Link attenuation A (i) and/or link attenuation sliding averageTo receiving node.

The uplink of mobile node in the sensor network of an embodiment of the present invention is illustrated referring to Fig. 5 and Fig. 6 Poewr control method.

Step S101：In wireless sensor network W1, when the data acquisition unit that sensor node Node5 passes through itself 101 collect after detection data, and setting sensor node Node5 initiates sensor node Node1 node data transmission request, By the Internet Routing Protocol in sensor network（Plane and hierarchical）It is " path A+ paths B " to generate routed path, Routing node is Node5 → Node2 → Node1.Afterwards the route requests to Node2 are initiated by Node5, in this routed path A On, Node5 is sending node, Node2 is receiving node, after routing node Node2 is waken up by the request, to sensor network W1 In all nodes with broadcasting power P_{DL_Beacon}Broadcast beacon signal is sent, the broadcast beacon signal adopts superframe structure, needed Illustrate, to make sensor network W1 in all nodes can in time and accurately receive the broadcast beacon signal, therefore, Broadcasting power P_{DL_Beacon}From being higher than the conventional transmit power of network, such as：20dBm.

Step S102：When the receiver module 1032 of sending node Node5 receives the transmitting element from receiving node Node2 After the 1031 broadcast beacon signals for sending, the superframe of the data processing unit 102 of sending node Node5 to this broadcast beacon signal Structure is parsed, and transmission power configured information P is extracted from the beacon frame of the superframe_{DL_Beacon}, and from sending node Node5 Receiver module 1032 in extract, receive the received signal strength P during broadcast beacon signal_{DL_RSSI}Value, by following equation 1-1 obtains link attenuation A (i)：

A(i)=P_{DL_Beaco}-P_{DL_RSSI}（Formula 1-1）；

Wherein,Unit be：dB;

For example：When receiving node Node2 transmission power configured informations P_{DL_Beacon}For 20dBm, sending node Node5's connects Receive signal strength signal intensity typical range P_{DL_RSSI}For：During -75dBm～-100dBm, understand that link attenuation A (i) is according to formula 1-1： 95dB～120dB.（Interior NLOS between node（Non line of sight）Distance about 80～100m）

Due to during actually used in sensor network W1, multiple data transfer being produced between sensor node, Therefore, the route record of Node5 → Node2 can be inquired about from the local history holding unit of above-mentioned sending node Node5, and is adjusted Take corresponding multiple link attenuation A (i) values；Such as：M has been had been received by sending node Node5 from receiving node Node2 Secondary beacon signal, therefore the link attenuation sliding average obtained by M link attenuation A (i) valueFor：

Wherein,Unit be：dB.

So as to can be according to above-mentioned link attenuation sliding averageIt is defined as link attenuation A (i), it can thus be appreciated that history note The record of link attenuation A (i) value in record is more, the current ink decay sliding average that it is obtainedIt is just more accurate.

Step S103：Sending node Node5 can be according to receiving sensitivity P of known receiving node Node2_Sen, receive section Receiving sensitivity P of point Node2_SenRefer to that the receiver module 1032 of receiving node Node2 can be received accurately and remain to normal The lowest signal intensity of work.According to receiving sensitivity P of receiving node Node2_SenAnd the link for being obtained in step s 102 Decay A (i) and equation 1 below -2 obtain up-link transmit power P_{UL_Node}For：

P_{UL_Node}=A(i)+P_Sen（Formula 1-2）；

If the receiver device that the receiver module 1032 of numerous nodes is adopted in sensor network W1 is consistent, in each section Receiving sensitivity P is preset in point_Sen, incremental sensitivity Δ now is 0.But in actual use, in sensor network W1 In default node may repeatedly be arranged, and it cannot be guaranteed that in the every time newly-increased or node changed receiver device one Cause；Another situation is, during the arranging net of sensor network W1, as shown in fig. 7, by a part therein such as： NodeA1～NodeA4, NodeA5～NodeA7 are set as sensing node, and node NodeB1, NodeB2 are set as into route section Point, so as to more saving the input cost of network node, therefore when in same sensor network W1 the receiver of each node connect When receipts sensitivity is inconsistent, i.e. when the receiving sensitivity of receiving node Node2 is higher than the receiving sensitivity of sending node Node5, Will there is receiving sensitivity increment Delta in the inter-node transmission of different performance receiver, therefore, when there is incremental sensitivity Δ When, above-mentioned formula 1-2 can be improved to following formula 1-3, so as to obtain the up-link transmit power of sending node Node5 P_{UL_Node}For：

P_{UL_Node}=A(i)–Δ+P_Sen.（Formula 1-3）；

For example：When receiving node Node2 with sending node Node5 using identical RF scheme is adopted, i.e. both of which makes When being the radio frequency scheme of node itself with common chip（Typical chip CC2530）, now Δ is 0, and receiving node Node2 is clever Sensitivity is -95～-98dBm；When receiving node Node2 uses external enhanced RF schemes, on original enhancement mode chip basis Increase external LNA（Low-noise amplifier）When, Δ is 10dB, and receiving node Node2 sensitivity is -105～-108dBm；When connecing Receive node Node2 enhanced using itself sensitivity using the RF schemes that cake core is strengthened, i.e. receiving node Node2 itself is strengthened Chip（Such as ADF7021 chips）It is that sending node Node5 uses common chip（Typical chip CC2530）When, Δ is 20dB, Receiving node Node2 receiving sensitivities are -120dBm.Receiving sensitivity P of above-mentioned each sensor node_SenCan be in sensor network By the record for giving in the physical layer equipment management module of network W1, and the participation calculating of data processing unit 102 is called in when needed.

Therefore, when link attenuation A (i) is：95dB～120dB；P_SenReceiving sensitivity be -95dBm～-98dBm, Δ For 0dB, 10dB or 20dB when, it can be seen from formula 1-3, up-link transmit power P of sending node Node5_{UL_Node}For 0dBm～5dBm.

Because sensor network is usable under use environments under various environment therefore different, radio communication quality Many factors can be subject to, such as：The impact of the environmental factors such as temperature, humidity and wind-force, so as to for make link transmit power obtain During can reasonable consideration to above-mentioned factor, it is therefore desirable in above-mentioned link transmit power P_{UL_Node}Acquisition process in introduce Radio link power surplus P_adj, radio link power surplus P_adjConcrete acquisition process be：

First, sliding average has been obtained in step S101Afterwards, link attenuation sliding average can be passed through And current link attenuation A (i) and below equation obtain attenuation standard difference σ_AI () is：

Wherein, σ_AI the unit of () is：dB

Afterwards, according to attenuation standard difference σ_A(i) setting wireless link power surplus L_adj；

The experiment of Jing actual tests understands, when attenuation standard difference is σ_ADuring (i)=4dB, L is set_adj=2dB；The decay Standard deviation is σ_ADuring (i)=8dB, L is set_adj=4dB；The attenuation standard difference is σ_ADuring (i)=12～15dB, L is set_adj=10dB。

Therefore, radio link power surplus P is introduced on the basis of formula 1-3_adjUp-link transmit power is obtained afterwards P_{UL_Node}For formula 1-4：

（Formula 1-4）；

Step S104：Sending node Node5 by the detection data collected from step S101 system data link Layer is encapsulated as the packet of superframe format, afterwards with up-link transmit power P obtained in step S103_{UL_Node}For 2dBm ～7dBm, and the packet is sent to into receiving node Node2.Meanwhile, for the ease of receiving node Node2 as sending node When Power Control, be also carried in this data transfer in above-mentioned steps S102 obtain link attenuation A (i) or link decline Subtract sliding average

After this, receiving node Node2 can send response message ACK to sending node Node5, in receiving node Node2 is produced under the pattern of response message ACK, and sending node Node5 can also predict reception by the setting to response time delay Whether node Node2 receives, and judges whether the repeating transmission that needs to carry out packet with this, such as：If not having during response time delay Receive and produce response message ACK from Node2, then carry out data re-transmitting.

Step S105：Path A has been completed by above-mentioned steps, and routing node is the data transfer of Node5 → Node2, Afterwards repeat the above steps, with Node2 as sending node, pass by route and data that receiving node completes path B of Node1 Pass, it can thus be appreciated that each routing node is capable of achieving the function of sending and receiving.So as to finally realize from path A+ paths B, road By the data transfer that node is Node5 → Node2 → Node1.

The uplink Power Control side according to mobile node in the sensor network of the present invention is illustrated referring to Fig. 7 Method, and provide sensor network in mobile node downlink transmission power control method.

The step of above-mentioned uplink Poewr control method after S104 or step S105, as receiving node Node2（Correspondence Path A）Or Node1（Respective path B）, need to be reversed data transfer, that is, realize routed path Node1 → Node2 → Node5, or to sending node Node5（Respective path A）Or Node2（Respective path B）Send feedback data when, Node1 or Node2 carries out data transfer as sending node is descending to Node2 and Node5, and included step is：

Sending node Node1 or Node2 carries out downlink data transmission to Node2 or Node5 is received, its power downlink Transmit power is according in up-link（Node5→Node2→Node1）In Node1 or Node2 as receiving node when, Reporting uplink link transmit power P for receiving_{UL_Node}It is determined that, i.e.,：Downlink transmit power=up-link transmit power P_{UL_Node}, it should be noted that above-mentioned downlink transmit power method preferably has phase in sending node with transmission node With using during sensitivity.Therefore, when sending node and transmission node sensitivity are inconsistent, sending node can be according to reported data Link attenuation A (i) for including or link attenuation sliding averageIndirect gain downlink transmit power, i.e. descending Link link attenuation B (i)=link attenuation A (i) or link attenuation sliding averageThen downlink transmit power reference Uplink transmission power algorithm is calculated.

The transmission power control method between mobile node in the present invention, by link attenuation A (i) of receiving node and connects Receive receiving sensitivity P of node_Sen, determine up-link transmit power P of sending node_{UL_Node}, so as to be in when sending node In the case of mobile in real time, dynamic link quality parameter, i.e., different link attenuations A (i) can be obtained from receiving node, and be joined Examine receiving node sensitivity P_SenAs the important evidence of up-link transmit power, so that transmitting power control is more accurate While, it is ensured that the transmitting of data between mobile node, it is particularly well-suited to transmission link in wireless sensor network not true Fixed situation, and equipment investment is reduced, effective transmission rate is improve, the overall transfer performance for making wireless sensor network is carried Rise.

Above-described is only some embodiments of the present invention.For the person of ordinary skill of the art, not On the premise of departing from the invention design, some deformations and improvement can also be made, these belong to the protection model of the present invention Enclose.

Claims (11)

1. in sensor network mobile node transmission power control method, it is characterised in that include：

Sending node obtains link attenuation by the beacon signal that receiving node is sent；

Up-link transmit power is determined by the receiving sensitivity of the link attenuation and the receiving node；

Protocol data bag is sent to the receiving node with the up-link transmit power；

Wherein, the step of sending node obtains link attenuation by the beacon signal that receiving node is sent includes：

The down transmitting power P included in the beacon signal that the sending node is sent according to the receiving node_{DL_Beacon}And Receive receiving end signal intensity P of the beacon signal_{DL_RSSI}Link attenuation A (i) is obtained by following formula：

A (i)=P_{DL_Beacon}-P_{DL_RSSI}。

2. transmission power control method according to claim 1, it is characterised in that by the link attenuation and described connect The receiving sensitivity for receiving node determines up-link transmit power P_{UL_Node}The step of include：

If the sending node has differences with the RF schemes of the receiving node, corresponding reception spirit is obtained according to the difference Sensitivity increment Delta；

According to receiving sensitivity P of the receiving sensitivity increment Delta, link attenuation A (i) and the receiving node_SenIt is logical Cross following formula and obtain up-link transmit power P_{UL_Node}：

P_{UL_Node}=A (i)-Δ+P_Sen。

3. transmission power control method according to claim 2, it is characterised in that if the sending node with it is described The RF schemes of receiving node have differences, then wrapped according to the step of difference acquisition corresponding receiving sensitivity increment Delta Include：

If the receiving node be using the enhanced RF schemes of external low-noise amplifier LNA, sending node be basic RF schemes When, receiving sensitivity increment Delta is 10dB；

If the receiving node be using the enhanced RF schemes of itself chip, sending node be basic RF schemes when, receive it is sensitive Degree increment Delta is 20dB.

4. transmission power control method according to claim 1, it is characterised in that the sending node passes through receiving node The step of beacon signal for being sent obtains link attenuation includes：

For the M link attenuation that the beacon signal that the receiving node received for M time from the sending node is sent is obtained, Link attenuation sliding average is obtained in the following manner

$\stackrel{\‾}{A}\left(i\right)=\frac{1}{M}\underset{j=i}{\overset{j=i+M-1}{\Σ}}A\left(i\right);$

By the link attenuation sliding averageIt is defined as link attenuation A (i).

5. transmission power control method according to claim 2, it is characterised in that described to be increased according to the receiving sensitivity Receiving sensitivity P of amount Δ, link attenuation A (i) and the receiving node_SenObtain up-link transmit power P_{UL_Node} The step of include：

For the M link attenuation that the beacon signal that the receiving node received for M time from the sending node is sent is obtained, Link attenuation sliding average is obtained in the following manner

$\stackrel{\‾}{A}\left(i\right)=\frac{1}{M}\underset{j=i}{\overset{j=i+M-1}{\Σ}}A\left(i\right);$

By the M link attenuation, the link attenuation sliding averageAnd current link attenuation A (i), and below Mode obtains attenuation standard difference σ_AI () is：

${\mathrm{\σ}}_A\left(i\right)=\sqrt{\frac{1}{M-1}\underset{j=1}{\overset{j=i+M-1}{\Σ}}{\[A\left(i\right)-\stackrel{\‾}{A}\left(i\right)\]}^2};$

According to attenuation standard difference σ_A(i) setting wireless link power surplus L_adj；

According to the receiving sensitivity increment Delta, link attenuation A (i), the receiving node receiving sensitivity P_SenAnd institute State radio link power surplus L_adjUp-link transmit power P is obtained in the following manner_{UL_Node}：

$P_{\mathrm{UL}\_\mathrm{Node}}=\stackrel{\_}{A}\left(i\right)-\mathrm{\Δ}+P_{\mathrm{Sen}}+L_{\mathrm{adj}}.$

6. transmission power control method according to claim 5, it is characterised in that described according to attenuation standard difference σ_A (i), setting wireless link power surplus L_adjThe step of include：

The attenuation standard difference is σ_ADuring (i)=4dB, L is set_adj=2dB；

The attenuation standard difference is σ_ADuring (i)=8dB, L is set_adj=4dB；

The attenuation standard difference is σ_ADuring (i)=12～15dB, L is set_adj=10dB.

7. the transmission power control method according to claim 1 or 4, it is characterised in that described to be sent out with the up-link The step of sending power to send protocol data bag to the receiving node includes：

With up-link transmit power P_{UL_Node}Protocol data bag is sent to the receiving node, or with the link attenuation A (i) or link attenuation sliding averageTo the receiving node.

8. transmission power control method according to claim 1, it is characterised in that described that work(is sent with the up-link Rate sends protocol data bag also to be included to after the step of the receiving node：

Receiving node is with up-link transmit power P_{UL_Node}Downlink data transmission is carried out to the sending node.

9. transmission power control method according to claim 7, it is characterised in that described that work(is sent with the up-link Rate P_{UL_Node}Send protocol data bag and link attenuation A (i) also includes to after the step of the receiving node：

Receiving node is according to link attenuation A (i) or link attenuation sliding averageObtain downlink transmit power；

Downlink data transmission is carried out to the sending node with the downlink transmit power.

10. wireless sensor network node device, it is characterised in that include：Transmitting element, link attenuation A (i) acquiring unit, Up-link transmit power P_{UL_ode}Acquiring unit and receiving unit,

The receiving unit is configured to receive the beacon signal that receiving node is sent；Or reception protocol data bag；

Link attenuation A (i) acquiring unit is configured to pass the beacon signal acquisition link attenuation A that receiving node is sent (i)；

Up-link transmit power P_{UL_Node}Acquiring unit is configured to pass link attenuation A (i) and the receiving node Receiving sensitivity P_SenDetermine up-link transmit power P_{UL_Node}；

The transmitting element is configured to up-link transmit power P_{UL_Node}Send protocol data bag and receive section to described Point；Or transmission broadcast beacon signal；Wherein：

Link attenuation A (i) acquiring unit is additionally configured to：Down transmitting power P in the beacon signal_{DL_Beacon} And receiving end signal intensity P of the reception beacon signal_{DL_RSSI}Link attenuation A (i) is obtained by following formula：

A (i)=P_{DL_Beacon}-P_{DL_RSSI}。

11. node apparatus according to claim 10, it is characterised in that

Link attenuation A (i) acquiring unit also includes link attenuation sliding averageModule, the module is configured to：For The M link attenuation that the beacon signal that the receiving node received for M time from sending node is sent is obtained, in the following manner Obtain link attenuation sliding average

$\stackrel{\‾}{A}\left(i\right)=\frac{1}{M}\underset{j=i}{\overset{j=i+M-1}{\Σ}}A\left(i\right);$

By the link attenuation sliding averageIt is defined as link attenuation A (i)；

Up-link transmit power P_{UL_Node}Acquiring unit also includes：

Receiving sensitivity increment Delta module is configured to：If the sending node has differences with the RF schemes of the receiving node, Then corresponding receiving sensitivity increment Delta is obtained according to the difference；If the receiving node is using external low noise amplification When the enhanced RF schemes of device LNA, sending node are basic RF schemes, receiving sensitivity increment Delta is 10dB；If described receive section Point be using the enhanced RF schemes of itself chip, sending node be basic RF schemes when, receiving sensitivity increment Delta be 20dB；

Up-link transmit power P_{UL_Node}Acquiring unit is additionally configured to：According to the receiving sensitivity increment Delta, the chain Road decay A (i) and receiving sensitivity P of the receiving node_SenUp-link transmit power P is obtained by following formula_{UL_Node}For：

P_{UL_Node}=A (i)-Δ+P_Sen；

Up-link transmit power P_{UL_Node}Acquiring unit also includes：

Radio link power surplus acquisition module is configured to for the receiving node received for M time from the sending node is sent M link attenuation being obtained of beacon signal, link attenuation sliding average is obtained in the following manner

$\stackrel{\‾}{A}\left(i\right)=\frac{1}{M}\underset{j=i}{\overset{j=i+M-1}{\Σ}}A\left(i\right);$

By the M link attenuation, link attenuation sliding averageAnd current link attenuation A (i), and in the following manner Obtain attenuation standard difference σ_AI () is：

${\mathrm{\σ}}_A\left(i\right)=\sqrt{\frac{1}{M-1}\underset{j=1}{\overset{j=i+M-1}{\Σ}}{\[A\left(i\right)-\stackrel{\‾}{A}\left(i\right)\]}^2};$

According to attenuation standard difference σ_A(i) setting wireless link power surplus L_adj；The attenuation standard difference is σ_A(i)=4dB When, set L_adj=2dB；The attenuation standard difference is σ_ADuring (i)=8dB, L is set_adj=4dB；The attenuation standard difference is σ_A During (i)=12～15dB, L is set_adj=10dB；

Up-link transmit power P_{UL_Node}Acquiring unit is additionally configured to：According to the receiving sensitivity increment Delta, the chain Road decay A (i), receiving sensitivity P of the receiving node_SenAnd radio link power surplus L_adjObtained by below equation Take up-link transmit power P_{UL_Node}For：

$P_{\mathrm{UL}\_\mathrm{Node}}=\stackrel{\_}{A}\left(i\right)-\mathrm{\Δ}+P_{\mathrm{Sen}}+L_{\mathrm{adj}};$

The transmitting element is additionally configured to：With up-link transmit power P_{UL_Node}Protocol data bag is sent, or with the chain Road decay A (i) or link attenuation sliding averageTo the receiving node.