CN103716201A - Open wireless sensing network performance test method and open wireless sensing network performance test system - Google Patents

Abstract

The invention relates to an open wireless sensor network testing method and system, in particular to the measurement of high-precision delay, packet loss rate, topology structure and other performances. The platform consists of an upper computer, a lower computer, a test backboard, a The write module and the node under test are composed; the test backplanes are connected by clock synchronization signal lines, and the high-precision time synchronization is completed by the cooperation of software and hardware; the node under test measures the transmission process of its air interface and low-speed wired interface. The variable delay is used to modify the transmission delay of the data packet; the fixed-length segmentation method adopted by the test backplane for the test data packet converts the variable delay into a fixed delay; the method of parameter positioning file is used to realize flexible remote programming; The link correlation method is used to obtain a stable sensor network topology; the sequence number mapping algorithm is used to solve the sequence number overflow problem and realize accurate packet loss rate calculation.

Description

An open wireless sensor network performance testing method and system

technical field

The invention relates to the communication field, in particular to an open wireless sensor network performance testing method and system.

Background technique

The wireless sensor network is composed of a large number of low-cost miniature sensor nodes, which collaboratively realize the perception, collection, processing and control tasks of the environment, and are widely used in national defense, military, industrial control, urban transportation, health care, environmental monitoring, Building monitoring and many other fields.

The capabilities of wireless sensor nodes in computing, storage and communication are very limited, and the performance testing of wireless sensor networks has always been a problem that plagues the research and large-scale application of wireless sensor networks. In addition, there are many software and hardware platforms for wireless sensor networks. The hardware platforms include Smart Dust, MICA, TELOS, μAMPS, and the software platforms include Contiki, TinyOS, LiteOS, Nano-RK, t-Kernel, etc. It is a huge technical challenge to provide a unified high-precision test system for many types of sensor network nodes.

MoteWorks is a sensor network test system for MICA nodes developed by Crossbow. The MoteWorks test system has three main disadvantages: it can only provide test services for MICA nodes; when it collects test data, it will interfere with the running status of nodes; when it transmits test data, it will interfere with the communication performance of the network. Harvard University's MoteLab test system is mainly aimed at TMote Sky nodes, and Ohio State University's Kansei is mainly aimed at starGate. These test systems cannot provide an open test system to provide test services for various sensor nodes.

Contents of the invention

The technical problem to be solved by the present invention is to provide an open wireless sensor network performance testing method and system for the deficiencies of the prior art.

The technical solution of the present invention to solve the above-mentioned technical problems is as follows: an open wireless sensor network performance testing method, comprising the following steps:

Step 1: The host computer sends a test command to the tested node of the wireless sensor network through the wired test channel;

Step 2: After the node under test of the wireless sensor network receives the test command, during the operation of the wireless sensor network, when the node under test sends or receives a service data packet on the wireless channel, it will generate a packet of encapsulated service data. And report to the host computer through the wired test channel;

Step 3: After receiving the end test command sent by the host computer, the tested node of the wireless sensor network stops reporting the test data packet to the host computer;

Step 4: The host computer processes and analyzes the received test data packets, and calculates the data packet transmission delay, network topology and packet loss rate of the wireless sensor network;

Wherein, each of the wired test channels includes a lower computer, a test backplane and a programming module, and each lower computer is connected to a test backplane through a wired high-speed interface; each test backplane provides several low-speed interfaces, each A low-speed interface is connected to a programming module; a clock synchronization signal line is connected between the test backplanes for synchronizing the clocks between the test backplanes.

The beneficial effects of the present invention are:

1. This test system realizes the collection of test information through a standard low-speed interface, and can provide test services for wireless sensor networks with various hardware and software structures. Since the test data is collected through the wired channel, it will not interfere with the normal test environment of the wireless channel.

2. This test system adopts the synchronization mechanism of software and hardware cooperation. On the hardware, high precision can be obtained through timing synchronization pulses. On the premise of high time precision, a more accurate transmission delay can be measured. , and also by measuring the air transmission delay and low-speed interface transmission delay of the node under test, and offsetting the influence of these two types of variable delays on the transmission delay calculation, finally, on the test backplane, through the fixed-length packet technology, the variable The long reception delay process is transformed into a fixed-length reception delay process, which further improves the accuracy of delay calculation.

3. The test backplane provides a large number of low-speed interfaces to provide connection channels for a large number of nodes under test. This method can not only reduce manufacturing costs, but also reduce the number of test backplanes required for test experiments; thus reducing the number of backplanes that need to be synchronized. The number of boards not only reduces the number of hardware, but also improves the synchronization accuracy between test backplanes.

On the basis of the above technical solutions, the present invention can also be improved as follows.

Further, the test data packet includes a node number field, a payload length field, a payload field, a check code, an air transmission delay, and a serial port transmission delay, wherein the node number of the node sending the test data packet to the upper computer is stored in the node number number, the length of the payload field is stored in the payload length field, the service data packet sent or received by the node is stored in the payload field, the check code field stores the cyclic redundancy check of the test data packet, and the air transmission The air transmission delay of the service data packet sent or received by the node is stored in the delay, and the serial port delay stored in the serial port transmission delay is the serial port delay when the node sent a test data packet to the host computer last time.

Further, the calculation of data packet transmission delay includes the air transmission delay of the transmission of business data packets between the nodes under test and the serial port transmission delay of the test data packets uploaded by the nodes under test. The specific calculation steps are as follows:

Air transmission delay calculation: When the node under test sends business data packets on the wireless channel, it records the sending start time stamp and the sending success time stamp of each business data packet, and subtracts the sending start time stamp from the sending success time stamp to get the air transmission delay , encapsulate the air transmission delay in the test data packet reported this time and report it to the host computer through the wired test channel, and the host computer calculates the accurate air delay parameter through the correction algorithm; after the node under test receives the business data packet in the wireless channel , in the test data packet reported to the host computer, the air transmission delay is zero.

Serial port transmission delay calculation: when the test data packet is reported to the host computer, record the report start time stamp and report success time stamp of each test data packet, subtract the report start time stamp from the report success time stamp to get the serial port transmission delay, and transmit the serial port The delay is encapsulated in the next test data packet to be reported to the host computer through the wired test channel, and the host computer calculates the accurate serial port delay parameters through the correction algorithm.

Further, when the test data packet is transmitted to the test backplane of the wired test channel, the test backplane adopts fixed-length segmentation to receive, marks the receiving time stamp for each fixed-length packet, and changes the variable delay into a fixed delay.

Further, specific steps to obtain the topology of the sensor network:

The upper computer adopts the data-driven mode, and divides the test process into several time periods according to the calculation interval specified by the user. In each time period, the tested node sends a test data packet to the upper computer through the wired test channel to report each tested data. The number of business data packets transmitted by the measurement node, the host computer then summarizes the number of business data packets transmitted by each link, and obtains the correlation degree of the link. Using a link with a high correlation degree, according to the depth-first topology tree algorithm, a stable network topology.

The beneficial effect of adopting the above-mentioned further scheme is: this test method adopts the data-driven mode to obtain the topology change of the wireless sensor network, which not only has a wide range of adaptability, but also overcomes the transient state of the topology change through the correlation index of the link. The impact of the process on topological computation.

Further, the packet loss rate calculation steps:

The service data packets transmitted between the nodes under test have serial numbers embedded in them. When the nodes under test send or receive service data packets, they will back up the sent or received service data packets to the payload field of the test data packets and encapsulate them in the test The data packet is transmitted to the host computer through the wired test channel and stored in the database;

The host computer takes out all received test data packets from the database according to the ascending order of the test data packet time stamps, parses each test data packet in turn, reads the serial number of the data packet stored in the payload field of the test data packet, and according to the sequence Number to judge whether there is out-of-sequence and overflow. If there is, update the serial number accordingly, put the updated serial number back into the database, and process the next test data packet until all the test data packets are processed, and then use Take out all test data packets in ascending order of sequence numbers, calculate the missing sequence numbers, and then calculate the packet loss rate.

The beneficial effect of adopting the above-mentioned further scheme is: adopting data packet sequential encoding technology, effectively solving the problem of packet loss rate error caused by problems such as message synchronization, repeated transmission, multi-path transmission, etc., and realizing a higher accuracy of sensor network packet loss rate measurement.

Further, it also includes realizing the remote programming code of the tested node. The specific steps are: the upper computer writes at least two basic programming files with different node numbers, channel numbers and transmission power; According to the difference caused by the transmission power, a parameter positioning file is generated; according to the basic programming file and its corresponding parameter positioning file, as well as the programming parameters selected by the user, the required programming file is produced; the programming file is passed through the wired test channel Send it to the corresponding programming module, and use the local programming technology to program the code to the node under test.

The beneficial effect of adopting the above-mentioned further scheme is: this test method uses the parameter positioning file to realize the flexible remote programming function, can adapt to the programming code changes of various types of nodes, and provides convenient node number, channel number and transmission power configuration .

Another technical solution of the present invention to solve the above-mentioned technical problems is as follows: an open wireless sensor network performance testing system, which is characterized in that it includes a host computer, several wired test channels and several tested nodes; The wired network is connected to several test channels, and the end of each test channel is connected to a node under test through a private interface;

The upper computer is used to send a test command to the node under test through the test channel, and is also used to process and analyze the feedback test data packet, and calculate the packet transmission delay, network topology and packet loss rate of the wireless sensor network ; The test channel is used to realize the interaction between the tested node and the upper computer test command and the report of the test data; the tested node is used to receive the test command and generate test data, which is fed back to the upper position through the test channel machine;

Wherein, each of the wired test channels includes a lower computer, a test backplane and a programming module, and each lower computer is connected to a test backplane through a wired high-speed interface; each test backplane provides several low-speed interfaces, each A low-speed interface is connected to a programming module; a clock synchronization signal line is connected between the test backplanes for synchronizing the clocks between the test backplanes.

On the basis of the above technical solutions, the present invention can also be improved as follows.

Further, the programming module is also used to receive the programming file sent by the upper computer, and use the local programming technology to program the code to the node under test.

Further, the test backplane is also used to receive the data reported by the node under test by using fixed-length division, mark the receiving time stamp for each fixed-length packet, and change the variable delay into a fixed delay.

Description of drawings

Fig. 1 is a kind of open wireless sensor network test system schematic diagram of the present invention;

Fig. 2 is the connection diagram of test backplane, programming module and measured node of the present invention;

Fig. 3 is a flow chart of an open wireless sensor network testing method according to the present invention

Fig. 4 is the format diagram of the test packet reported by the tested node of the present invention;

Fig. 5 is the clock synchronization signal flow diagram of the software and hardware cooperative work of the present invention;

Fig. 6 is a flow chart of calculating the packet loss rate of the wireless sensor network based on the serial number.

In the accompanying drawings, the list of parts represented by each label is as follows:

1. Upper computer, 2. Lower computer, 3. Test backplane, 4. Programming module, 5. Node under test.

Detailed ways

The principles and features of the present invention are described below in conjunction with the accompanying drawings, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

As shown in Figure 1, in this test system, there is only one upper computer 1, which is physically connected to N lower computers 2 through Ethernet, and the upper computer 1 and lower computers 2 realize information exchange through the TCP/IP protocol. The lower computer 2 is connected to the test backplane 3 through a high-speed interface, and uses the Serial Peripheral Protocol (SPI) to realize information exchange. Eight programming modules 4 are connected to each test backplane 3 , and each programming module 4 is connected to a node 5 under test.

As shown in Figure 2, the test backplane 3 is connected to the programming module 4 through a 9-pin low-speed connection, where 1 and 2 wires are used to supply power to the programming module, and 3 and 4 wires are used as serial ports (at a rate of 115200bps) and For programming module communication, wires 5 and 6 are used to supply power to the node under test, and wires 7 and 8 are used as serial ports (at a rate of 115200bps) to communicate with node 5 under test. The programming module 4 is connected to the node under test 5 by means of an internal connection, and uses a private protocol for current information interaction, among which line 10 is a common ground function, lines 11 and 12 are used as serial ports (at a rate of 115200bps) to communicate with the node under test, and lines 13 and 14 are used for communication with the node under test. The line is used to control the node under test to make it enter the programming state.

As shown in Figure 3, an open wireless sensor network performance testing method,

Step 1: The host computer sends a test command to the tested node of the wireless sensor network through the wired test channel;

Step 2: After the node under test of the wireless sensor network receives the test command, during the operation of the wireless sensor network, when the node under test sends or receives the service data packet on the wireless channel, it will generate a test packet encapsulated with the service data packet. Data packets, and report to the host computer through the wired test channel;

Step 3: After receiving the end test command sent by the host computer, the tested node of the wireless sensor network stops reporting the test data packet to the host computer;

Step 4: The host computer processes and analyzes the received test data packets, and calculates the data packet transmission delay, network topology and packet loss rate of the wireless sensor network;

Wherein, each of the wired test channels includes a lower computer, a test backplane and a programming module, and each lower computer is connected to a test backplane through a wired high-speed interface; each test backplane provides several low-speed interfaces, each A low-speed interface is connected to a programming module; a clock synchronization signal line is connected between the test backplanes for synchronizing the clocks between the test backplanes.

As shown in Figure 4, the test data packet reported by the test node to the host computer through the wired test channel includes the node number field, the payload length field, the payload field, the check code, the air transmission delay, and the serial port transmission delay. Store the node number of the node that sends the test data packet to the upper computer, store the length of the payload field in the payload length field, store the service data packet sent or received by the node in the payload field, and store the test code field in the payload field. The cyclic redundancy check of the data packet, the air transmission delay of the service data packet sent or received by the node stored in the air transmission delay, and the test data sent by the node to the host computer last time stored in the serial port transmission delay The serial delay of the package. The length of the node number is 2 bytes, the length of the payload is 2 bytes, the payload content is variable length, and the length of the check code is 2 bytes; the length of the air transmission delay is 2 bytes, which means The unit is millisecond; the length of the serial port transmission delay is 2 bytes, and the expressed unit is millisecond.

The system of the present invention has the following functions:

1. High precision delay measurement

a. In the existing testing technologies, software is mostly used to realize time synchronization, and this kind of time synchronization is realized between the lower computers. There are two deficiencies in software synchronization. One is that the synchronization accuracy is not high; the other is that the data packets need to pass through the buffer queue of the test backplane. The delay caused by the buffer queue is variable, and providing a timestamp on the lower computer will lead to a lower time precision.

The invention adopts the synchronous mechanism of software and hardware cooperating, and can obtain a high-precision synchronous clock through timing synchronous pulses.

As shown in FIG. 5 , among the N test backplanes participating in the test, test backplane 1 is a master clock controller, and other test backplanes are slave clock controllers. The test backplane 1 sends a software clock report signal S1 to the lower computer 1 once every integer minute passes 10 seconds, and is relayed to the upper computer. The content of the signal S1 is the current clock value when the test backplane 1 sends the signal S1. After the upper computer receives the signal S1, it sends a software clock update signal S2 to other lower computers, and is transferred to the corresponding test backplane. The value of the signal S2 is equal to the value of the signal S1. The test backplane 1 sends a signal S3 on the hardware synchronization line connected to other test backplanes at the moment when every integer minute passes 30 seconds. The test backplane 1 is usually low on the hardware synchronization line, and the signal S3 makes the hardware synchronization line high instantaneously. The clock synchronization algorithms of other test backplanes are as follows. After the signal S2 is received, the local clock is set to S2; after the signal S3 is received, the minutes of the local clock remain unchanged, and the seconds are set to 30 seconds.

b. During the data communication process between the nodes under test, the transmission of business data packets has to experience multiple delays, such as scheduling delays within the nodes, queuing delays within the wireless transmission module, carrier sense delays during transmission, and data collisions. Retransmission delays, these delay lengths often have a variable length, which will lead to large delay calculation errors. Air transmission delay calculation: When the node under test sends business data packets on the wireless channel, it records the sending start time stamp and the sending success time stamp of each business data packet, and subtracts the sending start time stamp from the sending success time stamp to get the air transmission delay , encapsulate the air transmission delay in the test data packet reported this time and report it to the host computer through the wired test channel, and the host computer calculates the accurate air delay parameter through the correction algorithm; after the node under test receives the business data packet in the wireless channel , in the test data packet reported to the host computer, the air transmission delay is zero.

In the process of reporting test data packets between the nodes under test, the transmission of test data packets has to experience multiple delays, such as scheduling delays in nodes and queuing delays in low-speed sending modules. Large profiling errors. Serial port transmission delay calculation: when the test data packet is reported to the host computer, record the report start time stamp and report success time stamp of each test data packet, subtract the report start time stamp from the report success time stamp to get the serial port transmission delay, and transmit the serial port The delay is encapsulated in the next test data packet to be reported to the host computer through the wired test channel, and the host computer calculates the accurate serial port delay parameters through the correction algorithm.

In addition, when the test data packet is transmitted to the test backplane of the wired test channel, the test backplane adopts fixed-length division to receive, marks the receiving time stamp for each fixed-length packet, changes the variable delay into a fixed delay, and further improves the calculation The precision of the delay. Specifically, the test data packet with variable length can be truncated into a packet every 10 bytes, and a timestamp can be added to each packet.

2. Universal Topological Computing

Since the wireless channel of the sensor network is susceptible to external interference, the topology structure will change dynamically, so there will be a short routing and topology transition period, so the traditional method is easily disturbed by the transition period, and the calculated topology structure is inaccurate; the sensor network type Various routing protocols and topology control algorithms are used. In order to make the topology analysis algorithm widely applicable, a data-driven model is adopted. Although there are various methods for topology control and routing calculation of sensor networks, the actual topology of sensor networks can be effectively revealed through data flow. This method divides the test process into several time periods specified by the user, and calculates the topology structure of the time period according to the data flow characteristics of each time period.

The upper computer adopts the data-driven mode, and divides the test process into several time periods according to the calculation interval specified by the user. In each time period, the tested node sends a test data packet to the upper computer through the wired test channel to report each tested data. The number of business data packets transmitted by the measurement node, the host computer then summarizes the number of business data packets transmitted by each link, and obtains the correlation degree of the link. Using a link with a high correlation degree, according to the depth-first topology tree algorithm, a stable network topology.

The specific implementation process of obtaining the link correlation degree is as follows:

Firstly, initialize the association degree of all measured nodes to 0, and secondly, start from the sink node, obtain the sub-nodes of the sink node, and set the association degree from these sub-nodes to the sink node according to the communication volume between these sub-nodes and the sink node; again , Find the grandchildren of these child nodes, and calculate the degree of association from the grandchildren to the child nodes, if the obtained degree of association is greater than the current degree of association of the grandchildren, change the parent node of the grandchildren; otherwise, do not update.

The above depth-first iterative process is adopted until all nodes are traversed.

3. Accurate packet loss rate statistics

In the process of calculating the packet loss rate, due to the difficulty of synchronous execution of the test start and test end commands among a large number of tested nodes, repeated transmission and multi-path transmission, etc., it will cause multiple copies of the same service data packets to be received. , leading to the problem that the calculation accuracy of the packet loss rate is not high. For this reason, serial numbers will be embedded in the business data packets transmitted between each tested node. Each tested node has several destination address counters, and each destination address maintains an independent counter. Every time the node sends a For a service data packet, the counter corresponding to the destination address is incremented. Each node under test will report a test data packet to the host computer when sending and receiving business data packets, where the payload field of the test data packet encapsulates the business data packet sent or received by the node (including the serial number) .

The host computer takes out all the test data packets from the database according to the ascending order of the time stamp of the test data packets, parses each test data packet in turn, reads the serial number of the business data packet stored in the payload field of the test data packet, and according to the serial number Determine whether there is disorder and overflow. If so, update the serial number accordingly, put the updated serial number back into the database, and process the next test data packet until all test data packets are processed. Take out all test data packets in ascending order, calculate the missing sequence numbers, and then calculate the packet loss rate.

For a network with a single sink node, the service data packets of other nodes are sent to the sink node, so each sensing node only needs to maintain a counter, and the counter is incremented every time a service data packet is sent. The storage size of this counter is 2 bytes, the initial value is 0x0, and the maximum value is 0xFFFF. When the value of the counter reaches 0xFFFF, due to the overflow of the counter, the next value is 0x0 again.

When the test data packet is stored in the database of the host computer, 4 bytes are used to store the sequence number of the service data packet. The problem of calculator overflow is solved through the algorithm shown in Figure 6, which also needs to consider the impact of out-of-order arrival of service data packets.

Step 1: From the database, according to the ascending order of the time stamp of the test data packets, take out all the test data packets, and read in the sequence number nseq of the service data packet in the first test data packet;

Step 2: Assign initial values to the parameters count, last_seq and M, where count is the number of overflow occurrences, last_seq is the latest received sequence number, and M is the minimum overflow value corresponding to the two-byte storage space, which is 0x10000 in this system ;

Step 3: Judging whether overflow occurs according to the relationship between nseq and last_seq, if it is greater than that, execute step 4; otherwise, execute step 5;

Step 4: Judging whether the growth rate is within a reasonable range based on the relationship between nseq and last_seq+M/2, to determine whether there is disorder. If it is less than, update nseq according to (a) module, and if it is larger, update nseq according to (b) module nseq;

Step 5: Judging the relationship between nseq and last_seq-M/2 according to the comparison to determine whether the growth rate is within a reasonable range, if it is less than, update nseq according to (c) module, if it is greater than, update nseq according to (d) module;

Among them, in the (a) module, the sequence number nseq of the new test data packet is greater than last_seq, and it is within a reasonable growth range, which means that the sequence number increases normally. The parameter last_seq can be updated normally, for example, nseq is 5 and last_seq is 4 ;(b) In the module, the sequence number nseq of the new test data packet is greater than last_seq, but it exceeds the reasonable growth rate, indicating that there is an overflow in the front, and currently another out-of-order business data packet is received, and the parameters last_seq and count are not It needs to be changed. For example, the current last_seq is 0, nseq is 0xFFFE, and it will enter such a situation after receiving three consecutive data packets with serial numbers (0xFFFF, 0x0, 0xFFFE); (c) In the module, the new test data packet The sequence number nseq is smaller than last_seq, but not within a reasonable growth range, which means that overflow occurs. last_seq is updated normally, but the count parameter needs to be incremented. For example, nseq is 0x0 and last_seq is 0xFFFF; in (d) module, the new test data packet The sequence number nseq is smaller than last_seq, and it is within a reasonable growth range, which means out of order. The parameter last_seq does not need to be updated. For example, nseq is 8 and last_seq is 9, indicating that the No. 8 service data packet is sent earlier than the No. 9 service data packet. But then reach the destination node. Update the nseq of the business data packet according to the conditions in a, b, c, and d respectively, write the updated serial number nseq back to the database, and then take out the serial number of the business data packet in the next test data packet, and repeat the above operation until the end.

After the operation, the serial number of the business data packet in the database does not overflow, so all the test data packets are taken out in ascending order of the serial number of the business data packet, and then the missing serial number is calculated to obtain the packet loss rate.

4. Remote programming

The programming code compiled by the sensor node development platform is configured for a specific node number, channel number, and transmission power. When programming remotely, it needs to be flexibly configured to different initialization values according to the requirements of the test scenario. By comparing the programming code differences of different node numbers, the coding position of the node number is obtained; by comparing the programming code differences of different channel numbers, the coding position of the channel number is obtained; by comparing the programming code differences of different transmission powers, the Get the encoded position of the transmit power. By putting the above location information into the parameter positioning file corresponding to the programming code, you can flexibly and remotely program various required node numbers, channel numbers and transmit power nodes.

When compiling the programming file of the tested node, two programming files with node number 1 and node number 2 are compiled, and the difference between the two files is automatically compared by the software, and the position of the difference is output to the parameter positioning file The node number of the location segment. Then compile two programming files with channel number 20 and channel number 21, automatically compare the differences between the two files through the software, and output the position of the difference to the channel number positioning section of the parameter positioning file. Then compile two programming files with transmit power 25 and channel number 26, automatically compare the differences between the two files through the software, and output the position of the difference to the transmit power positioning section of the parameter positioning file.

When executing the remote programming command, based on the node number, channel number and transmission power configured by the user, according to the offset indicated by the node number positioning section, channel number positioning section and transmission power positioning section in the parameter positioning file, Modify the burning file. Then send the customized programming file to the programming module to complete the final local programming work, and then the code update function of the node under test can be realized. This remote programming capability can facilitate the rapid deployment of test scenarios.

5. Diversified energy consumption display

In the process of testing the node under test, the test backplane samples the current value of the node under test at a rate of 300,000 times per second. From 10,000 sampling points, calculate a current average value and variance value. In the energy consumption display graph, the average current curve and the current variance curve are displayed at the same time.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (10)

1. an open wireless sensor network performance testing method, is characterized in that, comprises the steps: Step 1: The host computer sends a test command to the tested node of the wireless sensor network through the wired test channel; Step 2: After the node under test of the wireless sensor network receives the test command, during the operation of the wireless sensor network, when the node under test sends or receives the service data packet on the wireless channel, it will generate a test packet encapsulated with the service data packet. Data packets, and report to the host computer through the wired test channel; Step 3: After receiving the end test command sent by the host computer, the tested node of the wireless sensor network stops reporting the test data packet to the host computer; Step 4: The host computer processes and analyzes the received test data packets, and calculates the data packet transmission delay, network topology and packet loss rate of the wireless sensor network; Wherein, each of the wired test channels includes a lower computer, a test backplane and a programming module, and each lower computer is connected to a test backplane through a wired high-speed interface; each test backplane provides several low-speed interfaces, each A low-speed interface is connected to a programming module; a clock synchronization signal line is connected between the test backplanes for synchronizing the clocks between the test backplanes. 2. a kind of open wireless sensor network performance test method according to claim 1, is characterized in that, described test packet comprises node number field, payload length field, payload field, check code, air transmission delay , Serial port transmission delay, wherein the node number stores the node number of the node sending the test data packet to the upper computer, the payload length field stores the length of the payload field, and the payload field stores the service data packet sent or received by the node , the check code field stores the cyclic redundancy check of the test data packet, the air transmission delay of the service data packet sent or received by the node stored in the air transmission delay, and the serial port transmission delay stores the The serial port delay when the node sent a test packet to the host computer last time. 3. a kind of open wireless sensor network performance test method according to claim 1, is characterized in that, calculates the data packet transmission delay and comprises the air transmission delay of the transmission service data packet between the nodes under test and the upload test data packet of the node under test The serial port transmission delay, the specific calculation steps are as follows: Air transmission delay calculation: When the node under test sends business data packets on the wireless channel, it records the sending start time stamp and the sending success time stamp of each business data packet, and subtracts the sending start time stamp from the sending success time stamp to get the air transmission delay , encapsulate the air transmission delay in the test data packet reported this time and report it to the host computer through the wired test channel, and the host computer calculates the accurate air delay parameter through the correction algorithm; after the node under test receives the business data packet in the wireless channel , in the test data packet reported to the host computer, the air transmission delay is zero; Serial port transmission delay calculation: when the test data packet is reported to the host computer, record the report start time stamp and report success time stamp of each test data packet, subtract the report start time stamp from the report success time stamp to get the serial port transmission delay, and transmit the serial port The delay is encapsulated in the next test data packet to be reported to the host computer through the wired test channel, and the host computer calculates the accurate serial port delay parameters through the correction algorithm. 4. a kind of open wireless sensor network performance testing method according to claim 1, it is characterized in that, when test data packet is sent to the test backboard place of wired test channel, test backboard adopts fixed-length division to receive, for each A fixed-length packet marks the received timestamp, changing the variable delay into a fixed delay. 5. a kind of open wireless sensor network performance test method according to claim 1, is characterized in that, obtains the concrete steps of the topology of sensor network: The upper computer adopts the data-driven mode, and divides the test process into several time periods according to the calculation interval specified by the user. In each time period, the tested node sends a test data packet to the upper computer through the wired test channel to report each tested data. The number of business data packets transmitted by the measurement node, the host computer then summarizes the number of business data packets transmitted by each link, and obtains the correlation degree of the link. Using a link with a high correlation degree, according to the depth-first topology tree algorithm, a stable network topology. 6. a kind of open wireless sensor network performance testing method according to claim 1, is characterized in that, packet loss rate calculation step: The service data packets transmitted between the nodes under test have serial numbers embedded in them. When the nodes under test send or receive service data packets, they will back up the sent or received service data packets to the payload field of the test data packets and encapsulate them in the test The data packet is transmitted to the host computer through the wired test channel and stored in the database; The host computer takes out all received test data packets from the database according to the ascending order of the test data packet time stamps, parses each test data packet in turn, and reads the serial number of the business data packet stored in the payload field of the test data packet, according to The serial number judges whether there is disorder and overflow. If there is, update the serial number accordingly, put the updated serial number back into the database, and process the next test data packet until all the test data packets are processed. Take out all test data packets in ascending order of sequence number, calculate the missing sequence number, and then calculate the packet loss rate. 7. A kind of open type wireless sensor network performance test method according to claim 1, is characterized in that, also comprises realizing the remote programming code of the node under test, concrete steps are: upper computer writes at least two node numbers, channel number The basic programming file with different transmission power; by comparing the difference between the programming file due to the node number, channel number and transmission power, a parameter positioning file is generated; according to the basic programming file and its corresponding parameter positioning file, and the user Select the programming parameters to produce the required programming files; transmit the programming files to the corresponding programming module through the wired test channel, and use the local programming technology to program the code to the node under test. 8. An open wireless sensor network performance testing system is characterized in that it comprises an upper computer, several wired test channels and several tested nodes; the upper computer is connected with several test channels by a wired network, and each The end of the test channel is connected to a node under test through a private interface; The upper computer is used to send a test command to the node under test through the test channel, and is also used to process and analyze the feedback test data packet, and calculate the packet transmission delay, network topology and packet loss rate of the wireless sensor network ; The test channel is used to realize the interaction between the tested node and the upper computer test command and the report of the test data; the tested node is used to receive the test command and generate test data, which is fed back to the upper position through the test channel machine; Wherein, each of the wired test channels includes a lower computer, a test backplane and a programming module, and each lower computer is connected to a test backplane through a wired high-speed interface; each test backplane provides several low-speed interfaces, each A low-speed interface is connected to a programming module; a clock synchronization signal line is connected between the test backplanes for synchronizing the clocks between the test backplanes. 9. A kind of open wireless sensor network performance test system according to claim 8, it is characterized in that, described programming module is also used for receiving the programming file that host computer sends, utilizes local programming technology, code Burn to the node under test. 10. A kind of open wireless sensor network performance test system according to claim 8, it is characterized in that, described test backplane is also used for adopting fixed-length division to receive the data reported by the node under test, for each fixed-length Packets are stamped with receipt timestamps, turning variable latency into fixed latency.

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