RU2484586C1 - Communication system for collecting data and method of receiving data in communication system - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: communication system for collecting data has a distributed network for delivering data to a query initiator device, wherein the distributed network has a plurality of devices for reading parameter values of at least one sensor, a control processor assigned by the query initiator from a number of reading devices, designed to query a plurality of reading devices, wherein the control processor is configured to transmit to the distributed network query commands for a time which overlaps the wakeup period of the reading devices, having an arbitrary wakeup time, receive sensor data, sample said data according to priority and send acknowledgement to the selected reading device, in case of collision, sending negative acknowledgement; the reading devices are designed to receive query commands, transmit data, termination thereof upon receiving acknowledgement, and terminating data transmission upon receiving negative acknowledgement, and resumption thereof after a pseudorandom delay.

EFFECT: high coefficient of utilisation of capacity and reduced power consumption and shorter data collection time.

17 cl, 1 dwg

Description

The claimed invention relates to networks consisting of wireless transceivers (nodes), connected via a wireless line into a single network, as well as to methods used in this network for transmitting various types of information received from readers from sensors, which may be: field devices, sensors, counters of electricity, gas, water, etc., used to account for the consumption of resources.

Currently, widespread use of distributed and local networks in the field of communications for routing radio messages between the control processor, readers and sensors, while the readers (interfaces) of the wireless network are maintained in a low-power state with the exception of the communication period, while Until the end of the communication period, the reader operates in full power mode.

A method for constructing such networks includes specifying identifying parameters that define multicast groups of interfaces for each temporary network, and identifying these temporary networks using the mentioned identifying parameters. Identifying parameters for determining multicast groups forming a temporary network are specified by transmitting an identifying test message through one of the interfaces and waiting for a certain time for the corresponding response message. Interfaces, depending on whether they are included or not included in this multicast group, send the corresponding response message or do not respond to the test message.

There are several types of data collection:

1) Remote reading of readings, called “Walk by” (“passing by”), in which the person taking the indicators - the controller, takes the readings of the meters, has a portable terminal equipped with a radio interface, by which the indicators are collected in the central controller (RU 2247396 C1, publ. 02.27.2005).

This system uses sensors that work with periodic listening to the radio channel, capable of listening to the radio channel for a time overlapping the period of the request transmission by the reading device, which leads to increased power consumption when interrogating devices are constantly in active mode.

2) Remote reading based on a standard fixed network.

There is a communication method for remote reading of meter readings, in which the reading of meter readings by controllers is carried out in the UHF decimeter band, and information transfer between the controllers is carried out in the VHF meter band (WO 2008/107261 A1, publ. 12.09.2008).

This method also leads to increased power consumption when out of range of interrogating devices.

The closest technical solution to the claimed invention is an automatic utility accounting system, including an information processing device in the form of a central hub and intermediate hubs connected via telecommunication channels that collect information from the meter polling units. (RU 69653 U1, publ. 12/27/2007).

A disadvantage of the known technical solution is the large number of initial collisions (collisions) that occur during the processing of information with the simultaneous response of several blocks of the interrogation of counters, which reduces the throughput of radio channels and, as a result, increases the time of data collection; in addition, the meter polling unit transmits only a positive confirmation without indicating from which device the request was received, and a negative confirmation (conflict), which leads to disruption of the system; when transmitting data over the air, there is always the possibility of their distortion for reasons of a random nature, for example, due to interference; in the known solution there is no possibility of retransmission of data within the polling cycle; battery-powered meter polling units operating in the periodic listening mode of a radio channel cannot be detected immediately from the start of listening, because must wait for the start of a new cycle.

The technical result of the claimed invention is to increase the utilization rate of bandwidth, reducing power consumption and data collection time.

The essence of the invention lies in the fact that the communication system for collecting data, contains a distributed network for delivering data to the device - the initiator of the survey, while the distributed network contains many devices for reading the parameter value of at least one sensor, a control processor assigned by the initiator of the survey from the number of devices for reading, designed to interrogate many devices for reading, while the control processor is configured to transmit to the distributed network polling commands for a while I, which covers the awakening period of reading devices having an arbitrary awakening time; receiving data from sensors, their selection by priority and sending to the selected device for reading a personal confirmation, if there is a conflict - sending a negative confirmation; readers are designed to receive a polling command, transmit data, terminate it in the event of receiving a personal confirmation, and stop transmitting data in the event of a negative confirmation, and resume it through a pseudo-random delay.

The priority is determined by the highest level of the received signal of the data transmission command from the reader.

The polling command includes information about the last polled device, the polling cycle number, channel quality thresholds, and received signal strength.

The data transmission command of the parameter reading device includes the number of the reading device and the signal level measured at the time of receiving the polling command.

The personalized polling confirmation command includes a label in the form of the number of the reader.

Negative acknowledgment includes an indication of the range of levels of the received signal at which a collision has occurred.

Devices for reading a parameter are configured to transmit commands and are made in the form of a set of wired and wireless interfaces connected by a bus and designed to relay a request for polling, a polling command, data transmission commands, and confirmation / non-confirmation commands.

Any interface can initiate a polling cycle, from which a polling request is transmitted on the bus.

The fact of the interrogation of all devices for reading is the lack of data transmission commands for a given time.

The control processor reduces pauses between polling commands in the absence of receiving data transmission commands from reading devices.

The method for receiving data in a communication system consists in the fact that the polling initiating device transmits a polling request to the control processor, the control processor transmits to the distributed data delivery network, consisting of devices for reading a parameter, a polling command for a time that overlaps the awakening period of reading devices having an arbitrary awakening time; all readers for receiving a polling command transmit their data, in the control processor, when receiving data, a command is selected from the reader for priority; a personal confirmation is sent to the interrogated reader, after which it stops the data transfer, all other readers continue to transmit data until personal confirmations are received; if there is a collision when receiving signals with the same priorities, a negative acknowledgment is sent, the reading devices that have received a negative acknowledgment stop sending data and resume sending after a pseudo-random delay.

The priority is determined by the highest level of the received signal of the data transmission command from the reader.

The polling command includes information about the last polled device, the polling cycle number, channel quality thresholds, and received signal strength.

The data transmission command of the parameter reading device includes the number of the reading device and the signal level measured at the time of receiving the polling command.

The personalized polling confirmation command includes a label in the form of the number of the reader.

Negative acknowledgment includes an indication of the range of levels of the received signal at which a collision has occurred.

Devices for reading a parameter are configured to transmit commands and are made in the form of a set of wired and wireless interfaces connected by a bus and designed to relay a request for polling, a polling command, data transmission commands, and confirmation / non-confirmation commands.

Any interface can initiate a polling cycle, from which a polling request is transmitted on the bus.

The fact of the interrogation of all devices for reading is the lack of data transmission commands for a given time.

The control processor reduces pauses between polling commands in the absence of receiving data transmission commands from the reader.

The roles of the control processor and devices for reading the parameter value are set by the device initiating the survey for each poll cycle.

Devices are visualized by their serial number, and the levels of the received signal are displayed using a variable color background, which displays the serial numbers of the devices.

The structure of the radio network is displayed by cells of arbitrary arrangement with serial numbers of devices inside the cells, and the number of repeaters from the access point to the device is displayed using the color background of cells with serial numbers of devices.

Figure 1 presents the structural diagram of a communication system for collecting data.

The distributed wireless network 1 has a total of N nodes 2, where N = 1, 2, 3, etc. Each node 2 consists of a device 3 for reading the value of the parameter of the sensor 4, each of which has a receiving means for receiving a signal transmitted by the transmitting means of the device 3, and transmitting means for transmitting a signal containing information about the value of the fixed value of the desired parameter received by the device 3. A device 3 for reading a parameter value is an interface that performs the functions of a repeater, and is configured to transmit commands addressed to other devices 3, two 7. The radio apparatus of thoron - poll initiator 5 is the gateway between the microprocessor and the distributed wireless network system 1. Control Processor 6 can be assigned to any device 3 for reading. The reader 3 in each node is connected by a bus 10 with one or more sensors 4.

As sensors 4 use meters of water, gas, electricity, heat, etc. Data is exchanged between devices 3 and 5 on a two-way radio channel 7 using frequency modulation. Devices 3 are powered by an alternating current network or an autonomous source, while all devices 3 are in sleep mode with short-term waking up to read data from sensors; moreover, the moment of awakening of each of the devices 3 is arbitrary, therefore, constant synchronization of the time of awakening is not required. After waking up one of the requested devices 3, it relays the wake-up command to the next device 3, etc.

A communication system for collecting data starts transmitting an information packet containing the address of one of the reading devices 3, which is assigned to perform the functions of the control processor 6 in this polling cycle. The control processor 6 transmits the addressless polling commands 8 to other devices 3 for reading during a time spanning the awakening period of the devices 3.

The polling command 8 of devices 3 includes information about the last polled device 3, the number of the polling cycle, threshold channel quality values and the level (priority) of the received command. All devices 3 that have received a polling command transmit the data read from the sensor 4 during the waking period at the same time. The data transfer command 9 of the parameter reading device 3 includes the read data, as well as the number of the reading device.

When the processor 6 receives the data transfer command 9, the device 3 sends an acknowledgment. The acknowledgment command 8 includes a label in the form of the identification number of this device 3. The device 3, which has received the acknowledgment, stops issuing responses in the current cycle. As a result of this, the number of responding devices 3 decreases in the polling cycle.

When a collision is detected by the processor 6, the level of these received signals is measured and the measured level value is transmitted in the next polling command, it is assumed that in the request-response mode the received signal levels in both directions are the same. Devices 3 that create a collision respond to requests with different latencies. Devices 3, in which the level of the received signal is within a given range, recognize this condition as a collision that arose through their fault. The only way to eliminate the collision from devices 3 with a similar level is the diversity of their responses in time.

If there is a collision when receiving signals with the same priorities (signal levels), a negative acknowledgment is sent, the reading devices 3 that have received a negative acknowledgment stop sending data and resume sending after a pseudo-random delay.

In this case, a negative confirmation includes an indication of the signal level range of the data transmission command at which a collision occurred.

From this moment, the devices 3 that created the collision miss a certain number of requests from processor 6, which is determined by the two least significant digits of the decimal serial identification number, and then again respond to the request from processor 6. In the event of a repeated collision, the number of missed requests is determined by the following bits of the serial identification number and etc. During pauses arising from the elimination of collisions, the response is received from other devices 3 with a lower signal level, which leads to a more efficient use of the bandwidth of the radio channel.

The elimination of collisions at the receiving point in the processor 6 arising from the simultaneous response of several devices 3 is based on the use of the capture phenomenon known in radio engineering, consisting in the selective reception of one of a group of signals simultaneously input to the input. The capture phenomenon is manifested in the successful reception of a signal whose power exceeds the required total power of the remaining competing signals by the required value; thus, the entire set of surrounding devices is divided into several tens of subbands that differ in the level of the received signal, while collisions occur only within the subbands. Thus, in the process of detecting a large number of devices 3, the number of possible collisions is significantly less than when using known methods.

The polling cycle runs for a predetermined time or may end ahead of schedule when the receive buffer of processor 6 is full, then a response with a list of detected devices 3 and received signal levels is transmitted to the polling initiator 5 through the relay chain in the reverse sequence via radio channel 7.

A polling cycle is performed for each device 3, the results are used to search for other devices 3 and automatically build routes with control of signal levels between devices 3.

In the polling command, the processor 6 transmits the serial number of the device 3, called the label as confirmation of detection.

The polling command also transmits the received signal quality values for filtering routes with poor quality and the received signal level value for filtering devices 3, which create a collision due to close levels of the received signal.

To start the next polling cycle, sequential numbering of cycles is used. Upon receipt of a polling command 8 with a different number, all devices 3 resume the transmission of responses 9. Thus, devices 3 that are woken up by the polling command do not wait for the next cycle to begin, but begin to respond in the current cycle, which leads to a decrease in energy consumption.

All devices 3 can respond to requests from processor 6 synchronously using the same access code, which in this case is recognized without errors even when superimposing signals with the same level. This allows you to determine the fact of the absence of a response from devices 3 at the initial stage of reception and not to waste time on receiving missing answers. In the absence of responses from devices 3 due to their asynchronous exit to short-term listening to the radio channel, processor 6 increases the frequency of transmission of polling commands by reducing the pauses between requests.

This allows you to reduce the listening time of the radio channel and reduce power consumption. In contrast to measuring the level of the received signal, detecting the response of devices 3 by the access code provides the correct result in the entire range of received signal levels, especially when operating at the maximum sensitivity of the receiver of the processor 6.

If the number of surrounding devices 3 exceeds the size of the receive buffer of processor 6, then the polling cycle can be continued by re-submitting from the polling initiator 5 a request for polling with the same cycle number.

A condition confirming the discovery of all surrounding devices 3 is the absence of responses 9 to the polling commands 8 for a given time. To start the next polling cycle, the cycle number is changed.

For ease of analysis, the radio network structure is displayed by cells of arbitrary arrangement with serial numbers of devices inside the cells, and the number of repeaters from the access point to the device is displayed using the color background of cells with serial numbers of devices. The color of the cell with device number 3 indicates the number of repeaters between it and the device initiating the survey 5: the color changes from warm to cold tones, which simplifies the natural perception of the results.

For the convenience of analyzing the results of measuring signal levels relative to the selected device 6, all other devices 3 responding to it are highlighted in a certain color depending on the measured level of the received signal, when the level of the received signal decreases, the color changes from warm to cold tones, along with the device number in the cells displays a digital value of the measured level. Unanswered devices are grayed out.

Claims (23)

1. A communication system for collecting data, comprising a distributed network for delivering data to a polling initiator device, wherein the distributed network contains a plurality of devices for reading a parameter value of at least one sensor, a control processor designated by the polling initiator from among the reading devices is intended for polling a plurality of reading devices, characterized in that the control processor is adapted to transmit polling commands to a distributed network for a time that overlaps d awakening reader having an arbitrary time awakening; receiving data from sensors, their selection by priority and sending to the selected device for reading a personal confirmation, if there is a conflict - sending a negative confirmation; readers are designed to receive a polling command, transmit data, terminate it in the event of receiving a personal confirmation, and stop transmitting data in the event of a negative confirmation, and resume it through a pseudo-random delay. 2. The system according to claim 1, characterized in that the priority is determined by the highest level of the received signal of the data transmission command from the reader. 3. The system according to claim 1, characterized in that the polling command includes information about the last polled device, the number of the polling cycle, threshold channel quality and the level of the received signal. 4. The system according to claim 1, characterized in that the data transmission command of the device for reading the parameter includes the number of the device for reading and the signal level measured while receiving the polling command. 5. The system according to claim 1, characterized in that the personal survey confirmation command includes a label in the form of the number of the reader. 6. The system according to claim 1, characterized in that the negative acknowledgment includes an indication of the range of levels of the received signal at which a collision has occurred. 7. The system according to claim 1, characterized in that the device for reading a parameter is configured to transmit commands and is made in the form of a set of wired and wireless interfaces connected by a bus and designed to relay a request for polling, a polling command, data transfer commands and commands about confirmation / non-confirmation. 8. The system according to claim 7, characterized in that any interface can initiate a polling cycle from which a polling request is transmitted via the bus. 9. The system according to claim 1, characterized in that the fact of polling all the reading devices is the absence of data transmission commands for a given time. 10. The system according to claim 1, characterized in that the control processor reduces pauses between the polling commands in the absence of receiving data transmission commands from reading devices. 11. A method for receiving data in a communication system, the device initiating a survey transmits a request to perform a survey to the control processor, the control processor transmits to the distributed data delivery network, consisting of devices for reading a parameter, a polling command for a time that covers the waking period of reading devices having an arbitrary waking time; all readers for receiving a polling command transmit their data, in the control processor, when receiving data, a command is selected from the reader for priority; a personal confirmation is sent to the interrogated reader, after which it stops the data transfer, all other readers continue to transmit data until personal confirmations are received; if there is a collision when receiving signals with the same priorities, a negative acknowledgment is sent, the reading devices that have received a negative acknowledgment stop sending data and resume sending after a pseudo-random delay. 12. The method according to claim 11, characterized in that the priority is determined by the highest level of the received signal of the data transmission command from the reading device. 13. The method according to claim 11, characterized in that the polling command includes information about the last polled device, the number of the polling cycle, threshold values of the channel quality and the level of the received signal. 14. The method according to claim 11, characterized in that the data transmission command of the device for reading the parameter includes the number of the device for reading and the signal level measured while receiving the polling command. 15. The method according to claim 11, characterized in that the personal survey confirmation command includes a label in the form of the number of the reader. 16. The method according to claim 11, characterized in that the negative acknowledgment includes an indication of the range of levels of the received signal at which a collision has occurred. 17. The method according to claim 11, characterized in that the device for reading a parameter is configured to transmit commands and is made in the form of a set of wired and wireless interfaces connected by a bus and designed to relay a request for a survey, a polling command, data transmission commands and commands about confirmation / non-confirmation. 18. The method according to 17, characterized in that any interface can initiate a polling cycle, from which a polling request is transmitted on the bus. 19. The method according to claim 11, characterized in that the fact of polling all the reading devices is the absence of data transmission commands for a given time. 20. The method according to claim 11, characterized in that the control processor reduces pauses between the polling commands in the absence of receiving data transmission commands from the reader. 21. The method according to claim 11, characterized in that the roles of the control processor and devices for reading the parameter value are set by the device initiating the survey for each poll cycle. 22. The method according to claim 11, characterized in that the devices are visualized by their serial number, and the levels of the received signal are displayed using a variable color background on which the serial numbers of the devices are displayed. 23. The method according to claim 11, characterized in that the radio network structure is displayed by cells of arbitrary arrangement with serial numbers of devices inside the cells, and the number of repeaters from the polling initiator to the device is displayed using the color background of cells with serial numbers of devices.