CN111132291B - LPWAN synchronous awakening method based on LoRa - Google Patents
LPWAN synchronous awakening method based on LoRa Download PDFInfo
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- CN111132291B CN111132291B CN202010006881.3A CN202010006881A CN111132291B CN 111132291 B CN111132291 B CN 111132291B CN 202010006881 A CN202010006881 A CN 202010006881A CN 111132291 B CN111132291 B CN 111132291B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/02—Power saving arrangements
- H04W52/0209—Power saving arrangements in terminal devices
- H04W52/0225—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal
- H04W52/0248—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal dependent on the time of the day, e.g. according to expected transmission activity
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0644—External master-clock
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/02—Power saving arrangements
- H04W52/0209—Power saving arrangements in terminal devices
- H04W52/0212—Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave
- H04W52/0216—Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave using a pre-established activity schedule, e.g. traffic indication frame
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W56/00—Synchronisation arrangements
- H04W56/001—Synchronization between nodes
- H04W56/0015—Synchronization between nodes one node acting as a reference for the others
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
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- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The invention discloses an LPWAN synchronous awakening method based on LoRa, which comprises the following steps: s1, sending a beacon frame; s2, clock synchronization; s3, dividing the time slots Tw with the same length as the service on the basis of the sending interval of the beacon frame; s4, synchronizing the service time slots, and awakening and receiving the awakening frame by the timing Tw after the delay time arrives; s5, the sensing node awakens and receives downlink data regularly according to the beacon frame sending start time and the service period interval; s6, changing a synchronous timing cycle by the sensing node according to the RTC error calibration condition; s7, the sensing node increases Tg time for solving the conflict between the beacon frame and the downlink frame transmission of the server. The invention ensures that the clock beats of the gateway and the sensing nodes in the network are consistent, so that the gateway can predict the time when all the sensing nodes wake up the windowing receiving moment at regular time; on the premise of meeting the design requirement of low power consumption, the clock beat can be divided and dynamically adjusted so as not to influence the downlink transmission delay.
Description
Technical Field
The invention belongs to the technical field of communication processing, and particularly relates to an LPWAN synchronous awakening method based on LoRa.
Background
With the rapid development of the internet of things technology, how to simply, rapidly and safely connect everything is a technical problem faced by many intelligent terminal products. The appearance of the LPWAN communication technology based on the LoRa well solves the problem of short boards with insufficient bearing capacity of a mobile cellular network, the current application scene of the LoRa mainly comprises data transparent transmission and LoRaWAN protocol application, and the research and development cost of the gateway SX1301 is high, so that the LoRaWAN protocol application accounts for a small proportion. In order to meet the requirement of small-scale networking, SX1301 is obviously not suitable, but a gateway is needed to realize ad hoc networking, a star-type or mesh network adopting point-to-point transmission is a new application mode, the gateway and the sensing node in the networking mode both use SX1278 to communicate, and the networking mode is simple and efficient and has lower research and development cost. Because the sensing node needs to meet the power consumption design requirement and is in a dormant state most of the time, when the server needs to collect data, the gateway needs to immediately wake up the sensing node and call up the measured data, and how to effectively relieve the synchronous wake-up mechanism of the contradiction between dormancy and quick response is the key of the LPWAN communication technology.
Currently, LPWAN synchronous wake-up methods mainly include:
1、LoRaWAN ClassB
the gateway sends a beacon frame every 128 seconds, the sensing node wakes up to open a receiving window at regular time, the server sends downlink data in the receiving window, and the sensing node replies after receiving the data. The sensing node must search the beacon frame before the ClassA accesses the network and switches to the ClassB, and the time synchronization is completed after the beacon frame is searched, or the search can be accelerated, but the search can be accelerated only once within 1 hour. If the accelerated search fails then the node will wait 2 hours before switching to ClassA. The sensing node must request the timing windowing period, data rate, channel isochronal synchronization related parameters at ClassA. The gateway is calibrated by means of GPS (global positioning system) second, the sensing node is calibrated by means of the beacon frame, and in actual operation, the sensing node may not receive the beacon frame due to wireless interference, communication congestion or the fact that the node moves to a long distance and the like, which means that the node is disconnected for 2 hours. The beacon frame sending and fixed wakeup receiving time window of ClassB are a good solution to the problem, but the disadvantages of switching from ClassA, complex synchronization parameter request, rough time synchronization exception handling and the like need to be balanced.
2. TDMA-based MAC protocol
The protocol only reserves the beacon frame synchronization and timing awakening receiving strategy in ClassB, adopts a point-to-point star networking mode, is very suitable for small-scale networking, but still requires the time of the gateway and the sensing node to be the same, and due to the error of respective crystal oscillators, the phenomenon of clock drift still easily occurs, when the sensing node does not receive the beacon frame for a long time, the sensing node can continuously request the gateway for time synchronization, and the utilization rate of a network channel can be influenced.
3. Full coverage wake-up
All sensing nodes use fixed timing awakening periods, the gateway continuously sends N awakening frames, and the continuously sent time covers the terminal dormancy awakening time, so that each node can be ensured to be awakened in at least 2 awakening periods, the power consumption of a system is influenced if the timing awakening period is too short, the downlink response speed is influenced if the timing awakening period is too long, and other sensing nodes can be awakened by mistake during unicast, and the method is not an optimal solution.
Therefore, an LPWAN synchronous wake-up method based on LoRa is needed.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention provides an LPWAN synchronous awakening method based on LoRa.
In order to solve the technical problems, the invention provides the following technical scheme:
the invention provides an LPWAN synchronous awakening method based on LoRa, which comprises the following steps:
s1, the gateway uses the RTC inside the MCU to send the beacon frame at regular time;
s2, the sensing node sends a network access request frame before joining the network, the gateway carries the next beacon frame sending time Tnb in the replied confirmation frame, the sensing node calculates the delay time for receiving the next beacon frame through Tnb, clock synchronization is completed, and the sensing node does not lose steps when receiving the next beacon frame for time calibration;
s3, in order to reduce the downlink transmission delay, dividing the time slots Tw with the same length as the service on the basis of the sending interval of the beacon frame;
s4, after the sensing node successfully joins the network, calculating the next awakening windowing delay Tnw according to Tnb to complete the service time slot synchronization, and after the delay time is up, awakening and receiving the awakening frame at the fixed time Tw; when the gateway has downlink data to be sent, directly sending a wakeup frame at the beginning of the latest service time slot and immediately sending a data frame;
s5, the sensing node awakens and receives downlink data regularly according to the beacon frame sending start time and the service period interval;
s6, the sensing node changes a synchronization timing period Tc n Tb according to the RTC error calibration condition, the RTC error is within 3ms, the value of n is continuously increased, and if the RTC error is more than 5ms, the value of n is 1, so that unnecessary calibration actions can be reduced;
s7, in order to solve the conflict between the sending of the beacon frame and the downlink frame of the server, the sensing node increases the protection time Tg of the beacon frame, so that the service time slot is staggered with the sending time of the beacon frame;
tb in step S6 is the periodic interval of beacon frame transmission.
As a preferred technical scheme of the invention, Tb error in the step is controlled to be +/-1 ms/day, beacon frames are started from the time when the gateway starts networking until the time when the gateway is powered off, a uniform clock beat is always provided for the network, and communication between the sensing node and the gateway is established at the clock beat.
As a preferred technical solution of the present invention, the length of the time slot in step S3 is also the sensing node timed wake-up period, so long as the clock beats of the sensing node and the gateway are consistent, the gateway can predict the wake-up time of the sensing node and send a wake-up frame to complete synchronous wake-up, and the time slots are divided by the gateway.
The beneficial effects of the invention are: the invention ensures that the clock beats of the gateway and the sensing nodes in the network are consistent, so that the gateway can predict the time when all the sensing nodes wake up the windowing receiving moment at regular time; on the premise of meeting the design requirement of low power consumption, the clock beat can be divided and dynamically adjusted so as not to influence the downlink transmission delay; because the devices of the gateway and the sensing node are different, occasionally, the step loss occurs, the sensing node needs to perform clock synchronization once at regular intervals, and the synchronization interval can be dynamically calibrated according to the time deviation, so that unnecessary calibration times are reduced.
Detailed Description
The following description of the preferred embodiments of the present invention is provided for the purpose of illustration and description, and is in no way intended to limit the invention.
In order to achieve the purpose of the present invention, in one embodiment of the present invention, there is provided a method for LPWAN synchronous wake-up based on LoRa, including the following steps:
s1, the gateway uses an RTC inside the MCU to regularly send beacon frames, the sending period interval of the beacon frames is Tb, the error is controlled to be +/-1 ms/day, the beacon frames start from the time when the gateway starts networking to the time when the gateway is powered off, a uniform clock beat is always provided for the network, and the communication between the sensing nodes and the gateway is established at the clock beat;
s2, before joining the network, the sensing node sends a network access request frame, the gateway carries the next beacon frame sending time Tnb in the replied confirmation frame, the sensing node calculates the delay time for receiving the next beacon frame through Tnb, clock synchronization is completed, and the sensing node does not lose steps after receiving the next beacon frame and performing time calibration;
s3, in order to reduce downlink transmission delay, dividing equal-length time slots Tw of services on the basis of beacon frame sending intervals, wherein the length of the time slots is the timing awakening period of the sensing node, so that as long as the clock beats of the sensing node and the clock beats of the gateway are consistent, the gateway can predict the awakening time of the sensing node and send an awakening frame to complete synchronous awakening, and the time slots are divided by the gateway;
s4, after the sensing node successfully joins the network, calculating the next time of awakening windowing delay Tnw according to Tnb to complete the service time slot synchronization, and awakening and receiving an awakening frame by timing Tw after the delay time is up; when the gateway has downlink data to be sent, directly sending a wakeup frame at the beginning of the latest service time slot and immediately sending a data frame;
s5, the sensing node awakens and receives downlink data regularly according to the beacon frame sending start time and the service period interval;
s6, the sensing node changes a synchronization timing period Tc n Tb according to the RTC error calibration condition, the RTC error is within 3ms, the value of n is continuously increased, and if the RTC error is more than 5ms, the value of n is 1, so that unnecessary calibration actions can be reduced;
s7, in order to solve the conflict between the sending of the beacon frame and the downlink frame of the server, the sensing node increases the protection time Tg of the beacon frame, so that the service time slot is staggered with the sending time of the beacon frame;
tb in step S6 is the periodic interval of beacon frame transmission.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (3)
1. An LPWAN synchronous awakening method based on LoRa is characterized by comprising the following steps:
s1, the gateway uses the RTC inside the MCU to send the beacon frame at regular time;
s2, before joining the network, the sensing node sends a network access request frame, the gateway carries the next beacon frame sending time Tnb in the replied confirmation frame, the sensing node calculates the delay time for receiving the next beacon frame through Tnb, clock synchronization is completed, and the sensing node does not lose steps after receiving the next beacon frame and performing time calibration;
s3, dividing the time slots Tw with the same length as the service on the basis of the sending interval of the beacon frame;
s4, after the sensing node successfully joins the network, calculating the next time of awakening windowing delay Tnw according to Tnb to complete the service time slot synchronization, and awakening and receiving an awakening frame by timing Tw after the delay time is up; when the gateway has downlink data to be sent, directly sending a wakeup frame at the beginning of the latest service time slot and immediately sending a data frame;
s5, the sensing node awakens and receives downlink data regularly according to the beacon frame sending start time and the service period interval;
s6, the sensing node changes a synchronization timing period Tc n Tb according to the RTC error calibration condition, the RTC error is within 3ms, the value of n is continuously increased, if the RTC error is more than 5ms, the n is 1, thus unnecessary calibration action can be reduced;
s7, in order to solve the conflict between the sending of the beacon frame and the downlink frame of the server, the sensing node increases the protection time Tg of the beacon frame, so that the service time slot is staggered with the sending time of the beacon frame;
tb in step S6 is the periodic interval of beacon frame transmission.
2. The LPWAN synchronous awakening method based on LoRa (Long distance range) according to claim 1, wherein Tb error is controlled to be +/-1 ms/day in the step, a beacon frame is started from the time when a gateway starts networking until the time when the gateway is powered off, a uniform clock beat is always provided for the network, and communication between a sensing node and the gateway is established at the clock beat.
3. The LPWAN synchronous awakening method according to claim 1, wherein the length of the time slot in step S3 is also the sensing node timed awakening period, so that as long as the clock beats of the sensing node and the gateway are consistent, the gateway can predict the awakening time of the sensing node and send an awakening frame to complete synchronous awakening, and the time slot is divided into the segments allocated by the gateway.
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| CN113038541B (en) * | 2021-03-04 | 2022-05-20 | 重庆邮电大学 | Adaptive LoRaWAN network rate adjusting method based on conflict perception |
| CN113133127B (en) * | 2021-04-16 | 2023-12-12 | 成都易明半导体有限公司 | Wireless ad hoc network link quick network access method based on random sniffing |
| CN114143864B (en) * | 2022-02-07 | 2022-07-15 | 云丁网络技术(北京)有限公司 | Communication method and device |
| CN113645683B (en) * | 2021-10-14 | 2021-12-24 | 昂科信息技术（上海）股份有限公司 | Crystal oscillator self-adaptive clock synchronization method and system |
| CN116033532B (en) * | 2023-02-27 | 2023-06-30 | 高拓讯达(北京)微电子股份有限公司 | Wake-up method and device for wireless station, electronic equipment and storage medium |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103457685A (en) * | 2012-05-29 | 2013-12-18 | 中国科学院沈阳自动化研究所 | Method for precisely synchronizing time of industrial wireless network on basis of prediction and compensation |
| CN106162844A (en) * | 2016-06-03 | 2016-11-23 | 西安电子科技大学 | Implementation method based on the MAC protocol for wireless sensor networks of LoRa |
| CN108601089A (en) * | 2018-05-23 | 2018-09-28 | 上海电机学院 | Based on LoRa wireless network DRDS-TDMA slot allocation methods |
| CN108834213A (en) * | 2018-04-04 | 2018-11-16 | 西安电子科技大学 | Low downlink delays communication means and system in a kind of Internet of Things |
| CN108880775A (en) * | 2018-07-20 | 2018-11-23 | 东信和平科技股份有限公司 | A kind of awakening method and device based on ClassB mode |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6384318B2 (en) * | 2014-12-25 | 2018-09-05 | 沖電気工業株式会社 | COMMUNICATION DEVICE, COMMUNICATION DEVICE SYNCHRONIZATION METHOD, COMMUNICATION PROGRAM, AND COMMUNICATION SYSTEM |
| FR3047384B1 (en) * | 2016-01-28 | 2018-11-23 | Sagemcom Broadband Sas | METHOD FOR SYNCHRONIZING A GATEWAY IN A LORA NETWORK |
| KR102188552B1 (en) * | 2016-05-18 | 2020-12-08 | 니폰 덴신 덴와 가부시끼가이샤 | Wireless communication system, wireless terminal and time synchronization method |
-
2020
- 2020-01-03 CN CN202010006881.3A patent/CN111132291B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103457685A (en) * | 2012-05-29 | 2013-12-18 | 中国科学院沈阳自动化研究所 | Method for precisely synchronizing time of industrial wireless network on basis of prediction and compensation |
| CN106162844A (en) * | 2016-06-03 | 2016-11-23 | 西安电子科技大学 | Implementation method based on the MAC protocol for wireless sensor networks of LoRa |
| CN108834213A (en) * | 2018-04-04 | 2018-11-16 | 西安电子科技大学 | Low downlink delays communication means and system in a kind of Internet of Things |
| CN108601089A (en) * | 2018-05-23 | 2018-09-28 | 上海电机学院 | Based on LoRa wireless network DRDS-TDMA slot allocation methods |
| CN108880775A (en) * | 2018-07-20 | 2018-11-23 | 东信和平科技股份有限公司 | A kind of awakening method and device based on ClassB mode |
Non-Patent Citations (1)
| Title |
|---|
| 一种超低功耗无线传感器网络MAC协议;张轩等;《传感技术学报》;20141115(第11期);全文 * |
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