An electronic price tag adaptive concurrent communication method based on periodic broadcast

Abstract

The application discloses a kind of based on periodic broadcast electronic price tag adaptive concurrent communication method, it is related to electronic price tag field, including electronic price tag timing wake-up synchronous clock, and when meeting trigger condition, activate dynamic mapping module, according to own unique identification and current serial number carry out hash operation, report action is mapped to independent reply time slot, realize self-discipline concurrent report without roll call overhead, when downlink service priority, price tag is forced to suspend report, guarantee control flow absolute priority, access point is realized closed loop collision detection by aggregation implicit acknowledgement bitmap, and issue congestion coefficient to dynamically adjust backoff retransmission, avoid avalanche, global serial number is increased with period, so that collision price tag is determined to diverge in subsequent period because of hash seed change, fundamentally cut off sustained deadlock, the present application effectively reduces downlink bandwidth occupancy, improves concurrent success rate, optimizes terminal power consumption, and has service isolation and positioning extension capacity, applicable to high-density electronic price tag scene.

Description

Technical Field

[0001] This invention relates to the field of electronic shelf labels, specifically to an adaptive concurrent communication method for electronic shelf labels based on periodic broadcasting. Background Technology

[0002] Electronic Shelf Label (ESL) systems are widely used in retail, warehousing, and logistics. Their core function is to update product prices, inventory status, and promotional information in real time. A typical ESL network uses a star topology, consisting of one or more access points (APs) and a large number of terminal shelf labels. Communication links are mostly short-range wireless protocols such as Bluetooth Low Energy (BLE) or ZigBee. As store scale expands, a single AP needs to manage thousands or even tens of thousands of nodes, which places stringent demands on communication efficiency, power consumption, and reliability. In high-density store or warehouse networks with tens of thousands of nodes, electronic shelf labels (ESL) face the following pain points:

[0003] Severe downlink bandwidth congestion: The traditional point-to-point polling mechanism requires the access point to maintain a massive number of node states in memory and send wake-up commands one by one, resulting in extremely limited downlink bandwidth;

[0004] Concurrent collisions trigger avalanche: In connectionless communication architectures, if multiple price tags awakened from long-term sleep cycles simultaneously initiate heartbeat reporting, time slot collisions are highly likely to occur. Without a reasonable backoff and dynamic scheduling mechanism, this can lead to continuous deadlock collisions or retransmission avalanche.

[0005] Service priority interference: In two-way communication, disordered heartbeat reporting often occupies valuable channel resources, causing delays or failures in core services, such as the issuance of commercial price change instructions. Summary of the Invention

[0006] The purpose of this invention is to provide an adaptive concurrent communication method for electronic price tags based on periodic broadcasting. By reconstructing the uplink and downlink interaction logic at the protocol layer, it achieves efficient, low-power, and scheduling-free concurrent communication for a large number of nodes, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an adaptive concurrent communication method for electronic shelf labels based on periodic broadcasting, applied to a star-shaped Internet of Things (IoT) communication system containing at least one access point and multiple electronic shelf labels, comprising the following steps:

[0008] Access points generate and send broadcast frames periodically. The data payload of the broadcast frame contains a structured encapsulation of a global reporting sequence number and downlink service indication information. The global reporting sequence number increases with the broadcast period to provide a dynamic time reference for network-wide synchronization.

[0009] The electronic price tag is woken up within a preset sub-event window and receives the broadcast frame. It synchronizes the local clock by parsing the broadcast frame and extracts the current global reporting sequence number and the downlink service indication information.

[0010] In response to the downlink service indication information indicating that there is no downlink service pending on the electronic shelf label, and the difference between the historical serial number recorded locally on the electronic shelf label and the parsed global reporting serial number meets the preset trigger condition, the electronic shelf label activates the built-in dynamic mapping module.

[0011] The dynamic mapping module uses the physical unique identifier of the electronic price tag and the extracted global reporting sequence number as joint input parameters, performs a preset hash operation to output a time slot index value, thereby mapping the reporting action of the current period to an independent target response time slot within the sub-event window;

[0012] The electronic price tag sends the reported data to the access point within the target response time slot, and enters a dormant state after the transmission is completed, thereby achieving autonomous concurrent reporting without name-calling overhead.

[0013] Preferably, there is an asymmetric adaptive suspension interaction constraint between the downlink service indication information and the reporting action:

[0014] In response to the downlink service indication information indicating that the electronic price tag has a priority downlink service to be processed, the electronic price tag obtains the downlink interaction time slot from the broadcast frame and forcibly truncates the operation of the dynamic mapping module to suspend the reporting task of the current period.

[0015] The electronic price tag receives downlink service data from the access point during the downlink interaction time slot, ensuring the absolute priority of the core control flow, and resumes reporting when it is woken up again and the preset triggering condition is met again.

[0016] Preferably, the method further constructs uplink and downlink closed-loop collision detection by aggregating implicit confirmation bitmaps, specifically including:

[0017] After receiving data in the current period, the access point generates an implicit acknowledgment bitmap based on the data decoding status in each acknowledgment slot. Each bit in the implicit acknowledgment bitmap forms a one-to-one mapping relationship with the physical location of the acknowledgment slot. The access point encapsulates the implicit acknowledgment bitmap in the broadcast frame of the subsequent period.

[0018] In the next cycle after sending the reported data, the electronic price tag reads the implicit confirmation bitmap and uses the target response time slot calculated by the dynamic mapping module in the previous cycle as a lookup index to locate the corresponding bit in the implicit confirmation bitmap.

[0019] If the bit indicates a reception failure, the electronic price tag determines that a hash collision or channel fading occurred in the previous cycle, and triggers a random backoff and retransmission mechanism accordingly.

[0020] Preferably, the random backoff and retransmission mechanism utilizes network congestion status to dynamically adjust the backoff period, specifically including:

[0021] The access point periodically counts the proportion of bits indicating failure in the implicit acknowledgment bitmap, calculates the congestion backoff coefficient of the current network, and sends the congestion backoff coefficient with the broadcast frame.

[0022] When the electronic price tag triggers a retransmission, it extracts the congestion backoff coefficient and inputs it into the built-in random number generator to modulate the output range and generate a cross-cycle delay parameter K.

[0023] The electronic price tag sets the retransmission wake-up time in the local calendar to the current global reporting sequence number plus the delay parameter K, and remains in deep sleep until that time is reached, thereby spreading the concurrent flood to different future periods according to the real-time network congestion.

[0024] Preferably, the calculation process of the dynamic mapping module is controlled by the service type of the reported data to achieve service quality isolation at the physical layer.

[0025] The electronic price tag detects the data type to be reported;

[0026] If the data is determined to be in a normal state, the dynamic mapping module modulo the hash value of the physical unique identifier and the global reported sequence number with a first constant, and restricts the target response time slot to a pre-defined normal mapping area.

[0027] If the data is determined to be emergency alarm data, the dynamic mapping module takes the hash value modulo a second constant and adds a preset time slot offset to force the target response time slot to be routed to an emergency mapping area that is independent of the regular mapping area, so as to ensure that high-priority data is not affected by collisions with regular data when the channel is congested.

[0028] Preferably, the access point and the electronic price tag achieve predictive downlink piggyback interaction by sharing hash operation rules:

[0029] When the access point has non-urgent downlink data to be sent to the target electronic price tag, it places it in the buffer queue;

[0030] The access point extracts the unique identifier of the target electronic price tag and the current global reporting sequence number, performs a hash operation that is completely isomorphic to the electronic price tag, and positively predicts the target response time slot position that the target electronic price tag will use.

[0031] The access point triggers the downlink transmitter at the end edge of the target response time slot, and takes advantage of the very short receiver window after the target electronic price tag has been sent to send the non-urgent downlink data in the buffer queue without paging.

[0032] Preferably, the physical location of the target response time slot is multiplexed as an identity recognition carrier to achieve zero-load communication:

[0033] When the electronic price tag encapsulates and reports data, its physical unique identifier field is removed, and only a simplified business status code is retained. A zero-load data packet is generated and sent within the target response time slot.

[0034] After detecting the zero-load data packet within a specific response time slot, the access point extracts the index number of the response time slot and the current global reporting sequence number, runs a preset reverse derivation algorithm, and restores the physical unique identifier of the electronic price tag that sent the zero-load data packet on the access point side.

[0035] Preferably, the zero-load communication-based interactive network also integrates edge computing positioning functionality:

[0036] Multiple access points within adjacent coverage areas simultaneously listen to the specific response time slot and record the signal strength indication of the zero-load data packet they receive;

[0037] The edge computing gateway at the system backend receives signal strength indications from multiple access points in the same response time slot. Combined with the physical unique identifier derived in reverse as described in claim 7, it runs a spatial triangulation algorithm to obtain the real-time physical coordinates of the electronic price tag.

[0038] Preferably, the input parameters of the hash operation have a forced mutation interaction characteristic on the time axis:

[0039] Since the global reporting sequence number is forcibly incremented in each cycle, the combination of input parameters of the dynamic mapping module is different in each cycle. When at least two electronic price tags collide in the Nth cycle due to the same calculation result, in the N+1th cycle, the incrementing global reporting sequence number acts as a frequency hopping seed to cause the hash calculation result of the at least two electronic price tags to produce deterministic divergence, thereby cutting off the formation conditions of continuous deadlock collision at the protocol layer.

[0040] Preferably, the preset triggering condition establishes a long-term sleep interaction logic by comparing the local state with global variables:

[0041] The electronic price tag sets a long dormancy span threshold based on its own battery capacity or business frequency.

[0042] When the difference between the globally reported sequence number and the locally recorded historical sequence number is less than the long sleep span threshold, the electronic price tag immediately blocks the communication link and enters a low-power state after parsing the downlink service indication information, avoiding unnecessary hash operations and radio frequency activation, and realizing system-level adaptive power consumption control.

[0043] In summary, the beneficial effects of this invention are:

[0044] This invention transforms centralized scheduling into terminal-distributed autonomous triggering by introducing a globally reported sequence number, completely releasing the downlink computing power and bandwidth of the access point and greatly improving the network node capacity of the system. It utilizes a globally reported sequence number that increases periodically as a dynamic hash frequency hopping seed. Even if two terminals collide in a time slot during the current cycle, they will inevitably be mapped to different time slots in the next cycle due to the seed change, ensuring an extremely high first-time communication success rate.

[0045] An adaptive suspension strategy prioritizing control flow was established to ensure uninterrupted commercial pricing operations. Simultaneously, predictive piggybacking and aggregated implicit acknowledgment mechanisms maximized the value of the terminal's short-term wake-up window. Terminals without downlink traffic can quickly enter microampere-level deep sleep mode after sub-second-level micro-computation, significantly extending battery life.

[0046] The innovative zero-load communication not only significantly reduces the uplink air interface transmission time, but also enables the system to achieve real-time tracking of store assets and goods with zero additional communication cost while completing basic heartbeat maintenance. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a schematic diagram of the overall process framework of an adaptive concurrent communication method for electronic price tags based on periodic broadcasting according to the present invention.

[0049] Figure 2 This is a schematic diagram illustrating the electronic shelf label communication structure of an adaptive concurrent communication method for electronic shelf labels based on periodic broadcasting according to the present invention.

[0050] Figure 3 This is a schematic diagram illustrating the wireless data packets and time slots of an adaptive concurrent communication method for electronic price tags based on periodic broadcasting according to the present invention.

[0051] Figure 4This is a schematic diagram of a wireless communication sequence for an adaptive concurrent communication method for electronic price tags based on periodic broadcasting, according to the present invention. Detailed Implementation

[0052] The present invention will now be described in further detail with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0053] To facilitate understanding of the present invention, a more complete description of the invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the invention will be more thorough and complete.

[0054] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0055] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features for a similar purpose, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0056] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of at least two elements or the interaction relationship of at least two elements, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0057] Please see Figure 1 - Figure 4 This invention provides an embodiment of an adaptive concurrent communication method for electronic shelf labels based on periodic broadcasting. This method is primarily applied to a star-shaped Internet of Things (IoT) communication system containing at least one access point (AP) and a large number of electronic shelf labels (ESL). The underlying communication of this system can be based on, but is not limited to, the periodic broadcasting mechanism with response in the Bluetooth protocol, specifically including:

[0058] 1. Establishment of periodic broadcasting and dynamic time base

[0059] Access points (APs) continuously send broadcast frames into space according to a preset period. In this invention, the traditional broadcast frame payload has been restructured, which encapsulates the global reporting sequence number (REPORT_SN) and downlink service indication information.

[0060] REPORT_SN is a scalar that strictly increments with each broadcast cycle. It provides an absolutely synchronized dynamic time base and algorithm seed for all electronic price tags in a dormant state across the entire network.

[0061] Downlink business indication information can be in the form of a Bloom filter or a bitmap, used to indicate which electronic price tags currently have price change tasks pending.

[0062] 2. Long-term sleep interaction logic and triggering conditions

[0063] The electronic shelf label has a long dormancy span threshold set internally based on its own battery capacity or the store's heartbeat frequency requirements. For example, a threshold of 100 means that a heartbeat report is only made once every 100 broadcast cycles.

[0064] When an electronic shelf label briefly wakes up and receives a broadcast frame within its assigned subevent window, it extracts the REPORT_SN from the broadcast. The electronic shelf label then compares this REPORT_SN with its own stored historical serial number, i.e., the SN from the last successful report.

[0065] If the difference between the two is less than the long sleep span threshold, it means that there is no need to report a heartbeat in the current period. The electronic price tag will immediately block the subsequent processing of the communication link and directly enter a microampere-level deep sleep state with radio frequency shutdown to avoid invalid calculations and eavesdropping.

[0066] If the difference is greater than or equal to the threshold, the preset trigger condition is met, and the electronic price tag activates the built-in dynamic mapping module.

[0067] 3. Dynamic mapping and unscheduled transmission

[0068] The activated dynamic mapping module does not rely on any scheduling table issued by the access point, but performs time slot allocation calculations independently. It employs a pre-defined hash operation logic, using the electronic price tag's physical unique identifier (ESL_ID) and the extracted REPORT_SN as joint input parameters.

[0069] ;

[0070] Through the above calculations, the electronic price tag accurately maps the reporting action of this cycle to a target response time slot within the sub-event window.

[0071] Subsequently, the electronic price tag will periodically activate its radio frequency transmitter within this microsecond-level target response time slot to send reported data such as heartbeat or power level to the access point, and then immediately go into sleep mode after sending.

[0072] 4. Physical-level elimination of persistent deadlock collisions

[0073] Because REPORT_SN increments with the cycle, the input parameters of the hash operation exhibit a forced mutation characteristic on the time axis. Suppose that price tags A and B coincidentally have the same hash operation result in the Nth cycle, causing them to send data in the same target response time slot and resulting in an air collision; then in the N+1 or N+Kth cycle, when they try to report again, since the frequency hopping seed REPORT_SN has changed, their operation result will inevitably diverge. This fundamentally eliminates the conditions for the formation of continuous deadlock collisions between multiple devices.

[0074] It is worth mentioning that, in this embodiment, in order to solve the problem of service priority conflict in bidirectional communication.

[0075] In the actual commercial application of electronic price tag systems, the priority of price refresh operations must be under absolute control.

[0076] When the electronic price tag is activated and the downlink service indication information is parsed, it will trigger a hardware interrupt mechanism if it finds that it has been marked as having a priority downlink service such as "price change" or "configuration update".

[0077] Forced truncation: Regardless of whether the difference between the local historical serial number and the global serial number meets the reporting trigger condition, the electronic price tag will forcibly truncate the operation of the dynamic mapping module and suspend all heartbeat or power reporting tasks for this cycle.

[0078] Resource allocation: Electronic price tags obtain downlink interaction time slots allocated by the access point from the broadcast frame and keep the receiver on to prioritize and fully receive downlink service data, such as e-ink screen image dot matrix data.

[0079] Status recovery: After the price change is completed, the electronic price tag will resume its previously suspended reporting action only when it is woken up again at the next scheduled time and the long sleep span threshold is met again. This mechanism ensures high availability of price changes in complex radio frequency environments.

[0080] It should be noted that in this embodiment, the collision detection system possesses extremely strong self-healing capabilities, as detailed below:

[0081] The access point has eliminated the unicast ACK handshake response for uplink data. Instead, after receiving all acknowledgment slots in a complete cycle, the access point generates a highly compressed ACK_Bitmap. For example, if a sub-event contains 256 slots, the bitmap length is 256 bits. The value of the i-th bit represents the data decoding status of the i-th slot: 1 indicates success, and 0 indicates idle or CRC check failure due to a collision.

[0082] The bitmap is encapsulated in the broadcast frame of the subsequent cycle. The electronic price tag wakes up in the next cycle after completing the transmission action, and uses the target response slot index calculated in the previous round to look up the corresponding bit in the bitmap, thereby implicitly completing the closed-loop collision detection.

[0083] If the electronic price tag detects a corresponding bit as 0, a collision is determined. To prevent a large number of colliding price tags from being retransmitted simultaneously in the next cycle, causing a cascading failure, this embodiment introduces network congestion awareness:

[0084] The access point calculates the failure rate in the ACK_Bitmap in real time, determines the congestion backoff coefficient, and sends it out with the broadcast.

[0085] The electronic price tag extracts this coefficient and inputs it into the random number generator of the built-in microcontroller to generate an amplified cross-cycle delay parameter K.

[0086] Instead of immediately retransmitting, the electronic price tag modifies the local calendar, setting the next retransmission wake-up time to the current REPORT_SN plus a constant K. During this extended period, the terminal remains in deep sleep, successfully diluting the concentrated, instantaneous retransmission concurrency pressure over a broader timeline.

[0087] In addition, one embodiment provides a specific solution for service isolation at the physical layer.

[0088] The system can divide all available response time slot pools into different regions. For example, out of a total of 256 time slots, the first 200 are divided into a regular mapping region and the last 56 into an emergency mapping region.

[0089] Before packaging and reporting data, the electronic price tag detects the data type. The dynamic mapping module includes conditional branching logic:

[0090] Routine status data, such as 24-hour routine power consumption reporting:

[0091] Use formulas The reporting behavior is restricted to the regular mapping area.

[0092] Emergency alarm data (such as screen damage, anti-theft removal alarm):

[0093] Use formulas Due to the introduction of a change in the modulus base and a time slot offset (Offset=200), urgent data is forced to be routed to a separate interval.

[0094] Even if severe network congestion and frequent collisions occur in the regular mapping area, emergency alarm signals can still be delivered to the access point unimpeded in the open emergency mapping area.

[0095] In another embodiment, predictive downlink piggybacking and zero-load positioning based on network-wide isomorphic operations maximize the extraction of channel air interface time and space information, specifically including the following:

[0096] 1. Predictive downside carrying

[0097] Because the hash operation rules are completely symmetrical and isomorphic at the AP and ESL ends, when the access point has non-urgent downlink data, such as updating the internal font cache of electronic price tags, or sending a promotional template preview for the next day to the target price tag:

[0098] Access points should not proactively include wake-up commands in broadcasts to avoid increasing downlink scheduling bandwidth.

[0099] The access point simulates the joint hash calculation in the background server and positively predicts which microsecond time slot in which the target electronic price tag will initiate a heartbeat report in the future REPORT_SN cycle.

[0100] At the predicted moment, after the access point receives the reported data of the target price tag, it triggers the downlink transmitter during the few microseconds to tens of microseconds of the hold-overtime period before the target price tag's radio frequency receiver is completely turned off, thus "piggybacking" the buffered data to achieve seamless, paging-free bidirectional implicit synchronization.

[0101] 2. Zero-load communication and indoor triangulation

[0102] To minimize power consumption, a zero-load data structure can be used in regular heartbeat reporting.

[0103] In the data packets sent by the electronic price tag, the MAC address or ESL_ID, which takes up several bytes, is completely removed, and only a very simple business status code of 1 byte is retained. For example, 0x01 indicates that the battery is fully charged, and 0x02 indicates that the battery is below 20%.

[0104] After the access point antenna detects the radio frequency energy in a specific time slot and demodulates 0x02, the edge computing gateway extracts the index number of that time slot and the current REPORT_SN, runs a reverse derivation algorithm, such as building a pre-computed rainbow table or solving a reverse hash, and directly restores on the gateway side which ESL_ID sent the signal.

[0105] Meanwhile, if multiple adjacent access points deployed on the store ceiling simultaneously detect the zero-load data packet, they can obtain their respective Received Signal Strength Indication (RSSI) or Time Difference of Arrival (TDOA). The edge computing server integrates this physical layer information, combines it with the reverse-engineered ESL_ID, and runs a spatial triangulation algorithm to draw the real-time physical three-dimensional coordinate trajectory of the electronic shelf label on the store or warehouse shelf. This enables the electronic shelf label communication network to have both high-precision asset anti-loss and addressing functions.

[0106] In addition, the present invention also provides an example of a 24-hour operation log of a supermarket electronic price tag network.

[0107] Network nodes: Access point AP1, Electronic price tag ESL_A, Unique identifier 0x1A2B, Electronic price tag ESL_B, Unique identifier 0x3C4D.

[0108] Time slot configuration: Each Subevent contains 256 microsecond-level time slots. Slots 0-199 are the regular heartbeat zone, and Slots 200-255 are the emergency alarm zone.

[0109] Sleep threshold: The price tag is set to report the normal power consumption once every 100 broadcast cycles.

[0110] AP1 sends a periodic broadcast with the current global sequence number REPORT_SN=100, and the broadcast does not contain a price change indication.

[0111] The ESL_A internal timer wakes up and receives a broadcast. It finds that the locally recorded historical sequence number is 0, and the difference of 100 meets the trigger condition, so it prepares to report the battery level.

[0112] ESL_A removes the MAC address and generates only a simplified battery status code 0x01. The battery status code (S) is calculated using the formula. .

[0113] Airborne transmission: ESL_A transmits 0x01 in time slot 45.

[0114] Edge Backpropagation and Piggybacking: AP1 detects the signal in time slot 45 and confirms through reverse calculation that the sender is indeed ESL_A. At this time, AP1 finds a configuration for ESL_A's next-day promotional announcement in the buffer queue. Taking advantage of the microsecond gap between the end of time slot 45 and the start of ESL_A's radio frequency shutdown, AP1 "piggybacks" the configuration packet to ESL_A.

[0115] After receiving the piggyback configuration, ESL_A updates its local serial number to 100 and enters microampere-level deep hibernation.

[0116] A few minutes later, AP1 broadcast REPORT_SN=200. Currently, due to a large number of devices coming online at the store, AP1's calculated congestion rate has increased, and the broadcast includes a dynamic backoff coefficient Backoff_Multiplier=2.

[0117] ESL_A and ESL_B both reach their wake-up cycles simultaneously. Due to an extremely low probability of coincidence, their calculated hash mapping results collide:

[0118] ;

[0119] ;

[0120] Mid-air collision: Both transmitted data in time slot 88, causing signal overlap. AP1 verification failed, and decoding was impossible.

[0121] Loop closure detection: In the next broadcast cycle REPORT_SN=201, bit 88 of the ACK_Bitmap sent by AP1 is set to 0.

[0122] Dynamic backoff: ESL_A and ESL_B wake up to read the bitmap, find that bit 88 is 0, confirming the retransmission failure, and each extracts a backoff coefficient of 2, which is combined with an internal random number to generate delay parameters:

[0123] ESL_A generates a random number 3, with a final delay period. .

[0124] ESL_B generates a random number 1, with a final delay period. .

[0125] ESL_B will retransmit at SN=203, and ESL_A will retransmit at SN=207. Furthermore, since the SN (frequency hopping seed) has changed, the new time slots calculated by both are completely divergent, thus averting a collision.

[0126] The ESL_B, which was in deep sleep, was suddenly damaged by external force (the anti-tamper switch popped up), and the hardware interrupt instantly woke up the main control chip.

[0127] ESL_B listens for the most recent broadcast and obtains REPORT_SN=203.

[0128] If the current task is deemed urgent, different mapping formulas will be triggered:

[0129] ;

[0130] ESL_B issued an anti-tamper alarm in emergency time slot 230. Even though regular time slots 0-199 were crowded with other price tags that were retransmitting power, ESL_B's alarm still passed through the "dedicated lane" without hindrance, and was received by the AP in 1 second and triggered the store alarm.

[0131] The headquarters ERP system issued an instruction to reduce the price of product ESL_A by 50%. AP1 added ESL_A to the "downlink service instruction list" in the broadcast frame with REPORT_SN=300.

[0132] ESL_A just crossed the sleep threshold to wake up, and was originally scheduled to perform a routine power report.

[0133] After parsing the broadcast, ESL_A discovered that it had downlink traffic waiting to be received. Its underlying logic immediately and forcibly cut off the hash calculation for heartbeat reporting.

[0134] ESL_A dedicates all air interface time to receiving image dot matrix data containing promotional prices, successfully refreshing the screen display, and then immediately enters deep sleep mode. The originally scheduled power reporting task is suspended and postponed to the next wake-up cycle a few minutes later, ensuring 100% delivery rate and execution speed of the promotional business.

[0135] The above description is merely a specific embodiment of the invention, but the scope of protection of the invention is not limited thereto. Any variations or substitutions conceived without inventive effort should be included within the scope of protection of the invention. Therefore, the scope of protection of the invention should be determined by the scope defined in the claims.

Claims

1. An adaptive concurrent communication method for electronic shelf labels based on periodic broadcasting, applied to a star-shaped Internet of Things (IoT) communication system containing at least one access point and multiple electronic shelf labels, characterized in that: Includes the following steps: Access points generate and send broadcast frames periodically. The data payload of the broadcast frame contains a structured encapsulation of a global reporting sequence number and downlink service indication information. The global reporting sequence number increases with the broadcast period to provide a dynamic time reference for network-wide synchronization. The electronic price tag is woken up within a preset sub-event window and receives the broadcast frame. It synchronizes the local clock by parsing the broadcast frame and extracts the current global reporting sequence number and the downlink service indication information. In response to the downlink service indication information indicating that there is no downlink service pending on the electronic shelf label, and the difference between the historical serial number recorded locally on the electronic shelf label and the parsed global reporting serial number meets the preset trigger condition, the electronic shelf label activates the built-in dynamic mapping module. The dynamic mapping module uses the physical unique identifier of the electronic price tag and the extracted global reporting sequence number as joint input parameters, performs a preset hash operation to output a time slot index value, thereby mapping the reporting action of the current period to an independent target response time slot within the sub-event window; The electronic price tag sends the reported data to the access point within the target response time slot, and enters a dormant state after the transmission is completed, thereby achieving autonomous concurrent reporting without name-calling overhead.

2. The adaptive concurrent communication method for electronic price tags based on periodic broadcasting according to claim 1, characterized in that: There is an asymmetric adaptive suspension interaction constraint between the downlink service indication information and the reporting action, specifically including the following steps: In response to the downlink service indication information indicating that the electronic price tag has a priority downlink service to be processed, the electronic price tag obtains the downlink interaction time slot from the broadcast frame and forcibly truncates the operation of the dynamic mapping module to suspend the reporting task of the current period. The electronic price tag receives downlink service data from the access point during the downlink interaction time slot, ensuring the absolute priority of the core control flow, and resumes reporting when it is woken up again and the preset triggering condition is met again.

3. The adaptive concurrent communication method for electronic price tags based on periodic broadcasting according to claim 1, characterized in that: It also includes constructing uplink and downlink closed-loop collision detection by aggregating implicit confirmation bitmaps, specifically including the following steps: After receiving data in the current period, the access point generates an implicit acknowledgment bitmap based on the data decoding status in each acknowledgment slot. Each bit in the implicit acknowledgment bitmap forms a one-to-one mapping relationship with the physical location of the acknowledgment slot. The access point encapsulates the implicit acknowledgment bitmap in the broadcast frame of the subsequent period. In the next cycle after sending the reported data, the electronic price tag reads the implicit confirmation bitmap and uses the target response time slot calculated by the dynamic mapping module in the previous cycle as a lookup index to locate the corresponding bit in the implicit confirmation bitmap. If the bit indicates a reception failure, the electronic price tag determines that a hash collision or channel fading occurred in the previous cycle, and triggers a random backoff and retransmission mechanism accordingly.

4. The adaptive concurrent communication method for electronic price tags based on periodic broadcasting according to claim 3, characterized in that: The random backoff and retransmission mechanism utilizes network congestion status to dynamically adjust the backoff period, specifically including: The access point periodically counts the proportion of bits indicating failure in the implicit acknowledgment bitmap, calculates the congestion backoff coefficient of the current network, and sends the congestion backoff coefficient with the broadcast frame. When the electronic price tag triggers a retransmission, it extracts the congestion backoff coefficient and inputs it into the built-in random number generator to modulate the output range and generate a cross-cycle delay parameter K. The electronic price tag sets the retransmission wake-up time in the local calendar to the current global reporting sequence number plus the delay parameter K, and remains in deep sleep until that time is reached, thereby spreading the concurrent flood to different future periods according to the real-time network congestion.

5. The adaptive concurrent communication method for electronic price tags based on periodic broadcasting according to claim 1, characterized in that: The calculation of the dynamic mapping module is based on the service type control of the reported data, and specifically includes the following steps: The electronic price tag detects the data type to be reported; If the data is determined to be in a normal state, the dynamic mapping module modulo the hash value of the physical unique identifier and the global reported sequence number with a first constant, and restricts the target response time slot to a pre-defined normal mapping area. If the data is determined to be emergency alarm data, the dynamic mapping module takes the hash value modulo a second constant and adds a preset time slot offset to force the target response time slot to be routed to an emergency mapping area that is independent of the regular mapping area, so as to ensure that high-priority data is not affected by collisions with regular data when the channel is congested.

6. The adaptive concurrent communication method for electronic price tags based on periodic broadcasting according to claim 1, characterized in that: The access point and the electronic price tag achieve predictive downlink piggybacking by sharing hash operation rules, specifically including the following steps: When the access point has non-urgent downlink data to be sent to the target electronic price tag, it places it in the buffer queue; The access point extracts the unique identifier of the target electronic price tag and the current global reporting sequence number, performs a hash operation that is completely isomorphic to the electronic price tag, and positively predicts the target response time slot position that the target electronic price tag will use. The access point triggers the downlink transmitter at the end edge of the target response time slot, and takes advantage of the very short receiver window after the target electronic price tag has been sent to send the non-urgent downlink data in the buffer queue without paging.

7. The adaptive concurrent communication method for electronic price tags based on periodic broadcasting according to claim 5, characterized in that: The physical location of the target response time slot is multiplexed as an identity recognition carrier to achieve zero-load communication, specifically including the following steps: When the electronic price tag encapsulates and reports data, its physical unique identifier field is removed, and only a simplified business status code is retained. A zero-load data packet is generated and sent within the target response time slot. After detecting the zero-load data packet within a specific response time slot, the access point extracts the index number of the response time slot and the current global reporting sequence number, runs a preset reverse derivation algorithm, and restores the physical unique identifier of the electronic price tag that sent the zero-load data packet on the access point side.

8. The adaptive concurrent communication method for electronic price tags based on periodic broadcasting according to claim 7, characterized in that: The zero-load communication also integrates edge computing positioning, including multiple access points within adjacent coverage areas synchronously listening to the specific response time slot and recording the signal strength indication of the zero-load data packets they receive. The backend edge computing gateway receives the signal strength indication of the same response time slot reported by multiple access points and combines it with the physical unique identifier to run the spatial triangulation positioning algorithm to obtain the real-time physical coordinates of the electronic price tag.

9. The adaptive concurrent communication method for electronic price tags based on periodic broadcasting according to claim 7, characterized in that: The global reporting sequence number is forcibly incremented in each cycle, and the combination of input parameters of the dynamic mapping module is different in each cycle. When at least two electronic price tags collide in the Nth cycle due to the same calculation result, in the N+1th cycle, the incremented global reporting sequence number acts as a frequency hopping seed to cause the hash calculation result of the at least two electronic price tags to produce deterministic divergence, thereby cutting off the formation conditions of continuous deadlock collision at the protocol layer.

10. The adaptive concurrent communication method for electronic price tags based on periodic broadcasting according to claim 1, characterized in that: The preset triggering conditions establish a long-term sleep interaction logic by comparing the local state with global variables, specifically including: The electronic price tag sets a long dormancy span threshold based on its own battery capacity or business frequency. When the difference between the globally reported sequence number and the locally recorded historical sequence number is less than the long sleep span threshold, the electronic price tag immediately blocks the communication link and enters a low-power state after parsing the downlink service indication information, avoiding unnecessary hash operations and radio frequency activation, and realizing system-level adaptive power consumption control.

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