A wireless IO module and communication method based on dual-band cooperative transmission

Abstract

The present application relates to a kind of wireless IO module and communication method based on dual-band collaborative transmission, belong to industrial scene communication technical field.The wireless IO module of the present application uses dual-band radio frequency unit to be responsible for the wireless signal transmission on two independent frequency bands, signal processing is responsible by baseband processing unit, protocol execution and intelligent scheduling, and the logic of management device wired / wireless switching and wireless frequency band switching, not only can realize the seamless switching between wireless frequency bands, but also can realize the seamless switching between wired and wireless mode, improve the reliability of information transmission, while using differentiating strategy to deal with different frequency band environment, different frequency band uses different frequency hopping strategy, further improve the reliability of information transmission.

Description

Technical Field

[0001] This invention relates to a wireless I / O module and communication method based on dual-band cooperative transmission, belonging to the field of industrial communication technology. Background Technology

[0002] The industrial automation field is undergoing a transformation from wired to wireless communication, but traditional wireless technologies face numerous challenges in harsh industrial environments. Factors such as electromagnetic interference, equipment vibration, metal reflection, and extreme temperature fluctuations often lead to wireless connection interruptions, data packet loss, or increased latency, failing to meet the stringent requirements of determinism and reliability in industrial control.

[0003] In recent years, with the development of the Industrial Internet of Things (IIoT) and intelligent manufacturing, related research has mostly focused on improving the overall architecture and protocol performance of wireless communication systems, with less emphasis on anti-interference optimization design of wireless I / O modules themselves for harsh industrial environments. For example, CN215934863U discloses an interference-avoiding industrial bus I / O module that combines input / output modules with anti-interference circuits and oversampling technology to filter electromagnetic interference and interference pulses from equipment, thereby reducing malfunctions.

[0004] Therefore, current wireless I / O solutions on the market mainly suffer from the following defects: 1. Insufficient reliability: Traditional wireless technologies (such as Wi-Fi and Bluetooth) have high bit error rates in industrial electromagnetic interference environments, failing to meet the 1000 N / A reliability requirements of industrial control. -9 1. Packet error rate level. 2. Latency uncertainty: Most wireless protocols use a single frequency band for transmission. While retransmission mechanisms ensure reliability in the event of interference, they introduce unpredictable latency, failing to meet real-time control requirements. 3. Poor compatibility: Most existing wireless I / O modules are incompatible with wired interfaces, hindering a smooth transition from wired to wireless. Some solutions supporting wired connections suffer from data interruption during switching. 4. Limited transmission distance: Wireless modules operating in the 2.4GHz band have limited transmission distances and experience severe signal attenuation in complex industrial environments. A single Sub-1GHz solution cannot simultaneously meet bandwidth requirements.

[0005] To address this, some researchers have proposed a dual-band collaborative transmission wireless I / O module, such as the Chinese patent application CN 120129007A. This application discloses a wireless BMS management system with strong anti-interference capabilities, including a master node, multiple slave nodes, a dual-band communication module, a mesh network topology, a wideband ceramic antenna array, and an AI channel prediction module. The dual-band communication module uses the Sub-1GHz and 2.4GHz bands. The Sub-1GHz band is used for periodic transmission of voltage and temperature data from slave nodes to the master node, while the 2.4GHz band is used for the master node to issue real-time control commands to slave nodes. The master node dynamically triggers band switching based on RSSI and BER feedback from slave nodes. The AI ​​channel prediction module dynamically selects the optimal frequency band and time slot based on historical communication data. Although this solution considers dual-band communication transmission using the Sub-1GHz and 2.4GHz bands and discloses band switching and the main content transmitted on each band, various interferences in industrial automation scenarios still lead to low communication reliability. Summary of the Invention

[0006] The purpose of this invention is to provide a wireless I / O module and communication method based on dual-band cooperative transmission to solve the problem of low reliability of wireless communication in current industrial automation scenarios.

[0007] To address the aforementioned technical problems, this invention provides a wireless I / O module based on dual-band cooperative transmission in a first aspect. This module includes a dual-band radio frequency unit, a baseband processing unit, an I / O interface unit, and an antenna system. The dual-band radio frequency unit is responsible for simultaneously transmitting and receiving wireless signals on two independent frequency bands, employing different frequency hopping strategies for each band. The baseband processing unit is responsible for signal processing, protocol execution, and intelligent scheduling, and manages the wired / wireless switching logic and the switching logic between wireless frequency bands. The I / O interface unit is responsible for the physical connection with field sensors and actuators, sending received signals to the actuators and uploading data collected by the field sensors. The antenna system is used to realize the mutual conversion between electrical signals and electromagnetic waves.

[0008] The wireless I / O module of this invention uses a dual-band radio frequency unit to handle wireless signal transmission on two independent frequency bands. The baseband processing unit is responsible for signal processing, protocol execution, and intelligent scheduling, and manages the wired / wireless switching and wireless frequency band switching logic. It can not only achieve seamless switching between wireless frequency bands, but also seamless switching between wired and wireless modes, improving the reliability of information transmission. At the same time, it adopts a differentiated strategy to deal with different frequency band environments, and different frequency hopping strategies are used for different frequency bands, further improving the reliability of information transmission.

[0009] In one possible implementation, the dual-band radio frequency unit supports the Sub-1GHz band and the 2.4GHz band. The Sub-1GHz link is used to transmit non-real-time, large-packet data and as a redundancy backup; the 2.4GHz link is used to transmit control commands with high real-time requirements.

[0010] This invention utilizes the advantages of high output power and large transmission bandwidth of the Sub-1GHz band to transmit non-real-time, large-packet data and as a redundancy backup, and utilizes the high transmission speed of the 2.4GHz band to transmit control commands with high real-time requirements. This invention makes full use of the advantages of each frequency band, ensuring not only transmission reliability but also real-time requirements.

[0011] In one possible implementation, the baseband processing unit manages the wireless frequency band switching logic by: when the interference intensity of a certain frequency band is detected to be continuously higher than a set threshold, controlling the radio frequency switch inside the dual-band radio frequency unit to switch all services to another frequency band within a set time.

[0012] When switching frequency bands, this invention takes into account not only the intensity of interference but also the duration of interference, thus avoiding switching caused by temporary interference.

[0013] In one possible implementation, the baseband processing unit manages the wired / wireless switching logic using a mechanism combining pre-authentication and binding, connection state synchronization, and seamless data migration. This includes: upon initial wired connection, generating a unique device fingerprint based on the device MAC address, hardware ID, and the digital certificate exchanged during the initial connection; establishing a dual-band wireless connection channel based on the unique device fingerprint; enabling the wired and wireless interfaces to share a unified connection state machine; continuously monitoring the connection status of the wired and wireless links after the device is running normally; and immediately triggering the switching mechanism when a wired connection is detected to be disconnected or the wireless signal quality drops to a set threshold.

[0014] This invention establishes a secure wireless connection based on the authentication information from the initial wired connection, eliminating the need for re-authentication when establishing a wireless connection.

[0015] One possible approach is to use different frequency hopping strategies for different frequency bands: in the 2.4 GHz band, adaptive frequency hopping is used to avoid interfering frequencies through real-time spectrum monitoring; in the Sub-1 GHz band, fixed frequency hopping is used to provide a stable and deterministic communication path under compliance.

[0016] This invention employs a differentiated strategy to address different frequency band environments. In the congested 2.4GHz band, adaptive frequency hopping is used to maintain a clean communication path in the "spectrum maze." In the Sub-1GHz band, which has better propagation, a pre-set fixed frequency hopping sequence is used to ensure compliance with local radio regulations for the use of "licensed exemption" frequency bands.

[0017] In one possible implementation, the wireless I / O module constructs an end-to-end data assurance system from encoding to acknowledgment at the data transmission layer, including fault-tolerant coding and a multi-layer acknowledgment mechanism. The fault-tolerant coding adopts a concatenated coding method that combines the outer code of RS code with the inner code of convolutional code. The multi-layer acknowledgment mechanism adopts an end-to-end triple acknowledgment mechanism of physical layer, link layer and application layer.

[0018] This invention ensures highly robust data transmission and reliable delivery through forward-looking fault-tolerant coding and multi-layered confirmation mechanisms.

[0019] In one possible implementation, the wireless I / O module also employs a cross-band redundant transmission mechanism: transmitting critical control data simultaneously on both the 2.4GHz and Sub-1GHz dual-band frequencies.

[0020] This invention significantly eliminates the risk of communication interruption due to complete interference of a single frequency band by redundantly backing up key control data in the frequency domain, thereby improving the reliability of subsequent industrial control.

[0021] In one possible implementation, the wireless I / O module employs a double-buffered architecture at the data transmission level to ensure that data packets are not lost or duplicated during handover.

[0022] This invention uses a double-buffering architecture to avoid data packet loss and duplication during handover, thereby improving data reliability during handover.

[0023] In one possible implementation, the wireless I / O module also adjusts the transmission power at the communication link level based on real-time feedback of signal reception strength and bit error rate, reducing the transmission power when at close range or with good channel quality, and increasing the transmission power when the signal is blocked or interfered with.

[0024] This invention treats the transmission power as a dynamic variable and adjusts it based on real-time feedback of the signal reception strength and bit error rate. When the signal is close or the channel quality is good, the power is automatically reduced to reduce self-interference and power consumption. When the signal is blocked or interfered with, the power is intelligently increased to instantly enhance the signal penetration, thereby dynamically maintaining the optimal signal-to-noise ratio.

[0025] To address the aforementioned technical problems, this invention provides a communication method based on dual-band cooperative transmission in a second aspect. This communication method is implemented using a wireless I / O module based on dual-band cooperative transmission. The wireless I / O module includes a dual-band radio frequency unit, a baseband processing unit, an I / O interface unit, and an antenna system. The dual-band radio frequency unit is responsible for simultaneously transmitting and receiving wireless signals on two independent frequency bands, with different frequency hopping strategies employed for different bands. The baseband processing unit is responsible for signal processing, protocol execution, and intelligent scheduling, and manages the wired / wireless switching logic and the switching logic between wireless frequency bands. The I / O interface unit is responsible for the physical connection with field sensors and actuators, sending received signals to the actuators and uploading data collected by the field sensors. The antenna system is used to realize the mutual conversion between electrical signals and electromagnetic waves.

[0026] The wireless I / O module of this invention uses a dual-band radio frequency unit to handle wireless signal transmission on two independent frequency bands. The baseband processing unit is responsible for signal processing, protocol execution, and intelligent scheduling, and manages the wired / wireless switching and wireless frequency band switching logic. It can not only achieve seamless switching between wireless frequency bands, but also seamless switching between wired and wireless modes, improving the reliability of information transmission. At the same time, it adopts a differentiated strategy to deal with different frequency band environments, and different frequency hopping strategies are used for different frequency bands, further improving the reliability of information transmission.

[0027] In one possible implementation, the dual-band radio frequency unit supports the Sub-1GHz band and the 2.4GHz band. The Sub-1GHz link is used to transmit non-real-time, large-packet data and as a redundancy backup; the 2.4GHz link is used to transmit control commands with high real-time requirements.

[0028] This invention makes full use of the advantages of each frequency band, ensuring not only transmission reliability but also real-time transmission requirements.

[0029] In one possible implementation, the baseband processing unit manages the wireless frequency band switching logic by: when the interference intensity of a certain frequency band is detected to be continuously higher than a set threshold, controlling the radio frequency switch inside the dual-band radio frequency unit to switch all services to another frequency band within a set time.

[0030] When switching frequency bands, this invention takes into account not only the intensity of interference but also the duration of interference, thus avoiding switching caused by temporary interference.

[0031] In one possible implementation, the baseband processing unit manages the wired / wireless switching logic using a mechanism combining pre-authentication and binding, connection state synchronization, and seamless data migration. This includes: upon initial wired connection, generating a unique device fingerprint based on the device MAC address, hardware ID, and the digital certificate exchanged during the initial connection; establishing a dual-band wireless connection channel based on the unique device fingerprint; enabling the wired and wireless interfaces to share a unified connection state machine; continuously monitoring the connection status of the wired and wireless links after the device is running normally; and immediately triggering the switching mechanism when a wired connection is detected to be disconnected or the wireless signal quality drops to a set threshold.

[0032] This invention establishes a secure wireless connection based on the authentication information from the initial wired connection, eliminating the need for re-authentication when establishing a wireless connection.

[0033] One possible approach is to use different frequency hopping strategies for different frequency bands: in the 2.4 GHz band, adaptive frequency hopping is used to avoid interfering frequencies through real-time spectrum monitoring; in the Sub-1 GHz band, fixed frequency hopping is used to provide a stable and deterministic communication path under compliance.

[0034] This invention employs a differentiated strategy to address different frequency band environments. In the congested 2.4GHz band, adaptive frequency hopping is used to maintain a clean communication path in the "spectrum maze." In the Sub-1GHz band, which has better propagation, a pre-set fixed frequency hopping sequence is used to ensure compliance with local radio regulations for the use of "licensed exemption" frequency bands.

[0035] In one possible implementation, the wireless I / O module constructs an end-to-end data assurance system from encoding to acknowledgment at the data transmission layer, including fault-tolerant coding and a multi-layer acknowledgment mechanism. The fault-tolerant coding adopts a concatenated coding method that combines the outer code of RS code with the inner code of convolutional code. The multi-layer acknowledgment mechanism adopts an end-to-end triple acknowledgment mechanism of physical layer, link layer and application layer.

[0036] This invention ensures highly robust data transmission and reliable delivery through forward-looking fault-tolerant coding and multi-layered confirmation mechanisms.

[0037] In one possible implementation, the wireless I / O module also employs a cross-band redundant transmission mechanism: transmitting critical control data simultaneously on both the 2.4GHz and Sub-1GHz dual-band frequencies.

[0038] This invention significantly eliminates the risk of communication interruption due to complete interference of a single frequency band by redundantly backing up key control data in the frequency domain, thereby improving the reliability of subsequent industrial control.

[0039] In one possible implementation, the wireless I / O module employs a double-buffered architecture at the data transmission level to ensure that data packets are not lost or duplicated during handover.

[0040] This invention uses a double-buffering architecture to avoid data packet loss and duplication during handover, thereby improving data reliability during handover.

[0041] In one possible implementation, the wireless I / O module also adjusts the transmission power at the communication link level based on real-time feedback of signal reception strength and bit error rate, reducing the transmission power when at close range or with good channel quality, and increasing the transmission power when the signal is blocked or interfered with.

[0042] This invention treats the transmission power as a dynamic variable and adjusts it based on real-time feedback of the signal reception strength and bit error rate. When the signal is close or the channel quality is good, the power is automatically reduced to reduce self-interference and power consumption. When the signal is blocked or interfered with, the power is intelligently increased to instantly enhance the signal penetration, thereby dynamically maintaining the optimal signal-to-noise ratio. Attached Figure Description

[0043] Figure 1 This is a system architecture diagram of the wireless I / O module based on dual-band cooperative transmission of the present invention; Figure 2 This is a schematic diagram of the dual-band cooperative transmission mechanism used by the dual-band radio frequency unit in this invention; Figure 3 This is a flowchart of the wired-to-wireless seamless switching process of the wireless I / O module based on dual-band collaborative transmission according to the present invention. Figure 4 This is a schematic diagram of the active interference avoidance at the link level of the wireless IO module based on dual-band cooperative transmission according to the present invention; Figure 5 This is a schematic diagram illustrating the principle of the wireless I / O module based on dual-band collaborative transmission in this invention, ensuring end-to-end data transmission. Detailed Implementation

[0044] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0045] The IO module of this invention adopts a wired and dual-band wireless collaborative transmission mechanism, which can not only achieve seamless switching between wireless frequency bands, but also seamless switching between wired and wireless modes. At the same time, it adopts a differentiated strategy to deal with different frequency band environments, and different frequency hopping strategies are used for different frequency bands, further improving the reliability of information transmission.

[0046] Implementation Method 1 for Wireless I / O Module Based on Dual-Band Cooperative Transmission The wireless I / O module based on dual-band cooperative transmission adopts a modular design, mainly including a dual-band RF unit, a baseband processing unit, an I / O interface unit, a power management unit, and an antenna system. The dual-band RF unit is responsible for simultaneously transmitting and receiving wireless signals on two independent frequency bands; the baseband processing unit is responsible for signal processing, protocol execution, and intelligent scheduling; the I / O interface unit is responsible for physical connections with field sensors and actuators; the power management unit provides a stable, efficient, and flexible power supply for the entire module; and the antenna system realizes the mutual conversion between electrical signals and electromagnetic waves. The overall system architecture is as follows: Figure 1 As shown.

[0047] like Figure 2 As shown, the dual-band RF unit simultaneously supports the Sub-1GHz band (860-930MHz) and the 2.4GHz band. Through an intelligent link allocation algorithm, it achieves parallel data transmission and redundancy backup. The two RF systems can operate independently simultaneously. The Sub-1GHz link is responsible for transmitting non-real-time, large-packet data and serves as a redundancy backup, targeting bandwidth-sensitive non-real-time control data. It supports a high receive sensitivity of -124dBm and a maximum output power of +19dBm, possessing excellent long-distance and wall-penetrating capabilities. The 2.4GHz link is responsible for transmitting control commands with high real-time requirements, targeting time-sensitive real-time control data. It supports multiple 2.4GHz protocols such as Bluetooth and Zigbee, and integrates a high-gain PA and LNA, providing high-speed data transmission capabilities. The adopted dual-band transmission mechanism also has a band switching mechanism. For example, when continuous interference is detected in a certain band (such as a PER continuously exceeding a threshold), the RF switch inside the unit can switch all services to another band within 10ms under the control of the baseband processing unit. In addition, the built-in spectrum analysis engine can scan and evaluate the interference intensity within both frequency bands in real time, providing data support for intelligent link allocation. Both the Sub-1GHz and 2.4GHz bands employ a hybrid FDMA+TDMA multiple access approach, but with different focuses and parameters. 2.4GHz: FDMA allocates wideband channels, while TDMA performs fine-grained time division, emphasizing high throughput, low latency, and anti-collision performance; Sub-1GHz: FDMA allocates narrowband channels (core), with TDMA assisting in time division, emphasizing long-distance operation, low power consumption, and strong anti-interference capabilities. Control logic: FDMA selects channels, and TDMA schedules times; frequency domain isolation and time domain scheduling work together to avoid collisions and reduce interference.

[0048] The baseband processing unit, as the core hub of the I / O module, uses an ARM Cortex-M33 dual-core processor and undertakes dual core functions: first, it runs the real-time protocol stack, processing high-priority real-time data such as I / O status updates, ensuring a 5ms deterministic latency; second, it runs application-layer programs and network management algorithms, handling non-real-time tasks such as device discovery, link quality analysis, and intelligent routing. Based on the standard IO-Link Wireless protocol, this unit adds a frequency band selection field and a service type identifier, while managing wired / wireless switching and wireless frequency band switching logic. By maintaining connection status and sequence numbers, it ensures data transmission continuity.

[0049] The IO interface unit is responsible for the physical connection with the field sensors and actuators, and is used to send the received signals to the actuators and upload the data collected by the field sensors. Therefore, the IO interface unit used in this invention has a comprehensive range of interface types, high-precision signal processing capabilities and multiple electrical protections, is suitable for complex industrial scenarios, and supports flexible wired / wireless communication switching. It mainly includes: (1) Digital interface: The DI channel supports 24V sink / source input, has built-in optocoupler isolation, and is suitable for buttons, limit switches, etc.; the DO channel uses MOSFET output (0.5A) and can drive loads such as relays and indicator lights. (2) Analog interface: The AI ​​channel integrates a 16-bit ADC, supports 0-10V, ±10V, 0 / 4-20mA signal input, and is suitable for temperature and pressure transmitters, etc.; the AO channel has a 12-bit DAC, and the output signal range is consistent with the AI ​​channel. (3) Dedicated communication interface: The IO-Link master port supports device parameter configuration and advanced diagnostics; the RS-485 / Modbus RTU interface is used to connect traditional serial devices. All I / O channels employ a dual isolation design, including magnetic or capacitive isolation, to ensure reliable signal transmission; integrated gas discharge tubes and TVS diodes provide surge (±2kV) and electrostatic discharge protection; built-in overcurrent protection and reverse connection protection circuits effectively prevent equipment damage caused by wiring errors.

[0050] The power management unit provides a stable, efficient, and flexible power supply solution for the entire module. It supports a wide voltage input of 12-36VDC industrial standard and is compatible with 24V systems. At the same time, it meets the needs of different units through multi-channel voltage conversion: the DC-DC buck converter generates a 3.3V main power supply for the system with a conversion efficiency of up to 95%; the LDO linear regulator provides a clean 1.8V and 1.2V power supply for the analog part of the RF chip, effectively reducing noise interference. The unit has advanced power management capabilities and supports dynamic power adjustment, including three modes: (1) active mode, all units run at full speed, peak power consumption <2W; (2) listening mode, the RF unit periodically wakes up to listen, and the average power consumption drops to 20mW; (3) deep sleep mode, only the wake-up circuit of the IO interface works, and the power consumption <1mW. At the same time, with the intelligent wake-up mechanism, the IO interface unit can be configured as "change wake-up", which automatically wakes up the entire system when a change in DI status is detected, greatly reducing standby power consumption.

[0051] As the ultimate guarantee of wireless communication performance, the design quality of the antenna system directly determines the communication distance and reliability. In the wireless I / O module of this embodiment, the antenna adopts an integrated metal shell design, precisely casting both Sub-1GHz and 2.4GHz frequency band antennas inside the metal shell, combining radiation and protection functions. The two antennas are orthogonally arranged in physical structure, effectively reducing coupling interference between them and achieving spatial diversity. Simultaneously, the module is equipped with a standard SMA external antenna interface, facilitating the connection of high-gain antennas in environments with severe signal shielding, thus improving communication stability. Regarding key technologies, the antenna system employs antenna diversity technology, which monitors the received signal strength (RSSI) of the two antennas in real time and automatically switches to the antenna with the better signal using a built-in RF switch, thereby effectively suppressing the impact of small-scale fading. Furthermore, a π-type matching network is used to perform low-loss impedance matching between the antenna and the RF front end, controlling the voltage standing wave ratio (VSWR) below 1.5, improving energy transmission efficiency.

[0052] Meanwhile, the wireless I / O module based on dual-band collaborative transmission of this invention adopts a mechanism combining pre-authentication and binding, connection state synchronization, and seamless data migration to achieve seamless switching technology between wired and wireless connections. At the data transmission level, a dual-buffer architecture is used to ensure that data packets are not lost or duplicated during switching. Specifically, wireless transmission uses two independent data buffers, denoted as buffer A and buffer B, which are alternately written to and read from, preventing simultaneous reading and writing of the same block. No data loss: At the moment of switching, the old buffer has already stored all the data and will not be cleared or overwritten; new data is written to the backup buffer, and reading and writing do not interfere with each other, so the data will not be erased. No duplication: The two buffer states are mutually exclusive: the write area ≠ the read area; after reading, the marker is cleared, preventing the same data packet from being read repeatedly.

[0053] In terms of key technologies, the system achieves proactive and rapid handover based on a signal quality prediction model. This allows for handover to be initiated before link quality degrades to a threshold, avoiding interruptions caused by traditional reactive responses. Simultaneously, through cross-layer collaborative optimization across the physical, link, and application layers, the overall handover time is controlled within 5 milliseconds, effectively ensuring communication continuity and stability. Its core process is as follows: Figure 3 As shown, the process mainly consists of three stages: 1. Initialization Preparation: When the device first connects via wired connection, a unique device fingerprint is generated based on the device's MAC address, hardware ID, and the digital certificate exchanged during the initial connection. This fingerprint is securely stored in the system, establishing a dual-band (2.4GHz and Sub-1GHz) wireless connection channel for the device. 2. Operational Detection: After establishing the dual-band wireless connection, each link in operation is detected. The wired and wireless interfaces share a unified connection state machine. After the device is running normally, the system continuously monitors the connection status of the wired and wireless links, synchronizing link quality information in real time to provide a basis for switching decisions. 3. Intelligent Switching: Once a wired connection is detected to be disconnected or the wireless signal quality is severely degraded, the system immediately triggers the switching mechanism. Establishing a wireless connection channel based on a unique device fingerprint essentially compresses the traditional three-step process of "authentication-association-key negotiation" into a single "rapid re-association" based on local cache trust. The device fingerprint acts as a trust anchor, transforming the establishment of the wireless connection channel from "authentication from scratch" to "rapid credential reuse." This is the core technology for achieving seamless wired-wireless switching in industrial applications.

[0054] The core of the security of a device fingerprint-based fast reconnection mechanism lies in the secure authentication and key exchange process during the initial connection. This process must establish trust (generate a device fingerprint), pre-configure a security key (PMK, etc.) for subsequent seamless switching, and ensure that the entire process is protected against eavesdropping and tampering.

[0055] Switching process: This process occurs when the device is first wired connected and can be divided into three stages, as follows: Phase 1: Certificate Verification and Identity Binding (Establishing a Trusted Identity) The goal of this phase is to verify the legitimacy of the device identity and generate a unique device fingerprint.

[0056] Phase 2: Master Key Negotiation (Generating a "Master Key" for Fast Switching) The goal of this phase is to generate a long-term valid "Master Key" that will be used to derive the encryption keys for all subsequent sessions.

[0057] Phase 3: Session Key Derivation and Packet Storage (Initialization Completed) The goal of this phase is to derive a temporary key for the current wired session and prepare all necessary security packets for future wireless handovers.

[0058] "Pre-establishment" is a typical space-for-time strategy. "Pre-established wireless channel" does not mean that a fully active backup wireless link is already transmitting data before the handover occurs. If that were the case, it would create two parallel active links, causing network loops, IP address conflicts, and wasted power. Here, "pre-establishment" means that at the logical and security packet levels, the necessary conditions for the wireless channel are already prepared in advance, in a "standby" or "semi-active" state.

[0059] Therefore, the present invention can utilize pre-stored device fingerprints and pre-established wireless channels, eliminating the need for time-consuming authentication processes.

[0060] Furthermore, this invention constructs a collaborative anti-interference solution consisting of two levels: "active avoidance" and "fault tolerance guarantee," ensuring the highest reliability of industrial wireless communication in harsh electromagnetic environments.

[0061] 1. Active interference avoidance at the communication link layer like Figure 4 As shown, the IO module of this invention adopts a differentiated strategy to deal with different frequency band environments. In the congested 2.4GHz frequency band, it adopts adaptive frequency hopping and intelligently avoids interference frequency points through real-time spectrum monitoring to achieve "dynamic cleanliness". In the Sub-1GHz frequency band with better propagation, it adopts fixed frequency hopping to provide a stable and deterministic communication path under the premise of compliance.

[0062] Adaptive frequency hopping: In the congested 2.4GHz public band, the module can dynamically switch communication channels at a high rate of 50 times per second. By continuously monitoring spectrum quality, it intelligently avoids frequency bands occupied by persistent interference (such as Wi-Fi) or transient noise, thus maintaining a clean communication path in the "spectrum maze".

[0063] Fixed frequency hopping: In the Sub-1GHz band (such as 870MHz), where propagation characteristics are better and penetration is stronger, a pre-set fixed frequency hopping sequence is used. This mode provides a stable and predictable communication mode while ensuring compliance with local radio regulations for "licensed exemption" band usage requirements, and is particularly suitable for control commands with high deterministic requirements.

[0064] Real-time power control: The transmit power is not fixed but a dynamic variable. The module finely adjusts the power within a wide range of -20dBm to +19dBm based on real-time feedback of Received Signal Strength Indicator (RSSI) and Bit Error Rate (BER). It automatically reduces power at close range or in areas with good channel quality to minimize self-interference and power consumption; and intelligently increases power when the signal is blocked or interfered with, instantly enhancing signal penetration, thereby dynamically maintaining the optimal signal-to-noise ratio. This invention treats transmit power as a dynamic variable, finely adjusting it within the range of -20dBm to +19dBm based on RSSI and BER. This achieves intelligent power allocation that is weaker at close range and stronger at long range, always maintaining the optimal signal-to-noise ratio and saving energy.

[0065] 2. End-to-end fault tolerance guarantee at the data transmission layer like Figure 5 As shown, the IO module of this invention constructs an end-to-end data protection system from encoding to confirmation at the data transmission level. Through forward-looking fault-tolerant coding and multi-layer confirmation mechanisms, it jointly ensures highly robust data transmission and reliable delivery. Specifically, the fault-tolerant coding adopts strong error-correcting coding, and the multi-layer confirmation mechanism adopts a triple confirmation mechanism.

[0066] Strong error correction coding: It adopts concatenated coding technology, combining the outer code of Reed-Solomon (RS) code with the inner code of convolutional code. Convolutional code is good at correcting randomly distributed bit errors, while RS code can effectively repair bursty continuous data block errors. The two work together to form a powerful forward error correction (FEC) capability, which enables the receiver to discover and correct most transmission errors on its own without decoding, and can significantly improve the robustness of data transmission.

[0067] Triple confirmation mechanism: This invention designs an end-to-end confirmation mechanism that runs through the physical layer, link layer and application layer. Data packets must be validated at each layer. If the confirmation at any layer times out, a retransmission will be triggered immediately. This builds a defense-in-depth system and fundamentally eliminates data packet loss caused by the failure of a single layer confirmation.

[0068] Furthermore, to further improve transmission reliability, the IO module of this invention also employs cross-frequency band redundant transmission: For the most critical control data such as switch signals and emergency stop signals, i.e., the real-time control data mentioned earlier, this invention adopts a "redundant parallel" strategy. Data packets are transmitted simultaneously on both the 2.4GHz and Sub-1GHz frequency bands. The receiving end is considered successful as long as it receives the data correctly on either frequency band. This frequency domain redundancy greatly eliminates the risk of communication interruption due to complete interference of a single frequency band.

[0069] Through the aforementioned multi-layered and collaborative technical means, a complete anti-interference solution is formed, providing a solid guarantee for the stable operation of industrial wireless communication systems in harsh environments. Compared with traditional wireless I / O modules, this invention has significant improvements in spectrum utilization, error correction capabilities, power control, and data confirmation, as shown in Table 1.

[0070] Table 1 Implementation Method 2 for Wireless I / O Module Based on Dual-Band Cooperative Transmission The wireless I / O module based on dual-band cooperative transmission of the present invention includes a dual-band radio frequency unit, a baseband processing unit, an I / O interface unit, and an antenna system. The dual-band radio frequency unit is responsible for simultaneously transmitting and receiving wireless signals on two independent frequency bands, with different frequency hopping strategies employed for different frequency bands. The baseband processing unit is responsible for signal processing, protocol execution, and intelligent scheduling, and manages the wired / wireless switching logic and the switching logic between wireless frequency bands. The I / O interface unit is responsible for the physical connection with field sensors and actuators, sending received signals to the actuators and uploading data collected by the field sensors. The antenna system is used to realize the mutual conversion between electrical signals and electromagnetic waves.

[0071] The dual-band RF unit in this embodiment supports the Sub-1GHz and 2.4GHz bands. The Sub-1GHz link is used for transmitting non-real-time, large-packet data and serves as a redundancy backup; the 2.4GHz link is used for transmitting control commands with high real-time requirements. The baseband processing unit manages the wireless band switching logic, including: when the interference intensity of a certain band is detected to be continuously higher than a set threshold, controlling the RF switch inside the dual-band RF unit to switch all services to another band within a set time. The baseband processing unit manages the wired / wireless switching logic using a mechanism combining pre-authentication and binding, connection state synchronization, and seamless data migration. This includes: upon initial wired connection, generating a unique device fingerprint based on the device MAC address, hardware ID, and the digital certificate exchanged during the initial connection; establishing a dual-band wireless connection channel based on this unique device fingerprint; sharing a unified connection state machine between the wired and wireless interfaces; continuously monitoring the connection status of the wired and wireless links after the device is running normally; and immediately triggering the switching mechanism when a wired connection is detected to be disconnected or the wireless signal quality drops to a set threshold.

[0072] The wireless I / O module employs differentiated strategies to address different frequency band environments. In the 2.4GHz band, it uses adaptive frequency hopping, intelligently avoiding interference frequencies through real-time spectrum monitoring. In the Sub-1GHz band, it uses fixed frequency hopping, providing a stable and deterministic communication path while adhering to compliance requirements. At the data transmission level, the wireless I / O module constructs an end-to-end data assurance system from encoding to acknowledgment, including fault-tolerant coding and a multi-layered acknowledgment mechanism. The fault-tolerant coding uses a concatenated coding method combining the outer code of RS code with the inner code of convolutional code. The multi-layered acknowledgment mechanism employs an end-to-end triple acknowledgment mechanism at the physical layer, link layer, and application layer. Data packets must undergo validity verification at each layer, and a timeout at any layer will immediately trigger a retransmission.

[0073] The wireless I / O module also adopts a cross-band redundant transmission mechanism: critical control data is transmitted simultaneously on both the 2.4GHz and Sub-1GHz dual-band frequencies. As long as the receiver receives the data correctly on either band, it is considered successful, which further improves the reliability of critical control data transmission.

[0074] The wireless I / O module employs a double-buffered architecture at the data transmission layer to ensure that data packets are not lost or duplicated during handover. At the communication link layer, the wireless I / O module adjusts its transmit power based on real-time feedback of signal reception strength and bit error rate, reducing transmit power at close range or when channel quality is good, and increasing transmit power when the signal is blocked or interfered with.

[0075] Implementation of a Communication Method Based on Dual-Band Cooperative Transmission The communication method based on dual-band cooperative transmission of the present invention employs a wireless I / O module based on dual-band cooperative transmission, including a dual-band radio frequency unit, a baseband processing unit, an I / O interface unit, and an antenna system. The dual-band radio frequency unit is responsible for simultaneously transmitting and receiving wireless signals on two independent frequency bands, with different frequency hopping strategies employed for different frequency bands. The baseband processing unit is responsible for signal processing, protocol execution, and intelligent scheduling, and manages the wired / wireless switching logic and the switching logic between wireless frequency bands. The I / O interface unit is responsible for the physical connection with field sensors and actuators, sending received signals to the actuators and uploading data collected by the field sensors. The antenna system is used to realize the mutual conversion between electrical signals and electromagnetic waves. The specific implementation process of this method has been described in detail in Embodiments 1 and 2 of the wireless I / O module based on dual-band cooperative transmission, and will not be repeated here.

Claims

1. A wireless IO module based on dual-band cooperative transmission, characterized in that, This module includes a dual-band radio frequency unit, a baseband processing unit, an I / O interface unit, and an antenna system. The dual-band radio frequency unit is responsible for transmitting and receiving wireless signals simultaneously on two independent frequency bands, with different frequency hopping strategies used for different frequency bands. The baseband processing unit is responsible for signal processing, protocol execution, and intelligent scheduling, and manages the device's wired / wireless switching and wireless frequency band switching logic. The IO interface unit is responsible for the physical connection with field sensors and actuators, and is used to send received signals to the actuators and upload data collected by field sensors. Antenna systems are used to convert electrical signals into electromagnetic waves.

2. The wireless IO module based on dual-band collaborative transmission according to claim 1, characterized in that, The dual-band radio frequency unit supports the Sub-1GHz band and the 2.4GHz band. The Sub-1GHz link is used to transmit non-real-time, large-packet data and as a redundancy backup; the 2.4GHz link is used to transmit control commands with high real-time requirements.

3. The wireless IO module based on dual-band collaborative transmission according to claim 2, characterized in that, The baseband processing unit manages the wireless frequency band switching logic by controlling the radio frequency switch inside the dual-band radio frequency unit to switch all services to another frequency band within a set time when the interference intensity of a certain frequency band is detected to be continuously higher than a set threshold.

4. The wireless IO module based on dual-band collaborative transmission according to claim 3, characterized in that, The baseband processing unit manages the wired / wireless switching logic using a mechanism that combines pre-authentication and binding, connection state synchronization, and seamless data migration. This includes: upon initial wired connection, generating a unique device fingerprint based on the device MAC address, hardware ID, and the digital certificate exchanged during the initial connection; establishing a dual-band wireless connection channel based on this unique device fingerprint; enabling wired and wireless interfaces to share a unified connection state machine; continuously monitoring the connection status of wired and wireless links after the device is running normally; and immediately triggering the switching mechanism when a wired connection is detected to be disconnected or the wireless signal quality drops to a set threshold.

5. The wireless I / O module based on dual-band cooperative transmission according to claim 2, characterized in that, Different frequency hopping strategies are adopted for different frequency bands, including: in the 2.4GHz band, adaptive frequency hopping is used to avoid interference frequencies through real-time spectrum monitoring; in the Sub-1GHz band, fixed frequency hopping is used to provide a stable and deterministic communication path under the premise of compliance.

6. The wireless I / O module based on dual-band cooperative transmission according to claim 2, characterized in that, The wireless I / O module constructs an end-to-end data protection system from encoding to confirmation at the data transmission level, including fault-tolerant coding and multi-layer confirmation mechanism. The fault-tolerant coding adopts a concatenated coding method that combines the outer code of RS code with the inner code of convolutional code. The multi-layer confirmation mechanism adopts an end-to-end triple confirmation mechanism of physical layer, link layer and application layer.

7. The wireless I / O module based on dual-band cooperative transmission according to claim 2, characterized in that, The wireless I / O module also adopts a cross-band redundant transmission mechanism: critical control data is transmitted simultaneously on both the 2.4GHz and Sub-1GHz dual-band frequencies.

8. The wireless I / O module based on dual-band cooperative transmission according to claim 2, characterized in that, The wireless I / O module adopts a double-buffered architecture at the data transmission layer to ensure that data packets are not lost or duplicated during handover.

9. The wireless I / O module based on dual-band cooperative transmission according to claim 2, characterized in that, The wireless I / O module also adjusts the transmission power at the communication link level based on real-time feedback of signal reception strength and bit error rate, reducing the transmission power when at close range or with good channel quality, and increasing the transmission power when the signal is blocked or interfered with.

10. A communication method based on dual-band cooperative transmission, characterized in that, The communication method is implemented using the wireless I / O module based on dual-band cooperative transmission as described in any one of claims 1-9.

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