Wide-narrow integrated ad hoc network method

Abstract

The invention discloses a wide-narrow integrated ad hoc network method, and belongs to the technical field of network communication. The method comprises the following steps: a network node generates dynamic topology information based on a narrow-band communication module periodic broadcast state beacon; according to the link quality and the node load in the topological information, coordinating the resource allocation of broadband and narrowband channels by adopting a load-aware time slot allocation algorithm; data are classified according to service types, broadband data are modulated and transmitted by adopting orthogonal frequency division multiplexing, and narrowband control instructions are modulated and transmitted by adopting differential phase shift keying; when the link quality is deteriorated, the link is switched, and the transmitting power and the frequency band parameters are dynamically adjusted; and adaptive switching and data distribution of wide and narrow band communication modes are realized. According to the method, the problems of difficulty in topology maintenance and low bandwidth and narrowband resource allocation efficiency in a high-dynamic network scene are solved, the network adaptability, the anti-interference capability and the resource utilization rate are remarkably improved through a dynamic cooperative bandwidth and narrowband communication mode, and meanwhile, the protocol switching overhead and energy consumption are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of network communication, and in particular to a broadband-narrowband fusion self-organizing network method. Background Art

[0002] In scenarios such as drone swarms, emergency communications, and smart IoT, wireless ad hoc networks need to be rapidly deployed and dynamically networked without fixed infrastructure. However, such scenarios often face problems such as frequent topology changes caused by high mobility, insufficient communication stability under complex electromagnetic interference, and differentiated bandwidth and latency requirements for diversified services.

[0003] In existing ad hoc networking technologies, a single communication mode is difficult to balance coverage and transmission efficiency. For example, although pure narrowband networks (such as LoRa) support wide-area low-power communications, they cannot meet the needs of high-bandwidth services such as video surveillance; although pure broadband networks (such as Wi-Fi) provide high-speed transmission, they are prone to link interruption due to topology update delays when nodes move at high speeds. In addition, traditional resource allocation methods (such as fixed-time slot TDMA) lack the ability to perceive dynamic loads and node energy, which can easily cause resource waste or conflicts.

[0004] In terms of dynamic topology maintenance, existing routing protocols (such as AODV) rely on periodic network-wide signaling interactions, resulting in excessive control overhead and difficulty in coping with millisecond-level topology change scenarios such as drone clusters. In terms of broadband and narrowband collaboration, existing technologies mostly use static frequency band allocation or simple master-slave control (such as LTE-M), which cannot dynamically switch communication modes according to real-time business needs, resulting in narrowband channel overload or broadband channel idleness.

[0005] Furthermore, existing anti-interference technologies (such as frequency hopping) lack linkage mechanisms with topology management. For example, when a frequency band fails due to interference, the node needs to re-initiate the route discovery process, resulting in extended service interruption time. In scenarios such as emergency communications, the above defects may directly affect the real-time transmission of key instructions and even cause network cascading failures.

[0006] Therefore, there is an urgent need for a self-organizing network method that can dynamically coordinate broadband and narrowband resources, quickly respond to topology changes, and adapt to diversified business needs, so as to solve the problems of rigid resource allocation, low topology maintenance efficiency, and insufficient anti-interference ability in the existing technology. Summary of the invention

[0007] The present invention overcomes the problems of difficult topology maintenance and low efficiency of broadband and narrowband resource allocation in highly dynamic network scenarios. Through dynamic collaborative broadband and narrowband communication modes, it significantly improves network adaptability, anti-interference ability and resource utilization, while reducing protocol switching overhead and energy consumption.

[0008] In order to achieve the above object, the present invention adopts the following scheme: Wide - narrow integrated ad - hoc network method, which includes the following steps: S1: The network node periodically broadcasts a status beacon including node location and remaining energy through the narrow - band communication module based on a preset topology discovery protocol, and generates dynamic topology information according to the received beacons of adjacent nodes. The dynamic topology information includes node connection relationships and link quality indicators; S2: According to the node connection relationships and link quality indicators in the dynamic topology information, calculate the initial time - slot allocation scheme for each node based on a load - aware time - slot allocation algorithm. The time - slot allocation algorithm sends a time - slot allocation request to adjacent nodes through the narrow - band communication module, and establishes the transmission time - slots of the broadband communication module after receiving the confirmation response from adjacent nodes; S3: When the broadband communication module is activated, according to the allocation result of the transmission time - slots, divide the data packets to be sent into broadband data and narrow - band control instructions according to the service type. Among them, the broadband data is transmitted through the broadband channel using the orthogonal frequency - division multiplexing modulation method, and the narrow - band control instructions are transmitted through the narrow - band channel using the differential phase - shift keying modulation method; S4: When it is detected that the link quality indicator is lower than the preset threshold, trigger the narrow - band communication module to send a link interruption warning, re - select the next - hop node according to the current dynamic topology information, and at the same time adjust the transmission power and frequency - band selection parameters of the broadband communication module to match the channel characteristics of the new link; S5: Dynamically switch the communication mode of network nodes based on a hybrid multiple - access protocol. When the network load exceeds the broadband channel capacity, divert some broadband data to the narrow - band channel for transmission, and update the dynamic topology information through the narrow - band communication module to maintain network connectivity.

[0009] Preferably, the specific method for generating dynamic topology information in step S1 includes: When the network node sends a status beacon through the narrow - band communication module, extend the beacon transmission range to adjacent nodes within three hops; obtain the received signal strength indication (RSSI), statistically obtain the narrow - band channel bit - error rate by decoding the cyclic redundancy check result of the adjacent node beacon, and obtain the link quality indicator through weighted calculation of the received signal strength indication and the narrow - band channel bit - error rate; Establish an adjacency list, which includes all nodes within three hops and records the identifier, weighted value of the received signal strength indication, and remaining energy ratio of each adjacent node; when the weighted value of the received signal strength indication of an adjacent node drops by more than 20% continuously for three broadcast cycles, update the link status flag in the dynamic topology information; the remaining energy is collected by the node through real - time monitoring of the battery voltage and current consumption, and a sliding average filtering algorithm is used to eliminate instantaneous fluctuations; During the dynamic topology information generation process, if the beacon position coordinates from the same node jump by more than the preset maximum moving speed, discard this abnormal beacon and start spectrum scanning to detect the pseudo-node attack; the dynamic topology information is synchronized among network nodes through a distributed hash table, and each node stores a complete copy of the topology data of its directly adjacent nodes.

[0010] Preferably, the specific method for dynamically switching the communication mode and data shunting in step S5 includes: When it is detected that the network load exceeds the broadband channel capacity, based on a preset load threshold, the broadband data to be shunted is divided into high-delay tolerant data and low-delay tolerant data according to the service priority. The high-delay tolerant data is transmitted through the narrowband channel, and the low-delay tolerant data remains transmitted through the broadband channel; during the shunting process, the modulation mode of the narrowband channel is adjusted synchronously. When the proportion of the data volume in the narrowband channel exceeds 50%, the modulation is switched from differential phase shift keying to quadrature phase shift keying; after the data shunting is completed, a topology update request is sent to adjacent nodes through the narrowband communication module, and the update request includes the remaining broadband channel capacity and the narrowband channel load ratio of the current node. When it is detected that there is a transmission conflict in the narrowband channel due to the shunted data, based on the contention window backoff algorithm, the contention window size is dynamically adjusted according to the number of conflicts, and the transmission of low-priority narrowband control instructions is suspended during the backoff period; during the shunting process, if the narrowband channel fails to receive an acknowledgment response for three consecutive transmission cycles, the transmit power of the narrowband communication module is increased to 80% of the preset maximum value, and the modulation order of the broadband channel is downgraded from 64QAM to 16QAM. Calculate the broadband channel capacity by real-time measuring the signal-to-interference-plus-noise ratio of the orthogonal frequency division multiplexing subcarriers. When the channel quality difference of the subcarriers exceeds 30%, turn off the three subcarriers with the worst quality.

[0011] Preferably, the specific steps of the time slot allocation algorithm in step S2 include: According to the link quality index and the node remaining energy ratio in the dynamic topology information, calculate the initial time slot allocation weight for each node. The weight is obtained by multiplying the link quality index by the square root of the remaining energy ratio; the time slot allocation request is sent in a broadcast form through the narrowband communication module. The request frame includes the identifier of the requesting node, the required number of time slots, and the calculated time slot allocation weight; after receiving the time slot allocation request, if an adjacent node detects that the requested time slots overlap with the already allocated time slots, a rejection response including the conflict time slot numbers is returned to the requesting node; when the requesting node receives more than three rejection responses from adjacent nodes, reduce the required number of time slots to 70% of the original value and then resend the allocation request. When establishing the transmission time slots of the broadband communication module, node pairs with link quality indicators higher than the preset threshold adopt the standard time slot length, while node pairs with link quality indicators lower than the preset threshold use a time slot length extended to 1.5 times the standard value; after the time slot allocation is completed, a time slot mapping table is generated to record the occupied time slot numbers of each node, the adjacent node identifiers, and the corresponding link quality intervals, and is periodically synchronized to all associated nodes within two-hop range through the narrowband communication module; when it is detected that a new node joins the network, according to the remaining energy ratio in its broadcast beacon, the adjacent node with the lowest remaining energy ratio is selected from the time slot mapping table to release 20% of the allocated time slots for the new node to use.

[0012] Preferably, after the time slot allocation is completed, the following steps are also executed: According to the link quality intervals recorded in the time slot mapping table, node pairs with link quality intervals in the lowest 30% increase the transmission power of the broadband communication module to 90% of the preset maximum value, and node pairs with link quality intervals in the highest 20% reduce the transmission power to 50% of the preset maximum value; When the network load changes, if the time slot occupancy rate monitored by the narrowband communication module is higher than 80% for three consecutive cycles, then sort according to the time slot weight values, and allocate additional time slots to the top three nodes with the highest weight values; when a node exits the network, broadcast a time slot release instruction through the narrowband communication module, and the adjacent nodes that receive the instruction mark the invalid time slots according to the time slot mapping table and re-incorporate the invalid time slots into the available time slot pool in the next allocation cycle; during the time slot reallocation process, when the time slot request of a high-weight node is occupied by a low-weight node, force the low-weight node to release the target time slot and trigger it to re-request allocation; When it is detected that there are two consecutive unused time slots in the broadband channel, it is determined that there is time slot waste and the time slot recovery process is started, the idle time slots are re-marked as available, and the associated nodes are updated and notified through the time slot mapping table; in the time slot reallocation stage, if the remaining energy ratio of a node is lower than 20%, it is prohibited from participating in the time slot preemption operation, and the priority weight of its occupied time slots is reduced to 50% of the original value.

[0013] Preferably, the specific process of classifying and modulating the data packet to be sent in step S3 includes: According to the allocation result of the transmission time slots, parse the service type of the data packet to be sent. If the data packet includes a video stream or a file transfer protocol payload, it is marked as broadband data. If it includes a routing control instruction or a topology update signaling, it is marked as a narrowband control instruction; before modulation, perform a channel quality assessment on the broadband data. If it is detected that the signal-to-interference-plus-noise ratio of the broadband channel is lower than 20 dB, reduce the number of subcarriers and activate the cyclic prefix extension mechanism; When transmitting narrowband control instructions using differential phase shift keying modulation, if the bit error rate in three consecutive transmission periods is lower than 0.1%, switch to quadriphase differential phase shift keying modulation; when transmitting broadband data and narrowband control instructions in parallel, insert the synchronization header of the narrowband control instructions at the start position of the broadband time slot, and reserve a 2ms time slot protection interval before the end of the narrowband channel transmission time slot; when detecting a conflict in the transmission time slots of broadband data and narrowband control instructions, trigger a priority-based interrupt mechanism, pause the current subcarrier transmission of broadband data and give priority to transmitting narrowband control instructions, and resume the interrupted subcarriers after the narrowband transmission is completed; dynamically allocate the transmission power according to the channel quality differences of subcarriers, increase the power of the three subcarriers with the worst channel quality to 120% of the standard value, and reduce the power of the remaining subcarriers to 80% of the standard value; After the transmission of narrowband control instructions is completed, if the received acknowledgment signal from the adjacent node is not received, retransmit the narrowband control instructions through the idle broadband channel and mark them as high-priority data packets.

[0014] Preferably, the broadband data transmission process further includes the following steps: Fragment the broadband data into multiple data blocks, attach a frame header including a sequence number and a check code to each data block, and transmit them in parallel through different subcarrier groups of orthogonal frequency division multiplexing; the fragmentation size is dynamically adjusted according to the delay jitter of the current broadband channel. When the delay jitter exceeds 5ms, reduce the fragmentation size from 1024 bytes to 512 bytes; calculate the theoretically optimal fragmentation size through the Shannon formula and constrain it within the range of 256 bytes to 2048 bytes; When recombining the data blocks at the receiving end, if a missing sequence number is detected, request the retransmission of specific fragments from the sending end through the narrowband communication module, and carry the list of sequence numbers of the missing fragments and the corresponding subcarrier numbers in the request frame; the check code is generated by Turbo coding. When the number of decoding failures at the receiving end reaches three times, trigger a redundant fragment transmission mechanism, and send the exclusive OR operation result of the original fragment and two redundant fragments through the unused subcarriers; if it is detected that five consecutive fragments fail to be transmitted, determine that there is continuous interference in the current subcarrier group, turn off the corresponding three subcarriers and notify the adjacent nodes to update the channel occupancy information through the narrowband communication module; After the fragmentation recombination is completed, if the passing rate of the check code verification is lower than 95%, automatically reduce the orthogonal frequency division multiplexing modulation order, switch 64QAM to 16QAM and retransmit the data blocks that failed the verification.

[0015] Preferably, the fragmentation recombination and retransmission mechanism further includes the following steps: A shard cache queue is established at the receiving end, the received data blocks are sorted according to the sequence number, and the arrival timestamp and channel quality index of each shard are recorded; when requesting retransmission of missing shards, the sending end preferentially selects the three subcarriers with the best channel quality for retransmission and marks them as retransmission priority data packets in the frame header; the redundant shard transmission mechanism determines the number of redundant shards according to the current network load and historical bit error rate data, and generates twice the redundant shards when the bit error rate is higher than 1%; the shard cache queue automatically clears the residual shards that have not been requested for retransmission for more than 500 ms and sends a shard invalidation notice to the sending end through the narrowband channel; After the data is recombined at the receiving end, the recombination result is fed back to the sending end through the narrowband communication module. The feedback information includes the proportion of successfully received shards, the average delay, and the recommended shard size parameter for adjustment; the sending end updates the shard rule according to the recommended parameter in the feedback information. If the average delay exceeds 20 ms and the proportion of successfully received shards is lower than 90%, the shard size in the next cycle is adjusted to 75% of the current value; when the number of retransmission requests for the same data block exceeds five times, the link switching mechanism is triggered, and the subsequent shards are transmitted through the narrowband channel, and the link quality index in the dynamic topology information is updated after the transmission is completed.

[0016] Preferably, in step S4, the following method is used to handle link interruption and parameter adjustment: When the link quality index is lower than the preset threshold, a link interruption alarm is broadcast to the nodes within three-hop range through the narrowband communication module. The alarm frame includes the identifier of the interrupted link, the current channel interference intensity, and the priority list of candidate next-hop nodes; the priority list of candidate next-hop nodes is generated based on the link quality index and the remaining energy ratio in the dynamic topology information, and the nodes with the remaining energy ratio lower than 15% are excluded; when reselecting the next-hop node, a handshake request is initiated according to the priority list. If the target node does not respond within 200 ms, switch to the next candidate node in descending order of priority and update the node connection relationship in the dynamic topology information; When adjusting the transmission power of the broadband communication module, the target power value is dynamically calculated according to the channel characteristic parameters of the new link. The channel characteristic parameters include the signal-to-interference-noise ratio and the multipath fading coefficient, and the target power value is a linear function of the reference power value and the reciprocal of the signal-to-interference-noise ratio; scan the channel idle rate in the preset frequency band list and select the frequency band with an idle rate higher than 70% and the least historical interference times as the communication frequency band of the new link; After the frequency band switching is completed, send a frequency band synchronization instruction to the new next-hop node through the narrowband communication module. The instruction includes the new frequency band number and the synchronization timestamp, and start the retransmission process of broadband data after receiving the synchronization confirmation. If a stable link cannot be established after three consecutive frequency band switches, trigger the topology reconstruction process, re-broadcast the status beacon through the narrowband communication module, and generate a new candidate node list based on the updated dynamic topology information.

[0017] Preferably, after the frequency band switching is completed, the following steps are executed: Continuously monitor the channel quality of the new link through the broadband communication module, collect the signal-to-interference-and-noise ratio and bit error rate data every 50 ms, and calculate their sliding average value as the stability evaluation index. When the fluctuation range of the stability evaluation index exceeds 30% for five consecutive samples, it is determined that the channel state is unstable, trigger the narrowband communication module to send a channel switching suggestion request, and perform a secondary frequency band switch according to the candidate frequency band list feedback by the adjacent node. During the dynamic adjustment of the transmission power, if it is detected that the remaining energy ratio of the node is lower than 20%, enable the power limit mode and set the upper limit of the transmission power to 80% of the reference power value. When transmitting the frequency band synchronization instruction, if the decoding failure count at the receiving end reaches two, switch to the redundant transmission mode, repeat sending the synchronization instruction within three adjacent narrowband time slots and append the check code. In the broadband data retransmission process, adjust the subcarrier allocation scheme of the orthogonal frequency division multiplexing modulation according to the channel characteristic parameters of the previous transmission failure, turn off the two subcarriers with the lowest signal-to-interference-and-noise ratio, and recalculate the cyclic prefix length. If no data packet is successfully transmitted within 300 ms after the new link is established, mark it as an abnormal link and notify all network nodes through the narrowband communication module to update the link state mark in the dynamic topology information.

[0018] The present invention has at least the following beneficial effects: (1) Through the cooperation of narrowband and broadband and dynamic resource allocation, significantly improve the communication reliability and resource utilization efficiency of the network in high-mobility and strong-interference environments, while reducing the protocol switching overhead; (2) Combine multi-hop topology discovery and priority shunt strategy to ensure the real-time performance of key control instructions while achieving efficient load balancing of large-scale nodes and reducing the probability of channel conflicts; (3) Optimize the transmission success rate in weak link scenarios and extend the battery life of low-energy nodes through time slot weight calculation and dynamic power calibration mechanism; (4) Adopt service classification, dynamic fragmentation and intelligent retransmission strategies to effectively improve the robustness of broadband data transmission and reduce the risk of data loss caused by channel fluctuations; (5) Enhance the self-healing ability of the network in scenarios where nodes frequently fail or are maliciously attacked through the link quality-driven frequency band switching and topology reconstruction mechanism, and reduce the service interruption duration. Description of the Drawings

[0019] Figure 1It is a principle flowchart of the wide - narrow fusion ad - hoc network method provided by the present invention. Detailed implementation manners

[0020] The following further elaborates on the present invention with reference to the accompanying drawings, so that those skilled in the art can implement it according to the description in the specification.

[0021] As Figure 1 shown, the wide - narrow fusion ad - hoc network method provided by the present invention includes the following steps: S1: The network node periodically broadcasts a status beacon including node location and remaining energy through the narrow - band communication module based on a preset topology discovery protocol, and generates dynamic topology information according to the received beacons of adjacent nodes. The dynamic topology information includes node connection relationships and link quality indicators.

[0022] When the network node starts up, based on a preset topology discovery protocol (such as a simplified version of AODV or OLSR), it periodically broadcasts a status beacon through the narrow - band communication module (for example, a radio frequency unit using LoRa or NB - IoT technology). The beacon contains the real - time geographical location coordinates of the node (obtained through a GPS or Beidou module), the remaining energy value (calculated from the battery voltage and current data collected by the power management chip), and the device identifier (such as MAC address or unique ID). After each node receives the beacon of an adjacent node, it extracts the location, energy, and identification information therein, and generates dynamic topology information in combination with narrow - band channel measurement data (such as received signal strength RSSI, signal - to - noise ratio SNR). The dynamic topology information is stored in the form of an adjacency list, which records the connection status (such as reachable / unreachable) of each adjacent node, the link quality indicator (a weighted score combining RSSI and bit error rate), and the energy level. The node updates the topology information every fixed period (adjustable, for example, from 1 second to 5 seconds). When it detects that the signal strength of an adjacent node continuously decreases or the beacon is lost, it marks the link as an unstable state. The low - power consumption characteristic of the narrow - band communication module makes it suitable for periodic beacon broadcasting, and the generation of dynamic topology information depends on beacon interaction and local calculation between nodes. The geographical location information is used to judge the physical reachability between nodes, the remaining energy data provides a basis for subsequent resource allocation, and the link quality indicator directly serves routing selection and power control.

[0023] S2: According to the node connection relationships and link quality indicators in the dynamic topology information, calculate the initial time - slot allocation scheme for each node based on a load - aware time - slot allocation algorithm. The time - slot allocation algorithm sends a time - slot allocation request to adjacent nodes through the narrow - band communication module, and establishes the transmission time - slots of the broadband communication module after receiving the confirmation response from the adjacent nodes.

[0024] Based on the link quality and node residual energy in the dynamic topology information, a load-aware time slot allocation algorithm (such as an improved TDMA protocol) is used to calculate the initial time slot allocation scheme. Specifically, the node sends a time slot allocation request frame to adjacent nodes according to its current data volume to be sent (such as the cache queue length) and the load conditions of adjacent nodes (load status reports exchanged through the narrowband channel). The request frame contains the number of requested time slots, a priority flag (such as a real-time service identifier), and the remaining energy ratio of this node. After receiving the request, the adjacent node performs collision detection based on the time slot resources it has already allocated: if the requested time slot is not occupied, it returns an acknowledgment response and reserves the corresponding time slot; if there is a collision, it returns a rejection response and attaches a list of recommended time slots. Finally, the node determines the transmission time slots of its broadband communication module (such as a radio frequency unit based on Wi-Fi 6 or 5G NR) through iterative negotiation, and locally maintains a time slot mapping table, recording the time slot number, the occupied node, and the corresponding modulation parameters. The narrowband channel is used to transmit lightweight time slot request and response data, avoiding occupying broadband resources; the load-aware algorithm ensures that high-priority nodes obtain more time slots through dynamic weights (such as the product of energy and link quality); the time slot allocation result directly constrains the subsequent broadband data transmission timing, avoiding channel contention.

[0025] S3: When the broadband communication module is activated, according to the allocation result of the transmission time slots, the data packets to be sent are classified into broadband data and narrowband control instructions according to the service type. Among them, the broadband data is transmitted through the broadband channel using the orthogonal frequency division multiplexing modulation method, and the narrowband control instructions are transmitted through the narrowband channel using the differential phase shift keying modulation method.

[0026] When the broadband communication module is activated, the node classifies the data packets to be sent according to the transmission time slot allocation result by service type: broadband data (such as video streams, large files) is modulated using orthogonal frequency division multiplexing (OFDM) and transmitted through the broadband channel (such as a 20MHz bandwidth); narrowband control instructions (such as routing updates, topology synchronization signals) are modulated using differential phase shift keying (DPSK) and transmitted through the narrowband channel (such as a 200kHz bandwidth). The classification rule is based on the packet header identifier (such as the IP protocol type or a custom label): if it is a UDP video stream or an FTP payload, it is classified as broadband data, and if it is an RREQ routing request or a HELLO beacon, it is classified as a narrowband instruction. The two types of data use a time division multiplexing mechanism: the narrowband control instructions are preferentially sent within the allocated time slots, and the remaining time is filled with broadband data. If a transmission collision occurs (such as a burst arrival of control instructions), the broadband data transmission is paused through a hardware interrupt to prioritize the real-time performance of narrowband instructions. Service classification ensures the low-latency transmission of key control signaling; OFDM modulation improves the utilization rate of the broadband channel, and DPSK modulation enhances the anti-interference ability of narrowband signals; the time division multiplexing mechanism realizes conflict-free transmission of the two types of data through the time slot allocation result.

[0027] S4: When it is detected that the link quality index is lower than the preset threshold, trigger the narrowband communication module to send a link interruption warning, reselect the next-hop node according to the current dynamic topology information, and at the same time adjust the transmission power and frequency band selection parameters of the broadband communication module to match the channel characteristics of the new link.

[0028] When it is detected that the link quality index (such as the RSSI weighted value) of a certain link is lower than the preset threshold (for example, -90 dBm), trigger the narrowband communication module to send a link interruption warning. The warning frame contains the interrupted link identifier, the current interference level, and a list of candidate next-hop nodes. The candidate node list is generated based on the dynamic topology information, and the screening conditions include that the link quality is higher than the threshold, the remaining energy is greater than 20%, and the topology hop count does not exceed 3 hops. The node initiates a handshake request according to the list priority. If the target node responds with a timeout (for example, 200 ms), it will automatically switch to the sub-optimal node. At the same time, adjust the transmission power of the broadband communication module (such as increasing from 20 dBm to 25 dBm) and scan the standby frequency band (such as switching from 5.8 GHz to 2.4 GHz) to match the channel characteristics of the new link (such as the low-frequency penetration advantage in a multipath fading environment). The narrowband warning realizes fast fault notification; the candidate node list ensures the reliability of link switching; the power and frequency band adjustment realizes parameter adaptive optimization through closed-loop feedback (such as the ACK confirmation of the new link).

[0029] S5: Dynamically switch the communication mode of network nodes based on the hybrid multiple access protocol. When the network load exceeds the broadband channel capacity, divert some broadband data to the narrowband channel for transmission, and update the dynamic topology information through the narrowband communication module to maintain network connectivity.

[0030] Based on the hybrid multiple access protocol (such as a hybrid mode of CSMA / CA and TDMA), dynamically switch the communication mode of the node. When the broadband channel load exceeds the capacity threshold (such as the utilization rate reaches 80%), divert some low-priority broadband data (such as background file synchronization) to the narrowband channel for transmission. The diversion strategy is determined according to the QoS label of the data packet (such as the DSCP value): high-real-time data (such as VoIP) is retained on the broadband channel, and high-tolerance data (such as sensor logs) is transferred to the narrowband channel. During the diversion process, the narrowband channel uses dynamic modulation (such as switching from DPSK to QPSK) to improve the throughput, and reduces the narrowband signaling overhead through incremental topology update (only transmitting the changed part). The hybrid access protocol dynamically allocates channel resources according to the load status; data diversion alleviates broadband congestion; the incremental update mechanism reduces the bandwidth occupation of narrowband signaling.

[0031] Through the cooperation of wide and narrow bands and dynamic resource allocation, the communication reliability of the network can be significantly improved in high-mobility and interference environments; based on the traffic type splitting strategy and adaptive modulation technology, the transmission efficiency and energy consumption level can be effectively balanced; the fast link interruption recovery and topology self-healing mechanism can ensure the continuous connectivity of the network in scenarios where nodes frequently join / leave; the combination of hybrid multiple access and load-aware algorithms can achieve efficient utilization of channel resources and a significant reduction in the collision probability.

[0032] In another technical solution, the specific method for generating dynamic topology information in step S1 includes: When a network node sends a status beacon through the narrowband communication module, it uses a carrier-sensing-based multi-hop forwarding mechanism to extend the beacon transmission range to adjacent nodes within three hops; the radio frequency front-end of the narrowband communication module measures the received signal strength indication, and the narrowband channel bit error rate is statistically obtained by decoding the cyclic redundancy check result of the adjacent node beacon. The link quality index is obtained by calculating the weighted value of the received signal strength indication and the narrowband channel bit error rate; when generating the node connection relationship, an adjacency list including all nodes within three hops is established, and the adjacency list records the identifier of each adjacent node, the weighted value of the received signal strength indication, and the remaining energy ratio; when it is detected that the weighted value of the received signal strength indication of an adjacent node drops by more than 20% continuously for three broadcast cycles, a link quality alarm is triggered and the link status flag in the dynamic topology information is updated; The interval time of periodic broadcast is dynamically adjusted according to the network topology change rate, specifically determined by calculating the difference degree between two adjacent topology information: when the difference degree exceeds 50%, the broadcast cycle is shortened to one-third of the original cycle; when the difference degree is lower than 10%, the broadcast cycle is extended to twice the original cycle; a topology verification mechanism is introduced during the dynamic topology information generation process. When the position coordinates of the beacon received from the same node jump beyond the preset maximum moving speed, the abnormal beacon is discarded and the spectrum scanning of the narrowband communication module is started to detect the pseudo-node attack; The remaining energy is collected by the built-in power management chip of the node to monitor the battery voltage and current consumption in real time, and a sliding average filtering algorithm is used to eliminate the instantaneous fluctuation; the dynamic topology information is synchronized among network nodes through a distributed hash table, and each node stores a complete topology data copy of its directly adjacent nodes.

[0033] When the network node sends a status beacon, it adopts a carrier-sense based multi-hop forwarding mechanism (such as an improved Flooding protocol) to extend the transmission range of the beacon to adjacent nodes within three hops through a narrowband communication module. Specifically, the first-hop node performs carrier sensing (such as the LBT mechanism) before sending the beacon. If the channel is idle, it broadcasts the beacon. After receiving the beacon, the second-hop node re-forwards it after a random backoff time (such as 10 ms to 50 ms) and adds a hop count mark to prevent infinite loops. The link quality metric is obtained by weighted calculation of the received signal strength indication (RSSI, typical value -110 dBm to -60 dBm) and the narrowband channel bit error rate (BER, counted by the number of CRC check failures, such as 0.1% to 5%). The weight ratio can be configured according to the scenario (such as RSSI accounting for 70% and BER accounting for 30%). The receiving node stores the weighted value in the adjacency list for subsequent routing decisions. The multi-hop forwarding mechanism breaks through the single-hop distance limit and expands the topology discovery range; the comprehensive link quality assessment avoids misjudgment of a single metric (such as relying only on RSSI); the weighting coefficient can be dynamically adjusted according to the environment, for example, increasing the BER weight in a scenario with strong interference.

[0034] The adjacency list records the identifiers, RSSI weighted values, and remaining energy ratios (the percentage of the remaining battery capacity to the total capacity) of all nodes within three hops. When it is detected that the RSSI weighted value of a certain adjacent node drops by more than 20% (such as from -70 dBm to -84 dBm) continuously for three broadcast periods (for example, the period is 1 second), a link quality alarm is triggered, the link status mark in the dynamic topology information is updated to "degraded", and the next-hop node pre-selection process is started. The remaining energy data is collected in real time through a power management chip (such as the TIBQ series), and a moving average filter (the window size can be set to 5 samples) is used to eliminate instantaneous fluctuations (such as a sudden voltage drop caused by a sudden increase in load). The three-hop adjacency list provides redundant path selection for topology changes; the continuous drop detection mechanism prevents false alarms caused by instantaneous interference; the filtering process ensures the stability of the energy data and avoids resource waste caused by frequent switching.

[0035] The broadcast period is dynamically adjusted according to the topology change rate: calculate the difference degree between two adjacent topology information (such as the proportion of the number of newly added / disappeared nodes in the total number of nodes). When the difference degree exceeds 50% (for example, the positions of half of the nodes are updated), the broadcast period is shortened from the reference value of 1 second to 0.33 seconds; when the difference degree is lower than 10%, it is extended to 2 seconds. The topology verification mechanism identifies anomalies by detecting the position coordinate jumps in the beacons (such as the moving speed exceeding the preset maximum value of 30 m / s), discards such beacons and initiates spectrum scanning (such as RSSI detection for all channels in the 2.4 GHz band). If it is found that nodes with the same identifier exist in multiple frequency bands simultaneously, it is determined as a fake node attack and added to the blacklist. The dynamic broadcast period balances the timeliness of topology update and energy consumption; the position jump detection combined with spectrum scanning forms a two-fold defense to prevent malicious nodes from forging beacons to disrupt the topology.

[0036] Significantly improve the integrity and accuracy of topology discovery through multi-hop forwarding and comprehensive link evaluation; the dynamic broadcast period mechanism effectively reduces energy consumption while ensuring the real-time nature of the topology; the abnormal beacon identification and defense mechanism enhances the network's anti-forgery attack ability.

[0037] In another technical solution, the specific method of dynamically switching communication modes and data shunting in step S5 includes: When it is detected that the network load exceeds the broadband channel capacity, the broadband data to be shunted is divided into high-delay tolerant data and low-delay tolerant data according to the service priority based on a preset load threshold. Among them, the high-delay tolerant data is transmitted through the narrowband channel, and the low-delay tolerant data remains transmitted through the broadband channel; The hybrid multiple access protocol synchronously adjusts the modulation mode of the narrowband channel during the shunting process. When the proportion of the data volume in the narrowband channel exceeds 50%, the differential phase shift keying modulation is switched to the quadrature phase shift keying modulation to improve the throughput of the narrowband channel; After the data shunting is completed, a topology update request is sent to adjacent nodes through the narrowband communication module. The request includes the remaining broadband channel capacity and the narrowband channel load ratio of the current node, and an update confirmation signal returned by the adjacent node is received to verify the network connectivity; the dynamic topology information update adopts an incremental synchronization mechanism, only transmits the link state data that is different from the previous synchronization, and is encapsulated into a binary differential protocol format for transmission through the narrowband channel; when it is detected that a transmission conflict is introduced in the narrowband channel due to shunted data, a conflict resolution strategy based on the contention window backoff algorithm is triggered, which specifically includes: dynamically adjusting the contention window size according to the number of conflicts, and pausing the sending of low-priority narrowband control instructions during the backoff period; The broadband channel capacity is calculated by real-time measuring the signal-to-interference-plus-noise ratio (SINR) of orthogonal frequency division multiplexing (OFDM) subcarriers. When the channel quality difference of subcarriers exceeds 30%, the three subcarriers with the worst quality are turned off to improve the overall channel utilization rate. During the traffic splitting process, if the narrowband channel fails to receive an acknowledgment response for three consecutive transmission cycles, it is determined as channel congestion and dynamic power adjustment is triggered. The transmit power of the narrowband communication module is increased to 80% of the preset maximum value, and at the same time, the modulation order of the broadband channel is downgraded from 64QAM to 16QAM to release bandwidth resources.

[0038] When the network load exceeds the broadband channel capacity (e.g., the OFDM subcarrier utilization rate reaches 80%), data is split based on service priority (e.g., DSCP label or custom QoS field): high-delay tolerant data (such as environmental sensor logs) is transferred to the narrowband channel, and low-delay data (such as real-time video streams) remains on the broadband channel. During the splitting process, the modulation method of the narrowband channel is switched from DPSK to QPSK (e.g., when the proportion of narrowband data volume exceeds 50%), and the symbol rate is increased (e.g., from 1 bit / symbol to 2 bit / symbol). The broadband channel capacity is calculated by real-time measuring the SINR of subcarriers (typical range 5 dB to 25 dB). If the subcarrier quality difference exceeds 30% (e.g., the optimal subcarrier SINR = 20 dB, the worst = 14 dB), the three subcarriers with the worst quality are turned off to concentrate resources on ensuring high-quality channel transmission. Service priority splitting ensures that critical services are not restricted by bandwidth; modulation is dynamically adjusted to match the narrowband load changes; the subcarrier turning-off strategy optimizes the broadband resource utilization rate.

[0039] After the splitting is completed, incremental topology update information is sent through the narrowband channel: only the changed link states are transmitted (e.g., node A is disconnected from node B), encapsulated in the binary differential protocol format (to reduce the data volume). When conflicts occur in the narrowband channel due to increased split data, the contention window backoff algorithm is adopted: the initial contention window size is 8 time slots, and each time a conflict is detected, the window size is doubled (e.g., 16, 32). During the backoff period, the transmission of low-priority instructions (such as periodic status reports) is suspended. The receiving end returns an acknowledgment signal after successful decoding. If the sending end does not receive the acknowledgment and the broadband channel is idle, the narrowband instruction (marked as high priority) is retransmitted through the broadband channel. Incremental update reduces the narrowband signaling overhead; the contention backoff algorithm alleviates channel congestion; the cross-channel retransmission mechanism improves the arrival rate of control instructions.

[0040] If acknowledgments are not received for three consecutive periods (e.g., 50 ms each) on the narrowband channel, congestion is determined, triggering dynamic power adjustment: the transmission power of the narrowband module is increased from the reference value of 20 dBm to 24 dBm (80% of the maximum value), while the broadband modulation order is reduced (e.g., from 64QAM to 16QAM), and bandwidth resources are released (e.g., reduced from 10 MHz occupancy to 5 MHz). After power adjustment, the channel state is re-evaluated. If recovery is still not possible, the topology reconstruction process is initiated: the narrowband broadcast is used to request all network nodes to retransmit the status beacon, generating a new list of candidate nodes. The increased power enhances the penetration of the narrowband signal; the modulation order reduction reduces the occupancy of broadband resources; and the topology reconstruction, as the ultimate recovery means, ensures the robustness of the network.

[0041] The channel resource utilization can be effectively improved through the priority shunt and modulation adjustment strategies; the incremental update and backoff mechanism significantly reduces the collision probability of control signaling; and the joint power and modulation adjustment mechanism enhances the self-recovery ability of the network in congestion scenarios.

[0042] In another technical solution, the specific steps of the time slot allocation algorithm in step S2 include: Based on the link quality index and the ratio of the remaining energy of nodes in the dynamic topology information, an initial time slot allocation weight is calculated for each node. The weight is obtained by multiplying the link quality index by the square root of the remaining energy ratio; the time slot allocation request is sent in broadcast form through the narrowband communication module. The request frame includes the identifier of the requesting node, the required number of time slots, and the calculated time slot allocation weight; after receiving the time slot allocation request, adjacent nodes perform collision detection based on their current time slot occupancy status and the weight value of the requesting node. If it is detected that the requested time slot overlaps with the already allocated time slots, a rejection response including the conflicting time slot number is returned to the requesting node; When the requesting node receives rejection responses from more than three adjacent nodes, the time slot allocation recalculation is triggered. The required number of time slots is reduced to 70% of the original value and the allocation request is resent; when establishing the transmission time slots of the broadband communication module, the time slot length is dynamically adjusted according to the link quality index between nodes. Nodes pairs with a link quality index higher than the preset threshold use the standard time slot length, while nodes pairs with a link quality index lower than the preset threshold use a time slot length extended to 1.5 times the standard value; after the time slot allocation algorithm completes the allocation, a time slot mapping table is generated. The time slot mapping table records the occupied time slot numbers of each node, the identifiers of adjacent nodes, and the corresponding link quality intervals, and is periodically synchronized to all associated nodes within two-hop range through the narrowband communication module; when a new node joining the network is detected, according to the remaining energy ratio in its broadcast beacon, 20% of the already allocated time slots are released from the adjacent node with the lowest remaining energy ratio in the time slot mapping table for the new node to use.

[0043] The network node calculates the initial time slot allocation weight through a composite weight algorithm based on the link quality index (such as the RSSI weighted value) and the remaining energy ratio (the percentage of the remaining battery capacity) in the dynamic topology information. Specifically, the square root of the link quality index (for example, in the range of -90 dBm to -60 dBm) is multiplied by the remaining energy ratio (for example, 30% to 100%) to generate the weight value w. , Q r is the RSSI value, and P e is the remaining energy percentage. The higher the weight value, the higher the priority of the node's demand for time slot resources. The time slot allocation request is broadcast through the narrowband communication module, and the request frame carries the node identifier, the number of required time slots (such as 3 time slots), and the calculated weight value. After receiving the request, the adjacent node checks the occupancy status of the allocated time slots in the local time slot mapping table (such as the occupancy marks of time slot numbers 1-10). If the requested time slot overlaps with the allocated time slots (such as requesting time slot 5 while time slot 5 is already occupied), a rejection response is returned with a list of conflicting time slot numbers (such as conflicting time slots 5 and 8). The composite weight algorithm combines the link quality and energy status to prevent high-energy-consuming nodes from over-occupying resources; the conflict detection mechanism achieves distributed coordination through narrowband signaling interaction, reducing the probability of time slot allocation conflicts; the list of conflicting time slots in the rejection response provides a basis for the requesting node to reallocate.

[0044] When establishing the transmission time slots of the broadband communication module, the time slot length is dynamically adjusted according to the link quality index. For example, when the link quality index is higher than the preset threshold (such as -75 dBm), the standard time slot length (such as 5 ms) is adopted; if it is lower than the threshold, the time slot is extended to 1.5 times the standard value (such as 7.5 ms) to compensate for the transmission efficiency of the weak link. The time slot mapping table records the occupied time slot numbers of each node, the adjacent node identifiers, and the link quality intervals (such as high quality: above -75 dBm, medium quality: -75 dBm to -85 dBm, low quality: below -85 dBm). This table is synchronized to the associated nodes within two-hop range through the narrowband communication module periodically (such as every 10 seconds) to ensure topological consistency. When a new node joins, according to the remaining energy ratio (such as 50%) in its broadcast beacon, the adjacent node with the lowest remaining energy (such as 20%) is selected from the time slot mapping table, and it is required to release 20% of the allocated time slots (such as releasing 2 out of the original 10 occupied time slots) for the new node to use. The dynamic adjustment of the time slot length optimizes the data transmission success rate in the weak link scenario; the time slot mapping table synchronization mechanism ensures the consensus of all network nodes on the resource allocation status; the triggering of time slot release by the new node realizes dynamic reallocation of resources, avoiding resource rigidity caused by static allocation.

[0045] When the requesting node receives rejection responses from more than three adjacent nodes, it triggers the slot allocation recalculation process. The node reduces the required number of slots to 70% of the original value (e.g., from 10 slots to 7 slots) and resends the allocation request. During the recalculation, free slots other than the conflicting slot numbers are preferentially selected (e.g., conflicting slots 5 and 8 are skipped). If the demand still cannot be met, a cooperation request is sent to the nodes within two-hop range to borrow their free slots (e.g., adjacent node A provides slot 12). After the allocation is completed, the node updates the local slot mapping table and sends an acknowledgment frame through the narrowband channel to notify the associated nodes to update their copies of the mapping table. The adaptive reduction of the slot number avoids resource request deadlocks; the cross-node cooperation mechanism expands the sharing range of slot resources; the acknowledgment frame ensures the atomicity of mapping table updates and prevents data inconsistency.

[0046] The slot allocation based on composite weights can significantly improve the fairness and adaptability of resource allocation; the dynamic adjustment of slot length effectively enhances the transmission reliability in weak link environments; the slot reallocation and cooperation mechanism greatly reduces the probability of resource conflicts and improves the overall network throughput.

[0047] After the slot allocation is completed, the following steps are also executed: According to the link quality intervals recorded in the slot mapping table, the transmit power of the broadband communication module is dynamically calibrated. For node pairs with link quality intervals in the lowest 30%, the transmit power is increased to 90% of the preset maximum value. For node pairs with link quality intervals in the highest 20%, the transmit power is reduced to 50% of the preset maximum value; when the network load changes, slot reallocation is triggered based on the slot occupancy rate monitored by the narrowband communication module. If the slot occupancy rate is higher than 80% for three consecutive cycles, additional slots are allocated to the top three nodes with the highest weight values in the order of the weight values in the slot mapping table. When a node exits the network, a slot release instruction is broadcast through the narrowband communication module. The adjacent nodes that receive the instruction mark the invalid slots according to the slot mapping table and re-incorporate the invalid slots into the available slot pool in the next allocation cycle; a priority preemption mechanism is introduced during slot reallocation. When the slot request of a high-weight node is occupied by a low-weight node, the low-weight node is forced to release the target slot and trigger its re-request for allocation; the transmit power calibration result is encapsulated as a control instruction and sent to the target node through the narrowband channel. The target node returns an acknowledgment frame including the actual power value after completing the power adjustment. If the deviation between the actual power value and the instruction value exceeds 15%, the narrowband channel retransmission mechanism is triggered. When two consecutive time slots are detected to be unused in the broadband channel, it is determined as time slot waste and the time slot recovery process is initiated. The idle time slots are re - marked as available, and the associated nodes are notified through the time slot mapping table update. In the time slot re - allocation phase, if the remaining energy ratio of a node is lower than 20%, it is prohibited from participating in time slot pre - emption operations, and the priority weight of its occupied time slots is reduced to 50% of the original value.

[0048] According to the link quality intervals in the time slot mapping table, the transmission power of the broadband communication module is dynamically calibrated. For example, for node pairs in the lowest 30% of the link quality interval (such as RSSI weighted value lower than - 85dBm), the transmission power is increased from the reference value of 20dBm to 24dBm (90% of the preset maximum value); for node pairs in the highest 20% of the interval (such as RSSI weighted value higher than - 70dBm), the power is reduced to 10dBm (50% of the preset maximum value). The power calibration instruction is encapsulated as a control frame and sent through the narrow - band channel. The target node returns the actual power value (such as 23.5dBm) after the adjustment. If the deviation between the actual value and the instruction value exceeds 15% (such as instruction 24dBm, actual 20dBm), the narrow - band channel re - transmission mechanism is triggered until the calibration is successful. When the time slot occupancy rate is higher than 80% for three consecutive cycles (such as 5 seconds per cycle) due to network load changes, the top three nodes are allocated additional time slots (such as 2 additional time slots for each node) according to the weight value sorting (such as from high to low). Power calibration reduces energy consumption waste for high - quality links and compensates the signal strength for weak links at the same time; the time slot re - allocation mechanism dynamically expands the resource quota for high - priority nodes according to load changes; the re - transmission mechanism ensures the accuracy of power control.

[0049] When a node exits the network, a time slot release instruction (including a list of invalid time slot numbers) is broadcast through the narrow - band communication module. After receiving the instruction, adjacent nodes mark the invalid time slots as "available" in the local time slot mapping table and include them in the available time slot pool in the next allocation cycle (such as 10 seconds later). When two consecutive unused time slots are detected (such as no data transmission in time slots 3 and 4 within 5 cycles), the time slot recovery process is triggered: the status of the idle time slots is reset to "idle", and the associated nodes are notified through the mapping table update. For the time slot pre - emption request of a high - weight node (such as weight value exceeding the threshold of 200), if the target time slot is occupied by a low - weight node, the latter is forced to release the time slot (such as interrupting its current transmission), and the low - weight node is triggered to re - initiate the allocation request. The time slot release and recovery mechanism improves resource utilization; the priority pre - emption strategy guarantees the resource requirements of critical services; the forced release mechanism realizes fast response through narrow - band signaling.

[0050] When the remaining energy ratio of a node is below 20%, it is prohibited from participating in time slot preemption operations, and the priority weight of the occupied time slot is reduced to 50% of the original value (for example, the original weight of 150 is reduced to 75). If the node still cannot establish a stable link after power calibration (such as three consecutive handshake failures), trigger the topology reconstruction process: request all network nodes to re-report status beacons through narrowband broadcast, generate an updated candidate node list, and reallocate time slots based on the new list. During the reconstruction process, temporarily disable the historical fault frequency band (such as the 5.8 GHz frequency band) until it is automatically lifted after 100 transmission cycles. The energy consumption limit mechanism extends the battery life of low-power nodes; topology reconstruction solves persistent link failures; temporary frequency band disabling avoids repeated selection of interfering channels.

[0051] Significant optimization of the network energy efficiency ratio can be achieved through dynamic power calibration and load-responsive time slot reallocation; time slot recycling and preemption strategies effectively improve resource utilization and the ability to guarantee critical services; the energy consumption limit and topology reconstruction mechanisms enhance the stability and robustness of the network in scenarios with frequent node changes.

[0052] In another technical solution, the specific process of classifying and modulating the data packet to be sent in step S3 includes: According to the allocation result of the transmission time slot, analyze the service type of the data packet to be sent. If the data packet includes a video stream or a file transfer protocol payload, it is marked as broadband data. If it includes a routing control instruction or a topology update signaling, it is marked as a narrowband control instruction; before modulation, broadband data is subject to channel quality assessment, and the number of subcarriers is dynamically selected through orthogonal frequency division multiplexing modulation. When the signal-to-interference-noise ratio of the broadband channel is detected to be lower than 20 dB, the number of subcarriers is reduced from 64 to 32 and the cyclic prefix extension mechanism is activated; when the narrowband control instruction is transmitted using differential phase shift keying modulation, the modulation order is dynamically adjusted according to the historical bit error rate data of the narrowband channel. When the bit error rate for three consecutive transmission cycles is below 0.1%, it is switched to quadriphase differential phase shift keying modulation to improve transmission efficiency; When broadband data and narrowband control instructions are transmitted in parallel, the transmission time slots of the two types of data are aligned through a timestamp synchronization mechanism, which specifically includes: inserting the synchronization header of the narrowband control instruction at the starting position of the broadband time slot, and reserving a 2 ms time slot protection interval before the end of the narrowband channel transmission time slot; when a conflict is detected between the transmission time slots of the broadband data and the narrowband control instruction, trigger a priority-based interruption mechanism, pause the current subcarrier transmission of the broadband data and give priority to transmitting the narrowband control instruction, and resume the interrupted subcarrier after the narrowband transmission is completed; A power equalization algorithm is introduced during the orthogonal frequency division multiplexing modulation process, and the transmit power is dynamically allocated according to the channel quality difference of the subcarriers. The power of the three subcarriers with the worst channel quality is increased to 120% of the standard value, and the power of the remaining subcarriers is reduced to 80% of the standard value; After the narrowband control instruction is transmitted, a reception confirmation signal returned by an adjacent node is received through the narrowband communication module. If the confirmation signal is not received and the broadband channel is idle, the narrowband control instruction is retransmitted through the broadband channel and marked as a high-priority data packet.

[0053] Based on the transmission time slot allocation result, the network node analyzes the service type of the data packet to be transmitted: if the data packet contains a video stream (such as H.264 encoded data) or a File Transfer Protocol (such as FTP) payload, it is marked as broadband data; if it contains a routing control instruction (such as the RREQ routing request of AODV) or a topology update signaling (such as a HELLO beacon), it is marked as a narrowband control instruction. The broadband data is modulated using Orthogonal Frequency Division Multiplexing (OFDM), initially configured with 64 subcarriers. When the Signal-to-Interference-plus-Noise Ratio (SINR) of the broadband channel is detected to be below 20 dB (for example, in a strong multipath interference environment), the number of subcarriers is halved to 32, and the cyclic prefix length is extended (such as from 4 μs to 8 μs) to resist delay spread. The narrowband control instruction is modulated using Differential Phase Shift Keying (DPSK). When the bit error rate of the narrowband channel is below 0.1% for three consecutive transmission periods (for example, through CRC check statistics), it is switched to Quadrature Phase Shift Keying (QPSK) modulation to increase the symbol rate (such as from 1 Mbps to 2 Mbps). Service classification enables precise traffic splitting based on the protocol type; dynamic adjustment of OFDM subcarriers adapts to changes in channel quality; DPSK / QPSK switching balances the reliability and efficiency of the narrowband channel.

[0054] The transmission time slots of the broadband data and the narrowband control instruction are aligned through a timestamp synchronization mechanism. A narrowband synchronization header (such as a 2-byte specific sequence) is inserted at the start position of the broadband time slot, and the receiving end determines the time slot boundary based on the synchronization header. A 2 ms guard interval (configurable range from 1 ms to 5 ms) is reserved before the end of the narrowband channel transmission time slot to prevent time slot overlap caused by clock drift. When a time slot conflict between the broadband data and the narrowband instruction is detected (such as a control instruction arriving suddenly and occupying the broadband time slot), a priority interruption mechanism is triggered: the transmission of the current OFDM subcarriers is immediately paused, and the narrowband instruction is transmitted first. After the narrowband transmission is completed, the interrupted subcarriers are resumed. The broadband data lost during the interruption is retransmitted in subsequent time slots through a retransmission mechanism (such as ARQ). The synchronization header and the guard interval ensure strict time slot alignment; the interruption mechanism guarantees the real-time nature of the control instruction; the retransmission mechanism compensates for the interruption loss of the broadband data transmission.

[0055] During the OFDM modulation process, the transmission power is dynamically allocated according to the channel quality differences of subcarriers (such as the SINR fluctuation range of ±5 dB). For the three subcarriers with the worst quality (such as SINR < 15 dB), the power is increased to 120% of the standard value (for example, increased from 20 dBm to 24 dBm), and the power of the remaining subcarriers is reduced to 80% (such as 16 dBm) to balance the bit error rate. After the narrowband control instruction transmission is completed, if no acknowledgment signal is received (such as a timeout of 500 ms) and the broadband channel is idle, the instruction is retransmitted through the broadband channel and marked as a high-priority data packet (such as the priority field is set to the highest level) to ensure the reliable arrival of the control signaling. Power balancing optimizes the performance consistency among subcarriers; cross-channel redundant transmission uses broadband resources to make up for the unreliability of narrowband channels; priority marking prevents retransmitted data from being blocked by ordinary services.

[0056] Adopting the method of dynamic modulation adjustment can significantly improve the transmission reliability under poor channel conditions; the time slot synchronization and interruption mechanism effectively guarantees the real-time performance and determinacy of key control instructions; the power balancing and redundant transmission strategy enhances the robustness of the system in an interference environment.

[0057] The broadband data transmission process also includes the following steps: The broadband data is split into multiple data blocks according to a preset fragmentation rule. Each data block is attached with a frame header including a sequence number and a check code, and is transmitted in parallel through different subcarrier groups of orthogonal frequency division multiplexing; the fragmentation rule dynamically adjusts the fragmentation size according to the delay jitter of the current broadband channel. When the delay jitter exceeds 5 ms, the fragmentation size is reduced from 1024 bytes to 512 bytes to reduce the impact of a single transmission failure; when recombining the data blocks at the receiving end, if a missing sequence number is detected, the narrowband communication module is used to request the retransmission of a specific fragment from the sending end, and the list of sequence numbers of the missing fragments and the corresponding subcarrier numbers are carried in the request frame; The check code is generated by Turbo coding. When the number of decoding failures at the receiving end reaches three times, the redundant fragment transmission mechanism is triggered, and the exclusive OR operation result of the original fragment and two redundant fragments is sent through the unused subcarriers; During the dynamic adjustment of the fragmentation size, the Shannon formula is introduced to calculate the theoretical optimal value, and the upper limit of the fragmentation size is calculated according to the real-time bandwidth and signal-to-noise ratio of the broadband channel, and it is constrained within the range of 256 bytes to 2048 bytes; When it is detected that five consecutive fragment transmissions fail, it is determined that there is continuous interference in the current subcarrier group, and the corresponding three subcarriers are turned off and the adjacent nodes are notified through the narrowband communication module to update the channel occupancy information; After the fragment recombination is completed, if the passing rate of the check code verification is lower than 95%, the orthogonal frequency division multiplexing modulation order is automatically reduced, 64QAM is switched to 16QAM, and the data block that fails to pass the verification is retransmitted.

[0058] The broadband data is split into multiple data blocks according to a preset fragmentation rule (e.g., 1024 bytes for each fragment). The fragment header contains a sequence number (e.g., a 4-byte incrementing number) and a checksum generated by Turbo coding (e.g., 32-bit CRC). The fragment size is dynamically adjusted according to the delay jitter of the broadband channel: when the delay jitter exceeds 5 ms (e.g., by calculating the variance of the arrival times of the last 10 fragments through a sliding window), the fragment size is reduced from 1024 bytes to 512 bytes to reduce the impact of a single transmission failure. The fragment upper limit is calculated by the Shannon formula (e.g., the theoretical maximum fragment is 2048 bytes when the channel bandwidth is 20 MHz and the signal-to-noise ratio is 25 dB), and the actual fragment size is restricted between 256 bytes and 2048 bytes to avoid efficiency degradation caused by extreme values. The fragmentation mechanism reduces the failure risk of large-block data transmission; the dynamic fragmentation rule optimizes the fragmentation granularity according to the real-time channel state; the Shannon formula constraint ensures the theoretical rationality of the fragment size.

[0059] When a fragment loss is detected at the receiving end (e.g., the sequence numbers are not continuous), a retransmission request is sent through the narrowband channel, carrying the list of sequence numbers of the missing fragments (e.g., sequences 5, 8, 11) and the corresponding subcarrier numbers (e.g., subcarrier group 3). If the decoding of the same fragment fails three times (e.g., due to bit errors caused by deep fading), redundant fragment transmission is triggered: the exclusive OR result of the original fragment and two redundant fragments is sent through the unused subcarriers (e.g., fragment A ⊕ B ⊕ C), and the receiving end uses the redundant data to recover the original content. When it is detected that five consecutive fragments fail to be transmitted (e.g., the SINR of subcarrier group 2 is continuously lower than 10 dB), this subcarrier group is turned off and adjacent nodes are notified to update the channel occupancy information, and the transmission is switched to the backup subcarrier group. Redundant fragments enhance the ability to resist burst interference; turning off interfering subcarriers avoids resource waste; narrowband signaling coordinates the channel switching action.

[0060] After the fragment recombination is completed, if the passing rate of the checksum verification is lower than 95% (e.g., 5 out of 100 fragments fail the check), the OFDM modulation order is automatically downgraded from 64QAM to 16QAM (e.g., each symbol carries 4 bits instead of 6 bits), and the data blocks that fail the check are retransmitted. The fragmented pieces after the order reduction adopt a lower coding rate (e.g., from 3 / 4 to 1 / 2) to enhance the anti-noise ability. After successful recombination at the receiving end, the average delay (e.g., 15 ms) and the successful reception ratio (e.g., 98%) are fed back through the narrowband channel for the sending end to adjust the subsequent fragmentation strategy. Modulation order reduction adapts to the scenario of channel deterioration; the feedback mechanism forms a closed loop to optimize the link; the coding rate adjustment balances efficiency and reliability.

[0061] The overall failure probability of data transmission is effectively reduced through dynamic fragmentation and redundancy mechanisms; the interference detection and subcarrier turning-off strategy significantly improves the channel resource utilization rate; the closed-loop feedback and adaptive modulation mechanism enhances the system's adaptability to time-varying channels.

[0062] The fragmentation reassembly and retransmission mechanism further includes the following steps: At the receiving end, a fragmentation cache queue is established, the received data blocks are sorted according to the sequence number, and the arrival timestamp and channel quality index of each fragment are recorded; when requesting the retransmission of missing fragments, the sending end preferentially selects the three subcarriers with the best channel quality for retransmission and marks them as retransmission priority data packets in the frame header; in the redundant fragment transmission mechanism, dynamic redundancy calculation is introduced, and the number of redundant fragments is determined according to the current network load and historical bit error rate data. When the bit error rate is higher than 1%, twice as many redundant fragments are generated; After the data is reassembled at the receiving end, the reassembly result is fed back to the sending end through the narrowband communication module. The feedback information includes the proportion of successfully received fragments, the average delay, and the recommended adjusted fragment size parameter; The sending end updates the fragmentation rule according to the recommended parameters in the feedback information. If the average delay exceeds 20 ms and the proportion of successfully received fragments is lower than 90%, the fragmentation size in the next cycle is adjusted to 75% of the current value; When it is detected that the number of retransmission requests for the same data block exceeds five times, the link switching mechanism is triggered, and the subsequent fragments are transmitted through the narrowband channel, and the link quality index in the dynamic topology information is updated after the transmission is completed; The fragmentation cache queue adopts an aging elimination strategy, automatically clears the residual fragments that have not been requested for retransmission for more than 500 ms, and sends a fragmentation invalidation notice to the sending end through the narrowband channel to release the cache resources.

[0063] At the receiving end, a fragmentation cache queue is established, sorted by sequence number, and the arrival timestamp of the fragments (accurate to the microsecond level) and the channel quality index (such as the SINR value) are recorded. When requesting the retransmission of missing fragments, the sending end preferentially selects the three subcarriers with the best channel quality (such as subcarriers 1, 4, and 7 with SINR > 25 dB) for retransmission and marks them as retransmission priority (such as setting the priority bit to 1) in the fragment header to ensure that the retransmitted data is preferentially scheduled. The number of redundant fragments is dynamically calculated according to the current network load (such as channel utilization rate of 70%) and historical bit error rate (such as the average bit error rate of the last 100 fragments of 1.5%): when the bit error rate is higher than 1%, twice as many redundant fragments are generated (such as the original fragment + 2 redundant fragments); when the bit error rate is lower than 0.5%, only one redundant fragment is generated. The retransmission subcarrier selection driven by channel quality improves the retransmission success rate; the dynamic redundancy balances reliability and bandwidth overhead; the priority marking ensures the timely processing of retransmitted data.

[0064] After the recombination is completed, the receiver feeds back the successfully received shard ratio (e.g., 95%), the average delay (e.g., 18 ms), and the recommended shard size (e.g., recommended to be adjusted to 768 bytes) through the narrowband channel. The sender updates the sharding rule according to the feedback information: if the average delay exceeds 20 ms and the success rate is lower than 90%, the shard size in the next cycle is adjusted to 75% of the current value (e.g., reduced from 1024 bytes to 768 bytes). When the number of retransmission requests for the same data block exceeds five times (e.g., due to continuous channel blockage), the link switching mechanism is triggered: the subsequent shards of the data block are transmitted through the narrowband channel (e.g., the speed is reduced to 500 kbps), and the link quality mark in the dynamic topology information is updated after the transmission is completed (e.g., the quality level of link A - B is reduced from "high" to "medium"). The feedback parameters guide the real - time optimization of the sharding strategy; the link switching mechanism copes with extreme channel failures; the topology update ensures the accuracy of subsequent routing decisions.

[0065] The shard cache queue adopts an aging and elimination strategy: for residual shards (such as sequence numbers 10, 13) that have not been requested for retransmission for more than 500 ms (configurable range 300 ms to 1000 ms), they are automatically cleared and the cache space is released. The clearing operation triggers a narrowband signaling to notify the sender (such as sending a shard invalidation frame), and the sender releases the corresponding transmission cache resources accordingly. If the remaining energy of a node is lower than 20%, it is prohibited from participating in high - frequency retransmission operations (such as restricting the number of retransmission requests per second to no more than 5 times), and the priority weight of its cache queue is reduced by 50% (such as from 100 to 50), giving priority to ensuring the resource usage of high - energy nodes. The aging strategy prevents cache overflow; the energy - aware priority adjustment extends the network lifetime; the invalidation notification mechanism realizes the synchronization of the resource states between the sender and the receiver.

[0066] The data transmission efficiency and reliability are significantly improved through the intelligent retransmission strategy and dynamic redundancy control; the feedback - driven parameter optimization mechanism effectively adapts to the dynamic network environment; the cache management and energy - aware strategies significantly reduce resource waste and extend the node battery life.

[0067] In another technical solution, in step S4, the following method is used to handle link interruption and parameter adjustment: When the link quality index is lower than the preset threshold, a link interruption alarm is broadcast to the nodes within three - hop range through the narrowband communication module. The alarm frame includes the identifier of the interrupted link, the current channel interference intensity, and a priority list of candidate next - hop nodes; The priority list of candidate next-hop nodes is generated based on the link quality metrics and the remaining energy ratio in the dynamic topology information. The priority calculation method is to multiply the link quality metrics by the remaining energy ratio, and nodes with a remaining energy ratio lower than 15% are excluded. When reselecting the next-hop node, a handshake request is initiated according to the priority list. If the target node does not respond within 200 ms, the next candidate node is switched in descending order of priority, and the node connection relationship in the dynamic topology information is updated. When adjusting the transmit power of the broadband communication module, the target power value is dynamically calculated according to the channel characteristic parameters of the new link. The channel characteristic parameters include the signal-to-interference-plus-noise ratio and the multipath fading coefficient. The target power value is a linear function of the reference power value and the reciprocal of the signal-to-interference-plus-noise ratio. The adjustment of the frequency band selection parameter is achieved by scanning the channel idle rate in the preset frequency band list, and the frequency band with an idle rate higher than 70% and the least historical interference times is selected as the communication frequency band of the new link. After the frequency band switch is completed, a frequency band synchronization instruction is sent to the new next-hop node through the narrowband communication module. The instruction includes the new frequency band number and the synchronization timestamp, and the retransmission process of the broadband data is started after receiving the synchronization confirmation. If a stable link cannot be established after three consecutive frequency band switches, the topology reconstruction process is triggered, and the status beacon is re-broadcast through the narrowband communication module, and a new candidate node list is generated based on the updated dynamic topology information.

[0068] When the link quality metrics (such as the RSSI weighted value is lower than -90 dBm) trigger an interruption alarm, the node broadcasts an alarm frame within three hops through the narrowband communication module. The alarm frame contains the interrupted link identifier (such as the MAC address combination of node A - B), the current channel interference intensity (such as the -85 dBm background noise value measured by the spectrum analyzer), and the priority list of candidate next-hop nodes. When generating the candidate list, nodes that meet the link quality metrics higher than -80 dBm, the remaining energy ratio greater than 15% (such as 35% remaining battery), and the topology hop count not exceeding 3 hops (such as node C is two hops away from the interrupted node) are screened from the dynamic topology information. The priority calculation formula is to multiply the link quality metrics (such as -75 dBm) by the remaining energy ratio (such as 50%), generate a priority score (such as -75×0.5 = -37.5), and arrange them in descending order of the score. The three-hop broadcast ensures that the alarm information covers potential alternative paths; the composite priority calculation takes into account both link stability and node endurance; the dynamic screening excludes low-energy nodes to avoid the risk of secondary interruption.

[0069] The node initiates a handshake request based on the candidate list. If the target node does not return a response within 200 ms (configurable range: 100 ms to 500 ms) (e.g., due to channel congestion or moving out of range), it will automatically switch to the sub-optimal node. During the switching process, a topology update instruction (such as "link A - B disconnected, A - C connected") is sent through the narrowband channel. After adjacent nodes receive it, they update their local adjacency tables and feedback the update results through an acknowledgment frame. At the same time, the transmit power of the broadband module is adjusted: based on the signal - to - interference - plus - noise ratio (e.g., SINR = 15 dB) and the multipath fading coefficient (e.g., 0.3) of the new link, the target power is calculated as a linear function of the reference power (e.g., 20 dBm) and the reciprocal of the SINR (e.g., target power = 20+(1 / 15)×10≈23.3 dBm). The timeout switching mechanism ensures the timeliness of link recovery; the topology update instruction and the acknowledgment frame ensure the synchronization of the whole - network state; the power calculation formula dynamically adapts to the characteristics of the new link, avoiding power shortage or overload.

[0070] The frequency band selection parameter is realized by scanning a preset frequency band list (such as channels 1 - 13 in the 2.4 GHz frequency band), and the frequency band with a channel idle rate higher than 70% (e.g., the idle rate of channel 6 is 75%) and the fewest historical interference times (e.g., interference events ≤ 2 times in the past 10 minutes) is selected. After the switching is completed, a frequency band synchronization instruction (including the new frequency band number and the synchronization timestamp accurate to microseconds) is sent. If the target node does not return a synchronization acknowledgment within 50 ms, the instruction is re - sent three times through the narrowband channel. If the switching fails three times in a row (e.g., connections cannot be established for channels 1, 6, and 11), topology reconstruction is triggered: the status beacon is re - broadcast, the latest information of all network nodes is collected, a candidate list of nodes within five - hop range is generated, and the historical faulty frequency band (e.g., channel 6) is disabled for 100 transmission cycles. The combination of the frequency band idle rate and the interference history improves the reliability of channel selection; the synchronization timestamp aligns the clocks of the transmitter and receiver; topology reconstruction expands the candidate range to cope with large - scale topology changes.

[0071] The link switching success rate is significantly improved through the dynamic candidate node screening and priority mechanism; the adaptive adjustment of power and frequency band effectively enhances the communication quality of the new link; the topology reconstruction and frequency band disabling mechanism greatly reduces the probability of repeated interruptions.

[0072] After the frequency band switching is completed, the following steps are executed: The channel quality of the new link is continuously monitored through the broadband communication module. The signal - to - interference - plus - noise ratio and bit error rate data are collected every 50 ms, and their moving average values are calculated as the stability evaluation index; When the fluctuation amplitude of the stability evaluation index exceeds 30% for five consecutive samples, it is determined that the channel state is unstable, triggering the narrowband communication module to send a channel switching suggestion request, and performing a secondary frequency band switching according to the candidate frequency band list feedback by adjacent nodes; During the process of dynamic adjustment of transmission power, if it is detected that the remaining energy ratio of the node is lower than 20%, the power limit mode is enabled, the upper limit of the transmission power is set to 80% of the reference power value, and the low-power modulation method is preferentially selected; Forward error correction coding is used during the transmission of the frequency band synchronization instruction. When the number of decoding failures at the receiving end reaches two, it switches to the redundant transmission mode, and repeats the transmission of the synchronization instruction within three adjacent narrowband time slots and attaches a check code; In the broadband data retransmission process, adjust the subcarrier allocation scheme of the orthogonal frequency division multiplexing modulation according to the channel characteristic parameters of the previous transmission failure, turn off the two subcarriers with the lowest signal-to-interference-plus-noise ratio, and recalculate the cyclic prefix length; If no data packet is successfully transmitted within 300 ms after the establishment of a new link, it is marked as an abnormal link, and the whole network nodes are notified through the narrowband communication module to update the link status mark in the dynamic topology information; A blacklist mechanism is introduced in the topology reconstruction process. The frequency bands that have failed to switch twice consecutively are added to the temporary disable list, and the selection of this frequency band for communication is prohibited within the subsequent 100 transmission cycles.

[0073] After the establishment of a new link, the signal-to-interference-plus-noise ratio (such as the SINR fluctuates from 18 dB to 12 dB) and the bit error rate (such as rising from 0.5% to 2%) are collected through the broadband module every 50 ms (adjustable range 20 ms to 100 ms), and their sliding average value (such as the average value of the last 5 samples) is calculated. When the fluctuation amplitude of the sliding average value exceeds 30% for five consecutive times (such as the SINR mean value drops from 15 dB to 10.5 dB, a decrease of 30%), it is determined that the channel is unstable, and a narrowband channel transmission handover recommendation request is triggered. After receiving the request, the adjacent node returns the local candidate frequency band list (such as node C recommends channels 3 and 9), and the initiating node performs a secondary handover based on the historical interference data of the recommended frequency band (such as the number of interference times of channel 3 in the past hour is 1). The sliding average filters out instantaneous interference to avoid misjudgment; the secondary handover improves the rationality of channel selection based on neighbor recommendations; historical data-driven reduces the frequency of repeated handovers.

[0074] During the power adjustment phase, if the remaining energy of a node is less than 20% (e.g., the battery has 18% remaining), the power limit mode is enabled: the upper limit of the transmission power is set to 80% of the reference value (e.g., the original maximum of 25 dBm is limited to 20 dBm), and it is forced to switch to a low-power modulation mode (e.g., from 64QAM to QPSK). When transmitting the frequency band synchronization instruction, forward error correction coding is used (e.g., Reed-Solomon code). If the receiving end fails to decode twice (e.g., CRC check error), it switches to the redundant transmission mode: the synchronization instruction is repeatedly sent in three adjacent narrowband time slots (e.g., time slots 5, 6, and 7), and a double check code is added (e.g., 64-bit CRC) until the receiving end returns a successful confirmation. Power limitation extends the battery life of low-power nodes; redundant transmission and enhanced verification improve the reliability of the synchronization instruction; reduced-order modulation reduces energy consumption.

[0075] If no data packets are transmitted within 300 ms (configurable from 200 ms to 500 ms) after a new link is established (e.g., due to hidden node interference), it is marked as an abnormal link, and the whole network is notified via narrowband broadcast to update the topology information (e.g., set the link status of node A-C to "failed"). At the same time, the frequency bands that have failed to switch twice in a row (e.g., channels 6 and 11) are added to the temporary disable list, and the selection of this frequency band is prohibited within the subsequent 100 transmission cycles (e.g., if the cycle is 1 second, it is disabled for 100 seconds). After the disable period expires, a probe frame is sent via the narrowband channel (e.g., continuously 5 times at 1-second intervals) to evaluate the channel status. If the interference intensity is lower than the threshold (e.g., -90 dBm), the disable is lifted. Marking abnormal links prevents incorrect routing decisions; the frequency band blacklist avoids known interference sources; the probe frame mechanism enables the dynamic recovery of disabled frequency bands.

[0076] The adoption of the stability monitoring and secondary switching mechanism significantly improves the long-term reliability of channel selection; the power limitation and redundant transmission strategies effectively extend the node battery life and ensure the reachability of control signaling; the abnormal link handling and frequency band blacklist mechanism greatly reduce the network maintenance overhead.

[0077] It should be noted that although the above steps are described in a specific order, it does not mean that the steps must be executed in the above specific order. In fact, some of these steps can be executed concurrently or even in a different order, as long as the required functions can be achieved. The number of devices and the processing scale described here are used to simplify the description of the present invention, and the application, modification, and variation of the present invention are obvious to those skilled in the art.

[0078] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those skilled in the art, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the examples shown and described herein.

Claims

1. A method for a self-organizing network with wide and narrow integration, characterized in that, It includes the following steps: S1: The network node periodically broadcasts a status beacon including node location and remaining energy through the narrowband communication module based on a preset topology discovery protocol, and generates dynamic topology information according to the received beacons of adjacent nodes. The dynamic topology information includes node connection relationships and link quality indicators; S2: According to the node connection relationships and link quality indicators in the dynamic topology information, calculate the initial time slot allocation scheme for each node based on a load-aware time slot allocation algorithm. The time slot allocation algorithm sends a time slot allocation request to adjacent nodes through the narrowband communication module, and establishes the transmission time slots of the broadband communication module after receiving the confirmation response from adjacent nodes; S3: When the broadband communication module is activated, according to the allocation result of the transmission time slots, divide the data packets to be sent into broadband data and narrowband control instructions according to the service type. Among them, the broadband data is transmitted through the broadband channel using orthogonal frequency division multiplexing modulation, and the narrowband control instructions are transmitted through the narrowband channel using differential phase shift keying modulation; S4: When it is detected that the link quality indicator is lower than the preset threshold, trigger the narrowband communication module to send a link interruption alarm, reselect the next-hop node according to the current dynamic topology information, and at the same time adjust the transmission power and frequency band selection parameters of the broadband communication module to match the channel characteristics of the new link; S5: Dynamically switch the communication mode of the network node based on the hybrid multiple access protocol. When the network load exceeds the broadband channel capacity, divert some of the broadband data to the narrowband channel for transmission, and update the dynamic topology information through the narrowband communication module to maintain network connectivity.

2. The wide and narrow integration ad-hoc network method according to claim 1, wherein The specific method for generating dynamic topology information in step S1 includes: When the network node sends a status beacon through the narrowband communication module, extend the beacon transmission range to adjacent nodes within three hops; obtain the received signal strength indication (RSSI), and calculate the narrowband channel bit error rate by statistically decoding the cyclic redundancy check result of the adjacent node beacon. Obtain the link quality indicator through weighted calculation of the received signal strength indication and the narrowband channel bit error rate; Establish an adjacency list. The adjacency list includes all nodes within three hops and records the identifier, received signal strength indication weighted value, and remaining energy ratio of each adjacent node; when the received signal strength indication weighted value of an adjacent node drops by more than 20% continuously for three broadcast cycles, update the link status flag in the dynamic topology information; the remaining energy is collected by the node's real-time monitoring of battery voltage and current consumption, and a moving average filtering algorithm is used to eliminate instantaneous fluctuations; During the generation process of the dynamic topology information, if the beacon position coordinates from the same node jump more than the preset maximum moving speed, discard this abnormal beacon and start spectrum scanning to detect false node attacks; the dynamic topology information is synchronized among network nodes through a distributed hash table, and each node stores a complete topology data copy of its directly adjacent nodes.

3. The wide and narrow integrated ad-hoc network method according to claim 1, wherein The specific method for dynamically switching the communication mode and data diversion in step S5 includes: When it is detected that the network load exceeds the broadband channel capacity, the broadband data to be shunted is divided into high-latency tolerant data and low-latency tolerant data according to the service priority based on a preset load threshold. The high-latency tolerant data is transmitted through the narrowband channel, and the low-latency tolerant data remains transmitted through the broadband channel. During the shunting process, the modulation mode of the narrowband channel is synchronously adjusted. When the proportion of the data volume in the narrowband channel exceeds 50%, the modulation is switched from differential phase shift keying to quadrature phase shift keying. After the data shunting is completed, a topology update request is sent to adjacent nodes through the narrowband communication module. The update request includes the remaining broadband channel capacity and the narrowband channel load ratio of the current node. When it is detected that a transmission conflict is introduced in the narrowband channel due to shunted data, the contention window size is dynamically adjusted based on the contention window backoff algorithm according to the number of conflicts, and the transmission of low-priority narrowband control instructions is suspended during the backoff period. During the shunting process, if the narrowband channel fails to receive an acknowledgment response for three consecutive transmission cycles, the transmission power of the narrowband communication module is increased to 80% of the preset maximum value, and the modulation order of the broadband channel is downgraded from 64QAM to 16QAM. The broadband channel capacity is calculated by measuring the signal-to-interference-plus-noise ratio of orthogonal frequency division multiplexing subcarriers in real time. When the channel quality difference of the subcarriers exceeds 30%, the three subcarriers with the worst quality are turned off.

4. The wide and narrow integration ad-hoc network method according to claim 1, wherein The specific steps of the time slot allocation algorithm in step S2 include: According to the link quality index and the node remaining energy ratio in the dynamic topology information, an initial time slot allocation weight is calculated for each node. The weight is obtained by multiplying the link quality index by the square root of the remaining energy ratio. The time slot allocation request is sent in a broadcast form through the narrowband communication module. The request frame includes the identifier of the requesting node, the required number of time slots, and the calculated time slot allocation weight. After receiving the time slot allocation request, if an adjacent node detects that the requested time slots overlap with the already allocated time slots, a rejection response including the conflicting time slot numbers is returned to the requesting node. When the requesting node receives rejection responses from more than three adjacent nodes, the required number of time slots is reduced to 70% of the original value and the allocation request is resent. When establishing the transmission time slots of the broadband communication module, node pairs with a link quality index higher than the preset threshold use the standard time slot length, while node pairs with a link quality index lower than the preset threshold use a time slot length extended to 1.5 times the standard value. After the time slot allocation is completed, a time slot mapping table is generated to record the occupied time slot numbers of each node, the identifiers of adjacent nodes, and the corresponding link quality intervals, and is periodically synchronized to all associated nodes within two-hop range through the narrowband communication module. When it is detected that a new node joins the network, according to the remaining energy ratio in its broadcast beacon, the adjacent node with the lowest remaining energy ratio is selected from the time slot mapping table to release 20% of the already allocated time slots for the new node to use.

5. The self-organizing network method for wide-narrow integration according to claim 4, characterized in that After the time slot allocation is completed, the following steps are also executed: According to the link quality intervals recorded in the time slot mapping table, for node pairs where the link quality interval is in the lowest 30%, the transmit power of the broadband communication module is increased to 90% of the preset maximum value, and for node pairs where the link quality interval is in the highest 20%, the transmit power is reduced to 50% of the preset maximum value; When the network load changes, if the time slot occupancy rate monitored by the narrowband communication module is higher than 80% for three consecutive cycles, then sort according to the time slot weight value, and allocate additional time slots to the top three nodes with the highest weight values; when a node exits the network, broadcast a time slot release instruction through the narrowband communication module, and the adjacent nodes that receive the instruction mark the invalid time slots according to the time slot mapping table and re-incorporate the invalid time slots into the available time slot pool in the next allocation cycle; During the time slot reallocation process, when the time slot request of a high-weight node is occupied by a low-weight node, force the low-weight node to release the target time slot and trigger it to re-request allocation; When it is detected that there are two consecutive unused time slots in the broadband channel, it is determined that there is time slot waste and the time slot recovery process is started, the idle time slots are re-marked as available, and the associated nodes are notified through an update of the time slot mapping table; during the time slot reallocation phase, if the remaining energy ratio of a node is lower than 20%, it is prohibited from participating in time slot preemption operations, and the priority weight of the time slots it occupies is reduced to 50% of the original value.

6. The self-organizing network method for wide and narrow integration according to claim 1, wherein The specific process of classifying and modulating the data packet to be transmitted in step S3 includes: According to the allocation result of the transmission time slots, analyze the service type of the data packet to be transmitted. If the data packet includes a video stream or a file transfer protocol payload, it is marked as broadband data. If it includes a routing control instruction or a topology update signaling, it is marked as a narrowband control instruction; before modulation, perform a channel quality assessment on the broadband data. If it is detected that the signal-to-interference-plus-noise ratio of the broadband channel is lower than 20 dB, reduce the number of subcarriers and activate the cyclic prefix extension mechanism; When using differential phase shift keying modulation to transmit narrowband control instructions, if the bit error rate in three consecutive transmission cycles is lower than 0.1%, then switch to quadriphase differential phase shift keying modulation; when transmitting broadband data and narrowband control instructions in parallel, insert the synchronization header of the narrowband control instruction at the start position of the broadband time slot, and reserve a 2 ms time slot protection interval before the end of the narrowband channel transmission time slot; when it is detected that there is a conflict between the transmission time slots of the broadband data and the narrowband control instructions, trigger a priority-based interruption mechanism, pause the current subcarrier transmission of the broadband data and give priority to transmitting the narrowband control instructions, and resume the interrupted subcarriers after the narrowband transmission is completed; dynamically allocate the transmit power according to the channel quality differences of the subcarriers, increase the power of the three subcarriers with the worst channel quality to 120% of the standard value, and reduce the power of the remaining subcarriers to 80% of the standard value; After the narrowband control instruction transmission is completed, if the receive confirmation signal returned by the adjacent node is not received, retransmit the narrowband control instruction through the idle broadband channel and mark it as a high-priority data packet.

7. The method for a narrow-wide integrated ad hoc network according to claim 6, wherein The following steps are also included during the broadband data transmission process: The broadband data is fragmented into multiple data blocks. Each data block is appended with a frame header including a sequence number and a check code, and is transmitted in parallel through different sub - carrier groups of orthogonal frequency - division multiplexing. The fragmentation size is dynamically adjusted according to the delay jitter of the current broadband channel. When the delay jitter exceeds 5 ms, the fragmentation size is reduced from 1024 bytes to 512 bytes. The theoretical optimal value of the fragmentation size is calculated by the Shannon formula and is constrained within the range of 256 bytes to 2048 bytes. When recombining the data blocks at the receiving end, if a missing sequence number is detected, a narrow - band communication module is used to request the re - transmission of a specific fragment from the sending end, and the list of sequence numbers of the missing fragments and the corresponding sub - carrier numbers are carried in the request frame. The check code is generated by Turbo coding. When the number of decoding failures at the receiving end reaches three times, a redundant fragment transmission mechanism is triggered, and the exclusive - OR operation result of the original fragment and two redundant fragments is sent through the unused sub - carriers. If five consecutive fragment transmissions fail are detected, it is determined that there is persistent interference in the current sub - carrier group, and the corresponding three sub - carriers are turned off and the adjacent nodes are notified through the narrow - band communication module to update the channel occupancy information. After the fragmentation recombination is completed, if the passing rate of the check - code verification is lower than 95%, the orthogonal frequency - division multiplexing modulation order is automatically reduced, switching 64QAM to 16QAM and re - transmitting the data blocks that fail the verification.

8. The wide-narrow fusion ad-hoc network method according to claim 7, characterized in that The fragmentation recombination and re - transmission mechanism further includes the following steps: A fragmentation cache queue is established at the receiving end. The received data blocks are sorted by sequence number, and the arrival timestamp and channel quality index of each fragment are recorded. When requesting the re - transmission of missing fragments, the sending end preferentially selects the three sub - carriers with the best channel quality for re - transmission and marks them as re - transmission priority data packets in the frame header. The redundant fragment transmission mechanism determines the number of redundant fragments according to the current network load and historical bit - error rate data. When the bit - error rate is higher than 1%, twice the number of redundant fragments are generated. The fragmentation cache queue automatically clears the residual fragments that have not been requested for re - transmission for more than 500 ms and sends a fragment invalidation notice to the sending end through the narrow - band channel. After the data recombination is completed at the receiving end, the recombination result is fed back to the sending end through the narrow - band communication module. The feedback information includes the proportion of successfully received fragments, the average delay, and the recommended fragmentation size parameter for adjustment. The sending end updates the fragmentation rule according to the recommended parameters in the feedback information. If the average delay exceeds 20 ms and the proportion of successfully received fragments is lower than 90%, the fragmentation size in the next cycle is adjusted to 75% of the current value. When the number of re - transmission requests for the same data block exceeds five times, a link - switching mechanism is triggered, and the subsequent fragments are transmitted through the narrow - band channel, and the link quality index in the dynamic topology information is updated after the transmission is completed.

9. The method for a wide-and-narrowband integrated ad hoc network according to claim 1, characterized in that In step S4, the following method is used to handle link interruption and parameter adjustment: When the link quality index is lower than the preset threshold, a link - interruption warning is broadcast to the nodes within three - hop range through the narrow - band communication module. The warning frame includes the identifier of the interrupted link, the current channel interference intensity, and the priority list of candidate next - hop nodes. The priority list of candidate next-hop nodes is generated based on the link quality metrics and the remaining energy ratio in the dynamic topology information, and nodes with a remaining energy ratio lower than 15% are excluded; when reselecting the next-hop node, a handshake request is initiated according to the priority list. If the target node does not respond within 200 ms, switch to the next candidate node in descending order of priority and update the node connection relationship in the dynamic topology information; When adjusting the transmit power of the broadband communication module, the target power value is dynamically calculated according to the channel characteristic parameters of the new link. The channel characteristic parameters include the signal-to-interference-and-noise ratio and the multipath fading coefficient, and the target power value is a linear function of the reference power value and the reciprocal of the signal-to-interference-and-noise ratio; scan the channel idle rate in the preset frequency band list, and select the frequency band with an idle rate higher than 70% and the least historical interference times as the communication frequency band of the new link; After the frequency band switching is completed, send a frequency band synchronization instruction to the new next-hop node through the narrowband communication module. The instruction includes the new frequency band number and the synchronization timestamp, and start the retransmission process of the broadband data after receiving the synchronization confirmation; If a stable link cannot be established after three consecutive frequency band switches, trigger the topology reconstruction process, rebroadcast the status beacon through the narrowband communication module, and generate a new list of candidate nodes based on the updated dynamic topology information.

10. The wide and narrow integrated ad-hoc network method according to claim 9, wherein After the frequency band switching is completed, perform the following steps: Continuously monitor the channel quality of the new link through the broadband communication module, collect the signal-to-interference-and-noise ratio and the bit error rate data every 50 ms, and calculate their moving average value as the stability evaluation index; when the fluctuation amplitude of the stability evaluation index exceeds 30% for five consecutive samples, it is determined that the channel state is unstable, trigger the narrowband communication module to send a channel switching recommendation request, and perform a secondary frequency band switch according to the candidate frequency band list feedback by the adjacent nodes; During the dynamic adjustment of the transmit power, if it is detected that the remaining energy ratio of the node is lower than 20%, enable the power limit mode and set the transmit power upper limit to 80% of the reference power value; when transmitting the frequency band synchronization instruction, if the decoding failure times at the receiving end reach two, switch to the redundant transmission mode, repeat sending the synchronization instruction within the adjacent three narrowband time slots and attach a check code; in the broadband data retransmission process, adjust the subcarrier allocation scheme of the orthogonal frequency division multiplexing modulation according to the channel characteristic parameters of the previous transmission failure, turn off the two subcarriers with the lowest signal-to-interference-and-noise ratio and recalculate the cyclic prefix length; if no data packet is successfully transmitted within 300 ms after the new link is established, mark it as an abnormal link and notify all network nodes through the narrowband communication module to update the link state mark in the dynamic topology information.

Images