Dynamic resource allocation method and system based on dual-mode fusion carrier technology

Abstract

The present application relates to dual-mode fusion carrier communication technology field, specifically, it relates to dynamic resource allocation method and system based on dual-mode fusion carrier technology. Its method includes obtaining the time slot occupation number of each level relay hop in power line carrier mode and wireless mode, combining the end site number and the reported active rate to calculate the total time slot demand in two modes, calculating the time slot occupation rate according to the total time slot demand in the current transmission mode, judging that the time slot occupation rate exceeding the alarm threshold is overload relay hop, then calculating the number of releasable time slots after switching according to the total time slot demand in the alternative transmission mode, executing mode switching for the overload relay hop with the number of releasable time slots greater than zero, summarizing the number of releasable time slots and distributing to the end sites loaded by the non-overloaded relay hop, generating the time slot allocation table of the next superframe according to the switching instruction and the distribution result. The present application effectively improves the site carrying capacity of the network under the same time slot resource.

Description

Technical Field

[0001] This invention relates to the field of dual-mode fusion carrier communication technology, and more specifically, to a dynamic resource allocation method and system based on dual-mode fusion carrier technology. Background Technology

[0002] Dual-mode fusion carrier technology is a technology that integrates two physical transmission methods, power line carrier communication and low-power wireless communication, in the same communication network. This allows communication nodes to select and switch between the two modes based on channel quality. It is mainly used in IoT communication scenarios such as smart grid electricity consumption information collection and distribution automation.

[0003] In dual-mode converged carrier communication networks, remote stations need to complete data exchange through multiple levels of relays. Each additional relay level occupies a set of time slots, and with a large number of terminal stations, competition and conflicts further exacerbate resource consumption. With a fixed total number of time slots, both relays and terminal stations are vying for limited time slot resources, and data reporting from remote stations frequently times out, limiting the number of stations the entire network can support.

[0004] To address the aforementioned issues, existing technologies primarily employ two approaches: first, during the network planning phase, sufficient time slot resources are reserved based on the expected number of sites, and the superframe length is extended accordingly; second, after network deployment is completed, the network topology is periodically optimized by adjusting the access paths of some sites to compress the relay layer.

[0005] However, all of the above methods have certain limitations: the method of reserving time slots is fixed after the network is deployed, and cannot cope with situations where the actual number of sites exceeds expectations or the network topology changes; while topology optimization needs to be triggered periodically, and the adjustment cycle is long. When a path deteriorates due to interference or obstruction, the adjustment may not be completed in time, and the channel conditions may have changed again.

[0006] Therefore, there is an urgent need for a method that can dynamically allocate time slot resources by utilizing the characteristics of dual-mode heterogeneous channels. Summary of the Invention

[0007] One objective of this invention is to provide a dynamic resource allocation method based on dual-mode fusion carrier technology. This method obtains the resource occupancy status of each hop relay in dual-mode, identifies overloaded relay hops based on the load of the terminal sites, switches the overloaded relay hops to standby mode to release time slots, and then allocates the released time slots to the terminal sites connected to other high-load relay hops. This solves the problems mentioned in the background art, namely: In dual-mode converged carrier communication networks, as the number of access sites increases and the network hierarchy deepens, each additional relay level requires a set of time slots. The simultaneous competition for transmission by a large number of end sites further exacerbates resource consumption. With a fixed total number of time slots, data reporting from remote sites often times out, limiting the number of sites that the entire subnet can support.

[0008] To achieve the above objective, the method includes the following steps: S1. Obtain the number of time slots required for each level of relay hop to forward data frames in power line carrier mode and wireless mode, and obtain the number of terminal stations attached to each level of relay hop and the reporting activity rate. Calculate the total time slot requirement for each level of trunk hop in both modes based on the number of time slot occupancy, the number of terminal stations, and the reported activity rate; The mode currently used by each relay hop is recorded as the current transmission mode, and the other mode is recorded as the alternative transmission mode; S2. Calculate the time slot occupancy rate of each level of relay hop based on the total time slot requirement of each level of relay hop in the current transmission mode. The time slot occupancy rate is the ratio of the total time slot requirement to the total available time slots of the superframe. The trunk hops corresponding to the time slot occupancy rate exceeding the preset alarm threshold are identified as overload trunk hops; Calculate the number of releaseable time slots after each overloaded trunk jump switches to the alternative transmission mode based on the total time slot requirements of each level of trunk jump in the alternative transmission mode, and mark the overloaded trunk jump with a releaseable time slot number greater than zero as a switchable overloaded jump; S3. Generate a mode switching instruction based on the switchable overload jump. The mode switching instruction is used to instruct the switchable overload jump to switch to the alternative transmission mode to release the time slot it occupies. Sum the number of time slots that can be released to obtain the total number of time slots released. From the released time slots, allocate the total number of released time slots to the terminal stations attached to the non-overloaded relay hops, and append the allocated time slots to the reporting time slots of the corresponding terminal stations; The time slot allocation table for the next superframe is generated based on the mode switching command and allocation results.

[0009] In the above technical solution, the time slot occupancy and terminal site load information of each level of trunk hop in two modes are first obtained, and the total time slot demand in both modes is calculated separately. This aims to provide a data foundation for subsequent overload judgment and handover benefit assessment. If the total time slot demand in the alternative mode is not calculated, the number of time slots that can be released after handover cannot be quantified, and the handover decision lacks a basis. After calculating the time slot occupancy rate and identifying overloaded trunk hops, the number of releaseable time slots is further calculated in conjunction with the total time slot demand in the alternative mode. This is used to screen out trunk hops that can indeed release time slots after handover. If all overloaded trunk hops are handed over without this screening, some trunk hops may have even greater time slot demand after handover, making the handover ineffective and exacerbating resource shortages. After screening out the switchable overloaded hops, they are switched to the alternative mode to release time slots, and these time slots are then allocated to the terminal sites attached to trunk hops that are not overloaded and have a high time slot occupancy rate. The reason for using targeted allocation instead of returning released time slots to the idle time slot pool is that the total number of released time slots is usually small. If they were mixed into the idle pool for unified allocation, the time slots might be scattered across multiple relay hops, with each hop only receiving a small number of time slots, making it difficult to effectively alleviate the reporting queuing pressure on end stations. Targeted allocation, on the other hand, concentrates released time slots on the relay hops with the most scarce time slot resources, giving end stations a substantial queuing relief effect. In addition, the alarm threshold is adjusted based on the number of timeout sites in the previous superframe. Its purpose is to make the threshold adaptable to different network sizes and load conditions. If the threshold remains fixed, when the network size expands or the load fluctuates, the threshold may be too high, causing overloaded hops to not be identified in time, or too low, causing handovers to be too frequent, thus limiting the adaptability of the solution.

[0010] Based on this, the alarm threshold is used to determine the overload status of relay hops at all levels. The alarm threshold is adjusted after each superframe cycle based on the execution effect of the previous superframe. The adjustment method is as follows: obtain the total number of timeout sites in the entire network in the previous superframe, calculate the change in the total number of timeout sites between the previous superframe and the current superframe. If the number of timeout sites continues to decrease and remains zero in multiple consecutive superframes, the alarm threshold is lowered by a fixed step. If the number of timeout sites increases, the alarm threshold is raised by a fixed step. If the number of timeout sites remains the same, the alarm threshold is kept unchanged.

[0011] In another technical solution, the total number of released time slots is allocated as follows: After excluding relay hops determined to be overloaded from the entire network, the remaining relay hops are sorted from high to low according to their time slot occupancy rate. The target relay hops are determined according to the total number of released time slots, and release time slots are allocated to each target relay hop in descending order of time slot occupancy rate until the total number of released time slots is allocated. Relay hops with higher time slot occupancy rates are given priority in receiving the allocation of release time slots.

[0012] In this technical solution, the alarm threshold is adjusted based on the number of timeout sites in the previous superframe, allowing the threshold to dynamically adjust with changes in network load. This avoids the problem of a fixed threshold being too high or too low when the number of sites increases or when service fluctuates. If the threshold remains fixed, when the network expands, a high threshold will prevent relay hops with high time slot occupancy from being identified in a timely manner, causing overload to accumulate until a timeout is reported. When the load decreases, a low threshold will cause relay hops that are not yet overloaded to be frequently identified as overloaded, triggering unnecessary handovers and increasing system overhead. By adjusting the threshold in reverse based on the number of timeout sites, the threshold is always matched with the current network state, ensuring the accuracy of overload identification. In addition, the total number of released time slots is allocated after sorting the time slot occupancy rates of each relay hop from high to low, with relay hops with higher occupancy rates receiving priority for time slot release. If released time slots are evenly distributed without prioritization, time slot resources may be allocated to trunk hops with low occupancy rates, whose terminal stations do not experience significant queuing pressure. This results in inefficient use of released time slots, while truly scarce trunk hops do not receive sufficient time slot replenishment. By prioritizing and allocating time slots according to their occupancy rates, the limited released time slots are prioritized for trunk hops with the most scarce time slot resources, thus improving the utilization efficiency of released time slots.

[0013] The second objective of this invention is to provide a dynamic resource allocation system based on dual-mode fusion carrier technology, including a time slot occupancy sensing module, an overload identification module, a time slot reallocation module, and a threshold correction module. The time slot occupancy sensing module is used to obtain the number of time slots occupied and the reporting activity rate of each level of relay hop in power line carrier mode and radio mode, and to calculate the total time slot requirement of each level of relay hop in the two modes. The overload identification module is used to calculate the time slot occupancy rate based on the total time slot demand, identify overloaded relay hops whose time slot occupancy rate exceeds the alarm threshold, and calculate the number of time slots that can be released after each overloaded relay hop switches to the alternative transmission mode. The time slot reallocation module is used to generate mode switching instructions based on switchable overload hops, summarize the number of releaseable time slots to obtain the total number of release time slots, and allocate the total number of release time slots to the terminal stations attached to the non-overloaded relay hops. The threshold correction module is used to correct the alarm threshold based on the total number of timeout sites across the entire network, and to feed back the corrected alarm threshold to the overload identification module.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In each superframe period, the present invention updates the time slot allocation table for the next superframe according to the actual time slot occupancy of each relay hop, instead of determining the allocation scheme once and for all at the network planning stage and using it for a long time as in the conventional methods. When the network hierarchy is adjusted due to site access or channel changes, the conventional methods cannot respond in a timely manner, which easily leads to the continuous accumulation of time slot demand for certain relay hops until it exceeds the superframe capacity. By updating the allocation table superframe by superframe, the present invention enables resource allocation to be adjusted synchronously with network topology changes and load fluctuations, avoiding time slot resource shortage caused by the solidified allocation scheme.

[0015] 2. The present invention utilizes the complementary characteristics of the two physical channels of power line carrier and wireless in the dual-mode converged carrier network, switches the overloaded relay hop from the current transmission mode to the alternative mode to release time slots, and directionally reallocates the released time slots to the end sites of other high-load relay hops. In existing dual-mode networks, channel switching is mostly used as a link backup means, and the resources released after switching are usually returned to the public resource pool, failing to form effective resource reallocation. The present invention actively allocates the time slots released by switching to the link with the most strained time slot resources, so that the resources of the two channels cooperate with each other, and the flexibility of resource scheduling in the dual-mode network is improved.

[0016] 3. The present invention takes the time slot occupancy rate as the trigger condition for mode switching, and this indicator can comprehensively reflect the time slot consumption status of three factors: channel quality, number of end sites, and reporting activity rate, so that the switching decision can directly locate the link with the most strained time slot resources. In addition, the alarm threshold is corrected according to the actual number of timeout sites in the previous superframe, so that the judgment benchmark of the time slot occupancy rate can adapt to different network scales, and avoid identification deviation caused by the fixed threshold when the network scale changes. Brief Description of the Drawings

[0017] Figure 1 is a schematic diagram of the overall process of the dynamic resource allocation method based on dual-mode converged carrier technology of the present invention; Figure 2 is a structural flowchart of step S2 of the present invention; Figure 3 is a structural flowchart of step S3 of the present invention; Figure 4 is a schematic structural diagram of the dynamic resource allocation system based on dual-mode converged carrier technology of the present invention. Detailed Description of the Embodiments

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0019] Here are some explanations of technical terms: A relay hop refers to the communication link between a relay station and its parent node, where the parent node is the next higher-level relay station or central coordinator.

[0020] Currently, in dual-mode fused carrier communication networks, as the number of access sites increases and the network hierarchy deepens, each additional relay level occupies a set of time slots. The simultaneous competition for transmission by a large number of end sites further exacerbates resource consumption. With a fixed total number of time slots, data reporting from remote sites frequently times out, limiting the number of sites the entire subnet can support. One objective of this invention is to provide a dynamic resource allocation method based on dual-mode fused carrier technology. (See [link to relevant documentation]). Figure 1 As shown, it includes the following steps: S1. Obtain the number of time slots required for each level of relay hop to forward data frames in power line carrier mode and wireless mode, and obtain the number of terminal stations attached to each level of relay hop and the reporting activity rate. Calculate the total time slot requirement for each level of trunk hop in both modes based on the number of time slot occupancy, the number of terminal stations, and the reported activity rate; The mode currently used by each relay hop is recorded as the current transmission mode, and the other mode is recorded as the alternative transmission mode; S2. Calculate the time slot occupancy rate of each level of relay hop based on the total time slot requirement of each level of relay hop in the current transmission mode. The time slot occupancy rate is the ratio of the total time slot requirement to the total available time slots of the superframe. The trunk hops corresponding to the time slot occupancy rate exceeding the preset alarm threshold are identified as overload trunk hops; Calculate the number of releaseable time slots after each overloaded trunk jump switches to the alternative transmission mode based on the total time slot requirements of each level of trunk jump in the alternative transmission mode, and mark the overloaded trunk jump with a releaseable time slot number greater than zero as a switchable overloaded jump; S3. Generate a mode switching instruction based on the switchable overload jump. The mode switching instruction is used to instruct the switchable overload jump to switch to the alternative transmission mode to release the time slot it occupies. Sum the number of time slots that can be released to obtain the total number of time slots released. From the released time slots, allocate the total number of released time slots to the terminal stations attached to the non-overloaded relay hops, and append the allocated time slots to the reporting time slots of the corresponding terminal stations; The time slot allocation table for the next superframe is generated based on the mode switching command and allocation results.

[0021] This method evaluates the time slot occupancy of relay hops at each level within each superframe cycle and adjusts resource allocation as needed. By executing this method cyclically over each superframe, the rigid binding relationship between time slot consumption and the number of relay hops can be removed, thereby improving the site carrying capacity of the subnet under the same time slot resources.

[0022] In the dual-mode fused carrier communication network involved in this embodiment, a central coordinator and several relay stations are deployed. The relay stations are distributed in a hierarchical structure. Remote relay stations need to complete data interaction with the central coordinator through the relay stations at the next higher level. Each relay station has both power line carrier and wireless communication modes, and each relay station has several terminal stations connected to it. The central coordinator is responsible for the unified planning and management of the time slot resources of the entire network, and each relay station is responsible for the collection and forwarding of data from its connected terminal stations.

[0023] In step S1 of this invention, each relay station first measures and reports the channel quality of its respective link in both modes. The central coordinator calculates the number of time slots required for each relay hop to forward data in both modes based on the reported data. Then, combining the number of terminal stations attached to each hop and the reporting activity rate, the total time slot requirement for each relay hop in both modes is obtained. Specifically, this includes the following steps: S101: First, the central coordinator sends a channel quality reporting command through the beacon frame during the beacon period at the beginning of each superframe. The beacon frame carries a command type field, a measurement configuration field, and a reporting configuration field.

[0024] It should be noted that the instruction type field is used to indicate that the current beacon frame is a channel quality reporting instruction; the measurement configuration field is used to specify the time slot position for each relay station to perform the measurement. This field includes the measurement start time slot offset and the measurement duration. The measurement duration must contain at least one complete orthogonal frequency division multiplexing symbol period to ensure that the relay station can collect enough samples for parameter calculation; the reporting configuration field is used to specify the time slot position and reporting order for each relay station to report the measurement results. The reporting order is arranged in ascending order according to the relay station's hierarchical number. The hierarchical number is assigned by the central coordinator during the network deployment phase and remains unchanged.

[0025] After the central coordinator completes the beacon frame encapsulation, it broadcasts the message simultaneously on both the power line carrier and radio channels to ensure that all relay stations at all levels can receive the instruction regardless of their current operating mode.

[0026] Accordingly, after receiving the beacon frame from the central coordinator, each relay station first parses the instruction type field to confirm that the current superframe requires channel quality measurement and reporting. Each relay station then initiates the measurement process when the corresponding measurement time slot arrives, based on the measurement start time slot offset specified in the measurement configuration field.

[0027] Specifically, in power line carrier mode, each relay station couples to the power line to acquire and receive signals during the time period when its parent node transmits data frames. During the measurement period, the amplitude of the received signal is sampled using analog-to-digital conversion, with a sampling rate at least twice the highest frequency of the power line carrier signal to satisfy the Nyquist sampling theorem.

[0028] It's important to note that the Nyquist sampling theorem is a fundamental theory in signal processing. Its core meaning is that to recover the original continuous analog signal without distortion from discrete sampled values, the sampling frequency must be at least twice the highest frequency of the sampled signal. If the sampling rate is below this threshold, high-frequency components will alias into the low-frequency range, causing the measured signal-to-noise ratio and noise power to deviate from the true values, thus affecting the accuracy of subsequent modulation and coding scheme lookups based on channel quality.

[0029] Based on this, the signal-to-noise ratio (SNR) and background noise power are calculated separately. The SNR is calculated as follows: during the period when the parent node is transmitting a signal, the ratio of the received signal power to the noise power is calculated. The background noise power is calculated as follows: during the protection interval when the parent node is not transmitting a signal, environmental noise samples are collected and their average power is calculated. This measurement reflects the level of impulse noise from equipment such as variable frequency air conditioners starting up and high-power motors starting and stopping on the power line.

[0030] Furthermore, in wireless mode, each relay station receives wireless signals via its antenna during the period when its parent node sends wireless beacons or data frames. After the radio frequency front-end performs down-conversion and analog-to-digital conversion on the wireless signal, the baseband processor measures the received signal strength and packet loss rate.

[0031] It should be noted that the received signal strength is measured by calculating the average power of the received reference signal sequence during the period when the parent node sends a known reference signal sequence. The packet loss rate is measured by calculating the proportion of packets that were not correctly received out of the total number of packets sent by the parent node between the previous superframe and the current superframe. Incorrect reception includes situations such as failed cyclic redundancy check, lost synchronization headers, or abnormal frame lengths. If no valid signal is received from the parent node within the measurement period, the received signal strength is recorded as invalid, and the packet loss rate is set to 100%, indicating that the link is currently unavailable.

[0032] After each relay station completes all measurements, it sends the four parameters—power line carrier signal-to-noise ratio, power line carrier background noise power, wireless received signal strength, and wireless packet loss rate—to the central coordinator in the reporting time slot specified in the reporting configuration field, using the current communication mode.

[0033] The reporting frame carries the four parameters mentioned above in sequence. Each parameter is quantized as a 16-bit signed integer to balance the representation range and transmission overhead. For invalid measurement results, the corresponding parameter field in the reporting frame is filled with a preset invalid flag value. If a relay station fails to send a reporting frame within a specified reporting time slot due to channel congestion, the station will retry reporting after the beacon period of the next superframe. The maximum number of retransmissions is 3. If the retransmission fails after 3 attempts, the measurement data is discarded, and the measurement data for that relay hop will be used in subsequent calculations based on the value from the previous superframe.

[0034] After the beacon frame is sent, the central coordinator continuously monitors the reporting slots of each relay station and receives the reporting frames from each relay station. Upon receiving each reporting frame, the central coordinator checks the validity of the frame format. If an invalid flag value is found, the channel quality for that relay hop mode is marked as unavailable. If a relay station fails to send a reporting frame within a specified reporting slot and fails to successfully report in subsequent retransmissions, the central coordinator also marks the channel quality for that relay hop mode as unavailable.

[0035] Based on this, the central coordinator stores the dual-mode channel quality parameters of each relay hop into a local cache. The parameters are stored according to the superframe number index, and the data of at least the two most recent superframes are retained for the time slot occupancy calculation in step S102.

[0036] It should be noted that if the channel quality of a relay hop in both power line carrier mode and radio mode is marked as unavailable, then the relay hop and all its attached end stations will only use the resource allocation results of the previous superframe in subsequent resource allocations, and will no longer participate in the dynamic adjustment of this superframe.

[0037] S102: Based on the dual-mode channel quality parameters of each relay hop obtained in step S101, the central coordinator queries the modulation and coding strategy tables for both power line carrier and radio modes to determine the number of time slots required for each relay hop to forward data in both modes.

[0038] Specifically, for the i-th level relay hop, the central coordinator queries the modulation and coding strategy table for the power line carrier mode based on the power line carrier signal-to-noise ratio reported by the relay hop. This table is a reference table of existing modulation and coding strategies in the power line carrier communication standard. Each signal-to-noise ratio interval in the table corresponds to a set of modulation orders and coding rates. The query yields the modulation efficiency and coding efficiency that the relay hop can support under the current channel quality.

[0039] Based on the length of the data frame to be forwarded by the relay hop, the known power line carrier symbol rate, and the duration of a single time slot, the number of time slots required to forward the data frame in power line carrier mode is calculated using the following formula: ; In the formula, This represents the number of time slots required for the i-th level relay hop to forward data frames in power line carrier mode within the current superframe t; L i (t) represents the length of the data frame to be forwarded by the relay hop in the current superframe; The power line carrier symbol rate; The modulation efficiency obtained from the query; To improve the encoding efficiency obtained from the query; T slot The duration is for a single time slot; The rounding symbol indicates rounding up.

[0040] Furthermore, based on the radio received signal strength reported by the relay hop, the central coordinator queries the modulation and coding strategy table of the radio mode to determine the modulation efficiency and coding efficiency in the radio mode, and calculates the number of time slots required to forward the data frame in the radio mode according to the following formula: ; In the formula, This represents the number of time slots required for the i-th level relay hop to forward data frames in the current superframe t in radio mode, i.e., the number of time slots occupied. For wireless symbol rate; and These represent the modulation efficiency and coding efficiency in wireless mode, respectively.

[0041] Based on this, the central coordinator also records the transmission mode used in the current superframe for each relay hop. This transmission mode is either power line carrier mode or wireless mode. This information is taken from the mode switching execution result of the previous superframe and is preset by the system at the time of the initial superframe. The transmission mode currently used by each relay hop is called the current transmission mode, and the other transmission mode not currently used by each relay hop is called the alternative transmission mode.

[0042] S103: Based on the number of power line carrier mode time slots occupied and the number of radio mode time slots occupied obtained in S102, the central coordinator also needs to combine the number of terminal sites attached to each relay hop and their reporting activity rate to calculate the total time slot requirement of each relay hop under the current transmission mode and the total time slot requirement under the alternative transmission modes.

[0043] Specifically, the central coordinator first obtains the number of end sites attached to each relay hop within the current superframe. This data is maintained in real time by the topology information table established by the central coordinator after the network is completed. The topology information table records the list of end sites attached to each level of relay hop. The table is updated synchronously when a site joins the network or goes offline. Therefore, the central coordinator can directly find out the total number of end sites for each level of relay hop.

[0044] The central coordinator also obtains the reporting activity rate of each end station. This reporting activity rate is calculated based on the historical reporting logs recorded by the central coordinator itself, and is specifically defined as the ratio of the number of end stations that actually initiate reporting within the current superframe to the total number of end stations attached to that relay hop. The central coordinator updates the reporting records of each station after each superframe ends, so this activity rate can reflect the actual communication needs of the end stations under each relay hop in the current time period.

[0045] Based on this, the central coordinator calculates the total time slot requirement of the i-th level relay hop under the current transmission mode. Specifically, it first multiplies the number of end stations attached to the relay hop by the reporting activity rate to obtain the number of active end stations in the current superframe, then multiplies it by the number of time slots required to forward data reported by a single station under the current transmission mode to obtain the total number of time slots required for reporting by all active end stations, and finally adds the number of time slots required by the relay hop itself to forward data from the previous level, thus obtaining the total time slot requirement of the relay hop under the current mode.

[0046] Furthermore, the central coordinator calculates the total time slot requirement of the relay hop in the alternative transmission modes in the same way, that is, replacing the current mode time slot occupancy in the above calculation with the alternative mode time slot occupancy, while the rest of the calculation method remains unchanged.

[0047] The central coordinator stores the total time slot requirements of each level of relay hop in the current mode, the total time slot requirements in the alternative modes, and the current transmission mode in the buffer, and inputs them into step S2.

[0048] like Figure 2 As shown, in step S2 of the present invention, the time slot occupancy rate of each level of relay hop is first calculated based on the time slot requirements of each level of relay hop obtained in step S1. Then, overloaded relay hops whose time slot occupancy rate exceeds the alarm threshold are identified. Finally, the number of time slots that can be released after switching to the alternative mode is calculated for each overloaded hop, and switchable overloaded hops with time slot surplus after switching are selected. Specifically, the following steps are included: S201: Based on the total time slot demand of each level of relay hop obtained in S103 under the current mode, the central coordinator calculates the time slot occupancy rate for each level of relay hop. The time slot occupancy rate is defined as the ratio of the total time slot demand of that relay hop to the total available time slots in the current superframe, calculated according to the following formula: ; In the formula, Ui (t) represents the time slot occupancy rate of the i-th level relay hop in the current superframe t. This value is used to measure the time slot tension of the relay hop at this level and is the basis for subsequent identification of overloaded relay hops. D i (t) represents the total time slot requirement of this relay hop in the current mode; S total This represents the total number of available time slots in the current superframe. This total number of available time slots in the current superframe is obtained by dividing the superframe length by the duration of a single time slot. The superframe length and the duration of a single time slot are determined during system configuration and remain unchanged throughout the entire operation.

[0049] Based on this, the central coordinator also calculates the average time slot occupancy rate of the entire network, using the following formula: ; In the formula, This represents the average slot occupancy rate of the entire network within the current superframe t; N represents the total number of relay hops in the network.

[0050] The average time slot occupancy rate reflects the overall tightness of time slot resources across the entire network within the current superframe. When this value is close to 1, it indicates that the superframe time slots are nearly exhausted, and timeouts will occur in the reporting of end stations.

[0051] The central coordinator stores the time slot occupancy rate of each level of relay hop and the average time slot occupancy rate of the entire network into the cache, and inputs step S202.

[0052] S202: The central coordinator compares the time slot occupancy rate of each relay hop calculated by S201 with the preset alarm thresholds to identify the relay hops at each level where time slot resources are scarce in the current superframe.

[0053] Specifically, the central coordinator reads the occupancy rate U of each level of relay hop slot stored in S201 from the cache. i (t), and obtain the current alarm threshold U. th The alarm threshold is preset by the system and is subsequently adjusted in fixed steps by step S402 based on the actual execution effect to adapt to different network sizes and load conditions.

[0054] The physical meaning of this threshold is: when the time slot occupancy rate of a relay hop exceeds this value, it is considered that this level of relay hop has approached or reached the superframe capacity limit under the current transmission mode. If the current allocation method is maintained, the terminal station attached to it will report a timeout in subsequent superframes.

[0055] Central coordinator compares U level by level i (t) and U th The size of U. i (t)>Uth If the relay jump at that level is determined to be an overloaded relay jump, then all overloaded relay jumps constitute the overloaded jump set B(t).

[0056] Based on this, if B(t) is an empty set, meaning no overloaded relay hops are identified in the current superframe, it indicates that the time slot occupancy of all hops in the entire network is within the normal range, and there is no need to trigger subsequent mode switching and time slot reallocation processes. At this time, the central coordinator skips S3 and directly jumps to S4 to perform routine effect monitoring.

[0057] If B(t) is not empty, the central coordinator will use the overload jump set B(t) as the input data for the next step and continue to execute S203 to calculate the number of time slots that can be released by mode switching for each overload jump.

[0058] S203: For each overloaded trunk hop identified in S202, the central coordinator further calculates the number of time slots that can be released after switching from the current transmission mode to the alternative transmission mode, so as to filter out the switchable overloaded hops that actually have time slot surplus after the switch.

[0059] Specifically, for each overloaded relay hop in the overloaded hop set B(t), the central coordinator retrieves the total time slot requirement D for that overloaded relay hop in the current mode from the buffer of S103. i (t) and total time slot requirements in alternative modes The number of release slots after switching to the alternative mode is calculated using the following formula: ; In the formula, Δs i (t) represents the number of time slots that the i-th level relay hop can release after switching from the current transmission mode to the alternative transmission mode within the current superframe t.

[0060] If Δs i If (t) > 0, it indicates that the time slot demand under the alternative mode is less than the time slot demand under the current mode. This overloaded relay hop can release time slot resources after switching. Therefore, this overloaded relay hop is marked as a switchable overload hop, and the number of time slots released is the calculated number of releaseable time slots. If Δs i If (t)≤0, it means that the time slot demand under the alternative mode is greater than or equal to that of the current mode. After the switch, not only will the time slot not be released, but more time slots will be occupied or the same as the current time slot. The switch itself is not beneficial. Therefore, the overloaded relay jump will not participate in the subsequent time slot reallocation process.

[0061] Based on this, the central coordinator summarizes all switchable overload jumps and their corresponding number of releaseable time slots to form a switchable overload jump set B. sw (t), input step S3.

[0062] like Figure 3As shown, step S3 of the present invention involves generating a mode switching command based on the set of switchable overload hops and the number of releaseable time slots identified in step S2, and then distributing the released time slots to the end stations of other high-load relay hops in a targeted manner after sorting them according to the time slot occupancy rate of each relay hop. Finally, the time slot allocation table for the next superframe is updated and issued. Specifically, the steps include: S301: The central coordinator obtains the switchable overload jump set B based on S203. sw (t) and the number of releaseable time slots Δs corresponding to each jump i (t) generates the mode switching instruction for the next superframe and summarizes the total number of time slots that can be released after all switching.

[0063] Specifically, for B sw Each switchable overload jump R in (t) i The central coordinator generates a mode switching instruction, instructing the relay hop to change its transmission mode from the current mode m in the next superframe. i (t) Switch to alternative mode All switching instructions constitute the mode switching instruction set M(t+1), which records the relay hop number of each switching operation and the mode before and after the switching.

[0064] Based on this, the central coordinator sums up the number of releaseable time slots for each switchable overload jump to obtain the total number of time slots S released in this switchover. release (t), calculated using the following formula: ; S release (t) represents the total number of time slots that can be released after all switchable overload jumps perform mode switching within the current superframe t; B sw (t) is the set of switchable overload jumps; Δs i (t) represents the number of releaseable time slots for the i-th level relay hop.

[0065] The total number of time slots is the upper limit of the total amount of time slots to be redistributed in the future. The released time slots will be used to allocate to the end sites of other high-load relay hops, and will not be returned to the idle time slot pool.

[0066] Furthermore, the central coordinator will release the mode switching instruction set M(t+1) and the total number of time slots S. release (t) Input step S302.

[0067] S302: The central coordinator allocates the released time slots summarized in step S301 to the end stations attached to the relay jumps that are not overloaded but have a high time slot occupancy rate.

[0068] It's important to note that the time slots released in this step are not returned to the idle time slot pool but are redistributed by the central coordinator. This is because the total number of released time slots is usually much smaller than the number of available time slots in the idle time slot pool. If these released time slots were mixed into the idle pool and then redistributed according to the regular process, they might be scattered across multiple relay hops, with each hop receiving only a small number of time slots that wouldn't effectively alleviate the reporting queuing pressure at its end stations. The purpose of targeted allocation is precisely to concentrate the released time slots on the relay hops with the most strained time slot resources, enabling their end stations to achieve substantial queuing relief.

[0069] Follow these steps: ① First, determine the target set for redistribution. Specifically, the central coordinator excludes the set of overloaded relay hops identified in step S202 from all relay hops in the entire network. For the remaining relay hops, the central coordinator sorts them from high to low according to the time slot occupancy rate calculated in S201.

[0070] It should be noted that overloaded trunk hops have already released time slots through mode switching, alleviating their time slot shortage. Therefore, there is no need to allocate additional time slots to them, and they are excluded from the target set. On the other hand, trunk hops with higher time slot occupancy rates are closer to being overloaded, and the queuing of their connected end stations is more severe. They should be given priority in being allocated time slots.

[0071] Based on this, the central coordinator determines the number of targets to be redistributed, denoted as K, according to the total number of released time slots. The determination rule is: prioritize covering the relay hop with the highest time slot occupancy rate, until all released time slots have been allocated. If the remaining time slots are insufficient to allocate at least one time slot to the next relay hop, then the expansion of the target set is stopped.

[0072] ② Further, the release time slots are allocated in a weighted manner based on the number of terminal stations. Specifically, the central coordinator allocates the total number of release time slots to the K target relay hops determined in the first step, and the allocation weight is calculated based on the number of terminal stations attached to them.

[0073] The specific allocation method is as follows: First, count the total number of terminal stations attached to the K target relay hops. Then, allocate time slots according to the proportion of terminal stations attached to each target relay hop to the total number of stations, calculated using the following formula: ; In the formula, This represents the number of time slots allocated to the k-th target relay hop; n k (t) represents the number of terminal stations attached to this relay jump; This is the floor symbol.

[0074] After allocation, the remaining time slots after rounding will be filled one time slot in descending order of the number of terminal stations of each target relay hop, until all time slots are released and allocated.

[0075] It should be noted that the reason for weighted allocation based on the number of terminal stations is that the more terminal stations a relay hop has, the greater its reporting queuing pressure. Even if the time slot occupancy rate is similar, more time slot resources are needed to alleviate the queuing waiting of all terminal stations.

[0076] Based on this, the time slots allocated to each target relay hop are specifically distributed to each of its attached end stations. The allocation method is as follows: time slots are added sequentially according to the order of each end station in the reporting queue. The number of time slots added to each station is prioritized to meet the number of time slots required by the backlog of reported data frames in its current superframe. If the total number of allocated time slots exceeds the total number of time slots required by the backlog of data at that station, the allocation is carried out in a round-robin fashion to ensure that the time slot addition opportunities for each end station under the same relay hop are relatively balanced.

[0077] ③ Verify the lower limit of occupancy rate after handover. Specifically, the central coordinator verifies the occupancy rate after handover for each overloaded hop performing a mode switch. For each relay hop in the overloaded hop set that is about to perform a handover, its slot occupancy rate after switching to the alternative mode is calculated using the following formula: ; This represents the time slot occupancy rate after the i-th level relay switches to the alternative mode; This represents the total time slot requirement for the overloaded relay jumper in the alternative modes. S total This represents the total number of available time slots for the superframe.

[0078] Furthermore, the calculated Compare with the preset lower limit of occupancy rate.

[0079] It should be noted that when determining the switchable overload hop in step S203, only a greater than zero number of releaseable time slots is required; that is, as long as the time slot demand of the alternative mode is less than that of the current mode, no constraint is set on the absolute time slot occupancy rate after the switch. This may lead to the following situation: the current occupancy rate of an overloaded trunk hop is only slightly higher than the alarm threshold, and after the switch, the occupancy rate drops sharply to an extremely low level. At this time, the time slot resource utilization of the overloaded trunk hop drops drastically, a large number of time slots are idle, and the reporting latency of its attached end stations increases due to the extended waiting period. Therefore, it is necessary to set a lower limit for occupancy rate for verification to avoid excessive switching.

[0080] If the occupancy rate after the handover is not lower than the lower limit, it means that the time slot occupancy rate of the overloaded trunk hop is still within a reasonable range, and the handover is effective. If the time slot occupancy rate after the handover is lower than the preset lower limit, it means that the time slot resources of the overloaded trunk hop will be excessively idle after the handover, and the handover instruction is unreasonable. At this time, the central coordinator cancels the handover instruction for the overloaded trunk hop, removes the overloaded trunk hop from the mode handover instruction set, and deducts the corresponding number of releaseable time slots from the total number of releaseable time slots. The total number of releaseable time slots after the deduction becomes smaller, and the central coordinator returns to the first step, redetermines the redistribution target set and allocation quantity according to the total number of releaseable time slots after the deduction, and re-executes the allocation.

[0081] The above verification and rollback process is repeated until the occupancy rate of all overloaded trunks to be switched is not lower than the lower limit after the switch, or the switching instruction set becomes empty. If the switching instruction set becomes empty, it means that there is no reasonable switching instruction to execute in the current superframe, the total number of released time slots is reduced to zero, and no mode switching or time slot reallocation is performed in this superframe.

[0082] ④ Generate a time slot reallocation table. Specifically, the central coordinator generates a time slot reallocation table based on the allocation results of the second step. This table is used to record the time slot information added to each end station in the next superframe.

[0083] The time slot reallocation table contains the following fields: the target relay hop number that receives the additional time slots, the number of each end station attached to the target relay hop, and the number and specific time slot location of each end station in the next superframe. The added time slot locations are arranged after the original reported time slots of the end station and are arranged consecutively in order of station number.

[0084] It should be noted that the reason for using a continuous arrangement is to reduce the impact of time slot fragmentation on the allocation of subsequent superframe time slots and to avoid the problem of time slots not being fully utilized due to scattered arrangement.

[0085] Furthermore, the central coordinator inputs the verified mode switching instruction set and time slot reallocation table into step S303.

[0086] S303: The central coordinator updates the complete time slot allocation table for the next superframe based on the verified mode switching instruction set and time slot reallocation table obtained in step S302, and sends the updated time slot allocation table to relay stations at all levels and their attached end stations.

[0087] Specifically, the central coordinator first obtains the time slot allocation table of the current superframe as a basic template. For each switching instruction in the mode switching instruction set, the central coordinator finds the corresponding time slot segment of the relay hop in the basic template and relocates the entire time slot segment from the original transmission mode's time slot area to the time slot area of ​​the alternative transmission mode. During the relocation process, the number and arrangement order of time slots within the time slot segment remain unchanged; only the mode area to which it belongs changes.

[0088] Based on this, the central coordinator processes each end station that receives additional time slots according to the records in the time slot redistribution table. Specifically, the process involves finding the original reporting time slots of the end station in the basic template, appending the allocated additional time slots to the end of its original reporting time slots, with the appended time slots appearing consecutively after the original reporting time slots. If multiple end stations under the same relay hop receive additional time slots, they are appended sequentially according to their station numbers, processing the stations with smaller numbers first, followed by those with larger numbers.

[0089] After completing all the above adjustments, the central coordinator generates a complete time slot allocation table for the next superframe. This table is organized by relay hop number and terminal station number, and records the location and purpose of each station's time slots in the next superframe, including the relay hop's own forwarding time slots and the reporting time slots of each terminal station.

[0090] The central coordinator encapsulates the updated complete time slot allocation table into the beacon frame of the next superframe. In addition to the original synchronization header, beacon management information, and other fields, the beacon frame adds a time slot allocation table field, which carries the time slot allocation information for each station in the next superframe in order of station number.

[0091] After encapsulation, the central coordinator broadcasts the beacon frame simultaneously via both power line carrier and radio channels during the beacon period at the start of the next superframe, ensuring that all relay stations and terminal stations at all levels can receive it regardless of their current operating mode.

[0092] Upon receiving the beacon frame, each relay and terminal station parses the time slot allocation table from the beacon frame and extracts the time slot allocation information for the next superframe, including the start position, number, and purpose of each time slot. Each station then performs data transmission or forwarding operations in the designated time slots according to the parsing results, completing the communication task for the next superframe.

[0093] Step S4 of this invention involves collecting the actual number of timeout stations in the next superframe after the mode switching and time slot reallocation scheme issued in step S3 has been executed. The alarm threshold is then adjusted upwards or downwards by a fixed step size according to the direction of change in the number of timeout stations. The corrected threshold is then fed back to step S202 for overload identification in the next cycle. Specifically, this includes the following steps: S401: After the next superframe ends, the central coordinator counts the total number of timeout sites reported by the terminal sites attached to relays at all levels across the entire network.

[0094] Specifically, at the end of a superframe, each relay station checks whether each of its attached end stations has successfully completed its reporting within the superframe and records the station numbers that failed to report in the timeout station list. After completing the statistics, each relay station sends the timeout station list to the central coordinator within its allocated reporting time slot.

[0095] After receiving reports from all relay stations, the central coordinator aggregates and deduplicates the station numbers in all lists to obtain the total number of timeout stations across the entire network.

[0096] Based on this, the central coordinator subtracts the total number of timeout sites in the current superframe from the total number of timeout sites in the previous superframe to obtain the change in the number of timeout sites. If the change is negative, it means that the number of timeout sites has decreased, and the current handover and reallocation scheme is effective; if the change is positive, it means that the number of timeout sites has increased, and the current scheme is less effective; if the change is zero, it means that the number of timeout sites has not changed.

[0097] S402: The central coordinator adjusts the occupancy alarm threshold used in S202 based on the change in the number of timeout sites obtained in step S401. The alarm threshold is initially preset by the system and dynamically adjusted based on the execution effect after each superframe.

[0098] It should be noted that the specific correction methods fall into the following three categories: ① If the number of timeout sites in the current superframe is less than that in the previous superframe, indicating a decrease in the number of timeout sites, it means that the current mode switching and time slot reallocation scheme is effective. In this case, the central coordinator maintains the alarm threshold unchanged. Furthermore, if the number of timeout sites continues to decrease for several consecutive superframes and eventually reaches zero, it indicates that the network has converged to a stable state, and the current threshold setting can effectively control overload. At this point, the central coordinator will appropriately lower the alarm threshold by a fixed value to reduce alarm sensitivity and minimize unnecessary mode switching. The step size can be set according to actual needs.

[0099] ② If the number of timeout sites in this superframe is greater than that in the previous superframe, indicating an increase in the number of timeout sites, it means that the current handover and reallocation scheme has failed to effectively alleviate time slot tension, or even worsened the situation. In this case, the central coordinator will increase the alarm threshold by one step to improve alarm sensitivity, so that relay hops are identified as overloaded before the time slot occupancy rate reaches the original threshold, thereby triggering the mode handover and time slot reallocation process earlier.

[0100] It should be noted that when the number of timeout sites increases, the central coordinator simultaneously rolls back the mode switch instruction with the fewest available time slots, restoring it to the transmission mode before the switch. This is because when multiple overloaded trunk hops perform mode switches simultaneously, the switch with the fewest available time slots contributes the least to the release of time slots. If the overall solution deteriorates, prioritizing the rollback of this switch can reduce the negative impact, while retaining the switch with the larger number of available time slots to maintain the overall resource release.

[0101] ③ If the number of timeout sites in this superframe is the same as in the previous superframe, it indicates that the current solution has not had a significant impact on the timeout situation. In this case, the central coordinator maintains the alarm threshold unchanged and continues to observe the execution effect of the next superframe.

[0102] It should be noted that the alarm threshold is always constrained by upper and lower limits during the correction process; that is, the corrected threshold is not lower than the preset lower limit of occupancy and not higher than 1. If the corrected value exceeds this range, the boundary value is taken. This is to avoid the threshold being too low, causing normal load trunk trips to be frequently misjudged as overloaded, or the threshold being too high, causing overloaded trunk trips to be unable to be identified for a long time.

[0103] S403: The central coordinator stores the alarm threshold corrected in S402 into the local cache as the basis for judging the overload relay hop identification in the next superframe step S202.

[0104] At the start of the next superframe, the central coordinator reads the corrected threshold from the cache for overload relay hop identification in step S202. If no overload relay hop is identified in the next superframe, it indicates that the network's time slot resources are in a normal state, and the process skips steps S203 and S3, directly executing the routine monitoring in step S401 to continue collecting the number of timeout sites in the next superframe. If an overload relay hop is identified in the next superframe, the complete process from steps S203 to S4 is repeated, with each superframe cycle executing sequentially.

[0105] like Figure 4 As shown, a second objective of this invention is to provide a dynamic resource allocation system based on dual-mode fusion carrier technology, including a time slot occupancy sensing module, an overload identification module, a time slot reallocation module, and a threshold correction module.

[0106] The time slot occupancy awareness module is used to collect channel quality parameters of each level of relay station in power line carrier mode and radio mode in each superframe period, and query the corresponding modulation and coding strategy table according to the channel quality to calculate the number of single-hop time slots required to forward data frames in the two modes respectively. Then, combined with the number of terminal stations attached to each relay hop and the reporting activity rate, the total time slot requirement of each level of relay hop in the two modes is obtained.

[0107] The time slot occupancy awareness module specifically includes a channel quality acquisition unit, a single-hop time slot calculation unit, and a load information aggregation unit. The channel quality acquisition unit sends a channel quality reporting command through the beacon frame during the beacon period of each superframe, and receives four parameters reported by each relay station: power line carrier signal-to-noise ratio, power line carrier background noise power, radio received signal strength, and radio packet loss rate. The single-hop time slot calculation unit queries the modulation and coding strategy tables for both power line carrier and radio modes based on the aforementioned channel quality parameters to obtain the modulation efficiency and coding efficiency for each mode. Then, combining this with the length of the data frame to be forwarded, the symbol rate, and the single time slot duration, it calculates the number of time slots required to forward the data frame in each mode. The load information aggregation unit obtains the number of terminal sites attached to each level of relay hop from the topology information table, calculates the reporting activity rate of each terminal site from the historical reporting logs, multiplies the single-hop time slot occupancy by the number of active terminal sites and adds the time slots required for the relay hop itself to obtain the total time slot requirement of each level of relay hop in the current mode, and calculates the total time slot requirement in the alternative modes in the same way.

[0108] The overload identification module is used to calculate the time slot occupancy rate of each level of trunk hop based on the total time slot demand of each level of trunk hop output by the time slot occupancy sensing module, identify overloaded trunk hops whose time slot occupancy rate exceeds the alarm threshold, and calculate the number of time slots that can be released after each overloaded trunk hop switches to the alternative mode.

[0109] The overload identification module specifically includes a time slot occupancy rate calculation unit, an overload hop identification unit, and a surplus calculation unit. The time slot occupancy rate calculation unit divides the total time slot requirement of each relay hop level in the current mode by the total available time slots in the superframe to obtain the time slot occupancy rate of that level of relay hop. Simultaneously, it averages the time slot occupancy rates of all relay hops to obtain the network-wide average time slot occupancy rate. The overload hop identification unit compares the time slot occupancy rate of each level of relay hop with an alarm threshold. Relay hops exceeding the alarm threshold are identified as overloaded relay hops, and all overloaded relay hops constitute the overload hop set. If no overloaded relay hops are identified in the current superframe, subsequent steps are skipped, and the system directly enters the threshold correction module to perform routine monitoring. The surplus calculation unit subtracts the total time slot demand in the alternative mode from the total time slot demand in the current mode for each overloaded trunk jump, obtaining the number of releaseable time slots after switching. Overloaded trunk jumps with a releaseable time slot number greater than zero are marked as switchable overloaded jumps. The set of switchable overloaded jumps and their corresponding releaseable time slot numbers are then used as input to the time slot reallocation module.

[0110] The time slot reallocation module is used to generate mode switching instructions based on the set of switchable overload hops and the number of releaseable time slots output by the overload identification module, and to allocate the time slots released by the switch to the end stations attached to the relay hops that are not overloaded but have a high time slot occupancy rate. It also generates and distributes the complete time slot allocation table for the next superframe.

[0111] The time slot reallocation module specifically includes a handover instruction generation unit, a directional reallocation unit, and a time slot table update and distribution unit. The handover instruction generation unit generates a mode switching instruction for each switchable overloaded hop, instructing the hop to switch its transmission mode from the current mode to a candidate mode in the next superframe. Simultaneously, it aggregates the number of releaseable time slots for each switchable overloaded hop to obtain the total number of releaseable time slots. The directional reallocation unit does not return the released time slots to the idle time slot pool. Instead, after excluding overloaded hops from the entire network, it sorts the remaining hops by time slot occupancy rate from high to low, determines the target allocation number based on the total number of releaseable time slots, and allocates the release time slots weighted by the number of end stations attached to each target hop. Simultaneously, it verifies whether the time slot occupancy rate of each overloaded hop performing the handover is lower than the lower limit. If it is lower, the handover instruction is canceled, the corresponding number of releaseable time slots is deducted, and the time slots are reallocated until all post-handover occupancy rates are not lower than the lower limit or the handover instruction set is empty. The time slot table update and distribution unit adjusts the time slot segment of the corresponding relay hop from the original mode time slot area to the new mode time slot area according to the verified switching instruction. Based on the redistribution result, it adds an extra time slot to the end of the original reporting time slot of the terminal station attached to each target relay hop, generates a complete time slot allocation table for the next superframe, encapsulates it into a beacon frame, and broadcasts it to relay stations and terminal stations at all levels through two channels during the beacon period at the beginning of the next superframe.

[0112] The threshold correction module is used to collect the actual number of timeout sites in the next superframe after the scheme issued by the time slot reallocation module is executed, correct the alarm threshold according to the direction of change of the number of timeout sites, and feed the corrected threshold back to the overload identification module for overload identification in the next cycle.

[0113] The threshold correction module specifically includes a timeout site count acquisition unit and a threshold adaptive correction unit. The timeout site count acquisition unit receives the timeout site list reported by relay sites at all levels after the next overframe ends, summarizes and deduplicates it to obtain the total number of timeout sites across the entire network, and then subtracts it from the total number of timeout sites in the previous overframe to obtain the change. The threshold adaptive correction unit processes the change as follows: if the number of timeout sites decreases, the alarm threshold remains unchanged; if the number of timeout sites decreases and reaches zero in multiple consecutive overframes, the threshold is lowered by a fixed step; if the number of timeout sites increases, the threshold is raised by a fixed step, and the mode switching command with the smallest number of release slots is rolled back; if the number of timeout sites remains the same, the threshold remains unchanged. The threshold correction process is always constrained by upper and lower limits; the corrected threshold is not lower than the lower occupancy rate limit and not higher than 1. The corrected threshold is stored in a cache and fed back to the overload identification module as the basis for judging overload identification in the next overframe.

[0114] The above modules are executed sequentially in each superframe cycle. After the time slot occupancy sensing module completes data acquisition and calculation in the current superframe, it transmits the results to the overload identification module for overload judgment. If there is an overload jump, the time slot reallocation module performs mode switching and time slot reallocation, and then the threshold correction module evaluates the execution effect and corrects the threshold. The corrected threshold is fed back to the overload identification module for comparison and judgment in the next superframe. If there is no overload jump, the allocation module is skipped, and the threshold correction module directly performs regular timeout monitoring. The entire process advances sequentially with each superframe cycle, forming a closed-loop control that cycles through each superframe.

[0115] Through the coordinated operation of the above modules, the system can complete time slot occupancy perception, overload identification, mode switching, time slot reallocation, and threshold correction feedback in each superframe cycle, thereby breaking the rigid binding relationship between time slot consumption and relay level and improving the site carrying capacity of the subnet under the same time slot resources.

[0116] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A dynamic resource allocation method based on dual-mode fusion carrier technology, characterized in that, Includes the following steps: S1. Obtain the number of time slots required for each level of relay hop to forward data frames in power line carrier mode and wireless mode, and obtain the number of terminal stations attached to each level of relay hop and the reporting activity rate. Calculate the total time slot requirement for each level of trunk hop in both modes based on the number of time slot occupancy, the number of terminal stations, and the reported activity rate; The mode currently used by each relay hop is recorded as the current transmission mode, and the other mode is recorded as the alternative transmission mode; S2. Calculate the time slot occupancy rate of each level of relay hop based on the total time slot requirement of each level of relay hop in the current transmission mode. The time slot occupancy rate is the ratio of the total time slot requirement to the total available time slots of the superframe. The trunk hops corresponding to the time slot occupancy rate exceeding the preset alarm threshold are identified as overload trunk hops; Calculate the number of releaseable time slots after each overloaded trunk jump switches to the alternative transmission mode based on the total time slot requirements of each level of trunk jump in the alternative transmission mode, and mark the overloaded trunk jump with a releaseable time slot number greater than zero as a switchable overloaded jump; S3. Generate a mode switching instruction based on the switchable overload jump. The mode switching instruction is used to instruct the switchable overload jump to switch to the alternative transmission mode to release the time slot it occupies. Sum the number of time slots that can be released to obtain the total number of time slots released. From the released time slots, allocate the total number of released time slots to the terminal stations attached to the non-overloaded relay hops, and append the allocated time slots to the reporting time slots of the corresponding terminal stations; The time slot allocation table for the next superframe is generated based on the mode switching command and allocation results.

2. The dynamic resource allocation method based on dual-mode fusion carrier technology according to claim 1, characterized in that: The time slot occupancy number is used to characterize the number of time slots occupied by each relay hop in forwarding data frames. The time slot occupancy number is obtained by the central coordinator by querying the modulation and coding strategy table based on the channel quality parameters reported by each relay hop. The channel quality parameters include the signal-to-noise ratio and background noise power of each relay hop in power line carrier mode, and the received signal strength and packet loss rate in radio mode.

3. The dynamic resource allocation method based on dual-mode fusion carrier technology according to claim 1, characterized in that: The reporting activity rate is used to characterize the actual reporting needs of terminal stations at each level of relay hop within the current superframe. The reporting activity rate is the ratio of the number of terminal stations that actually initiate reporting within the current superframe to the total number of terminal stations attached to the relay hop, which is obtained by the central coordinator based on historical reporting logs.

4. The dynamic resource allocation method based on dual-mode fusion carrier technology according to claim 1, characterized in that: The total time slot requirement is calculated as follows: multiply the number of end stations attached to the relay hop by the reporting activity rate to obtain the number of active end stations in the current superframe, then multiply by the number of time slots required to forward data reported by a single station in the current transmission mode to obtain the total number of time slots required for all active end stations to report, and add the number of time slots required for the relay hop itself to forward data from the previous level.

5. The dynamic resource allocation method based on dual-mode fusion carrier technology according to claim 1, characterized in that: The alarm threshold is used to determine the overload status of relay hops at each level. The alarm threshold is adjusted after each superframe cycle based on the execution effect of the previous superframe. The adjustment method is as follows: obtain the total number of timeout sites in the entire network in the previous superframe, calculate the change in the total number of timeout sites between the previous superframe and the current superframe. If the number of timeout sites continues to decrease and remains zero in multiple consecutive superframes, the alarm threshold is lowered by a fixed step. If the number of timeout sites increases, the alarm threshold is raised by a fixed step. If the number of timeout sites remains the same, the alarm threshold is kept unchanged.

6. The dynamic resource allocation method based on dual-mode fusion carrier technology according to claim 1, characterized in that: If there are no relay hops in the current superframe whose time slot occupancy rate exceeds the alarm threshold, skip the mode switching and time slot allocation steps, carry over the time slot allocation table of the previous superframe to the next superframe, and continue to perform timeout station number monitoring in the next superframe.

7. The dynamic resource allocation method based on dual-mode fusion carrier technology according to claim 1, characterized in that: The total number of time slots to be released is allocated as follows: After excluding relay hops determined to be overloaded from the entire network, the remaining relay hops are sorted from high to low according to their time slot occupancy rate. The target relay hops are determined according to the total number of time slots to be released, and the release time slots are allocated to each target relay hop in order of high to low time slot occupancy rate until the total number of time slots to be released is allocated. The relay hop with the higher time slot occupancy rate is given priority in receiving the allocation of release time slots.

8. The dynamic resource allocation method based on dual-mode fusion carrier technology according to claim 1, characterized in that: The total number of release time slots is allocated according to the proportion of the number of terminal stations attached to each target relay hop to the total number of terminal stations. During allocation, the number of time slots allocated to each target relay hop is first calculated according to the proportion and rounded down. The remaining time slots after rounding are then filled in order of the number of terminal stations of each target relay hop from most to least, until all release time slots are allocated.

9. The dynamic resource allocation method based on dual-mode fusion carrier technology according to claim 1, characterized in that: When the allocated time slot is added to the reporting time slot of the corresponding terminal station, the added time slot is located after the original reporting time slot of the terminal station. The added time slots of each terminal station hopped under the same relay are arranged consecutively in the order of station number. If a terminal station has no backlog data in the current superframe during the time slot addition process, the station is skipped and the corresponding time slot is allocated to other terminal stations hopped under the same relay.

10. A dynamic resource allocation system based on dual-mode fusion carrier technology, used to execute the dynamic resource allocation method based on dual-mode fusion carrier technology as described in any one of claims 1-9, characterized in that, It includes a time slot occupancy sensing module, an overload identification module, a time slot reallocation module, and a threshold correction module; The time slot occupancy sensing module is used to obtain the number of time slots occupied and the reporting activity rate of each level of relay hop in power line carrier mode and radio mode, and to calculate the total time slot requirement of each level of relay hop in the two modes. The overload identification module is used to calculate the time slot occupancy rate based on the total time slot demand, identify overloaded relay hops whose time slot occupancy rate exceeds the alarm threshold, and calculate the number of time slots that can be released after each overloaded relay hop switches to the alternative transmission mode. The time slot reallocation module is used to generate mode switching instructions based on switchable overload hops, summarize the number of releaseable time slots to obtain the total number of release time slots, and allocate the total number of release time slots to the terminal stations attached to the non-overloaded relay hops. The threshold correction module is used to correct the alarm threshold based on the total number of timeout sites across the entire network, and to feed back the corrected alarm threshold to the overload identification module.

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