Multi-band transmission control method for power line communication network

Abstract

This invention discloses a multi-band transmission control method for power line communication networks, belonging to the field of communication technology. The method includes: the power line communication network having at least one new transformer substation and one old substation; communication nodes in the new substation support communication on newly added frequency bands, while communication nodes in the old substation only support communication on existing frequency bands; when communication nodes in the new substation need to communicate on the newly added frequency band, and the newly added frequency band overlaps with the existing frequency band, the transmission strategy of the target communication node enabling communication on the newly added frequency band is adjusted, including: restricting the target communication node from executing an adaptive transmission strategy based on the channel detection results of the newly added frequency band; and adjusting the signal transmission mode of the target communication node on the newly added frequency band to a low-speed transmission mode. This invention improves the communication reliability and transmission success rate of power line carrier signals in newly added frequency bands where new and old substations coexist.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, and in particular relates to a multi-band transmission control method for power line communication networks. Background Technology

[0002] With the development of Power Line Communication (PLC) networks, multi-band communication technology has been introduced to improve the spectrum utilization and transmission rate of power line carrier communication. This technology allows different devices or nodes to operate on the same or different frequency bands for signal transmission, adapting to channel characteristics and service requirements.

[0003] In related technologies, devices or nodes typically determine whether a channel is occupied by detecting the physical layer preamble before sending data. That is, they listen for valid signals in the channel that match their own frequency band and synchronization sequence, and trigger a backoff mechanism accordingly.

[0004] However, in scenarios where multiple frequency bands coexist and overlap, communication nodes in older distribution areas that only support communication on the original frequency bands cannot identify the preambles with different phase rotation factors used by communication nodes in new distribution areas that support communication on the new frequency bands. This causes conflicts when both sides transmit signals simultaneously, resulting in inaccurate channel detection results and reducing the reliability and transmission success rate of power line carrier communication. Summary of the Invention

[0005] This invention aims to address at least one of the technical problems existing in the prior art. To this end, this invention proposes a multi-band transmission control method for power line communication networks, which improves the communication reliability and transmission success rate of power line carrier signals in newly added frequency bands where communication nodes coexist in both old and new distribution areas.

[0006] In a first aspect, the present invention provides a multi-band transmission control method for a power line communication network, wherein the power line communication network has at least one new transformer substation and one old transformer substation, the communication nodes in the new substation support communication on newly added frequency bands, and the communication nodes in the old substation only support communication on existing frequency bands; the method includes: When communication nodes within the new distribution area need to communicate on the newly added frequency band, and the new frequency band overlaps with the existing frequency band, the transmission strategy for the target communication node enabling communication on the new frequency band will be adjusted, including: The target communication node is restricted from implementing an adaptive transmission strategy based on the channel detection results of the newly added frequency band; Adjust the signal transmission mode of the target communication node on the newly added frequency band to a low-speed transmission mode.

[0007] According to one embodiment of the present invention, the new frequency band and the original frequency band are in master-slave mode, and the phase rotation factor of the synchronization sequence of the new frequency band is different from that of the synchronization sequence of the original frequency band.

[0008] According to one embodiment of the present invention, when the newly added frequency band and the existing frequency band are in master-slave mode, if the total number of communication frequency bands in master-slave mode is two, the communication nodes in the new substation area transmit signals on their respective corresponding communication frequency bands; wherein, the preamble, frame control field, and frame payload field of the signal are transmitted on the same communication frequency band; if the total number of communication frequency bands in master-slave mode exceeds two, the communication nodes in the new substation area corresponding to the newly added frequency band transmit the preamble and frame control field of the signal on the same communication frequency band, and the frame payload field of the signal is transmitted on their respective communication frequency bands.

[0009] According to one embodiment of the present invention, after restricting the target communication node from executing an adaptive transmission strategy based on the channel detection results of the newly added frequency band, the method further includes: instructing the target communication node to send a detection signal on the newly added frequency band to detect the signal characteristics of the communication nodes in the old distribution area; when no signal characteristics are detected within the detection time, releasing the restriction on the adaptive transmission strategy executed by the target communication node based on the channel detection results.

[0010] According to one embodiment of the present invention, the adaptive transmission strategy includes at least one of the following: instructing the target communication node to use a bit loading mode for signal transmission on the newly added frequency band; or instructing the target communication node to perform subcarrier allocation on the newly added frequency band according to the OFDMA strategy.

[0011] According to one embodiment of the present invention, the low-speed transmission mode includes: signal modulation based on BPSK modulation with a diversity number of not less than 2 times; or signal modulation based on QPSK modulation with a diversity number of not less than 4 times.

[0012] According to one embodiment of the present invention, the method further includes: obtaining interference parameters of communication nodes in the old distribution area on the newly added frequency band, the interference parameters including the signal strength and / or interference probability of the communication nodes in the old distribution area; and determining, based on the interference parameters, whether to adjust the signal transmission mode of the target communication node on the newly added frequency band to a low-speed transmission mode.

[0013] According to one embodiment of the present invention, adjusting the transmission strategy of a target communication node that enables communication in a newly added frequency band further includes: controlling the target communication node to send beacon messages and discovery list messages on the original frequency band and the newly added frequency band respectively according to the message sending ratio, wherein the message sending ratio is dynamically adjusted according to the channel communication quality between the target communication node and the associated node; wherein the beacon message sending frequency on the original frequency band remains unchanged.

[0014] According to one embodiment of the present invention, when a communication node in a new substation area needs to communicate on a new frequency band, and the new frequency band overlaps with the original frequency band, the method further includes: obtaining the channel detection success rate of the target communication node, and determining the credibility of the channel detection result based on the channel detection success rate; when the credibility is lower than the credibility threshold, adjusting the transmission strategy of the target communication node on the new frequency band.

[0015] According to one embodiment of the present invention, when a communication node in a new substation area needs to communicate on a new frequency band, and the new frequency band overlaps with the existing frequency band, the method further includes: determining the bandwidth ratio between the new frequency band and the current communication frequency band of the target communication node; and adjusting the transmission strategy of the target communication node on the new frequency band when the bandwidth ratio exceeds a ratio threshold.

[0016] In a second aspect, the present invention provides a multi-band transmission control device for a power line communication network, the device comprising: The transmission module is used to adjust the transmission strategy for target communication nodes that need to communicate on a new frequency band within a new substation area, where the new frequency band overlaps with the existing frequency band. This includes: The target communication node is restricted from implementing an adaptive transmission strategy based on the channel detection results of the newly added frequency band; Adjust the signal transmission mode of the target communication node on the newly added frequency band to a low-speed transmission mode.

[0017] Thirdly, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the multi-band transmission control method for the power line communication network as described in the first aspect above.

[0018] Fourthly, the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the multi-band transmission control method for power line communication networks as described in the first aspect above.

[0019] Fifthly, the present invention provides a chip including a processor and a communication interface, the communication interface being coupled to the processor, the processor being used to run programs or instructions to implement the multi-band transmission control method for power line communication networks as described in the first aspect.

[0020] In a sixth aspect, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the multi-band transmission control method for power line communication networks as described in the first aspect above.

[0021] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: By adjusting the transmission strategy of the target communication node when it is detected that a communication node in the new distribution area needs to communicate on a newly added frequency band that overlaps with the existing frequency band, problems such as inaccurate channel detection results, misjudgment of transmission strategies, and decreased communication reliability caused by the inability of communication nodes in the old distribution area to recognize signals in the newly added frequency band can be effectively avoided. This significantly improves the communication reliability under the newly added frequency band and enables the stable coexistence of communication nodes in the old and new distribution areas. Furthermore, since communication nodes in the old distribution area cannot perform carrier sense backoff on signals in the newly added frequency band, unpredictable burst interference may be mixed into the channel detection results. By restricting the target communication node to execute an adaptive transmission strategy based on the channel detection results of the newly added frequency band, misadjustment caused by inaccurate detection results can be effectively avoided, making transmission decisions more deterministic and resistant to interference. Meanwhile, since the signals of communication nodes in the new distribution area may be interfered with by communication nodes in the old distribution area at any time, by adjusting the signal transmission mode of the target communication node on the new frequency band to a low-speed transmission mode, the robustness of the signal in the interference environment can be significantly enhanced, the number of retransmissions can be reduced, thereby improving the signal transmission success rate and link stability on the new frequency band.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a flowchart illustrating a multi-band transmission control method for a power line communication network provided in some embodiments of the present invention; Figure 2 This is a schematic diagram of the relationship between packet error rate and signal-to-noise ratio under different interference powers for the transmission mode TMI1 provided in some embodiments of the present invention; Figure 3 This is a schematic diagram of the relationship between packet error rate and signal-to-noise ratio under different interference powers for the transmission mode TMI3 provided in some embodiments of the present invention; Figure 4 This is a schematic diagram of the structure of a multi-band transmission control device for a power line communication network provided in some embodiments of the present invention; Figure 5 This is a schematic diagram of the structure of an electronic device provided in some embodiments of the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0025] The terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0026] In power communication networks, a distribution area refers to the power supply area covered by a distribution transformer, typically including all power lines and communication nodes within the transformer's low-voltage side supply range. Generally, communication nodes within a distribution area share the power line medium for power line carrier communication, and different distribution areas are electrically isolated from each other through transformers.

[0027] With the continuous development of power infrastructure, the demand for power communication is constantly increasing, resulting in construction needs such as access to new power consumption areas, grid expansion and upgrades, and the introduction of wider communication frequency bands to improve communication performance. As PLC power communication networks evolve towards multi-frequency bands, newly deployed distribution areas (i.e., new distribution areas) adopt communication nodes that support wider new frequency bands (such as bands 0 to 7) and can dynamically switch between multiple frequency bands according to channel conditions, thereby achieving higher throughput and stronger anti-interference capabilities. At the same time, communication nodes in older distribution areas still exist in the PLC network, supporting only narrowband frequency bands (such as bands 0 to 3).

[0028] To improve spectrum utilization and network flexibility, multi-band communication technology has been introduced into power communication networks. It allows different nodes in the same power communication network to select multiple communication frequency bands for signal transmission according to channel conditions, i.e., multi-band mode. Typically, it mainly includes single-band mode, orthogonal mode, and master-slave mode.

[0029] Among them, single-band mode refers to a signal transmission mode in which the entire network uses the same communication frequency band and all nodes transmit and receive signals on this frequency band; while in multi-band mode, orthogonal mode refers to a signal transmission mode in which different communication frequency bands are completely separated in frequency and do not overlap, and the signals of each frequency band do not interfere with each other; master-slave mode refers to a signal transmission mode in which one communication frequency band is defined as the master frequency band and one or more other frequency bands are defined as sub-frequency bands, and there is some frequency overlap between the master frequency band and the sub-frequency bands.

[0030] Furthermore, newly added frequency bands refer to one or more frequency ranges additionally supported by communication nodes within the new distribution area, which may overlap with existing frequency bands. These include, but are not limited to, frequency band 4 (0.78 MHz to 5.615 MHz) and frequency band 5 (0.781 MHz to 11.96 MHz) as defined in industry standards. Existing frequency bands refer to the traditional frequency ranges supported by communication nodes within the old distribution area, excluding newly added frequency bands, such as frequency band 0 (1.953 MHz to 11.96 MHz), frequency band 1 (2.441 MHz to 5.615 MHz), and frequency band 2 (0.781 MHz to 2.930 MHz). When newly added frequency bands and existing frequency bands share a common frequency coverage area, overlapping frequency bands are formed.

[0031] To balance the communication needs of both new and old distribution centers within limited spectrum resources, related technologies employ a method of superimposing wider frequency bands with one or more narrower frequency bands to improve spectrum utilization. Typical overlapping frequency bands include bands 4 and 5. However, this superposition deployment faces a fundamental physical layer problem: if the preambles (synchronization sequences) on different communication frequency bands use the same generation method, missynchronization may occur at the receiver during correlation detection due to frequency band overlap. This means that a preamble that should belong to another frequency band may be locked on the wrong frequency band, leading to incorrect frame start position determination. To avoid missynchronization, industry standards require the introduction of different phase rotation factors into the synchronization sequences of overlapping frequency bands to reduce the cross-correlation of preambles in each frequency band.

[0032] When a new frequency band and an existing frequency band form a master-slave mode, the synchronization sequences of the new frequency band and the existing frequency band have different phase rotation factors. The phase rotation factor is a parameter used to generate the synchronization sequence; using different factors for different frequency bands can reduce cross-correlation and prevent the signal receiver from locking the preamble on an incorrect frequency band.

[0033] Communication nodes in the new distribution area support frequency band detection for both existing and newly added frequency bands. Their preamble detection module can simultaneously match synchronization sequences with two different phase rotation factors, thus enabling them to identify preambles on both existing and newly added frequency bands and perform effective carrier sensing and backoff for signals in these two bands. Communication nodes in the old distribution area only support frequency band detection for existing frequency bands. Their preamble detection module only matches factors corresponding to existing frequency bands and cannot match factors for newly added frequency bands. Therefore, they cannot identify preambles on newly added frequency bands and will not backoff signals on these bands. Based on this difference in detection capabilities, when a communication node in the new distribution area is identified as needing to communicate on a newly added frequency band overlapping with existing frequency bands, it can be determined that this communication node is the target communication node requiring transmission strategy adjustment, while communication nodes in the old distribution area do not require adjustment.

[0034] Frequency band detection refers to the correlation detection performed by communication nodes on physical layer preambles in a specific frequency band to determine whether a valid signal exists in that specific frequency band. Nodes that support multi-band detection can match various phase rotation factors and identify signal preambles from different frequency bands; communication nodes that only support single-band detection can only match fixed factors and cannot identify signals from other frequency bands.

[0035] Furthermore, when deploying multiple communication bands in a master-slave mode, the number of communication bands directly affects the complexity of synchronization detection and network overhead. If each communication band uses an independent and unrelated synchronization sequence (with different phase rotation factors), while inter-band synchronization errors can be avoided, communication nodes in the new substation area need to perform blind detection on each communication band. The computational load increases linearly with the number of communication bands, potentially leading to excessively long synchronization times or insufficient hardware resources, especially when the number of communication bands exceeds two, where the cost becomes even higher. Therefore, in some embodiments, when the total number of communication bands in the master-slave mode is two, communication nodes in the new substation area transmit signals on their respective corresponding communication bands; wherein the preamble, frame control field, and frame payload field of the signal are transmitted on the same communication band. When the total number of communication bands in the master-slave mode exceeds two, communication nodes in the new substation area corresponding to the newly added band transmit the preamble and frame control field of the signal on the same communication band, and the frame payload field of the signal is transmitted on their respective communication bands.

[0036] Among them, the preamble refers to a known sequence located at the beginning of the physical layer frame, which is used for signal detection, time synchronization, frequency synchronization and channel estimation; the frame control field is a fixed part of the power line communication frame that carries control information such as frame type, address and sequence number; and the frame payload field is a variable-length field that carries user service data.

[0037] When there are two communication frequency bands in master-slave mode, each frequency band includes a master band and a sub-band. Communication nodes within the new substation transmit signals on their respective corresponding frequency bands. Specifically, for a communication node operating on the master band, its preamble, frame control field, and frame payload fields are all transmitted on that master band; for a communication node operating on a sub-band, these same fields are also transmitted on their respective sub-bands. In other words, each communication node's complete signal (preamble, frame control field, and frame payload field) is transmitted within the same communication frequency band, without cross-band multiplexing. The two communication frequency bands use different synchronization sequences (different phase rotation factors) to ensure that their synchronization sequences are independent, thus avoiding missynchronization between frequency bands. Communication nodes within the new substation need to perform synchronization detection for both frequency bands separately, with a total of two detections. This detection frequency is within a reasonable range that the current hardware can handle and will not significantly increase synchronization latency or power consumption.

[0038] When there are more than two communication frequency bands in master-slave mode, each communication frequency band includes one master band and multiple sub-bands. To reduce the computational load of synchronization detection, communication nodes in the new substation area corresponding to the newly added frequency band transmit their preamble and frame control fields on the same communication frequency band, while transmitting their frame payload fields on their respective communication frequency bands. In other words, regardless of which sub-band a communication node actually operates in, its preamble and frame control fields share the same physical frequency band (e.g., the master band or a designated common band). Since the preamble and frame control fields of all communication nodes are concentrated on the same frequency band and use the same synchronization sequence, the signal receiver only needs to perform synchronization detection once on this common frequency band to capture signals from all sub-bands, thereby reducing the computational complexity of synchronization detection and significantly reducing the computational load and synchronization time of blind detection. After synchronization is completed and the frame control field is parsed, the signal receiver can further interpret the frequency band change identifier (such as the sub-band index) from the frame payload field, or determine the actual communication frequency band to which the current signal belongs through different subcarrier mapping methods, so as to perform subsequent signal data processing.

[0039] It should be noted that in the above embodiments, the modification of the phase rotation factor is transparent to communication nodes in the new distribution area because these nodes support multi-band detection and can identify multiple different synchronization sequences. However, for communication nodes in the old distribution area, their physical layer preamble detection module only matches the synchronization sequences corresponding to the original frequency bands (i.e., frequency bands 0-3) and cannot identify the preamble of the overlapping frequency bands with the added phase rotation factor. Therefore, when a communication node in the new distribution area transmits a signal on the newly added frequency band, the correlation value obtained by the node in the old distribution area after performing correlation calculations is extremely low, and it will not be determined as a valid preamble. Consequently, it will not consider the channel to be occupied and will not trigger the Carrier Sense Multiple Access (CSMA) backoff mechanism. As a result, communication nodes in both the new and old distribution areas may transmit signals simultaneously on the aforementioned overlapping frequency bands, resulting in direct collisions.

[0040] To address the above issues, relevant technologies typically employ the following two approaches: Firstly, frequency band orthogonalization involves completely separating the communication frequency bands used by communication nodes in both new and old distribution areas to prevent frequency overlap. However, given the increasing scarcity of spectrum resources, this orthogonal approach often requires sacrificing the available bandwidth of the new distribution area, failing to fully utilize the advantages of multiple frequency bands, and reducing signal transmission efficiency.

[0041] Secondly, a unified upgrade of all communication nodes is required, meaning that all communication nodes in the PLC network must support the communication frequency band of the new distribution area, thereby completely eliminating the aforementioned problems. However, in the actual operation of the PLC network, the number of communication nodes in the old distribution area is enormous and widely distributed, making individual upgrades extremely costly in terms of hardware.

[0042] Therefore, the above methods are difficult to deal with the conflicts between communication nodes in the old and new substations on the newly added frequency bands, and it is difficult to balance the communication reliability and efficiency of communication nodes in the old and new substations on the newly added frequency bands without sacrificing frequency band utilization and without large-scale hardware upgrades.

[0043] Based on the above understanding, the inventors discovered during their research on communication nodes in both old and new transformer substations within a PLC network that a power line multi-band transmission control strategy could be designed. This strategy focuses on allowing communication nodes in new substations to proactively adapt to environments with uncontrollable interference, rather than attempting to change the signal transmission methods of communication nodes in old substations. When it is identified that there are communication nodes in old substations supporting only the original frequency bands and communication nodes in new substations supporting the newly added frequency bands in the PLC network, and the communication frequency bands used by the two overlap, there is no need to upgrade the hardware of the communication nodes in the old substations. Instead, the transmission method of the communication nodes in the new substations on the newly added frequency bands is directly adjusted. The conflict on the newly added frequency bands is treated as tolerable noise, thus avoiding reliance on backoff mechanisms. Therefore, without sacrificing spectrum utilization or increasing hardware upgrade costs, the communication reliability and transmission success rate of communication nodes in both old and new substations on the newly added frequency bands are significantly improved.

[0044] In view of this, embodiments of the present invention provide a multi-band transmission control method for power line communication networks, aiming to solve the problem of decreased communication reliability caused by the inability of communication nodes in the old distribution area to recognize signals on newly added frequency bands when communication nodes in the new and old distribution areas are incompatible. By identifying the scenario of frequency band overlap between communication nodes in the new and old distribution areas, the method restricts the adaptive transmission strategy of communication nodes in the new distribution area based on channel detection results and adopts a low-speed robust transmission mode. This effectively improves the communication reliability and transmission success rate of the PLC network on newly added frequency bands without increasing the hardware upgrade cost of communication nodes in the old distribution area or sacrificing signal spectrum utilization.

[0045] The multi-band transmission control method for power line communication networks provided by the present invention will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0046] The multi-band transmission control method for power line communication networks provided by this invention can be applied to the communication process between a centralized communication management node and its directly connected communication nodes, as well as to the communication process between an intermediate communication management node and its directly connected communication nodes.

[0047] For example, the centralized communication management node includes, but is not limited to, a Central Coordinator (CCO) or a concentrator main control module, and its directly connected communication nodes include, but are not limited to, one or more of the following: a Proxy Coordinator (PCO), a communication station with subnet management function, or a station (STA) directly connected to the CCO; the intermediate communication management node includes, but is not limited to, a PCO or a relay node, and its directly connected communication nodes may be, for example, one or more of the following: a STA or a terminal communication module.

[0048] The execution entity in this invention embodiment can be a Control Operational Unit (CCO), a Power Operational Unit (PCO), or a functional module or entity within a CCO or PCO capable of implementing the method. Further, the CCO and PCO can be electronic devices, including but not limited to power line communication terminals, concentrator devices, smart meters, communication module embedded devices, or communication test terminals. They can also be devices with computing capabilities or intelligent robots, used to execute steps such as signal transmission, signal reception, channel evaluation, and transmission strategy adjustment in this invention.

[0049] The following uses CCO as the executing entity to illustrate the multi-band transmission control method for power line communication networks provided in this embodiment of the invention.

[0050] Figure 1 This is a flowchart illustrating a multi-band transmission control method for a power line communication network provided in some embodiments of the present invention. For example... Figure 1 As shown, the multi-band transmission control method of the power line communication network includes: step 110.

[0051] Step 110: When communication nodes in the new area need to communicate on the new frequency band, and the new frequency band overlaps with the original frequency band, adjust the transmission strategy of the target communication node that enables communication on the new frequency band.

[0052] Among them, the transmission strategy of the target communication node that enables communication in the newly added frequency band is adjusted, including: restricting the target communication node from executing an adaptive transmission strategy based on the channel detection results of the newly added frequency band; and adjusting the signal transmission mode of the target communication node in the newly added frequency band to a low-speed transmission mode.

[0053] Furthermore, the target communication nodes include, but are not limited to, one or more of the STAs or PCOs within the new substation area that need to use the newly added frequency band for communication.

[0054] When the CCO detects that a communication node in the new substation needs to communicate on a new frequency band, and the new frequency band overlaps with the existing frequency band, the CCO will adjust the transmission strategy of the target communication node that enables communication on the new frequency band.

[0055] In some embodiments, the CCO first determines, through one or more of the node capability reporting mechanism or historical configuration information, whether communication nodes in old distribution areas that only support the original frequency band and communication nodes in new distribution areas that support the new frequency band coexist in the current PLC network. When the CCO detects that any target communication node in the new distribution area is preparing to transmit a signal on the new frequency band, and that the new frequency band overlaps with the original frequency band used by any communication node in the old distribution area, it triggers a transmission strategy adjustment.

[0056] In some implementations, the CCO adjusts the transmission strategy of the target communication node that enables communication in the new frequency band, which may be to restrict the target communication node from executing an adaptive transmission strategy based on the channel detection results of the new frequency band.

[0057] Adaptive transmission strategy refers to a method by which communication nodes dynamically adjust transmission parameters based on channel detection results. For example, adaptive transmission strategies include, but are not limited to, one or more of the following: Transmission Mode Index prediction (TMI) mode, bitloading mode, and Orthogonal Frequency Division Multiple Access (OFDMA) subcarrier allocation.

[0058] The CCO issues a configuration command to the target communication node, prohibiting the node from using one or more of the following functions on the newly added frequency band: modulation and coding scheme prediction, bit loading, and OFDMA subcarrier allocation, which depend on channel sounding results. For example, this configuration command could be clearing the enable bit of the node's internal adaptive algorithm module, or it could directly instruct the communication node to use a set of preset non-adaptive parameters.

[0059] With the above restrictions, the target communication node will no longer dynamically adjust its transmission parameters based on the real-time measured channel quality (signal-to-noise ratio, packet error rate, etc.), thereby avoiding misadjustment caused by the distortion of channel detection results due to the failure of communication nodes in the old distribution area to back off.

[0060] In other implementations, the CCO adjusts the transmission strategy of the target communication node that enables communication on the new frequency band, or adjusts the signal transmission mode of the target communication node on the new frequency band to a low-speed transmission mode.

[0061] Low-speed transmission mode refers to a transmission method that employs low-order modulation combined with multiple diversity repetitions. For example, low-speed transmission mode includes, but is not limited to, one or more of the following: binary phase shift keying (BPSK) modulation or quadrature phase shift keying (QPSK) modulation. In feasible implementations, low-speed transmission mode can also limit the number of diversity repetitions during signal transmission to a preset threshold while using BPSK or QPSK modulation, thereby improving the robustness of signal transmission.

[0062] The CCO sends a mode switching command to the target communication node, enabling it to use a low-speed transmission mode on the newly added frequency band. This command can override the node's original adaptive rate selection logic, allowing the node to always transmit signals in a low-order modulation and multiple repetition manner on the overlapping frequency bands.

[0063] By adjusting the signal transmission mode as described above, the target communication node can stably output signals in the newly added frequency band using low-order modulation, which can effectively combat the interference caused by the failure of communication nodes in the old distribution area to back off, thereby significantly reducing the packet error rate and the number of retransmissions and improving the communication reliability under the newly added frequency band.

[0064] In some other implementations, the CCO may adjust the transmission strategy of the target communication node that enables communication in the new frequency band. Alternatively, it may restrict the target communication node from executing an adaptive transmission strategy based on the channel detection results of the new frequency band, while adjusting the signal transmission mode of the target communication node in the new frequency band to a low-speed transmission mode.

[0065] The CCO issues a joint configuration command to the target communication node, restricting one or more of the following functions of the communication node: modulation and coding scheme prediction, bit loading, and OFDMA subcarrier allocation on the newly added frequency band. The command also instructs the target communication node to adopt a preset low-order modulation method (such as BPSK or QPSK). In feasible implementations, the CCO can configure the target communication node to transmit diversity repeats no less than a preset number of times.

[0066] The advantage of the above-mentioned joint adjustment is that, through the synergistic effect of limiting adaptive strategies and using low-speed transmission modes, it can effectively maintain the basic smooth operation of communication links under severe interference conditions and improve the signal transmission success rate under the new frequency band.

[0067] The multi-band transmission control method for power line communication networks provided by this invention adjusts the transmission strategy of the target communication node when it detects that a communication node in a new distribution area needs to communicate on a newly added frequency band that overlaps with the existing frequency band. This effectively avoids problems such as inaccurate channel detection results, misjudgment of transmission strategies, and decreased communication reliability caused by communication nodes in the old distribution area being unable to identify signals in the newly added frequency band. This significantly improves communication reliability under the newly added frequency band and enables stable coexistence of communication nodes in both the old and new distribution areas. Furthermore, since communication nodes in the old distribution area cannot perform carrier sense backoff on signals in the newly added frequency band, unpredictable burst interference may be mixed into the channel detection results. By restricting the target communication node from executing an adaptive transmission strategy based on the channel detection results of the newly added frequency band, misadjustments caused by inaccurate detection results can be effectively avoided, making transmission decisions more deterministic and resistant to interference. Meanwhile, since the signals of communication nodes in the new distribution area may be interfered with by communication nodes in the old distribution area at any time, by adjusting the signal transmission mode of the target communication node on the new frequency band to a low-speed transmission mode, the robustness of the signal in the interference environment can be significantly enhanced, the number of retransmissions can be reduced, thereby improving the signal transmission success rate and link stability on the new frequency band.

[0068] In conventional power line communication scenarios, when channel conditions are good and there is no sudden interference, adaptive transmission strategies can significantly improve spectrum utilization and data throughput. However, the prerequisite for using adaptive transmission strategies to improve communication rates is that the signal communication performance under the current frequency band remains good. In the case of newly added frequency bands, because communication nodes in the old distribution area cannot trigger backoff, the channel detection results are mixed with unpredictable sudden interference. Incorrect channel quality estimation will lead to severe mismatch in subcarrier bit allocation and user resource allocation conflicts, resulting in higher packet error rates and retransmission rates.

[0069] Based on this, in some embodiments, the adaptive transmission strategy includes at least one of the following: instructing the target communication node to use a bit loading mode for signal transmission on the newly added frequency band; or instructing the target communication node to allocate subcarriers on the newly added frequency band according to the OFDMA strategy.

[0070] Bit loading mode refers to a transmission method that allocates different modulation and coding bits to different subcarriers based on the channel quality (such as signal-to-noise ratio and gain) of each subcarrier. Typically, subcarriers with relatively good channel quality are assigned higher-order modulation, while subcarriers with relatively poor channel quality are assigned lower-order modulation or no bits are assigned, thereby maximizing spectrum utilization.

[0071] OFDMA strategy refers to a multiple access method that dynamically allocates different subcarrier resources to different communication nodes based on orthogonal frequency division multiplexing. It can allocate non-overlapping subcarrier resources to multiple users at the same time, so as to achieve parallel transmission.

[0072] In some implementations, the Control Controller (CCO) instructs the target communication node to transmit signals using a bit-loaded mode on the newly added frequency band. Upon receiving the CCO's instruction, the target communication node transmits a probe signal on the new frequency band to measure parameters such as the received signal strength and signal-to-noise ratio (SNR) of each subcarrier. Based on the measurement results, it calculates the maximum modulation order that each subcarrier can support (e.g., using a preset bit error rate threshold-to-SNR mapping table), and then allocates the corresponding number of bits to each subcarrier. Finally, the target communication node maps different numbers of bits onto different subcarriers, forming OFDM symbols, and transmits them.

[0073] In other implementations, the Control Center (CCO) instructs the target communication node to allocate subcarriers on the newly added frequency band according to the OFDMA strategy. Based on the target communication node's channel quality assessment, the CCO divides the subcarrier resources on the newly added frequency band into several subbands and allocates a dedicated subset of subcarriers to the target communication node. The CCO considers one or more factors during allocation, including the node's channel peak position, load balancing, and quality of service requirements. The CCO then sends the subcarrier allocation map to the target communication node via control signaling, enabling the target communication node to transmit data on the designated subcarriers accordingly.

[0074] In some other implementations, the CCO instructs the target communication node to use a bit-loaded mode for signal transmission on the newly added frequency band, while simultaneously instructing the target communication node to allocate subcarriers on the newly added frequency band according to the OFDMA strategy. The CCO first allocates subcarrier resources to different nodes according to the OFDMA strategy; then, each node further performs bit loading on its allocated subcarrier group, that is, independently determines the modulation scheme and number of bits for each subcarrier based on the channel quality of each subcarrier within the subcarrier group.

[0075] In the above embodiments, by instructing the target communication node to use a bit loading mode on the newly added frequency band and to allocate subcarriers on the newly added frequency band according to the OFDMA strategy, the waste of using uniform low-order modulation on all subcarriers is avoided, while different subcarriers are used in parallel, thereby effectively reducing collision and contention delay between communication nodes and improving the transmission reliability and robustness of the target communication node on the newly added frequency band.

[0076] Figure 2 This is a schematic diagram illustrating the relationship between packet error rate and signal-to-noise ratio under different interference powers for the transmission mode TMI1 provided in some embodiments of the present invention. For example... Figure 2As shown, the simulation curves of packet error rate (BER) versus signal-to-noise ratio (SNR) under transmission mode TMI1 have SNR (Short-to-Noise Ratio) on the x-axis and BER on the y-axis. The solid black line represents the BER curve under interference-free conditions, while the three different dashed black lines represent the BER curves when the interference power is -8dBm, -5dBm, and -3dBm, respectively. Under interference-free conditions, the BER decreases rapidly with increasing SNR, indicating that TMI1 mode can achieve high-reliability communication at low SNR in an interference-free channel environment. When interference power is -3dBm, the BER curve shifts significantly to the right relative to the interference-free curve, and the curve shifts further to the right as the interference power increases. The increase in SNR required to achieve the same BER as the interference-free curve is larger, indicating that communication reliability decreases with increasing interference power.

[0077] Figure 3 This is a schematic diagram illustrating the relationship between packet error rate and signal-to-noise ratio under different interference powers for the transmission mode TMI3 provided in some embodiments of the present invention. Figure 3 As shown, the simulation curves of packet error rate (BER) versus signal-to-noise ratio (SNR) under transmission mode TMI3 have SNR on the x-axis (in decibels, dB) and BER on the y-axis (indicating packet error rate). The solid line represents the BER curve under interference-free conditions, while the dashed line represents interference power of -8 dBm. Under interference-free conditions, the BER decreases rapidly with increasing SNR, indicating that TMI3 mode has good reliability in good channels. However, under interference power of -8 dBm, the BER curve increases significantly and decreases slowly with increasing SNR, indicating that TMI3 mode is also sensitive to interference from newly added frequency bands; even slight interference can lead to reduced communication reliability.

[0078] As shown in the above diagrams illustrating the packet error rate (BER) versus signal-to-noise ratio (SNR) relationships of TMI1 and TMI3 under different interference powers, while the high-speed transmission mode achieves high communication efficiency in an interference-free environment, the BER increases sharply and communication reliability decreases significantly under the presence of interference in the newly added frequency band. Therefore, in scenarios where communication nodes coexist in old and new distribution areas and frequency bands overlap, it is necessary to limit the adaptive high-speed transmission strategy that relies on channel detection results and switch to a low-speed robust transmission mode to avoid frequent transmission failures caused by communication nodes in the old distribution area not backing up, thereby ensuring the stability of the communication link under the newly added frequency band.

[0079] However, if the transmission mode is too conservative (e.g., using extremely low-order modulation and too high diversity), it may significantly reduce spectrum utilization and link throughput; conversely, if the transmission mode is not robust enough, a high packet error rate may still occur.

[0080] Based on this, in some embodiments, the low-speed transmission mode includes signal modulation based on BPSK modulation with a diversity number of not less than 2 times; or signal modulation based on QPSK modulation with a diversity number of not less than 4 times.

[0081] Among them, BPSK modulation is a modulation method that uses carrier phases of 0° and 180° to represent binary bits 0 and 1 respectively, with each symbol carrying 1 bit of information; while QPSK modulation is a modulation method that uses four different phases (usually 45°, 135°, 225°, 315°) to represent combinations of two binary bits (00, 01, 10, 11) respectively, with each symbol carrying 2 bits of information.

[0082] Diversity count refers to the number of times the same data symbol is repeatedly transmitted in the time domain. The signal receiver obtains diversity gain by combining multiple copies (such as maximum ratio combining or equal gain combining), thereby improving the probability of correct demodulation of the signal under fading or interference environments. In PLC networks, a higher diversity count results in stronger resistance to sudden interference, but correspondingly lower transmission efficiency.

[0083] In some implementations, the CCO configures the target communication node to use BPSK modulation and diversity twice, that is, to repeatedly send two copies of each symbol in order to deal with communication scenarios with extremely low signal-to-noise ratio or severe interference, and to provide basic communication reliability through low-order modulation and a small amount of diversity.

[0084] In other implementations, the CCO configures the target communication node to use QPSK modulation with a diversity frequency of 4, meaning that each symbol is repeatedly transmitted 4 times. This maintains a certain spectral efficiency (2 bits per symbol) while using relatively high diversity gain to offset burst interference.

[0085] The CCO can send the selected mode parameters to the target communication node via broadcast signaling or unicast configuration messages. After receiving the instruction, the node switches to the specified mode and continues to use it on the newly added frequency band until it receives a new configuration instruction or meets the release condition (such as signal feature detection not finding any communication nodes in the old distribution area).

[0086] In the above embodiments, by explicitly defining two specific low-speed robust transmission modes, compared to arbitrarily reducing the modulation order or increasing the diversity number without limit, the low-speed transmission methods in this invention not only effectively resist sudden interference from communication nodes within the old distribution area, but also avoid the waste of spectrum resources caused by excessive conservatism. Furthermore, these two low-speed transmission methods do not require additional hardware or complex algorithms, making them simple to implement and highly compatible.

[0087] When adjusting transmission strategies, the actual interference intensity on different newly added frequency bands may vary significantly. For example, some newly added frequency bands (such as band 4) have a small overlap with existing frequency bands, and the leakage power of communication nodes in the old distribution area may be low on these bands; while other newly added frequency bands (such as band 5) have a larger overlap with existing frequency bands, and the interference may be more severe. If a low-speed mode is applied indiscriminately to all newly added frequency bands, unnecessary throughput loss will occur on frequency bands with less interference.

[0088] Based on this, in some embodiments, the CCO obtains the interference parameters of the communication nodes in the old distribution area on the newly added frequency band. The interference parameters include the signal strength and / or interference probability of the communication nodes in the old distribution area. Based on the interference parameters, it determines whether to adjust the signal transmission mode of the target communication node on the newly added frequency band to a low-speed transmission mode.

[0089] Interference parameters are quantitative indicators characterizing the degree of interference caused by communication nodes within the old distribution area to the target communication node on the newly added frequency band. In this embodiment of the invention, interference parameters include, but are not limited to, one or more of signal strength and interference probability. Specifically, signal strength refers to the received signal power from communication nodes within the old distribution area measured by the target communication node on the newly added frequency band; interference probability refers to the statistical proportion of signals detected by the target communication node from communication nodes within the old distribution area on the newly added frequency band per unit time.

[0090] The CCO first instructs the target communication node to activate interference monitoring mode on the newly added frequency band. The target communication node continuously performs correlation detection on the received signal during the monitoring period. In some implementations, the target communication node may, for example, match the synchronization sequence (i.e., the phase rotation factor of the original frequency band) corresponding to the old substation node.

[0091] After the monitoring period ends, the target communication node counts one or more interference parameters, including signal strength and interference probability, and reports them to the CCO. The CCO receives and stores these parameters and determines whether to force the target communication node to enable low-speed transmission mode according to preset decision rules.

[0092] In some implementations, the decision rule may be, for example, that if the signal strength is higher than a first strength threshold (e.g., -60dBm) or the interference probability is higher than a first probability threshold (e.g., 30%), then the interference severity is determined and the target communication node needs to be switched to a low-speed transmission mode.

[0093] In other implementations, if the signal strength is below a second strength threshold (e.g., -80dBm) and the interference probability is below a second probability threshold (e.g., 10%), the interference is determined to be mild, and the original adaptive high-speed transmission strategy of the target communication node can be maintained (i.e., low-speed mode is not enabled).

[0094] In some other implementations, if the interference parameter is in the middle range, the CCO may choose the default conservative strategy (enabling low-speed mode) or further combine other factors (such as business priority) for a comprehensive judgment.

[0095] The CCO sends the decision result (whether to enable low-speed mode) to the target communication node via unicast signaling. If the decision is to enable, the target communication node transmits signals according to the parameters of the corresponding low-speed mode; if the decision is to disable, the target communication node can continue to use the adaptive transmission strategy based on the channel sounding results.

[0096] In the above embodiments, by introducing an interference parameter measurement and decision-making mechanism, the on-demand activation of the low-speed transmission mode is achieved, avoiding the spectral efficiency loss caused by indiscriminate speed reduction on all newly added frequency bands. When the actual interference of communication nodes in the old distribution area on the newly added frequency band is small, the communication nodes in the new distribution area can still maintain high-speed adaptive transmission; when the interference is severe, timely switching to the low-speed mode can effectively improve the overall throughput and spectrum utilization of the system, and improve the reliability of communication.

[0097] In master-slave mode scenarios, because communication nodes in older distribution areas cannot recognize the preamble of newly added frequency bands and therefore fail to back off, channel probing results are severely distorted. Therefore, it is necessary to restrict adaptive transmission strategies and force low-speed transmission to ensure reliability. However, when the network is deployed in orthogonal mode (different frequency bands are completely separated with no frequency overlap) or single-band mode (the entire network uses the same frequency band), there is no energy leakage or mutual interference between frequency bands, and channel probing results can accurately reflect channel quality. If the adaptive capabilities of new distribution area nodes are still indiscriminately restricted in these modes, unnecessary spectral efficiency losses will occur even under good channel conditions.

[0098] Based on this, in some embodiments, after restricting the target communication node from executing an adaptive transmission strategy based on the channel detection results of the newly added frequency band, when the frequency band mode of the target communication node is orthogonal mode or single-band mode, the target communication node removes the restriction on the adaptive transmission strategy executed based on the channel detection results.

[0099] The frequency band mode of the communication network segment where the target communication node is located is pre-configured by the CCO, and the mode information is communicated to each node via broadcast or unicast signaling. After completing the initial transmission strategy adjustment for the target communication node (i.e., restricting its adaptive strategy based on channel probing results), the CCO further determines the frequency band mode of the current network segment.

[0100] In some implementations, if the CCO determines that the current frequency band mode is orthogonal mode or single-band mode, the CCO issues a de-restriction command to the target communication node. Upon receiving the command, the target communication node immediately removes the restriction on the adaptive transmission strategy and resumes using functions such as modulation and coding scheme prediction, bit loading, and OFDMA subcarrier allocation based on channel sounding results. If the CCO determines that the current frequency band mode is master-slave mode (with overlap between frequency bands), it maintains the original restriction status, continues to prohibit the target communication node from executing the adaptive strategy, and maintains the low-speed transmission mode.

[0101] In other implementations, after the CCO completes the initial transmission strategy adjustment of the target communication node (i.e., prohibits it from using the adaptive strategy based on channel detection results), it further instructs the target communication node to periodically send detection signals on the newly added frequency band and starts receiving and listening, attempting to capture the signal characteristics of communication nodes in the old station area on the newly added frequency band.

[0102] For example, the target communication node can perform preamble correlation detection on the received signal in real time and compare it with the synchronization sequence (i.e., the original phase rotation factor) corresponding to the communication node in the old distribution area. If the signal characteristics of the communication node in the old distribution area are not matched within a preset detection time (e.g., 30 seconds), it is determined that there are no active communication nodes in the old distribution area on the newly added frequency band, or that the old distribution area nodes have stopped communicating. Based on this, the target communication node can remove the restriction on the adaptive transmission strategy and restore the function based on the channel detection results. If the signal characteristics of the communication node in the old distribution area are detected again later, the target communication node can perform transmission strategy adjustment again, that is, re-restrict the adaptive strategy and perform low-speed transmission, etc.

[0103] In the above embodiments, by removing the restrictions of the adaptive transmission strategy according to different frequency band modes, the spectral efficiency loss caused by indiscriminate speed reduction in non-overlapping or single-band scenarios is effectively avoided. In orthogonal mode and single-band mode, since there is no cross-band interference, the channel detection results are accurate and reliable. After the restrictions are removed, the target communication node can resume high-speed adaptive transmission, making full use of channel conditions to improve throughput, and improving the overall spectral utilization and transmission efficiency in multi-band deployment scenarios.

[0104] In scenarios involving newly added frequency bands, communication nodes within the new distribution area not only need to adjust their signal transmission modes but also periodically send beacon messages and discovery list messages to maintain PLC network synchronization. If all communication nodes send these management messages at the same frequency, it may introduce additional collisions on the new frequency band. Especially when communication nodes in the old distribution area do not back off, the loss of management messages will further affect the stability of the PLC network.

[0105] Based on this, in some embodiments, the transmission strategy of the target communication node that enables communication in the new frequency band is adjusted, which further includes: controlling the target communication node to send beacon messages and discovery list messages on the original frequency band and the new frequency band according to the message sending ratio, wherein the message sending ratio is dynamically adjusted according to the channel communication quality between the target communication node and the associated node; wherein the beacon message sending frequency on the original frequency band remains unchanged.

[0106] Beacon messages are management frames periodically broadcast by the CCO (Control Center Operator) to announce the existence of the PLC network, synchronize PLC network time, transmit network parameters, and schedule beacon time slot information. Discovery list messages are management frames used by communication nodes to discover and detect neighboring networks, maintaining network topology. Furthermore, the message transmission ratio refers to the proportion of beacon messages and discovery list messages allocated by the target communication node to the existing frequency band and the newly added frequency band per unit time. For example, a message transmission ratio of 60%:40% could mean 60% of management messages are transmitted on the existing frequency band and 40% on the newly added frequency band. Associated nodes are superior nodes that have a direct communication relationship with the target communication node, such as the CCO or PCO.

[0107] The Control Center (CCO) obtains channel communication quality parameters between the target communication node and its associated nodes based on existing channel sounding results, message reception success rate, or signal-to-noise ratio (SNR), and determines the message transmission ratio according to the obtained channel communication quality parameters. In some implementations, when the target communication node has good channel quality on the newly added frequency band (e.g., high received signal strength and low packet error rate), the CCO can instruct the target communication node to increase the proportion of management messages transmitted on the newly added frequency band, while correspondingly reducing the transmission ratio on the original frequency band. When the channel quality on the newly added frequency band is poor, the transmission ratio on the newly added frequency band is reduced, and more management messages are retained for transmission on the original frequency band.

[0108] In other implementations, the CCO presets an initial message transmission ratio, setting the ratio between the existing frequency band and the new frequency band to a default value (e.g., a first ratio higher than a second ratio). The CCO monitors the channel communication quality of the target communication node on the new frequency band and compares it with the channel quality of the existing frequency band. When it detects that the channel quality of the new frequency band is better than that of the existing frequency band, and the quality difference between the two exceeds a preset switching threshold, the CCO gradually adjusts the message transmission ratio to increase the transmission share on the new frequency band. In feasible implementations, the adjustment of the transmission ratio can be carried out in stages, with each stage increasing or decreasing a fixed percentage step until a set upper or lower limit is reached.

[0109] When the channel quality of the newly added frequency band continues to deteriorate and fails to meet the quality requirements in multiple consecutive detection cycles, it is determined that the frequency band is no longer suitable for transmitting management messages, and the message transmission ratio is restored to the initial state.

[0110] For example, the dynamic adjustment of the message transmission ratio can be based on a default ratio of 70%:30% for the original frequency band and 30%:30% for the new frequency band. If the channel quality on the new frequency band is better than that on the original frequency band and the difference exceeds a preset threshold, the ratio will be adjusted to 50%:50% or 30%:70%. If the quality of the new frequency band continues to deteriorate (e.g., consecutive detection failures within a threshold number), the ratio will be restored to 100%:0%, meaning all management messages will be transmitted on the original frequency band. After this, the CCO will send the adjusted ratio to the target communication node via configuration signaling, and the node will then transmit management messages proportionally on the specified frequency band.

[0111] It should be noted that the beacon message transmission frequency on the existing frequency band remains unchanged. This is because beacon messages carry PLC network synchronization and basic management information, and the original time base and transmission cycle must be maintained to ensure that communication nodes in the old distribution area and those that do not support the new frequency band can receive them normally. The transmission frequency of discovery list messages can be adjusted proportionally, but the beacon frequency will not be reduced.

[0112] In the above embodiments, by adjusting the frequency band allocation ratio of management messages, the balance between network management overhead and channel adaptability is optimized. When the channel quality of the newly added frequency band is excellent, migrating more management messages to the new frequency band can reduce the load on the original frequency band and lower the probability of collisions on the original frequency band. When the quality of the new frequency band deteriorates, management messages are automatically reverted to the original frequency band, ensuring reliable transmission of management information and preventing network fragmentation due to lost management messages. Furthermore, maintaining the original beacon frequency ensures that communication nodes within the old distribution area and network-wide synchronization remain unaffected, demonstrating strong practicality and flexibility.

[0113] In scenarios involving newly added frequency bands, communication nodes in older distribution areas may fail to recognize the signals of newer nodes and thus fail to trigger backoff. During channel probing, the probe signals from newer nodes may collide with signals from older distribution areas, leading to lost probe feedback or measurements that significantly deviate from the true channel conditions. Directly using such distorted probe results for transmission strategy decisions can result in misjudgments. However, not all probe results are entirely unreliable. A high success rate indicates fewer actual collisions, and the probe results still have reference value.

[0114] Based on this, in some embodiments, when communication nodes in the new substation area need to communicate on the newly added frequency band, and the newly added frequency band overlaps with the original frequency band, the channel detection success rate of the target communication node is obtained, and the credibility of the channel detection result is determined based on the channel detection success rate; when the credibility is lower than the credibility threshold, the transmission strategy of the target communication node on the newly added frequency band is adjusted.

[0115] Channel detection success rate refers to the proportion of a target communication node that successfully receives a detection response or successfully completes a channel measurement sample after sending a detection request on a newly added frequency band. Credibility characterizes the degree to which the channel detection results accurately reflect channel quality. Generally, credibility is positively correlated with channel detection success rate; a higher success rate indicates less impact from sudden interference during the detection process, leading to more reliable results. Conversely, a lower success rate indicates more outliers caused by interference in the detection results, resulting in lower credibility.

[0116] The credibility threshold refers to a preset credibility threshold value (e.g., 70% or 80%). When the credibility is lower than this threshold, the CCO determines that the current channel detection result is unreliable and needs to initiate transmission strategy adjustment; conversely, transmission strategy adjustment can be initiated if the credibility is higher than this threshold.

[0117] The CCO instructs the target communication node to perform periodic channel probing on the newly added frequency band. It instructs the communication node to send a probe request frame and wait to receive a response frame or measure channel quality parameters (such as received signal strength, signal-to-noise ratio, etc.). It also counts the number of successful probes within a preset time window (e.g., 100 probes) and calculates the channel probing success rate.

[0118] In some implementations, the Control Center (CCO) can directly set the confidence level equal to the channel detection success rate. When the confidence level is greater than or equal to a confidence threshold, the CCO determines that the current channel detection result has high reference value and can continue to execute the adaptive transmission strategy based on the detection result. When the confidence level is less than the confidence threshold, the CCO determines that the current channel detection result triggers a transmission strategy adjustment, restricting the target communication node's adaptive transmission strategy based on the channel detection result and adjusting the signal transmission mode to a low-speed transmission mode. The details of the transmission strategy adjustment have been described in the aforementioned embodiments and will not be repeated here.

[0119] In other implementations, to avoid frequent switching due to short-term fluctuations, the CCO can set a hysteresis mechanism, for example, triggering an adjustment only when the confidence level falls below the threshold three times in a row; and releasing the adjustment when the confidence level recovers to above the threshold three times in a row.

[0120] In the above embodiments, by introducing a reliable quantification method based on channel detection success rate, a more accurate triggering basis is provided for transmission strategy adjustment, avoiding the efficiency loss caused by indiscriminately forcing low speed or blindly adhering to adaptive mode. When the actual interference is relatively mild (the detection success rate is still relatively high), communication nodes in the new substation area can continue to use adaptive high-speed transmission to make full use of spectrum resources; when the interference is severe and the detection success rate drops significantly, it automatically switches to low-speed robust mode to ensure communication reliability and has good stability.

[0121] In PLC networks, the frequency overlap between newly added and existing frequency bands can vary significantly depending on the band definition. For example, the overlap between band 4 (0.781 MHz to 5.615 MHz) and existing frequency bands (such as band 2, 0.781 MHz to 2.930 MHz) is only a portion of the existing band; while the overlap between band 5 (0.781 MHz to 11.96 MHz) and existing frequency bands almost covers the entire existing band. Generally, the larger the overlap ratio, the higher the probability that communication nodes in the new distribution area will experience interference from communication nodes in the old distribution area when communicating on the newly added frequency band. This is because the activities of communication nodes in the old distribution area during the overlap directly affect the signals of communication nodes in the new distribution area. If a low-speed mode is adopted indiscriminately, transmission efficiency will be unnecessarily sacrificed on newly added frequency bands with a small overlap ratio.

[0122] Based on this, in some embodiments, when communication nodes in the new substation area need to communicate on the new frequency band, and the new frequency band overlaps with the original frequency band, the bandwidth ratio between the new frequency band and the current communication frequency band of the target communication node is determined; when the bandwidth ratio exceeds the ratio threshold, the transmission strategy of the target communication node on the new frequency band is adjusted.

[0123] The current communication frequency band refers to the original frequency band that the target communication node is using before the new frequency band is enabled (i.e., the frequency band supported by the old station area node).

[0124] The bandwidth ratio refers to the ratio of the frequency width of the overlapping portion between the newly added frequency band and the current communication frequency band to the total frequency width of the current communication frequency band, reflecting the degree to which the newly added frequency band encroaches on the current communication frequency band.

[0125] Correspondingly, the ratio threshold refers to a preset critical value (e.g., 30% or 50%). When the bandwidth ratio exceeds this threshold, the CCO considers the overlap to be severe and needs to initiate transmission strategy adjustment. (When the ratio is below the threshold, the overlap is mild and the adaptive strategy can continue to be used.)

[0126] The CCO (Control Center Operator) pre-determines the frequency range of each band based on the band allocation table (e.g., the definition of bands 0-7). When the CCO identifies a new substation node that needs to activate a new band (e.g., band 4 or band 5), it first queries the frequency range between the new band and the node's currently used band (e.g., band 1 or band 2). Afterward, the CCO calculates the frequency intersection of the two bands to obtain the overlap width. Then, it calculates the bandwidth ratio; finally, it compares the calculated bandwidth ratio with a preset ratio threshold (e.g., 30%).

[0127] For example, when the ratio threshold is set to 30%, if the bandwidth ratio is greater than 30%, it is determined that the overlap is significant, and the activity of communication nodes in the old area is likely to interfere with the communication nodes in the new area, thus triggering the transmission strategy adjustment; if it is less than or equal to 30%, it is considered that the overlap is slight, and most of the newly added frequency bands are far from the original frequency bands, so the target communication node can continue to use the adaptive high-speed transmission strategy based on the channel detection results.

[0128] In the above embodiments, by introducing a judgment based on bandwidth ratio, a simple and efficient triggering mechanism is provided for transmission strategy adjustment that does not require real-time detection and only relies on static frequency band configuration. Compared with indiscriminate speed reduction, it can significantly improve the overall spectrum efficiency of the network.

[0129] The multi-band transmission control method for power line communication networks provided in this embodiment of the invention can be executed by a multi-band transmission control device for power line communication networks. This embodiment of the invention uses the execution of the multi-band transmission control method for power line communication networks by a multi-band transmission control device as an example to illustrate the multi-band transmission control device for power line communication networks provided in this embodiment of the invention.

[0130] Figure 4 This is a schematic diagram of the structure of a multi-band transmission control device for a power line communication network provided in some embodiments of the present invention. For example... Figure 4 As shown, the multi-band transmission control device for the power line communication network includes: transmission module 401.

[0131] Transmission module 401 is used to adjust the transmission strategy of the target communication node that needs to communicate on a new frequency band in the new substation area, where the new frequency band overlaps with the existing frequency band. This adjustment includes: The target communication node is restricted from implementing an adaptive transmission strategy based on the channel detection results of the newly added frequency band; Adjust the signal transmission mode of the target communication node on the newly added frequency band to a low-speed transmission mode.

[0132] The multi-band transmission control device for power line communication networks provided in this embodiment of the invention adjusts the transmission strategy of the target communication node when it detects that a communication node in a new distribution area needs to communicate on a newly added frequency band that overlaps with the existing frequency band. This effectively avoids problems such as inaccurate channel detection results, misjudgment of transmission strategies, and decreased communication reliability caused by communication nodes in the old distribution area being unable to identify signals in the newly added frequency band. This significantly improves communication reliability under the newly added frequency band and enables stable coexistence of communication nodes in both the old and new distribution areas. Furthermore, since communication nodes in the old distribution area cannot perform carrier sense backoff on signals in the newly added frequency band, unpredictable burst interference may be mixed into the channel detection results. By restricting the target communication node from executing an adaptive transmission strategy based on the channel detection results of the newly added frequency band, misadjustments caused by inaccurate detection results can be effectively avoided, making transmission decisions more deterministic and resistant to interference. Meanwhile, since the signals of communication nodes in the new distribution area may be interfered with by communication nodes in the old distribution area at any time, by adjusting the signal transmission mode of the target communication node on the new frequency band to a low-speed transmission mode, the robustness of the signal in the interference environment can be significantly enhanced, the number of retransmissions can be reduced, thereby improving the signal transmission success rate and link stability on the new frequency band.

[0133] In some embodiments, the transmission module is further configured to instruct the target communication node to send a detection signal on the newly added frequency band to detect the signal characteristics of the communication nodes in the old distribution area; when no signal characteristics are detected within the detection time, the restriction of the adaptive transmission strategy executed by the target communication node based on the channel detection results is lifted.

[0134] In some embodiments, the transmission module is further configured to instruct the target communication node to perform signal transmission using a bit loading mode on the newly added frequency band; or to instruct the target communication node to perform subcarrier allocation on the newly added frequency band according to the OFDMA strategy.

[0135] In some embodiments, the transmission module is further configured to acquire interference parameters of communication nodes in the old distribution area on the newly added frequency band, the interference parameters including the signal strength and / or interference probability of the communication nodes in the old distribution area; and determine, based on the interference parameters, whether to adjust the signal transmission mode of the target communication node on the newly added frequency band to a low-speed transmission mode.

[0136] In some embodiments, the transmission module is further configured to control the target communication node to send beacon messages and discovery list messages on the original frequency band and the newly added frequency band respectively according to the message sending ratio, wherein the message sending ratio is dynamically adjusted according to the channel communication quality between the target communication node and the associated node; wherein the beacon message sending frequency on the original frequency band remains unchanged.

[0137] In some embodiments, the transmission module is further configured to obtain the channel detection success rate of the target communication node and determine the credibility of the channel detection result based on the channel detection success rate; when the credibility is lower than the credibility threshold, the transmission strategy of the target communication node on the newly added frequency band is adjusted.

[0138] In some embodiments, the transmission module is further configured to determine the bandwidth ratio between the newly added frequency band and the current communication frequency band of the target communication node; when the bandwidth ratio exceeds the ratio threshold, the transmission strategy of the target communication node on the newly added frequency band is adjusted.

[0139] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0140] The multi-band transmission control device for the power line communication network in this embodiment of the invention can be an electronic device or a component within an electronic device, such as an integrated circuit or a chip. This electronic device can be a terminal or other devices besides a terminal, such as a server.

[0141] The multi-band transmission control device for power line communication networks provided in this embodiment of the invention can realize the various processes implemented in the above-described embodiments of the multi-band transmission control method for power line communication networks. To avoid repetition, these processes will not be described again here.

[0142] In some embodiments, Figure 5 These are schematic diagrams of the structure of an electronic device provided in some embodiments of the present invention. For example... Figure 5 As shown, this embodiment of the invention also provides an electronic device 500, including a processor 501, a memory 502, and a computer program stored in the memory 502 and executable on the processor 501. When the program is executed by the processor 501, it implements the various processes of the above-described embodiment of the multi-band transmission control method for power line communication networks and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0143] This invention provides a non-transitory computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the various processes of the above-described multi-band transmission control method embodiment for power line communication networks and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0144] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable media, such as computer read-only memory (ROM), random-access memory (RAM), magnetic disks, or optical disks.

[0145] The computer-readable storage medium may include: read-only memory (ROM), random-access memory (RAM), magnetic disk or optical disk, etc.

[0146] This invention provides a computer program product, including a computer program that, when executed by a processor, implements the multi-band transmission control method for the power line communication network described above.

[0147] This invention provides a chip that includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described multi-band transmission control method embodiment for power line communication networks, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0148] It should be understood that the chip mentioned in the embodiments of the present invention may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0149] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of the present invention is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0150] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the related technology, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0151] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

[0152] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0153] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A multi-band transmission control method for a power line communication network, characterized in that, The power line communication network has at least one new transformer substation and one old transformer substation. Communication nodes in the new substation support communication on newly added frequency bands, while communication nodes in the old substation only support communication on existing frequency bands. The method includes: When communication nodes within the new distribution area need to communicate on the newly added frequency band, and the newly added frequency band overlaps with the existing frequency band, the transmission strategy for the target communication node enabling communication on the newly added frequency band will be adjusted, including: The target communication node is restricted from executing an adaptive transmission strategy based on the channel detection results of the newly added frequency band; The target communication node adjusts its signal transmission mode on the newly added frequency band to a low-speed transmission mode.

2. The multi-band transmission control method for power line communication networks according to claim 1, characterized in that, The newly added frequency band and the original frequency band are in master-slave mode, and the phase rotation factor of the synchronization sequence of the newly added frequency band is different from that of the synchronization sequence of the original frequency band.

3. The multi-band transmission control method for power line communication networks according to claim 1 or 2, characterized in that, When the newly added frequency band and the existing frequency band are in master-slave mode, and there are a total of 2 communication frequency bands in master-slave mode, the communication nodes in the new substation area transmit signals on their respective corresponding communication frequency bands; wherein, the preamble, frame control field and frame payload field of the signal are transmitted on the same communication frequency band. When the total number of communication frequency bands in master-slave mode exceeds two, the communication nodes in the new substation area corresponding to the newly added frequency band will send the preamble and frame control field of the signal on the same communication frequency band, and the frame payload field of the signal will be sent on their respective communication frequency bands.

4. The multi-band transmission control method for power line communication networks according to claim 1 or 2, characterized in that, After the method restricts the target communication node from executing an adaptive transmission strategy based on the channel detection results of the newly added frequency band, the method further includes: when the frequency band mode of the target communication node is orthogonal mode or single-band mode, the target communication node removes the restriction on the adaptive transmission strategy executed based on the channel detection results.

5. The multi-band transmission control method for power line communication networks according to claim 1, characterized in that, The adaptive transmission strategy includes at least one of the following: Instruct the target communication node to use a bit-loaded mode for signal transmission on the newly added frequency band; or The target communication node is instructed to allocate subcarriers on the newly added frequency band according to the OFDMA strategy.

6. The multi-band transmission control method for power line communication networks according to claim 1, characterized in that, The low-speed transmission mode includes: signal modulation based on BPSK modulation with a diversity number of no less than 2 times; or signal modulation based on QPSK modulation with a diversity number of no less than 4 times.

7. The multi-band transmission control method for power line communication networks according to claim 1 or 6, characterized in that, The method further includes: Obtain the interference parameters of the communication nodes in the old distribution area on the newly added frequency band, the interference parameters including the signal strength and / or interference probability of the communication nodes in the old distribution area; Based on the interference parameters, determine whether to adjust the signal transmission mode of the target communication node on the newly added frequency band to a low-speed transmission mode.

8. The multi-band transmission control method for power line communication networks according to claim 1, characterized in that, The adjustment of the transmission strategy for the target communication node that enables communication on the newly added frequency band also includes: The target communication node is controlled to send beacon messages and discovery list messages on the original frequency band and the newly added frequency band respectively according to the message sending ratio. The message sending ratio is dynamically adjusted according to the channel communication quality between the target communication node and the associated node. The frequency of beacon message transmission on the original frequency band remains unchanged.

9. The multi-band transmission control method for power line communication networks according to claim 1, characterized in that, When communication nodes within the new distribution area need to communicate on the newly added frequency band, and the newly added frequency band overlaps with the existing frequency band, the method further includes: Obtain the channel detection success rate of the target communication node, and determine the reliability of the channel detection result based on the channel detection success rate; When the credibility is lower than the credibility threshold, the transmission strategy of the target communication node on the newly added frequency band is adjusted.

10. The multi-band transmission control method for power line communication networks according to claim 1, characterized in that, When communication nodes within the new distribution area need to communicate on the newly added frequency band, and the newly added frequency band overlaps with the existing frequency band, the method further includes: Determine the bandwidth ratio between the newly added frequency band and the current communication frequency band of the target communication node; When the bandwidth ratio exceeds the ratio threshold, the transmission strategy of the target communication node on the newly added frequency band is adjusted.

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