Disclosure of Invention
In view of the above, the present invention has been made to provide a coverage adaptive adjustment method, apparatus, computer storage medium and device that overcome or at least partially solve the above problems.
In one aspect of the present invention, a coverage adaptive adjustment method is provided, including:
monitoring KPI information of each user terminal in the process of random access, and counting access success rate corresponding to each coverage enhancement grade according to the coverage enhancement grade of each user terminal and corresponding KPI information;
judging whether each coverage enhancement grade meets a preset self-adaptive adjustment condition or not according to the access success rate corresponding to each coverage enhancement grade;
and adjusting the coverage range of the coverage enhancement grade meeting the self-adaptive adjustment condition.
Optionally, the determining whether each coverage enhancement level meets a preset adaptive adjustment condition according to the access success rate corresponding to each coverage enhancement level includes:
respectively judging whether the access success rate corresponding to each coverage enhancement grade is greater than a preset first threshold value or less than a preset second threshold value, wherein the first threshold value is greater than or equal to the second threshold value;
and if the access success rate corresponding to the coverage enhancement grade is larger than the first threshold value or smaller than the second threshold value, determining that the corresponding coverage enhancement grade meets the preset self-adaptive adjustment condition.
Optionally, the method further comprises:
the values of the first threshold values corresponding to different coverage enhancement levels are different, and/or
And the values of the second threshold values corresponding to different coverage enhancement levels are different.
Optionally, the performing coverage adjustment on the coverage enhancement level meeting the adaptive adjustment condition includes:
when the access success rate corresponding to the coverage enhancement grade is larger than the first threshold value, the coverage range of the corresponding coverage enhancement grade is enlarged;
and when the access success rate corresponding to the coverage enhancement grade is smaller than the second threshold value, reducing the coverage range of the corresponding coverage enhancement grade.
Optionally, the performing coverage adjustment on the coverage enhancement level meeting the adaptive adjustment condition further includes:
and reducing the coverage range of the corresponding coverage enhancement grade or expanding the coverage range of the corresponding coverage enhancement grade according to the preset adjustment granularity.
Optionally, before performing coverage adjustment on the coverage enhancement level satisfying the adaptive adjustment condition, the method further includes:
judging whether the current coverage range meeting the coverage enhancement grade of the self-adaptive adjustment condition is within a preset threshold interval or not;
and if the current coverage range of the coverage enhancement grade meeting the self-adaptive adjustment condition is not in the threshold interval, abandoning the coverage range adjustment operation.
In another aspect of the present invention, there is provided a coverage adaptive adjusting apparatus, including:
the KPI counting module is used for monitoring KPI information of each user terminal in the process of random access, and counting the access success rate corresponding to each coverage enhancement grade according to the coverage enhancement grade of each user terminal and the corresponding KPI information;
the judgment management module is used for judging whether each coverage enhancement grade meets the preset self-adaptive adjustment condition according to the access success rate corresponding to each coverage enhancement grade;
and the coverage grade management module is used for adjusting the coverage range of the coverage enhancement grade meeting the self-adaptive adjustment condition.
Optionally, the decision management module is specifically configured to respectively determine whether an access success rate corresponding to each coverage enhancement level is greater than a preset first threshold or smaller than a preset second threshold, where the first threshold is greater than or equal to the second threshold; and if the access success rate corresponding to the coverage enhancement grade is larger than the first threshold value or smaller than the second threshold value, determining that the corresponding coverage enhancement grade meets the preset self-adaptive adjustment condition.
Optionally, the coverage level management module is configured to, when the access success rate corresponding to the coverage enhancement level is greater than the first threshold, expand a coverage range of the corresponding coverage enhancement level; and when the access success rate corresponding to the coverage enhancement grade is smaller than the second threshold value, reducing the coverage range of the corresponding coverage enhancement grade.
Furthermore, the invention also provides a computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method as described above.
Furthermore, the present invention also provides an apparatus comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the steps of the method as described above when executing the program.
The coverage adaptive adjustment method, the coverage adaptive adjustment device, the computer storage medium and the equipment provided by the embodiment of the invention can adaptively adjust the coverage of the coverage grade according to the user access success rate of the coverage corresponding to different coverage enhancement grades after the NB-IoT base station is started, ensure the maximum utilization of the base station resources occupied by the users falling into each coverage grade, and avoid the problems that the users with good signal quality occupy the base station resources for a long time due to unreasonable setting of different coverage grade thresholds, other users cannot be scheduled, and the resource utilization rate is low.
The invention can not only improve the access success rate in the coverage range of each coverage enhancement grade, enhance the resource utilization rate in each coverage grade in the base station cell, but also ensure that the terminal saves more electricity and improves the performance of the system.
The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.
Detailed Description
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Fig. 1 is a schematic diagram of a network architecture to which the method provided in the embodiment of the present invention is applied. Referring to fig. 1, the system architecture includes:
NB-IoT MME (NB-IoT type MME): responsible for signaling interaction between NB-IoT type user terminals and the core network, unlike LTE type MMEs.
UE (User Equipment, User terminal): NB-IoT signals are accepted and processed.
NB-IoT base station (NB-IoT type base station): the method is responsible for scheduling and managing NB-IoT wireless resources, maintaining the resource configuration of the terminal in the base station and signaling interaction between the terminal and the MME.
Fig. 2 is a flowchart of a coverage adaptive adjustment method according to an embodiment of the present invention. Referring to fig. 2, the coverage adaptive adjustment method of the embodiment of the present invention specifically includes the following steps:
s11, monitoring KPI information of each user terminal in the process of random access, and counting access success rate corresponding to each coverage enhancement grade according to the coverage enhancement grade of each user terminal and corresponding KPI information.
In practical applications, NB-IoT base stations generally have three coverage levels, such as CE0, CE1, and CE 2.
In the embodiment of the invention, an NB-IoT base station sends downlink System Information to establish an initial coverage range, such as CE0, CE1 and CE 2; the UE within each coverage class range determines the coverage class in which it is located according to the received RSRP (Reference Signal Receiving Power) value in combination with the threshold parameter RSRP-threshold prachlnfolist-r 13 configured by the system information. The parameter rsrp-threshold prachinfolist determines the decision thresholds of different levels of coverage enhancement, and the UE decides the random grade number through the rsrp-threshold prachinfolist. A user terminal UE initiates a Random Access process by using a corresponding PRACH (Physical Random Access Channel) parameter NPRACH-Parameters-NB-r13 under the coverage level of the user terminal UE; when detecting preamble information of a PRACH (Physical Random Access Channel), the NB-IoT base station allocates scheduled resources to the UE, and completes the entire Random Access process. And the NB-IoT base station is responsible for monitoring KPI information of the user terminal in the random access process under each coverage enhancement grade, and further counting information such as access success rate and the like in each coverage enhancement grade.
The KPI information in this embodiment refers to key indicator information for evaluating an access success rate in a random access process. Specifically, the information may include information such as CRC cyclic check result and access result identification parameter in the random access process.
And S12, judging whether each coverage enhancement grade meets the preset self-adaptive adjustment condition according to the access success rate corresponding to each coverage enhancement grade.
In the embodiment of the present invention, the determination of the adaptive adjustment condition may be implemented by a preset threshold value. Specifically, when a certain threshold value is reached, it is determined that a preset adaptive adjustment condition is satisfied, at this time, an adjustment event is triggered, and the content of the event includes enlarging or reducing the coverage of a certain coverage enhancement level.
And S13, performing coverage range adjustment on the coverage enhancement level meeting the adaptive adjustment condition.
In the embodiment of the present invention, after the coverage is adjusted, the rsrp-threshold prachinfolist-r13 parameter of the system information needs to be modified, and new system information is re-encoded to be sent to the user terminal, so that the whole adaptive adjustment process is finished.
The coverage range self-adaptive adjusting method provided by the embodiment of the invention can self-adaptively adjust the coverage range of the coverage grade according to the access success rate of the users corresponding to the coverage ranges of different coverage enhancement grades after the NB-IoT base station is started, ensure the maximized utilization of the base station resources occupied by the users falling into each coverage grade, and avoid the problems that the users with good signal quality occupy the base station resources for a long time, other users cannot be scheduled and the resource utilization rate is low because the thresholds of different coverage grades are unreasonable set.
In this embodiment of the present invention, the determining whether each coverage enhancement level meets the preset adaptive adjustment condition according to the access success rate corresponding to each coverage enhancement level in step S12 specifically includes the following implementation steps: respectively judging whether the access success rate corresponding to each coverage enhancement grade is greater than a preset first threshold value or less than a preset second threshold value, wherein the first threshold value is greater than or equal to the second threshold value; and if the access success rate corresponding to the coverage enhancement grade is larger than the first threshold value or smaller than the second threshold value, determining that the corresponding coverage enhancement grade meets the preset self-adaptive adjustment condition.
Specifically, in consideration of the specific situation of the actual application scenario, in a specific example, the values of the first threshold values corresponding to different coverage enhancement levels are different, and/or the values of the second threshold values corresponding to different coverage enhancement levels are different.
Further, for the coverage enhancement level satisfying the adaptive adjustment condition, the specific implementation steps of adjusting the coverage range thereof are as follows: when the access success rate corresponding to the coverage enhancement grade is larger than the first threshold value, the coverage range of the corresponding coverage enhancement grade is enlarged; and when the access success rate corresponding to the coverage enhancement grade is smaller than the second threshold value, reducing the coverage range of the corresponding coverage enhancement grade. In the specific adjustment process, the coverage of the corresponding coverage enhancement level may be reduced or expanded according to a preset adjustment granularity.
In the embodiment of the present invention, before performing coverage adjustment on the coverage enhancement level satisfying the adaptive adjustment condition, it may be further determined whether a current coverage of the coverage enhancement level satisfying the adaptive adjustment condition is within a preset threshold interval, if the current coverage of the coverage enhancement level satisfying the adaptive adjustment condition is within the threshold interval, the coverage adjustment is performed on the coverage enhancement level satisfying the adaptive adjustment condition, and if the current coverage of the coverage enhancement level satisfying the adaptive adjustment condition is not within the threshold interval, the coverage adjustment operation is abandoned. The specific threshold intervals (upper limit and lower limit) corresponding to each coverage grade can be different, so that the condition of unreasonable adjustment is prevented.
Specifically, coverage adjustment of different coverage enhancement levels can be realized by setting an RSRP threshold value.
In the embodiment of the invention, before the coverage range adjustment is executed, whether the self-adaptive adjustment function is started is firstly judged, and if the self-adaptive adjustment function is not started, the communication is realized according to the prior art. Specifically, in practical application, the adaptive function can be turned off and on at any time.
Compared with the prior art, the coverage range self-adaptive adjusting method provided by the invention has the following advantages and beneficial effects:
through counting KPI information in the coverage range, information such as access success rate in each coverage grade can be accurately mastered, event judgment can be carried out aiming at each coverage grade, the information is accurate, and errors are not easy to occur.
Statistics is that the access conditions of all UE in each coverage grade are counted, the judgment is carried out according to all UE access information, overall optimization can be carried out according to the dimensionality of the coverage grade, the optimization purpose is achieved, resources in the base station can be well overall adjusted, and each coverage grade has a good access KPI under reasonable resource configuration.
By planning the configuration resources of the UE within the coverage grade range, the UE in the base station can use more optimized parameters, uses less repetition times and saves more electricity.
For simplicity of explanation, the method embodiments are described as a series of acts or combinations, but those skilled in the art will appreciate that the embodiments are not limited by the order of acts described, as some steps may occur in other orders or concurrently with other steps in accordance with the embodiments of the invention. Further, those skilled in the art will appreciate that the embodiments described in the specification are presently preferred and that no particular act is required to implement the invention.
Fig. 3 schematically shows a structural diagram of a coverage adaptive adjusting apparatus according to an embodiment of the present invention. Referring to fig. 3, the coverage adaptive adjusting apparatus in the embodiment of the present invention specifically includes a KPI statistics module 201, a decision management module 202, and a coverage level management module 203, where:
a KPI statistics module 201, configured to monitor KPI information of each user terminal in a random access process, and count an access success rate corresponding to each coverage enhancement level according to a coverage enhancement level to which each user terminal belongs and corresponding KPI information;
a decision management module 202, configured to determine whether each coverage enhancement level meets a preset adaptive adjustment condition according to an access success rate corresponding to each coverage enhancement level;
and the coverage level management module 203 is configured to perform coverage range adjustment on the coverage enhancement level meeting the adaptive adjustment condition.
In this embodiment of the present invention, the decision management module 202 is specifically configured to respectively determine whether an access success rate corresponding to each coverage enhancement level is greater than a preset first threshold or smaller than a preset second threshold, where the first threshold is greater than or equal to the second threshold; and if the access success rate corresponding to the coverage enhancement grade is larger than the first threshold value or smaller than the second threshold value, determining that the corresponding coverage enhancement grade meets the preset self-adaptive adjustment condition.
The values of the first threshold values corresponding to different coverage enhancement levels are different; and/or the values of the second threshold values corresponding to different coverage enhancement levels are different.
In this embodiment of the present invention, the coverage level management module 203 is specifically configured to, when the access success rate corresponding to the coverage enhancement level is greater than the first threshold, expand the coverage range of the corresponding coverage enhancement level; and when the access success rate corresponding to the coverage enhancement grade is smaller than the second threshold value, reducing the coverage range of the corresponding coverage enhancement grade. Specifically, the coverage of the corresponding coverage enhancement level may be reduced or expanded according to a preset adjustment granularity.
In this embodiment of the present invention, the decision management module 202 is further configured to, before the coverage level management module performs coverage range adjustment on the coverage enhancement level meeting the adaptive adjustment condition, determine whether a current coverage range of the coverage enhancement level meeting the adaptive adjustment condition is within a preset threshold interval; and if the current coverage range of the coverage enhancement grade meeting the self-adaptive adjustment condition is not in the threshold interval, abandoning the coverage range adjustment operation.
The coverage area adaptive adjusting device provided in the embodiment of the present invention includes, in addition to the KPI statistics module 201, the decision management module 202, and the coverage level management module 203, a random access module, a system information module, and a data processing module, which are not shown in the drawings.
In the coverage area adaptive adjusting device provided by the embodiment of the invention:
a random access module: receiving and processing preamble information reported by UE, distributing related resources of the UE random access process, and completing the random process of the UE;
KPI statistics module: counting and managing KPI information in a base station, carrying out classified statistics aiming at the access process and the service process of three coverage grades, and distinguishing different coverage grades;
a judgment management module: performing algorithm judgment according to data statistics in the KPI module, thresholds configured in the base station and other information, and triggering a coverage range adjustment event;
a coverage level management module: managing the coverage range of the coverage grade, dynamically adjusting the coverage range of the three coverage grades within a reasonable value range, setting a switch, and turning on and off the self-adaptive adjustment process; (ii) a
A system information module: the system information management module in the base station manages the system information of the whole base station, and if the system information changes, new system information content is triggered;
a data processing module: the method is used for processing data information in the base station, scheduling related resources and sending data to the terminal.
The coverage adaptive adjusting device of the present invention is explained by a specific embodiment, and the specific embodiment is as follows:
1) the NB-IoT base station sends downlink System Information, establishes initial parameters and initially distributed coverage ranges such as CE0, CE1 and CE 2;
2) the terminal UE falling in each coverage grade range judges the coverage grade of the terminal UE according to the received RSRP value and a threshold parameter RSRP-threshold PrachInfoList-r13 configured by system information;
3) the terminal UE initiates a random access process by using a corresponding PRACH parameter NPRACH-Parameters-NB-r13 under the coverage level of the terminal UE;
4) the NB-IoT base station detects preamble information of the PRACH, allocates scheduled resources for the UE and completes the whole random access process;
5) the KPI counting module of the NB-IoT base station is responsible for monitoring the success rate of random access under each coverage grade and carrying out distinguishing counting according to the coverage grade;
6) the judgment management module periodically inquires information such as KPI (key performance indicator) of the coverage grade, and when the information reaches a certain threshold value, an adjustment event is triggered to be sent to the coverage grade processing module, and the content of the event comprises the expansion or reduction of the coverage range and the coverage grade range to which the event belongs;
7) after receiving the adjustment event, the coverage level processing module compares the adjustment event with a threshold value of a set coverage level range, and if the adjustment event is in a reasonable range, the coverage level processing module adjusts according to the content of the event; and if the event information is not in a reasonable range, discarding the event information;
8) after the coverage range is adjusted, the rsrp-threshold PrachInfoList-r13 parameter of the system information needs to be modified, and the system information module receives the parameter, re-encodes new system information and sends the system information to the data processing module;
9) and after receiving the new system information, the data processing module issues the new system information to the terminal, the coverage range is adjusted again, and the whole self-adaptive adjustment process is finished.
In the embodiment of the invention, the KPI counting module distinguishes different coverage grades and carries out KPI success rate counting aiming at random access processes in different coverage grade ranges. The UE access process and the service process of the NB-IoT both trigger uplink scheduling by a random access process, and the UE generates more random processes in one process and the service process, so that the random access process of the coverage grade range can be distinguished and counted through the access process. A KPI statistical threshold of random access is set in the judgment management module, when the statistical data is lower than or higher than a certain threshold, an adjustment event is triggered and reported to the coverage level management module; the triggered event content includes which coverage level the event belongs to and what event (narrowing or widening the coverage). A switch is arranged in the coverage level management module, and the self-adaptive function can be turned off and on at any time; and meanwhile, specific threshold values (upper limit and lower limit) of three coverage grades are set, so that the condition of unreasonable adjustment is prevented.
For the device embodiment, since it is basically similar to the method embodiment, the description is simple, and for the relevant points, refer to the partial description of the method embodiment.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
The coverage range self-adaptive adjusting method and device provided by the embodiment of the invention can self-adaptively adjust the coverage range of the coverage grade according to the access success rate of the users corresponding to the coverage ranges with different coverage enhancement grades after the NB-IoT base station is started, ensure the maximum utilization of the base station resources occupied by the users falling into each coverage grade, and avoid the problems that the users with good signal quality occupy the base station resources for a long time, other users cannot be scheduled and the resource utilization rate is low because the thresholds with different coverage grades are unreasonable set. The invention can not only improve the access success rate in the coverage range of each coverage enhancement grade and enhance the resource utilization rate in each coverage grade in the base station cell, but also ensure that the terminal saves more power, improve the experience degree of users and improve the performance of the system.
Furthermore, an embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored, which when executed by a processor implements the steps of the method as described above.
In this embodiment, the integrated module/unit of the coverage adaptive adjusting apparatus may be stored in a computer readable storage medium if it is implemented in the form of a software functional unit and sold or used as an independent product. Based on such understanding, all or part of the flow of the method according to the embodiments of the present invention may also be implemented by a computer program, which may be stored in a computer-readable storage medium, and when the computer program is executed by a processor, the steps of the method embodiments may be implemented. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, and the like. It should be noted that the computer readable medium may contain content that is subject to appropriate increase or decrease as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media does not include electrical carrier signals and telecommunications signals as is required by legislation and patent practice.
Fig. 4 is a schematic diagram of an apparatus provided in an embodiment of the present invention. The device provided in the embodiment of the present invention includes a memory 301, a processor 302, and a computer program stored in the memory 301 and operable on the processor 302, where the processor 302 implements the steps in each coverage adaptive adjustment method embodiment described above when executing the computer program, for example, S11 shown in fig. 2, monitors KPI information of each user terminal in a random access process, and counts an access success rate corresponding to each coverage enhancement level according to a coverage enhancement level to which each user terminal belongs and corresponding KPI information. And S12, judging whether each coverage enhancement grade meets the preset self-adaptive adjustment condition according to the access success rate corresponding to each coverage enhancement grade. And S13, performing coverage range adjustment on the coverage enhancement level meeting the adaptive adjustment condition. Alternatively, the processor 302, when executing the computer program, implements the functions of the modules/units in the coverage adaptive adjustment apparatus embodiments, such as the KPI statistics module 201, the decision management module 202, and the coverage level management module 203 shown in fig. 3.
Illustratively, the computer program may be partitioned into one or more modules/units that are stored in the memory and executed by the processor to implement the invention. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, which are used to describe the execution process of the computer program in the coverage adaptive adjusting apparatus. For example, the computer program may be partitioned into a KPI statistics module 201, a decision management module 202 and a coverage level management module 203.
The device may be a desktop computer, a notebook, a palm top computer, a cloud server, or other computing device. The apparatus may include, but is not limited to, a processor, a memory. It will be appreciated by those skilled in the art that the schematic diagram 3 is merely an example of the device and does not constitute a limitation of the device, and may include more or less components than those shown, or some components in combination, or different components, for example, the device may also include input output devices, network access devices, buses, etc.
The Processor may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like that is the control center for the device and that connects the various parts of the overall device using various interfaces and lines.
The memory may be used to store the computer programs and/or modules, and the processor may implement the various functions of the apparatus by running or executing the computer programs and/or modules stored in the memory, as well as by invoking data stored in the memory. The memory may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data (such as audio data, a phonebook, etc.) created according to the use of the cellular phone, and the like. In addition, the memory may include high speed random access memory, and may also include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), at least one magnetic disk storage device, a Flash memory device, or other volatile solid state storage device.
In the embodiments of the present invention, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the described units or division of units is only one type of division of logical functions, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical or other form.
Those skilled in the art will appreciate that while some embodiments herein include some features included in other embodiments, rather than others, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments may be used in any combination.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.