CN111356200A

CN111356200A - Downlink base station selection method, device, equipment and storage medium

Info

Publication number: CN111356200A
Application number: CN201811564852.8A
Authority: CN
Inventors: 陈东杰; 王�华; 谢玖实; 李国银; 揭鸿
Original assignee: Alibaba Group Holding Ltd
Current assignee: Alibaba Group Holding Ltd
Priority date: 2018-12-20
Filing date: 2018-12-20
Publication date: 2020-06-30
Anticipated expiration: 2038-12-20
Also published as: TW202025829A; CN111356200B; WO2020125485A1

Abstract

The invention provides a downlink base station selection method, a device, equipment and a storage medium. Responding to an uplink message sent by a receiving node through a base station, and judging whether the uplink message is received for the first time; under the condition that the uplink message is judged to be received for the first time, processing the uplink message to determine whether the downlink message needs to be sent to the node or not; under the condition that a downlink message needs to be sent to a node, judging whether a base station belongs to a candidate base station set of the node, wherein a signal index of a candidate base station in the candidate base station set aiming at the node is larger than a preset threshold value; and under the condition that the base station is judged to belong to the candidate base station set of the node, determining the base station as a downlink base station so as to send a downlink message to the node by the base station. Therefore, a basis can be provided for selecting the downlink base station based on the candidate base station set, so that the base station with better performance can be selected as the downlink base station of the node under the condition of low delay, and the success rate of the downlink data packet is improved.

Description

Downlink base station selection method, device, equipment and storage medium

Technical Field

The present invention relates to the field of data communications, and in particular, to a method, an apparatus, a device, and a storage medium for selecting a downlink base station.

Background

LoRaWAN has three modes of operation: ClassA, ClassB, and ClassC. The downlink mechanisms of the three working modes are different, and the requirements of different modes on the downlink base station selection scheme are different. The downlink receiving window of the node working in the ClassB mode is periodically opened, and the downlink receiving window of the node working in the ClassC mode is always opened, so that under ClassB and ClassC, the requirement on the downlink base station selection scheme is to select the base station with the best performance, and no requirement is imposed on delay.

The node working in the ClassA mode opens the rx1 receiving window shortly after the rxdelay only after sending the uplink data packet, and opens the rx2 receiving window after 1s if the downlink data is not received in the rx1 window opening period. If the NS has a downlink instruction, the NS must select a downlink base station within the short delay time, and if the processing delay of the NS is relatively large, the open time of the two windows is missed, which may result in a downlink failure.

Therefore, for a node operating in the ClassA mode, it is necessary to reduce the delay as much as possible while considering the performance of the downlink base station when selecting the downlink base station for the node.

Disclosure of Invention

An object of the present invention is to provide a downlink base station selection scheme suitable for the ClassA mode, which can simultaneously consider the performance and delay of a base station when selecting a downlink base station for a node operating in the ClassA mode.

According to a first aspect of the present invention, a downlink base station selection method is provided, including: responding to an uplink message sent by a receiving node through a base station, and judging whether the uplink message is received for the first time; under the condition that the uplink message is judged to be received for the first time, processing the uplink message to determine whether the downlink message needs to be sent to the node or not; under the condition that a downlink message needs to be sent to a node, judging whether a base station belongs to a candidate base station set of the node, wherein a signal index of a candidate base station in the candidate base station set aiming at the node is larger than a preset threshold value; and under the condition that the base station is judged to belong to the candidate base station set of the node, determining the base station as a downlink base station so as to send a downlink message to the node by the base station.

Optionally, the method further comprises: and under the condition that the uplink message is judged not to be received for the first time, adding the base station information of the base station sending the uplink message into the base station queue.

Optionally, the method further comprises: under the condition that the base station is judged not to belong to the candidate base station set of the node, judging whether the base station in the base station queue belongs to the candidate base station set of the node or not; and under the condition that the base station in the base station queue is judged to belong to the candidate base station set of the node, determining the base station as a downlink base station.

Optionally, the method further comprises: under the condition that the base station is judged not to belong to the candidate base station set of the node, judging whether the base station corresponding to the subsequently received uplink message belongs to the candidate base station set of the node; and under the condition that the base station corresponding to the subsequently received uplink message belongs to the candidate base station set of the node, determining the base station as a downlink base station.

Optionally, the method further comprises: and under the condition that the base stations corresponding to the subsequently received uplink message do not belong to the candidate base station set of the node, selecting the base station with the best signal quality from at least part of the base stations corresponding to the received uplink message as a downlink base station.

Optionally, the method further comprises: the steps of setting a lock service for an uplink message and judging whether the uplink message is received for the first time comprise: requesting to acquire a lock corresponding to the uplink message, judging that the uplink message is received for the first time under the condition of successfully acquiring the lock, and judging that the uplink message is not received for the first time under the condition of failing to acquire the lock.

Optionally, the method further comprises: under the condition that the base station is judged to belong to the candidate base station set of the nodes, whether the base station meets the requirement of a downlink base station indicated by the uplink message is further judged; and under the condition that the base station is judged to meet the requirement of the downlink base station indicated by the uplink message, determining the base station as the downlink base station.

According to a second aspect of the present invention, there is also provided a downlink base station selection method, including: responding to an uplink message sent by a node through a base station, determining a signal quality index of the node by the base station according to signal quality data of one or more uplink messages sent by the node through the base station, and adding the base station to a candidate base station set of the node under the condition that the signal quality index is greater than a preset threshold value; judging whether an uplink message is received for the first time, processing the uplink message to determine whether a downlink message needs to be sent to a node or not under the condition that the uplink message is received for the first time, judging whether a base station belongs to a candidate base station set of the node or not under the condition that the downlink message needs to be sent to the node, and taking the base station as a downlink base station under the condition that the base station belongs to the candidate base station set of the node so as to send the downlink message to the node.

According to a third aspect of the present invention, there is provided a downlink base station selection method, including: responding to an uplink message sent by a node through a base station, and judging whether the base station belongs to a candidate base station set of the node, wherein a signal index of a candidate base station in the candidate base station set aiming at the node is larger than a preset threshold value; judging whether the uplink message is processed or not under the condition that the base station is judged to belong to the candidate base station set of the node; under the condition that the uplink message is not processed, processing the uplink message to determine whether the downlink message needs to be sent to the node or not; and under the condition that a downlink message needs to be sent to the node, determining the base station as a downlink base station, and sending the downlink message to the node by the base station.

Optionally, the method further comprises: judging whether the uplink message is processed or not under the condition that the base station is judged not to belong to the candidate base station set of the node; under the condition that the uplink message is not processed, adding the uplink message received this time or the base station corresponding to the uplink message into a candidate set; after a preset time interval, judging whether the uplink message is processed or not; under the condition that the uplink message is judged not to be processed, selecting a base station with the best signal quality from the candidate set; processing an uplink message corresponding to the selected base station to determine whether a downlink message needs to be sent to the node; and determining the selected base station as a downlink base station under the condition that a downlink message needs to be sent to the node.

Optionally, the method further comprises: the method comprises the steps of setting a locking service for an uplink message, and processing the uplink message, wherein the steps comprise: acquiring a lock corresponding to the uplink message, processing the uplink message under the condition of successfully acquiring the lock, and judging whether the uplink message is processed or not comprises the following steps: and requesting to acquire a lock corresponding to the uplink message, and judging that the uplink message is processed under the condition that the lock acquisition fails.

According to a fourth aspect of the present invention, there is provided a downlink base station selection method, including: responding to an uplink message sent by a node through a base station, determining a signal quality index of the node by the base station according to signal quality data of one or more uplink messages sent by the node through the base station, and adding the base station to a candidate base station set of the node under the condition that the signal quality index is greater than a preset threshold value; judging whether a base station belongs to a candidate base station set of a node or not, wherein a signal index of the base station in the candidate base station set aiming at the node is larger than a preset threshold value, judging whether an uplink message is processed or not under the condition that the base station belongs to the candidate base station set of the node, processing the uplink message under the condition that the uplink message is not processed to determine whether a downlink message needs to be sent to the node or not, and determining the base station as the downlink base station under the condition that the downlink message needs to be sent to the node so that the base station sends the downlink message to the node.

According to the fifth aspect of the present invention, there is also provided a downlink base station selection method, including: in response to receiving an uplink message sent by a node through a base station, determining a signal quality index of the base station for the node according to signal quality data of one or more uplink messages sent by the node through the base station; in case the signal quality indicator is larger than a predetermined threshold, adding the base station to the set of candidate base stations of the node.

Optionally, the signal quality data includes a signal strength and/or a signal-to-noise ratio of the uplink packet received by the base station.

Optionally, the step of determining the signal quality indicator of the base station for the node includes: and processing the signal quality data of one or more uplink messages sent by the node through the base station by utilizing a moving average algorithm or a weighted average algorithm to obtain a signal quality index of the node by the base station.

Optionally, the method further comprises: and deleting the base station from the candidate base station set under the condition that the signal quality index is smaller than a preset threshold value.

According to the sixth aspect of the present invention, there is also provided a downlink base station selection apparatus, including: the first judgment module is used for responding to an uplink message sent by a receiving node through a base station and judging whether the uplink message is received for the first time; the processing module is used for processing the uplink message under the condition of judging that the uplink message is received for the first time so as to determine whether the downlink message needs to be sent to the node or not; the second judging module is used for judging whether the base station belongs to a candidate base station set of the node or not under the condition that a downlink message needs to be sent to the node, wherein the signal index of a candidate base station in the candidate base station set aiming at the node is larger than a preset threshold value; and the determining module is used for determining the base station as a downlink base station under the condition that the base station is judged to belong to the candidate base station set of the node, so that the base station sends a downlink message to the node.

According to the seventh aspect of the present invention, there is also provided a downlink base station selection apparatus, including: the node comprises a first processing module and a second processing module, wherein the first processing module and the second processing module are executed in parallel in response to receiving an uplink message sent by a node through a base station, the first processing module determines a signal quality index of the node by the base station according to signal quality data of one or more uplink messages sent by the node through the base station, and the base station is added to a candidate base station set of the node when the signal quality index is greater than a preset threshold value; the second processing module judges whether an uplink message is received for the first time, processes the uplink message to determine whether a downlink message needs to be sent to the node or not under the condition that the uplink message is received for the first time, judges whether the base station belongs to a candidate base station set of the node or not under the condition that the downlink message needs to be sent to the node, and takes the base station as a downlink base station under the condition that the base station belongs to the candidate base station set of the node so that the base station sends the downlink message to the node.

According to the eighth aspect of the present invention, there is also provided a downlink base station selection apparatus, including: the first judgment module is used for responding to the received uplink message sent by the node through the base station and judging whether the base station belongs to a candidate base station set of the node, wherein the signal index of the candidate base station in the candidate base station set aiming at the node is larger than a preset threshold value; the second judgment module is used for judging whether the uplink message is processed or not under the condition that the base station is judged to belong to the candidate base station set of the node; the processing module is used for processing the uplink message under the condition of judging that the uplink message is not processed so as to determine whether the downlink message needs to be sent to the node or not; and the determining module is used for determining the base station as a downlink base station under the condition that the downlink message needs to be sent to the node, so that the base station sends the downlink message to the node.

According to the ninth aspect of the present invention, there is also provided a downlink base station selection apparatus, including: the node comprises a first processing module and a second processing module, wherein the first processing module and the second processing module are executed in parallel in response to receiving an uplink message sent by a node through a base station, the first processing module determines a signal quality index of the node by the base station according to signal quality data of one or more uplink messages sent by the node through the base station, and the base station is added to a candidate base station set of the node when the signal quality index is greater than a preset threshold value; the second processing module judges whether the base station belongs to a candidate base station set of the node, wherein the signal index of the base station in the candidate base station set aiming at the node is larger than a preset threshold value, judges whether the uplink message is processed under the condition that the base station belongs to the candidate base station set of the node, processes the uplink message under the condition that the uplink message is not processed so as to determine whether the downlink message needs to be sent to the node, and determines the base station as the downlink base station under the condition that the downlink message needs to be sent to the node so that the base station sends the downlink message to the node.

According to the tenth aspect of the present invention, there is also provided a downlink base station selection apparatus, including: the signal quality index determining module is used for responding to the received uplink message sent by the node through the base station and determining the signal quality index of the node by the base station according to the signal quality data of one or more uplink messages sent by the node through the base station; and the candidate base station set adding module is used for adding the base station to the candidate base station set of the node under the condition that the signal quality index is larger than a preset threshold value.

According to an eleventh aspect of the present invention, there is also provided a computing device comprising: a processor; and a memory having executable code stored thereon, which when executed by the processor, causes the processor to perform the method as set forth in any one of the first to fifth aspects of the invention.

According to a twelfth aspect of the present invention, there is also provided a non-transitory machine-readable storage medium having stored thereon executable code, which when executed by a processor of an electronic device, causes the processor to perform a method as set forth in any one of the first to fifth aspects of the present invention.

The invention can provide basis for selecting the downlink base station by determining the candidate base station set of the node, thereby selecting the base station with better performance as the downlink base station of the node under the condition of low delay and improving the success rate of the downlink data packet.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent by describing in greater detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals generally represent like parts throughout.

Fig. 1 shows a schematic flow chart of a method of acquiring a candidate base station set of a node according to an exemplary embodiment of the invention.

Fig. 2 shows a schematic flow chart of a downlink base station selection method according to an embodiment of the invention.

Fig. 3 shows a schematic flow chart of a downlink base station selection method according to another embodiment of the present invention.

Fig. 4 is a schematic block diagram showing the structure of a downlink base station selection apparatus according to an embodiment of the present invention.

Fig. 5 is a schematic block diagram showing the structure of a downlink base station selection apparatus according to another embodiment of the present invention.

Fig. 6 is a schematic block diagram showing the structure of a downlink base station selection apparatus according to another embodiment of the present invention.

Fig. 7 is a schematic block diagram showing the structure of a downlink base station selection apparatus according to another embodiment of the present invention.

Fig. 8 is a schematic structural diagram of a computing device that can be used to implement the downlink base station selection method according to an embodiment of the present invention.

Detailed Description

Preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While the preferred 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.

[ term interpretation ]

LoRa: a low-power consumption long-distance wireless transmission scheme based on spread spectrum technology.

LoRaWAN: the Low Power Wide Area Network (LPWAN) standard, which is introduced by the LoRa alliance and is based on an open source MAC layer protocol. This technology can provide a low power, scalable, long-range wireless network for battery-powered wireless devices.

And NS: the Network Server is a core part-core Network in the solution of the Internet of things.

A base station: the gateway transmits the wireless network signal of the node to the NS device through the backhaul network.

Rxpk: the uplink message is a data message uploaded to the NS by the base station.

Txpk: the downlink packet, i.e. the data packet downlink from the NS to the base station.

tmst: a base station internal counter.

And Rssi is the signal strength of the node data packet when the node data packet is received by the base station.

Snr: signal-to-noise ratio of node packets as received by the base station.

And EUI: the device unique identification code is a globally unique ID similar to IEEE EUI64 and corresponds to the MAC address of the device.

gwEui: a unique identification code of the base station.

[ scheme overview ]

The invention provides a downlink base station selection scheme suitable for a ClassA mode, which can simultaneously give consideration to the performance and delay of a base station when selecting the downlink base station for a node (namely a terminal) working in the ClassA mode, so that the performance of the selected downlink base station is better, and the delay of the whole process is lower.

The base station selection scheme of the present invention mainly comprises two parts. The first part is the determination (or update) of a candidate base station set for a node, where the candidate base station set is used to provide a basis for selecting a downlink base station. The second part is directed to the processing of uplink messages and the selection of downlink base stations. The first part and the second part can be executed concurrently without mutual influence, and can be processed by two system processes respectively in practice. The following describes the implementation of these two parts.

The first part is mainly to calculate a signal indicator of a node by a base station according to signal quality data (e.g., Rssi and/or Snr) of one or more uplink messages sent by the node through the base station in response to receiving an uplink message sent by the node through a certain base station, for example, the signal indicator may be obtained by a moving average algorithm or a weighted average algorithm. The signal index may then be compared with a predetermined threshold, and if the signal index is greater than the predetermined threshold, the signal reception condition of the base station may be considered to be good, and the base station is suitable as a downlink base station, and may be added to the candidate base station set of the node. If the signal index is smaller than the predetermined threshold, the signal receiving condition of the base station may be considered to be unstable and not suitable as a downlink base station, and if the base station exists in the candidate base station set, the base station may be deleted from the candidate base station set. Therefore, in response to receiving an uplink message uploaded by a node through one or more base stations, the candidate base station set of the node can be updated, and all the candidate base stations in the updated candidate base station set can be regarded as downlink base stations suitable for sending downlink messages to the node. Therefore, the obtained candidate base station set can provide a basis for selecting the downlink base station.

The second part mainly aims at the processing of uplink messages and the selection of downlink base stations. In the invention, for a plurality of repeated uplink messages uploaded by a plurality of base stations by a received node, the first received uplink message can be processed, and then the downlink base station is selected under the condition that the downlink message needs to be sent. In addition, the downlink base station may be selected first, and then the uplink message corresponding to the selected downlink base station may be processed. That is, the base station corresponding to the uplink message may or may not be consistent with the downlink base station.

For example, after an uplink packet sent by a node through a base station is received for the first time, it may be determined whether the base station belongs to a candidate base station set of the node, and if it is determined that the base station belongs to the candidate base station set, the uplink packet may be processed, and the base station may be used as a downlink base station. If the uplink message does not belong to the candidate base station set, the uplink message uploaded by the base station is processed, and the base station is used as a downlink base station.

For example, after an uplink message sent by a node through a base station is received for the first time, the uplink message may be directly processed, and then it is determined whether the base station belongs to a candidate base station set of the node, if so, the base station may be directly used as a downlink base station of the node, and if not, it is determined whether a base station subsequently passed through by the node to send the uplink message belongs to the candidate base station set, if a base station belonging to the candidate base station set exists, the base station is used as a downlink base station, otherwise, a base station with better signal quality is selected from the base stations passed through by the node to send the same uplink message as the downlink base station.

In summary, by determining the candidate base station set of the node, a basis can be provided for selecting the downlink base station, so that a base station with better performance can be selected as the downlink base station of the node (i.e., the terminal) under the condition of low delay, and the success rate of the downlink data packet (i.e., the downlink packet) is improved.

The aspects of the invention are further described below.

[ set of candidate base stations ]

Fig. 1 shows a schematic flow chart of a method of acquiring a candidate base station set of a node according to an exemplary embodiment of the invention. Among other things, the method shown in fig. 1 may be performed by a Network Server (NS).

Referring to fig. 1, in step S110, in response to receiving an uplink packet sent by a node through a base station, a signal quality indicator of the base station for the node is determined according to signal quality data of one or more uplink packets sent by the node through the base station.

According to the signal quality data of one or more uplink messages sent by a node through a base station, the signal quality index of the base station for the node can be calculated in various ways. For example, the signal quality indicator of the base station for the node may be obtained by calculating an average value of the signal quality data of the one or more uplink packets. For another example, the signal quality data of one or more uplink packets sent by the node through the base station may also be processed through a weighted average algorithm or a moving average algorithm, so as to obtain a signal quality index of the base station for the node. In addition, the signal quality index of the base station for the node may also be calculated by other various statistical methods, which is not described herein again.

The following is merely an exemplary description of the process of obtaining the signal quality indicator through a weighted average algorithm or a moving average algorithm.

Example 1: a weighted average algorithm.

Different weights may be assigned to the signal quality data of the plurality of uplink packets sent by the node through the base station. As an example, the weight is proportional to the time of receiving the uplink packet sent by the base station, that is, the closer the time of receiving the uplink packet of the base station to the current time, the greater the weight is, otherwise, the smaller the weight is. And then the signal quality index of the base station for the node can be obtained by weighted summation and averaging.

Example 2, moving average algorithm.

The calculation formula is as follows: s (t) ═ a × y (t) + (1-a) × S (t-1). Wherein S (t) represents the current signal quality index of the base station. And y (t) represents the signal quality data of the received uplink message currently sent by the base station. S (t-1) represents the historical signal quality indicator of the base station, i.e. the signal quality indicator of the base station determined previously, such as the signal quality indicator of the base station determined last time. a is a sliding factor which is proportional to the time interval between the two uplink messages sent by the node through the base station and received recently.

Optionally, the value range of a may be between [ 0,1 ]. When the time interval of recently receiving the two uplink messages sent by the node through the base station is smaller, a is closer to 0, and when the time interval of recently receiving the two uplink messages sent by the node through the base station is larger, a is closer to 1. For example, a can be determined by the following formula:

wherein, alpha is a scaling factor, t is the time of currently receiving the uplink message sent by the node through the base station, t _ last is the time of last receiving the rxpk of the base station, and the meaning of the formula is that a is closer to 0 when the time interval of recently receiving the two uplink messages sent by the node through the base station is smaller, and a is closer to 1 when the time interval of recently receiving the two uplink messages sent by the node through the base station is larger.

Therefore, for a node with a short reporting period, it can be considered that the channel quality between the base station and the node does not change drastically during the period, the signal quality index is greatly influenced by a historical value (historical signal quality index), and the curve change of the signal quality index is relatively gentle. For a node with a long reporting period, it can be considered that the channel quality between the base station and the node may change greatly in this period, so that the signal quality index is greatly affected by the current value (signal quality data of an uplink packet currently sent by the base station).

In the present invention, the signal quality data may include a signal strength (Rssi) and/or a signal-to-noise ratio (Snr) of the uplink packet received by the base station. Therefore, the signal quality indicator may also include a signal strength indicator and/or a signal-to-noise ratio indicator, which may be denoted as Rssi 'and Snr', respectively. The signal strength indicator may be determined according to the signal strength of one or more uplink messages sent by the node through the base station, and the signal-to-noise ratio indicator may be determined according to the signal-to-noise ratio of one or more uplink messages sent by the node through the base station. For the calculation process of the signal strength indicator and/or the signal-to-noise ratio indicator, see the above related description, and will not be described herein again.

In step S120, in case the signal quality indicator is larger than a predetermined threshold, the base station is added to the candidate base station set of the node.

The signal quality index can represent the signal quality of the base station for the node under the current condition. When the signal quality index is large, the link quality between the base station and the node may be considered to be good, and the node is suitable for serving as a downlink base station of the node. When the signal quality index is smaller than the predetermined threshold, the link quality between the base station and the node may be considered to be poor, and the base station is not suitable as a downlink base station of the node.

As an example, the base station may be added to the set of candidate base stations of the node as a candidate base station of the node in case the signal quality indicator is greater than a predetermined threshold. In case the signal quality indicator is smaller than a predetermined threshold, the base station is deleted from the set of candidate base stations of the node (in case the base station is present in the set of candidate base stations). The predetermined threshold may be set according to an actual situation, and is not described herein again.

In the case where the signal quality indicator includes a signal strength indicator and a signal-to-noise ratio indicator, a first predetermined threshold and a second predetermined threshold may be set for the signal strength indicator and the signal-to-noise ratio indicator, respectively. The base station may be added to the set of candidate base stations for the node as a candidate base station for the node if the signal strength indicator is greater than a first predetermined threshold and the signal-to-noise ratio indicator is greater than a second predetermined threshold. Otherwise, the base station is deleted from the candidate base station set of the node.

As an example, an expiration time may be set for a candidate base station in the candidate base station set, the base station may be automatically removed from the candidate set after a certain time, the candidate base station set is updated whenever a node has a new uplink packet, and the update is usually only effective for selecting a downlink base station in a ClassA mode of the node at the next time.

[ selection of Downlink base station ]

Fig. 2 shows a schematic flow chart of a downlink base station selection method according to an exemplary embodiment of the present invention. Among other things, the method shown in fig. 2 may be performed by a Network Server (NS).

As shown in fig. 2, in response to receiving the uplink packet sent by the node through the base station, the process shown in step S111 to step S114 may be executed, or the process shown in step S210 to step S295 may be executed. Alternatively, in response to receiving the uplink packet sent by the node through the base station, the processes shown in step S111 to step S114 and the processes shown in step S210 to step S295 may be executed in parallel.

Step S111 to step S114 mainly analyze whether the base station belongs to the candidate base station of the node, so as to update the candidate base station set of the node. Details related to steps S111 to S114 may be referred to the description above in conjunction with fig. 1, and only the flow shown in fig. 2 is exemplarily described here.

Referring to fig. 2, first, in step S111, in response to receiving an uplink packet sent by a base station, a signal quality indicator of the base station for a node is determined. The specific implementation process for determining the signal quality index may refer to the description above in conjunction with step S110 in fig. 1, and is not described herein again.

In step S112, it is determined whether the signal quality indicator is greater than a predetermined threshold.

In case the signal quality indicator is larger than the predetermined threshold, step S113 may be performed to add the base station to the set of candidate base stations of the node.

In case the signal quality indicator is smaller than the predetermined threshold, step S114 may be performed, and in case the base station exists in the candidate base station set of the node, the base station is deleted from the candidate base station set. Thus, real-time updating of the candidate base station set of nodes can be achieved.

Steps S210 to S295 are mainly used to process the uplink packet and select a suitable downlink base station when the downlink packet needs to be sent. The following describes an exemplary implementation of steps S210 to S295.

Referring to fig. 2, in response to receiving an uplink packet sent by a node through a base station, step S210 is executed to determine whether the uplink packet is received for the first time. Here, whether the uplink message is received for the first time may be determined by acquiring a lock (e.g., a distributed lock). Specifically, a lock service may be set for the uplink packet, and the lock may be acquired only when the uplink packet is received for the first time, and the lock may not be acquired when a subsequent node receives a repeated uplink packet sent by another base station. Therefore, in response to receiving an uplink message sent by a node through a base station, the node can request to acquire a lock corresponding to the uplink message, and when the lock is successfully acquired, the uplink message is determined to be received for the first time, and when the lock is unsuccessfully acquired, the uplink message is determined not to be received for the first time.

In case that it is determined that the uplink packet is received for the first time, step S220 may be executed to process the uplink packet. The process of processing the uplink packet may be the existing logic of the NS for processing the uplink packet. Here, the uplink packet is mainly analyzed to determine whether a downlink packet needs to be sent to the node. Optionally, in the process of executing step S220, it may also be analyzed whether there are other special requirements in the uplink message uploaded by the node, for example, whether there is an instruction with special requirements for the downlink base station in the uplink message may be analyzed, for example, whether the uplink message contains a deviceTimeReq command, which requires that the base station needs to have gps time.

In step S230, it is determined whether a downlink packet needs to be sent. Here, the determination may be made based on the processing result of step S220.

And under the condition that the downlink message does not need to be sent, the downlink base station does not need to be selected for the node. If a downlink message needs to be sent (for example, there is a downlink command or an ack is needed for an uplink message), in step S240, it is determined whether the base station belongs to the candidate base station set of the node. Wherein the candidate base station set may be determined by performing scheme 1 in parallel. If the base station belongs to the candidate base station set of the node, the base station is determined as a downlink base station (step S250), and a downlink packet is transmitted to the base station (step S260).

Under the condition that the base station does not belong to the candidate base station set of the node, whether the base station corresponding to the same uplink message (the repeated uplink message which belongs to the same uplink message as the uplink message received for the first time) subsequently belongs to the candidate base station set of the node can be judged. And under the condition that the base station corresponding to the subsequently received uplink message belongs to the candidate base station set of the node, determining the base station as a downlink base station.

Under the condition that the base stations corresponding to the subsequently received uplink messages do not belong to the candidate base station set of the node, the base station with the best signal quality (signal receiving strength and/or signal to noise ratio) can be selected from at least part of the base stations corresponding to all the currently received same uplink messages to serve as the downlink base station. For example, the base station with the best signal reception strength and/or signal-to-noise ratio may be selected as the downlink base station from all base stations through which the node transmits the uplink packet.

As an example, when it is determined that the uplink packet is not received for the first time, step S270 may be executed to add the base station information of the base station that transmits the uplink packet into the base station queue, for example, the base station information may be added into the base station queue corresponding to the uplink packet that is transmitted by the node this time. The base station information may include gwEUI, tmst, rssi, snr, and the like. Thus, the base station queue may include base station information of all base stations through which the same uplink message is currently received. Step S280 may then be performed to determine whether the base stations in the base station queue belong to the candidate base station set. Here, the base stations may be determined one by one in the order of addition of the base stations in the base station queue. If there is a base station belonging to the candidate base station set in the base station queue, the base station may be determined as a downlink base station (step S250), and a downlink packet is sent to the base station (step S260). If there is no base station belonging to the candidate base station set in the base station queue, in step S290, the base station with the best signal quality (signal receiving strength and/or signal to noise ratio) is selected from the base station queue as the downlink base station. In step S295, a downlink message is sent to the selected base station.

Alternatively, in the case that none of the base stations in the base station queue belongs to the candidate base station set, the step S280 may be repeated with a delay of a certain time. In practice, asynchronous delay can be realized by using a delay queue, a current thread is not blocked, the throughput rate of the system is improved, and meanwhile, in order to ensure that base stations in a candidate set station set are found in time after arriving, sleep time can be shortened, and multiple attempts are made in step S280.

Optionally, if there is an instruction having a special requirement for the downlink base station in the uplink message, when selecting the downlink base station, it may further consider whether the base station meets the requirement of the downlink base station indicated by the uplink message. For example, when it is determined that the base station belongs to the candidate base station set of the node, it may be further determined whether the base station satisfies the downlink base station requirement indicated by the uplink packet, and when it is determined that the base station satisfies the downlink base station requirement indicated by the uplink packet, the base station is determined as the downlink base station. For another example, when selecting the base station with the best quality from the base stations through which the node transmits the uplink packet, the base station may also be selected from the base stations that satisfy the downlink base station requirement indicated by the uplink packet.

Fig. 3 shows a schematic flow chart of a downlink base station selection method according to another exemplary embodiment of the present invention. Among other things, the method shown in fig. 3 may be performed by a Network Server (NS).

As shown in fig. 3, in response to receiving the uplink packet sent by the node through the base station, the process shown in step S111 to step S114 may be executed, or the process shown in step S310 to step S329 may be executed. Alternatively, in response to receiving the uplink packet sent by the node through the base station, the processes shown in step S111 to step S114 and the processes shown in step S310 to step S329 may be executed in parallel. For steps S111 to S114, the above description in conjunction with fig. 2 can be referred to, and details are not repeated here.

In this embodiment, steps S310 to S329 mainly include selecting a downlink base station, and then processing an uplink packet corresponding to the selected downlink base station. The following mainly illustrates a specific implementation procedure of steps S310 to S329 in this embodiment.

Referring to fig. 3, in response to receiving an uplink packet sent by a node through a base station, step S310 is executed to determine whether the base station belongs to a candidate base station set of the node. Wherein the signal indicator of the candidate base station in the candidate base station set for the node is greater than the predetermined threshold, and the candidate base station set may be determined by performing scheme 1 in parallel.

If the base station is determined to belong to the candidate base station set, step S311 is executed to determine whether the uplink packet is processed. The processing for uplink messages mentioned in the present invention refers to selecting one uplink message from a plurality of repeated uplink messages sent by a node through one or more base stations for processing, and the plurality of repeated uplink messages can be regarded as messages with the same content. If the uplink packet has been processed, the processing logic according to this embodiment indicates that the downlink base station has been selected. If the uplink packet is not processed, which indicates that the downlink base station has not determined, step S312 may be executed to process the uplink packet. Here, the uplink packet is mainly analyzed to determine whether a downlink packet needs to be sent to the node.

In this embodiment, the operation of determining whether the uplink packet is processed may be determined by determining whether a lock (e.g., a distributed lock) can be acquired. For example, a lock service may be set for the same uplink packet sent by a node, when the uplink packet is processed, a lock corresponding to the uplink packet may be requested to be acquired, and when the lock is successfully acquired, the uplink packet may be processed. If the lock can not be acquired or exists, the uplink message is processed.

In step S313, it is determined whether a downlink packet needs to be sent. Here, the determination may be made based on the processing result of step S312. And under the condition that the downlink message does not need to be sent, the downlink base station does not need to be selected for the node. If the downlink packet needs to be sent, in step S314, the base station is determined as a downlink base station. In step S315, a downlink message is sent to the base station.

If the result of step S310 is that the base station does not belong to the node candidate base station set, step S321 may be executed to determine whether the uplink packet is processed. If the uplink packet has been processed, the processing logic according to this embodiment indicates that the downlink base station has been selected.

If the uplink message is not processed, which indicates that the downlink base station has not been determined, step S322 may be executed to add the uplink message received this time or the base station corresponding to the uplink message to the candidate set.

In step S323, the processing is delayed. In the process of the delay processing, in response to receiving the repeated uplink packet sent by the node through another base station or base stations, the processing may continue according to the processing logic of scheme 2. Therefore, after the delay processing, the candidate set includes a plurality of repeated uplink messages or a plurality of base stations through which the node sends the same uplink message. In step S323, a delay queue may implement asynchronous delay, so as to not block the current thread and improve the system throughput. And the time interval of the delay processing can be set according to the actual situation, and is not suitable to be too large.

After the delay processing is completed (or after a predetermined time interval), step S324 may be executed to determine whether the uplink packet is processed. If the uplink message is processed, it indicates that the downlink base station has already determined.

If the uplink packet is not processed, it indicates that none of the base stations through which the currently received node transmits the uplink packet belongs to the candidate base station set, so step S325 may be executed to select the base station with the best signal quality (signal reception strength and/or signal-to-noise ratio) from the candidate set, and then step S326 is executed to process the uplink packet corresponding to the selected base station. The process of processing the uplink packet may be the existing logic of the NS for processing the uplink packet. Here, the uplink packet is mainly analyzed to determine whether a downlink packet needs to be sent to the node.

In step S327, it is determined whether a downlink message needs to be sent. Here, the determination may be made based on the processing result of step S326. And under the condition that the downlink message does not need to be sent, the downlink base station does not need to be selected for the node. In the case that the downlink message needs to be sent, in step S328, the base station is determined as a downlink base station. In step S329, a downlink message is sent to the base station.

In conclusion, the downlink base station selection scheme of the invention achieves good balance between delay and performance, and ensures that the performance of the downlink base station in the A mode is within a predictable range by analyzing the candidate set base station. Meanwhile, because the base station with the signal arriving first has relatively good performance, the invention can realize that no extra delay is generated due to waiting in most scenes, and can obtain relatively less delay even in a few scenes needing to delay and wait for the arrival of other base station signals without waiting for the arrival of all the base station signals. The invention can select the downlink base station after the uplink signal processing is finished, and can conveniently process if the node uplink message has special instructions for special requirements on the routing base station.

The downlink base station selection scheme of the invention has at least the following beneficial effects.

1. The uplink message received by the NS includes the internal time (tmst) when the base station receives the uplink message, and different base stations tmst are different, so if a downlink base station is desired to be selected in advance, time synchronization needs to be performed, clocks of all base stations are kept consistent, and thus, the uplink message is very complex and delay tends to be high. Therefore, the downlink base station of the ClassA mode must be selected from the uplink reachable base stations in real time. The invention can provide a basis for the real-time selection of the downlink base station through the candidate base station set. The base station with better selectivity can be used as the downlink base station of the terminal under the condition of low delay without time synchronization, and the success rate of downlink data packets is improved.

2. The decoupling of repetition elimination and routing of the ClassA mode is realized, and no extra waiting delay exists in NS for processing the uplink message.

3. The concept of a candidate base station set is provided, the candidate base station set provides data support for decision making of a downlink routing base station, and meanwhile analysis and processing of the candidate base station set are independent processes and cannot influence the core flow of uplink and downlink of the node.

4. The signal quality of the base station is analyzed in real time by using a moving average algorithm or a weighted average algorithm, so that the real-time performance and high robustness of the candidate base station set can be ensured.

5. The present invention can implement another type of mode over a and under B, i.e. the source base station of the processed uplink message is the a base station, but the downlink base station (the base station sending the downlink message) is the B base station. The downlink message arrives from the base station B, so that the internal time tmst of the base station B can be obtained, and the complex time synchronization work is avoided.

6. The mode of A, up and B realized by the invention can also lead the expansibility to be good, and the subsequent routing base station aiming at the ClassA mode can be conveniently expanded if new restriction requirements exist.

[ Downlink base station selection apparatus ]

Fig. 4 to 7 are schematic block diagrams illustrating the structure of a downlink base station selection apparatus according to various embodiments of the present invention. The functional modules of the downlink base station selection apparatus can be implemented by hardware, software or a combination of hardware and software for implementing the principles of the present invention. It will be appreciated by those skilled in the art that the functional blocks described in fig. 4-7 may be combined or divided into sub-blocks to implement the principles of the invention described above. Thus, the description herein may support any possible combination, or division, or further definition of the functional modules described herein.

The functional modules that the downlink base station selection apparatus may have and the operations that each functional module may perform are briefly described, and for the details related thereto, reference may be made to the above description, which is not repeated herein.

Referring to fig. 4, the downlink base station selection apparatus 400 includes a first determining module 410, a processing module 420, a second determining module 430, and a determining module 440.

The first determining module 410 is configured to determine whether an uplink packet is received for the first time in response to receiving the uplink packet sent by the node through the base station. The processing module 420 is configured to process the uplink packet to determine whether a downlink packet needs to be sent to the node when it is determined that the uplink packet is received for the first time. The second determining module 430 is configured to determine whether a base station belongs to a candidate base station set of the node when a downlink packet needs to be sent to the node, where a signal indicator of a candidate base station in the candidate base station set for the node is greater than a predetermined threshold. The determining module 440 is configured to determine the base station as a downlink base station, so that the base station sends a downlink packet to the node, when it is determined that the base station belongs to the candidate base station set of the node.

As an example of the present invention, the second determining module 430 may determine whether a base station corresponding to a subsequently received uplink packet belongs to the candidate base station set of the node, when determining that the base station does not belong to the candidate base station set of the node. When it is determined that the base station corresponding to the subsequently received uplink packet belongs to the candidate base station set of the node, the determining module 440 may determine the base station as a downlink base station.

Optionally, the downlink base station selecting apparatus 400 may further include a selecting module. Under the condition that the base stations corresponding to the subsequently received uplink message are judged not to belong to the candidate base station set of the node, the selection module can select the base station with the best signal quality from at least part of the base stations corresponding to the received uplink message as the downlink base station.

As another example of the present invention, the downlink base station selecting apparatus 400 may further include an adding module, configured to add, in the base station queue, the base station information of the base station that sent the uplink packet, if the first determining module 410 determines that the uplink packet is not received for the first time. In the case that the second determination module 430 determines that the base station does not belong to the candidate base station set of the node, it may be further determined whether the base station in the base station queue belongs to the candidate base station set of the node, and in the case that it is determined that the base station in the base station queue belongs to the candidate base station set of the node, the base station may be determined as a downlink base station.

As another example of the present invention, the second determining module 430 may further determine whether the base station meets the downlink base station requirement indicated by the uplink packet, in case of determining that the base station belongs to the candidate base station set of the node. The determining module 440 determines the base station as a downlink base station only when it is determined that the base station meets the downlink base station requirement indicated by the uplink message.

Referring to fig. 5, in the present embodiment, the downlink base station selecting apparatus 500 includes a first determining module 510, a second determining module 520, a processing module 530 and a determining module 540.

The first determining module 510 is configured to determine, in response to receiving an uplink packet sent by a node through a base station, whether the base station belongs to a candidate base station set of the node, where a signal indicator of a candidate base station in the candidate base station set for the node is greater than a predetermined threshold. The second determining module 520 is configured to determine whether the uplink packet is processed or not when determining that the base station belongs to the candidate base station set of the node. The processing module 530 is configured to process the uplink packet to determine whether a downlink packet needs to be sent to the node when it is determined that the uplink packet is not processed. The determining module 540 is configured to determine the base station as a downlink base station when a downlink packet needs to be sent to the node, so that the base station sends the downlink packet to the node.

As an example of the present invention, the downlink base station selecting apparatus 500 may further include a third determining module, an adding module, and a selecting module.

In the case that the first determining module 510 determines that the base station does not belong to the candidate base station set of the node, the third determining module may determine whether the uplink packet is processed. Under the condition that the third judging module judges that the uplink message is not processed, the adding module adds the received uplink message or the base station corresponding to the received uplink message to the candidate set; after a preset time interval, the third judging module judges whether the uplink message is processed again; the adding module may select a base station with the best signal quality from the candidate set when it is determined that the uplink packet is not processed yet. The processing module 530 may process the uplink packet corresponding to the selected base station to determine whether a downlink packet needs to be sent to the node. In a case that a downlink packet needs to be sent to a node, the determining module 540 may determine the selected base station as a downlink base station.

Referring to fig. 6, in the present embodiment, the downlink base station selection apparatus 600 includes a signal quality indicator determining module 610 and a candidate base station set adding module 620.

The signal quality indicator determining module 610 is configured to determine, in response to receiving an uplink packet sent by a node through a base station, a signal quality indicator of the base station for the node according to signal quality data of one or more uplink packets sent by the node through the base station. The signal quality data may include signal strength and/or signal to noise ratio of the uplink message as received by the base station.

The signal quality indicator determining module 610 may process, by using a moving average algorithm or a weighted average algorithm, signal quality data of one or more uplink packets sent by a node through a base station to obtain a signal quality indicator of the node by the base station. For the specific determination process, see the above description, and no further description is provided herein.

The candidate base station set adding module 620 is configured to add a base station to the candidate base station set of the node if the signal quality indicator is greater than the predetermined threshold.

Optionally, the downlink base station selecting apparatus 600 may further include a deleting module. The deletion module may be configured to delete the base station from the set of candidate base stations if the signal quality indicator is less than a predetermined threshold.

Referring to fig. 7, in this embodiment, the downlink base station selecting apparatus 700 may include a first processing module 710 and a second processing module 720. In response to receiving an uplink packet sent by a node through a base station, the first processing module 710 and the second processing module 720 may execute in parallel.

The first processing module 710 may include functional modules included in the downlink base station selection apparatus in fig. 6, and execute functions that can be executed by the downlink base station selection apparatus in fig. 6. Briefly, the first processing module 710 may determine a signal quality indicator of a base station for a node according to signal quality data of one or more uplink packets sent by the node through the base station, and add the base station to a candidate base station set of the node if the signal quality indicator is greater than a predetermined threshold. For operations that the first processing module 710 can also perform, reference may be made to the description of fig. 6, which is not described herein again.

The second processing module 720 may include functional modules included in the downlink base station selection apparatus in fig. 4, and execute the functions that can be executed by the downlink base station selection apparatus in fig. 4. The second processing module 720 may include functional modules included in the downlink base station selection apparatus in fig. 5, and execute functions that can be executed by the downlink base station selection apparatus in fig. 5.

For example, the second processing module 720 may be configured to determine whether an uplink packet is received for the first time, process the uplink packet to determine whether a downlink packet needs to be sent to a node if it is determined that the uplink packet is received for the first time, determine whether a base station belongs to a candidate base station set of the node if it is determined that the base station belongs to the candidate base station set of the node, and regard the base station as a downlink base station if it is determined that the base station transmits the downlink packet to the node. For operations that the second processing module 720 can also execute, refer to the description of fig. 4, which is not described herein again.

For another example, the second processing module 720 may also be configured to determine whether a base station belongs to a candidate base station set of a node, where a signal indicator of the base station in the candidate base station set for the node is greater than a predetermined threshold, determine whether an uplink packet is processed when determining that the base station belongs to the candidate base station set of the node, process the uplink packet when determining that the uplink packet is not processed, to determine whether a downlink packet needs to be sent to the node, and determine the base station as the downlink base station when the downlink packet needs to be sent to the node, so that the base station sends the downlink packet to the node. For operations that the second processing module 720 can also execute, reference may be made to the description of fig. 5, which is not described herein again.

[ calculating device ]

Referring to fig. 8, computing device 800 includes memory 810 and processor 820.

The processor 820 may be a multi-core processor or may include multiple processors. In some embodiments, processor 820 may include a general-purpose host processor and one or more special coprocessors such as a Graphics Processor (GPU), a Digital Signal Processor (DSP), or the like. In some embodiments, processor 820 may be implemented using custom circuitry, such as an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate Array (FPGA).

The memory 810 may include various types of storage units, such as system memory, Read Only Memory (ROM), and permanent storage. Wherein the ROM may store static data or instructions for the processor 820 or other modules of the computer. The persistent storage device may be a read-write storage device. The persistent storage may be a non-volatile storage device that does not lose stored instructions and data even after the computer is powered off. In some embodiments, the persistent storage device employs a mass storage device (e.g., magnetic or optical disk, flash memory) as the persistent storage device. In other embodiments, the permanent storage may be a removable storage device (e.g., floppy disk, optical drive). The system memory may be a read-write memory device or a volatile read-write memory device, such as a dynamic random access memory. The system memory may store instructions and data that some or all of the processors require at runtime. In addition, the memory 810 may include any combination of computer-readable storage media, including various types of semiconductor memory chips (DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), magnetic and/or optical disks, may also be employed. In some embodiments, memory 810 may include a removable storage device that is readable and/or writable, such as a Compact Disc (CD), a read-only digital versatile disc (e.g., DVD-ROM, dual layer DVD-ROM), a read-only Blu-ray disc, an ultra-density optical disc, a flash memory card (e.g., SD card, min SD card, Micro-SD card, etc.), a magnetic floppy disc, or the like. Computer-readable storage media do not contain carrier waves or transitory electronic signals transmitted by wireless or wired means.

The memory 810 has stored thereon executable code, which when processed by the processor 820, causes the processor 820 to perform the above-mentioned downlink base station selection method.

The downlink base station selection method, apparatus and computing device according to the present disclosure have been described in detail above with reference to the accompanying drawings.

Furthermore, the method according to the present disclosure may also be implemented as a computer program or computer program product comprising computer program code instructions for performing the above-mentioned steps defined in the above-mentioned method of the present disclosure.

Alternatively, the present disclosure may also be embodied as a non-transitory machine-readable storage medium (or computer-readable storage medium, or machine-readable storage medium) having stored thereon executable code (or a computer program, or computer instruction code) which, when executed by a processor of an electronic device (or computing device, server, etc.), causes the processor to perform the various steps of the above-described method according to the present invention.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems and methods according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

Having described embodiments of the present disclosure, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A downlink base station selection method is characterized by comprising the following steps:

responding to an uplink message sent by a receiving node through a base station, and judging whether the uplink message is received for the first time;

under the condition that the uplink message is judged to be received for the first time, processing the uplink message to determine whether a downlink message needs to be sent to the node or not;

under the condition that a downlink message needs to be sent to the node, judging whether the base station belongs to a candidate base station set of the node, wherein a signal index of a candidate base station in the candidate base station set for the node is larger than a preset threshold value;

and under the condition that the base station is judged to belong to the candidate base station set of the node, determining the base station as a downlink base station, and sending the downlink message to the node by the base station.

2. The downlink base station selection method according to claim 1, further comprising:

and adding the base station information of the base station which sends the uplink message into a base station queue under the condition that the uplink message is judged not to be received for the first time.

3. The downlink base station selection method according to claim 2, further comprising:

under the condition that the base station is judged not to belong to the candidate base station set of the node, judging whether the base station in the base station queue belongs to the candidate base station set of the node;

and under the condition that the base station in the base station queue is judged to belong to the candidate base station set of the node, determining the base station as a downlink base station.

4. The downlink base station selection method according to claim 1, further comprising:

under the condition that the base station is judged not to belong to the candidate base station set of the node, judging whether a base station corresponding to the subsequently received uplink message belongs to the candidate base station set of the node;

and under the condition that the base station corresponding to the subsequently received uplink message belongs to the candidate base station set of the node, determining the base station as a downlink base station.

5. The downlink base station selection method of claim 4, further comprising:

and under the condition that the base stations corresponding to the subsequently received uplink message do not belong to the candidate base station set of the node, selecting the base station with the best signal quality from at least part of the base stations corresponding to the received uplink message as a downlink base station.

6. The downlink base station selection method according to claim 1, further comprising: setting a lock service for the uplink message,

the step of judging whether the uplink message is received for the first time comprises the following steps: requesting to acquire a lock corresponding to the uplink message, judging that the uplink message is received for the first time under the condition of successfully acquiring the lock, and judging that the uplink message is not received for the first time under the condition of failing to acquire the lock.

7. The downlink base station selection method according to claim 1, further comprising:

under the condition that the base station is judged to belong to the candidate base station set of the node, further judging whether the base station meets the requirement of a downlink base station indicated by the uplink message;

and under the condition that the base station is judged to meet the requirement of the downlink base station indicated by the uplink message, determining the base station as the downlink base station.

8. A downlink base station selection method is characterized by comprising the following steps: in response to receiving an uplink message sent by a node through a base station, determining a signal quality index of the base station for the node according to signal quality data of one or more uplink messages sent by the node through the base station, and adding the base station to a candidate base station set of the node under the condition that the signal quality index is greater than a preset threshold value;

judging whether the uplink message is received for the first time, processing the uplink message under the condition that the uplink message is received for the first time to determine whether a downlink message needs to be sent to the node, judging whether the base station belongs to a candidate base station set of the node under the condition that the downlink message needs to be sent to the node, and taking the base station as a downlink base station under the condition that the base station belongs to the candidate base station set of the node to send the downlink message to the node.

9. A downlink base station selection method is characterized by comprising the following steps:

responding to an uplink message sent by a node through a base station, and judging whether the base station belongs to a candidate base station set of the node, wherein a signal index of a candidate base station in the candidate base station set for the node is larger than a preset threshold value;

judging whether the uplink message is processed or not under the condition that the base station is judged to belong to the candidate base station set of the node;

under the condition that the uplink message is not processed, processing the uplink message to determine whether a downlink message needs to be sent to the node;

and under the condition that a downlink message needs to be sent to the node, determining the base station as a downlink base station, and sending the downlink message to the node by the base station.

10. The downlink base station selection method according to claim 9, further comprising:

judging whether the uplink message is processed or not under the condition that the base station is judged not to belong to the candidate base station set of the node;

under the condition that the uplink message is not processed, adding the uplink message received this time or the base station corresponding to the uplink message into a candidate set;

after a preset time interval, judging whether the uplink message is processed or not;

under the condition that the uplink message is judged not to be processed, selecting a base station with the best signal quality from the candidate set;

processing the uplink message corresponding to the selected base station to determine whether a downlink message needs to be sent to the node;

and determining the selected base station as a downlink base station under the condition that a downlink message needs to be sent to the node.

11. The downlink base station selection method according to claim 9, further comprising: setting a lock service for the uplink message,

the step of processing the uplink message comprises: acquiring a lock corresponding to the uplink message, processing the uplink message under the condition of successfully acquiring the lock,

the step of judging whether the uplink message is processed comprises the following steps: and requesting to acquire a lock corresponding to the uplink message, and judging that the uplink message is processed under the condition that the lock acquisition fails.

12. A downlink base station selection method is characterized by comprising the following steps: in response to receiving an uplink message sent by a node through a base station, determining a signal quality index of the base station for the node according to signal quality data of one or more uplink messages sent by the node through the base station, and adding the base station to a candidate base station set of the node under the condition that the signal quality index is greater than a preset threshold value;

judging whether the base station belongs to a candidate base station set of the node, wherein a signal index of the base station in the candidate base station set aiming at the node is larger than a preset threshold value, judging whether the uplink message is processed under the condition that the base station belongs to the candidate base station set of the node, processing the uplink message under the condition that the uplink message is not processed to determine whether the downlink message needs to be sent to the node, and determining the base station as a downlink base station under the condition that the downlink message needs to be sent to the node so that the base station sends the downlink message to the node.

13. A downlink base station selection method is characterized by comprising the following steps:

responding to an uplink message sent by a node through a base station, and determining a signal quality index of the base station aiming at the node according to signal quality data of one or more uplink messages sent by the node through the base station;

adding the base station to a set of candidate base stations for the node if the signal quality indicator is greater than a predetermined threshold.

14. The downlink base station selection method according to claim 13,

the signal quality data includes a signal strength and/or a signal-to-noise ratio of the uplink packet as received by the base station.

15. The method of claim 13, wherein the step of determining the signal quality indicator of the base station for the node comprises:

and processing the signal quality data of one or more uplink messages sent by the node through the base station by utilizing a moving average algorithm or a weighted average algorithm to obtain a signal quality index of the node by the base station.

16. The downlink base station selection method of claim 13, further comprising:

deleting the base station from the set of candidate base stations if the signal quality indicator is less than the predetermined threshold.

17. A downlink base station selection apparatus, comprising:

the first judgment module is used for responding to an uplink message sent by a receiving node through a base station and judging whether the uplink message is received for the first time;

the processing module is used for processing the uplink message under the condition that the uplink message is judged to be received for the first time so as to determine whether a downlink message needs to be sent to the node or not;

a second determining module, configured to determine whether the base station belongs to a candidate base station set of the node when a downlink packet needs to be sent to the node, where a signal indicator of a candidate base station in the candidate base station set for the node is greater than a predetermined threshold;

and the determining module is used for determining the base station as a downlink base station under the condition that the base station is judged to belong to the candidate base station set of the node, so that the base station sends the downlink message to the node.

18. A downlink base station selection apparatus, comprising: a first processing module and a second processing module, wherein in response to receiving an uplink message sent by a node through a base station, the first processing module and the second processing module are executed in parallel,

the first processing module determines a signal quality index of the base station for the node according to signal quality data of one or more uplink messages sent by the node through the base station, and adds the base station to a candidate base station set of the node when the signal quality index is greater than a predetermined threshold;

the second processing module judges whether the uplink message is received for the first time, processes the uplink message to determine whether a downlink message needs to be sent to the node under the condition that the uplink message is received for the first time, judges whether the base station belongs to a candidate base station set of the node under the condition that the downlink message needs to be sent to the node, and takes the base station as a downlink base station under the condition that the base station belongs to the candidate base station set of the node, so that the base station sends the downlink message to the node.

19. A downlink base station selection apparatus, comprising:

the first judging module is used for responding to a received uplink message sent by a node through a base station and judging whether the base station belongs to a candidate base station set of the node, wherein the signal index of a candidate base station in the candidate base station set aiming at the node is larger than a preset threshold value;

a second judging module, configured to judge whether the uplink packet is processed or not when it is determined that the base station belongs to the candidate base station set of the node;

the processing module is used for processing the uplink message under the condition that the uplink message is not processed so as to determine whether the downlink message needs to be sent to the node or not;

and the determining module is used for determining the base station as a downlink base station under the condition that a downlink message needs to be sent to the node, so that the base station sends the downlink message to the node.

20. A downlink base station selection apparatus, comprising: a first processing module and a second processing module, wherein in response to receiving an uplink message sent by a node through a base station, the first processing module and the second processing module are executed in parallel,

the second processing module judges whether the base station belongs to a candidate base station set of the node, wherein a signal index of the base station in the candidate base station set for the node is larger than a preset threshold value, judges whether the uplink message is processed under the condition that the base station belongs to the candidate base station set of the node, processes the uplink message under the condition that the uplink message is not processed so as to determine whether a downlink message needs to be sent to the node, and determines the base station as a downlink base station under the condition that the downlink message needs to be sent to the node so that the base station sends the downlink message to the node.

21. A downlink base station selection apparatus, comprising:

a signal quality index determining module, configured to determine, in response to receiving an uplink packet sent by a node through a base station, a signal quality index of the base station for the node according to signal quality data of one or more uplink packets sent by the node through the base station;

a candidate base station set adding module, configured to add the base station to a candidate base station set of the node if the signal quality indicator is greater than a predetermined threshold.

22. A computing device, comprising:

a processor; and

a memory having executable code stored thereon, which when executed by the processor, causes the processor to perform the method of any one of claims 1 to 16.

23. A non-transitory machine-readable storage medium having stored thereon executable code, which when executed by a processor of an electronic device, causes the processor to perform the method of any of claims 1-16.