CN113507683A

CN113507683A - Asset tag and broadcasting method thereof

Info

Publication number: CN113507683A
Application number: CN202010211022.8A
Authority: CN
Inventors: 胡新振; 唐志文; 莫峰; 陈可; 彭彬; 孙崑泉
Original assignee: TDK Corp
Current assignee: TDK Corp
Priority date: 2020-03-24
Filing date: 2020-03-24
Publication date: 2021-10-15

Abstract

The invention provides an asset tag and a broadcasting method thereof. The method comprises the following steps: detecting a parameter representing the moving state of an asset, wherein an asset tag is arranged on the asset; judging whether the asset is in a static state or a moving state according to the detected parameters; under the condition that the assets are judged to be in a static state, the asset tag sets a broadcast interval as a first broadcast interval and broadcasts asset information of the assets at the first broadcast interval; and under the condition that the asset is judged to be in the moving state, the asset tag sets a broadcast interval to be a second broadcast interval, and broadcasts the asset information of the asset at the second broadcast interval, wherein the first broadcast interval is larger than the second broadcast interval. The invention can meet the two requirements of on-line query and asset tracking at different broadcast intervals, thereby greatly reducing the power consumption of the asset tag and prolonging the service life of the asset tag.

Description

Asset tag and broadcasting method thereof

Technical Field

The invention relates to the technical field of wireless communication, in particular to an asset tag and a broadcasting method of the asset tag.

Background

Asset tags are typically placed on assets. There are two primary purposes of using asset tags: determine if the asset is online and not lost (low real-time requirements) and track mobile assets (high real-time requirements). For purpose one, it is desirable to increase the broadcast interval of the tag in order to confirm whether the asset is online. For example, the broadcast interval of the asset tag is set to 1 min. For purpose two, to track mobile assets, it is desirable to reduce the tag's broadcast interval to meet real-time requirements. For example, the broadcast interval of the asset tag is set to 200 ms. With the reduction of the broadcast interval to meet the real-time requirements, the power consumption of the asset tag must increase significantly.

However, the asset tags on the market are basically powered by small-sized button batteries. The battery capacity of button cells is small, so that the life of asset tags becomes a major issue. In the case of reducing the broadcast interval to meet the real-time requirement, the life of the asset tag is short.

Based on the above analysis, a technical solution that can both implement two operating modes of an asset tag and maximize the lifetime of the asset tag is needed.

Disclosure of Invention

Problems to be solved by the invention

The invention aims to provide a technical scheme which can realize two working modes of an asset tag and can also maximize the service life of the asset tag.

Means for solving the problems

According to a first aspect of the present invention, there is provided a method of broadcasting an asset tag, comprising:

detecting a parameter characterizing a movement status of an asset on which the asset tag is disposed;

judging whether the asset is in a static state or a moving state according to the detected parameters;

under the condition that the assets are judged to be in a static state, the asset tag sets a broadcast interval as a first broadcast interval and broadcasts asset information of the assets at the first broadcast interval;

the asset tag sets a broadcast interval to a second broadcast interval and performs broadcasting of asset information of the asset at the second broadcast interval in a case where it is determined that the asset is in a moving state,

wherein the first broadcast interval is greater than the second broadcast interval.

According to the above method, the asset tag may set different broadcasting intervals according to the status of the asset, and perform broadcasting of the message at the set broadcasting intervals. The broadcasting interval corresponding to the static state is larger than that corresponding to the mobile state, so that the two requirements of online inquiry and asset tracking can be met at different broadcasting intervals. In addition, the power consumption of the asset tag can be greatly reduced in a static state, so that the service life of the asset tag can be prolonged.

Preferably, the parameter indicative of the state of movement of the asset is acceleration.

Preferably, the step of determining whether the asset is in a stationary state or a moving state according to the detected acceleration includes:

judging whether the detected acceleration is smaller than a preset acceleration threshold value or not;

determining that the asset is in a stationary state if the detected acceleration is determined to be less than the acceleration threshold;

determining that the asset is in a mobile state if the detected acceleration is determined to be above the acceleration threshold.

According to the method, the acceleration parameter is selected to determine the moving state of the asset, so that the real moving state of the asset can be reliably reflected, and the reliability of the algorithm is improved.

Preferably, each of the first broadcast intervals includes a broadcast period and a non-broadcast period,

the step of the asset tag broadcasting asset information of the asset at a first broadcast interval includes:

the asset tag broadcasts asset information for the asset during a broadcast period of each first broadcast interval;

during the non-broadcast period of each first broadcast interval, the processor of the asset tag is powered down.

According to the method, the first broadcast interval refers to the time between two adjacent broadcast events when the asset is in a static state, the first broadcast interval is divided into a broadcast time period and a non-broadcast time period, the asset tag broadcasts a message in the broadcast time period, the asset tag is in a deep sleep mode in the non-broadcast time period, and the processor of the asset tag is powered off. Therefore, the power consumption of the asset tag in the non-broadcast time period can be effectively reduced, and the service life of the asset tag is further prolonged.

Preferably, each of the second broadcast intervals includes a broadcast period and a non-broadcast period,

the step of the asset tag broadcasting asset information of the asset at a second broadcast interval includes:

the asset tag broadcasts asset information for the asset during a broadcast period of each second broadcast interval;

during the non-broadcast period of each second broadcast interval, the processor of the asset tag is powered down.

According to the method, the second broadcast interval refers to the time between two adjacent broadcast events when the asset is in a moving state, the second broadcast interval is divided into a broadcast time period and a non-broadcast time period, the asset tag broadcasts a message in the broadcast time period, the asset tag is in a deep sleep mode in the non-broadcast time period, and the processor of the asset tag is powered off. Therefore, even if the assets are in a moving state, the power consumption of the asset tags in the non-broadcasting time period can be effectively reduced, and the service life of the asset tags is further prolonged.

Preferably, the method for broadcasting the asset tag further includes:

after the asset tag broadcasts the asset information of the asset at a second broadcast interval, if the asset is judged to be in a static state according to the latest detected parameters, the asset tag resets the broadcast interval to a first broadcast interval, and broadcasts the asset information of the asset at the first broadcast interval.

According to the method, after the asset tag broadcasts the asset information of the asset at the second broadcast interval, if the real-time detected data indicates that the asset recovers the static state, the asset tag immediately increases the broadcast interval from the second broadcast interval to the first broadcast interval, so that the broadcast interval can be adjusted in real time according to the real-time detected parameters.

Preferably, the broadcast interval for broadcasting can be set by setting a Clock chip (RTC) of the asset tag.

Preferably, the method for broadcasting the asset tag further includes:

and the asset management system generates and outputs alarm information when the broadcast interval of the asset tag is judged to be the second broadcast interval based on the received asset information from the asset tag.

According to the above method, in the case where the asset is a special asset whose movement is prohibited (the tag provided thereon is an antitheft tag), if it is determined that the asset is in a moving state and a packet of asset information is broadcast to the asset management system at the second broadcast interval, the asset management system immediately generates and outputs alarm information according to the second broadcast interval of the received packet. Therefore, the moving state of the assets can be discovered immediately and asset tracking can be started, so that the safety of the assets is protected to the maximum extent.

According to a second aspect of the present invention there is provided an asset tag comprising:

a detector that detects a parameter that characterizes a movement status of an asset on which the asset tag is disposed;

a clock chip;

a processor which judges whether the asset is in a stationary state or a moving state according to the parameter detected by the detector, sets the clock chip to set a broadcasting interval to a first broadcasting interval and perform broadcasting of asset information of the asset at the first broadcasting interval in a case where the asset is judged to be in the stationary state, and sets the clock chip to set a broadcasting interval to a second broadcasting interval and perform broadcasting of asset information of the asset at the second broadcasting interval in a case where the asset is judged to be in the moving state,

According to the above configuration, the asset tag can set different broadcast intervals according to the status of the asset, and broadcast the message at the set broadcast intervals. The broadcasting interval corresponding to the static state is larger than that corresponding to the mobile state, so that the two requirements of online inquiry and asset tracking can be met at different broadcasting intervals. In addition, the power consumption of the asset tag can be greatly reduced in a static state, so that the service life of the asset tag can be prolonged.

Preferably, the parameter indicative of the state of movement of the asset is acceleration and the detector is an acceleration sensor.

According to the structure, the acceleration parameter is selected to determine the moving state of the asset, so that the real moving state of the asset can be reliably reflected, and the reliability of the algorithm is improved.

Drawings

The scope of the present disclosure may be better understood by reading the following detailed description of exemplary embodiments in conjunction with the accompanying drawings. Wherein the included drawings are:

fig. 1 is a flowchart illustrating a method for broadcasting an asset tag according to a first embodiment of the present invention.

FIG. 2 illustrates a schematic diagram of a broadcast interval of an asset tag of an embodiment of the present invention.

Fig. 3 shows a schematic circuit diagram of an asset tag according to a second embodiment of the invention.

Fig. 4 is a flowchart illustrating a broadcasting method of an asset tag according to a second embodiment of the present invention.

Figure 5 shows a topology diagram of a prior art bluetooth low energy mesh network.

Fig. 6 shows a topology diagram of a bluetooth low energy mesh network according to a third embodiment of the present invention.

Fig. 7 shows a scanning strategy diagram of a gateway in the prior art.

Fig. 8 shows a schematic structural diagram of a gateway in the third embodiment of the present invention.

Fig. 9 shows a scanning policy diagram of a gateway in the third embodiment of the present invention.

Fig. 10 is a flowchart illustrating a subnet configuration method of a bluetooth low energy mesh network according to a fourth embodiment of the present invention.

Fig. 11 is a flowchart illustrating a method for determining a target subnet according to subnet information by a light gateway in the fourth embodiment of the present invention.

Fig. 12 is a diagram showing an example of a subnet configuration method of a bluetooth low energy mesh network according to a fourth embodiment of the present invention.

Fig. 13 is a flowchart illustrating a message uploading method based on a bluetooth low energy mesh network according to a fifth embodiment of the present invention.

Fig. 14 is a diagram illustrating an example of a message uploading method based on a bluetooth low energy mesh network according to a fifth embodiment of the present invention.

Fig. 15 is a flowchart illustrating a bluetooth tag location determining method based on a bluetooth low energy mesh network according to a sixth embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the following will describe in detail an implementation method of the present invention with reference to the accompanying drawings and embodiments, so that how to apply technical means to solve the technical problems and achieve the technical effects can be fully understood and implemented.

In the prior art, the broadcasting interval of the asset tag is usually constant, which cannot satisfy the requirements of both the asset online query and the asset real-time tracking. Asset online query requirements: for a fixed asset, most of the time it is stationary, it is moved only occasionally, when it is stationary, it only needs to know if it is online to ensure it is not lost, its position can be reported every few minutes, which requires a large broadcast interval. Asset real-time tracking requirements: once an asset moves, the asset management system should respond immediately and track its location for easy management, which requires a small broadcast interval. Based on the above analysis, a technical solution that can both implement two operating modes of an asset tag and maximize the lifetime of the asset tag is needed.

In order to solve the above technical problem, an embodiment of the present invention provides an asset tag and a broadcasting method thereof.

Example one

Fig. 1 is a flowchart illustrating a method for broadcasting an asset tag according to a first embodiment of the present invention. As shown in fig. 1, the asset tag broadcasting method of the embodiment of the present invention mainly includes steps S1 through S4.

In step S1, a parameter characterizing the movement status of the asset is detected, and an asset tag is set on the asset.

In particular, asset tags are typically placed on assets. Parameters that can characterize the movement state of an asset are first obtained. In a preferred embodiment of the invention, the acceleration of the asset is used as a parameter characterizing the movement state of the asset. The acceleration parameter is selected to determine the moving state of the asset, so that the real moving state of the asset can be reliably reflected, and the reliability of the algorithm is improved. Of course, other parameters may be detected, such as the speed, displacement, etc. of the asset.

In step S2, it is determined whether the asset is in a stationary state or a moving state based on the detected parameters.

Specifically, the acceleration is described by taking a parameter as an example. First, an acceleration threshold is preset, which may be determined by trial and error. And then determining whether the detected acceleration is less than a preset acceleration threshold. In the event that the detected acceleration is determined to be less than the acceleration threshold, the asset is determined to be in a stationary state. In the event that the detected acceleration is determined to be above the acceleration threshold, it is determined that the asset is in a moving state.

In step S3, in the case where it is determined that the asset is in a stationary state, the asset tag sets a broadcast interval to a first broadcast interval, and broadcasts asset information of the asset at the first broadcast interval. The broadcasting interval refers to the time between two adjacent broadcasting events, and the larger the broadcasting interval is set, the lower the broadcasting frequency is, and the worse the real-time performance is; conversely, the smaller the broadcast interval is set, the higher the broadcast frequency and the better the real-time performance. Here, the first broadcast interval when the asset is in a stationary state is greater than the second broadcast interval when the asset is in a moving state. In a preferred embodiment of the present invention, the first broadcast interval may be set to 1min, and the second broadcast interval may be set to 1 s.

In step S4, in the case where it is determined that the asset is in the moving state, the asset tag sets the broadcast interval to a second broadcast interval, and broadcasts asset information of the asset at the second broadcast interval.

According to the present embodiment, the asset tag may set different broadcasting intervals according to the status of the asset and perform broadcasting of the message at the set broadcasting intervals. The broadcasting interval corresponding to the static state is larger than that corresponding to the mobile state, so that the two requirements of online inquiry and asset tracking can be met at different broadcasting intervals. Namely, when the assets are queried online, the broadcasting interval is large, and the requirement of low real-time performance is met. And when asset tracking is carried out, the broadcasting interval is smaller, and the requirement of high real-time performance is met. In addition, the power consumption of the asset tag can be greatly reduced in a static state, so that the service life of the asset tag can be prolonged.

FIG. 2 illustrates a schematic diagram of a broadcast interval of an asset tag of an embodiment of the present invention. As shown in fig. 2, the first broadcast interval T1 includes a broadcast period of a high level and a non-broadcast period of a low level. The asset tag broadcasts asset information for the asset during a broadcast period of each first broadcast interval. During the non-broadcast period of each first broadcast interval, the processor of the asset tag is powered down.

Still referring to fig. 2, the second broadcast interval T2 includes a broadcast period of a high level and a non-broadcast period of a low level. The asset tag broadcasts asset information for the asset during a broadcast period of each second broadcast interval. During the non-broadcast period of each second broadcast interval, the processor of the asset tag is powered down.

In a preferred embodiment of the present invention, after the asset tag broadcasts the asset information of the asset at the second broadcast interval, if it is determined that the asset is in a static state according to the latest detected parameter, the asset tag resets the broadcast interval to the first broadcast interval, and broadcasts the asset information of the asset at the first broadcast interval.

According to the method, after the asset tag broadcasts the asset information of the asset at the second broadcast interval, if the real-time detected data indicates that the asset is restored to the static state, the asset tag immediately increases the broadcast interval from the second broadcast interval to the first broadcast interval, so that the broadcast interval can be adjusted in real time according to the real-time detected parameters.

According to the method described above, the asset management system generates and outputs alarm information when it is determined that the broadcast interval of the asset tag is the second broadcast interval based on the reception of the asset information from the asset tag.

According to the above method, in the case where the asset is a special asset whose movement is prohibited, if it is determined that the asset is in a moving state and a data packet of asset information is broadcast to the asset management system at the second broadcast interval, the asset management system instantly generates and outputs alarm information according to the second broadcast interval of the received data packet. Therefore, the moving state of the assets can be discovered immediately and asset tracking can be started, so that the safety of the assets is protected to the maximum extent.

Example two

Fig. 3 shows a schematic circuit diagram of an asset tag according to a second embodiment of the invention. As shown in fig. 3, the asset tag includes a battery 1, an accelerometer 2 (also referred to as an acceleration sensor), an RTC chip 3 (also referred to as a clock chip) and a wireless chip 4 (also referred to as a wireless MCU, processor).

The accelerometer 2 is in the wake-up mode. As the accelerometer 2, an accelerometer of model ADXL363 or BMA400 can be selected from the viewpoint of lower power consumption in the wake-up mode. The RTC chip 3 is AM1805 from AM18X5 with supply current of only 14NA with an RC oscillator.

The asset tag operates in a stationary mode (stationary state) and a mobile mode (mobile state). These two modes are described in detail below with reference to fig. 4.

A static mode:

when the asset is in a quiescent state, the accelerometer 2 is in a deep sleep mode and there will be no interrupt output to the EXI pin of the RTC chip 3. The RTC chip 3 will not wake up immediately. At this time, the RTC chip 3 will operate according to the setting of the internal timer. Assuming that the broadcast period is set to the first broadcast period T1, after a low level (non-broadcast period) in the first broadcast period T1, the RTC chip 3 will wake up and the wireless chip 4 will be powered on. At this point, if there is any acceleration data, the wireless chip 4 will query the accelerometer 2. Typically, in the quiescent state, there is no data from the accelerometer 2. After the query, the wireless chip 4 broadcasts the asset information package to the asset management system.

Here, the wireless technology may be BLE, LORA, NB-IoT, etc., and then the asset management system will receive the asset information packet and display the asset status on the web page. After broadcasting the asset information package, the wireless chip 4 will pass through I²The C/SPI sends a command to the RTC chip 3, and the RTC chip 3 will go to deep sleep and the wireless chip 4 will power down. The sleep current of the RTC chip 3 is much lower than that of the wireless chip 4 itself. For example, the deep sleep current of BLE chip NRF52832 is 2uA, which is almost 100 times the sleep current of RTC chip 3. This can greatly reduce the output power consumption of the tag, thereby enabling a significant increase in the battery life of the tag.

Moving mode:

if the asset moves suddenly, the accelerometer 2 will wake up immediately and then generate an interrupt signal to the EXTI pin of the RTC chip 3. The RTC chip 3 will wake up immediately and the wireless chip 4 is powered up. Then, if there is a pass I²C/SPI, the wireless chip 4 will interrogate the accelerometer 2. Here, the accelerometer 2 transmits acceleration data to the wireless chip 4. The wireless chip 4 will then process the acceleration data and change the broadcast interval to a second broadcast interval T2 and broadcast the asset information packets to the asset management system at the second broadcast interval T2 until there is no acceleration data from the accelerometer 2. If the special asset is prohibited from moving, the asset management system will alert at a first time. The system will then track the move assets in real timeAnd (4) producing. If no acceleration data is present, the wireless chip 4 will pass I²The C/SPI sends a command to the RTC chip 3, and the RTC chip 3 will go to deep sleep and the wireless chip 4 will power down.

The asset tag and the broadcasting method thereof in the first and second embodiments of the present invention can be applied to asset management and tracking, personnel tracking, monitoring of special experimental conditions, and the like. The asset tag may be a bluetooth tag, and the broadcasted message may be uploaded to a cloud server through a bluetooth mesh network.

The bluetooth mesh network, a subnet configuration method based on the bluetooth mesh network, a message uploading method, and a bluetooth tag position determining method will be described in detail below.

It should be noted that BLE (Bluetooth Low Energy) mesh network is taken as an example to describe the following embodiments in detail.

EXAMPLE III

In conventional designs, BLE communications are peer-to-peer. The BLE tag or sensor node communicates directly with the gateway. As shown in fig. 5, the tags are respectively connected with the cloud server through two gateways. With this communication approach, due to the hardware limitations of BLE technology, messages cannot be transmitted over long distances, so the gateway must be deployed very close to the BLE tag to receive BLE messages sent by the BLE tag. In addition, the cost of the air gates is high, and the deployment density of the gateways is high, so that the deployment cost of the whole network is high.

In order to solve the technical problems in the prior art, embodiments of the present invention provide a bluetooth low energy mesh network that is capable of transmitting messages over long distances and has a low deployment cost.

The bluetooth low energy mesh network of the present embodiment is provided with a plurality of subnets. Each subnet is provided with one gateway and at least one light gateway. Here, the gateway acts as an access device and the light gateway acts as a relay device. The light gateway has only partial functions of the gateway, and thus the deployment cost of the light gateway is lower than that of the gateway. The gateway is in communication connection with the cloud server. Each light gateway may be in communication with the gateway directly or via other light gateways. The messages output by the Bluetooth tag are relayed to the gateway through one or more light gateways, then the received messages are processed by the gateway and uploaded to the cloud server, and the uploaded messages are stored and analyzed by the cloud server.

Fig. 6 shows a topology diagram of a bluetooth low energy mesh network according to a third embodiment of the present invention. Referring to fig. 6, the bluetooth low energy mesh network 200 is provided with a subnet 201, a subnet 202, and a subnet 203. The structure of the subnet is described below by taking the subnet 201 as an example. The subnet 201 comprises one gateway GW1 and two light gateways LGW1, LGW 2. The TAG1 is communicatively connected to the gateway GW1 via a light gateway LGW 1. The TAG2 is communicatively connected to the gateway GW1 via a light gateway LGW 2. Gateway GW1 is communicatively coupled to cloud server 100. The light gateways belonging to the same subnet may be not communicatively connected to each other (e.g., the light gateway in subnet 201) or may be communicatively connected to each other (e.g., the light gateways in subnet 202 and subnet 203), which is not limited by the embodiment of the present invention.

In this embodiment, the light gateway only has partial functions of the gateway, such as a message receiving function, a message sending function, and a message filtering function. The function of the light gateway is not limited to this, and the light gateway may further include an assisted positioning function of the gateway, which is to perform assisted positioning based on a Received Signal Strength Indication value (RSSI).

By applying the bluetooth low energy mesh network of the embodiment, the light gateway for relaying the message is added between the bluetooth tag and the gateway, and the message can be transmitted to the gateway deployed outside the long distance after being relayed by the light gateway, so that the long distance transmission of the message can be realized. In addition, the light gateway only has partial functions of the gateway, so that the deployment cost of the light gateway is lower than that of the gateway, and the deployment cost of the Bluetooth low-power mesh network can be effectively reduced.

The embodiment of the invention is mainly used for establishing a simple, reliable and low-cost wireless transmission network, solves the problem that the transmission distance of the Bluetooth low-power mesh network is limited, and can assist in positioning the asset position. The bluetooth low energy mesh network of the embodiments of the present invention can implement many-to-many (M: M) device communication for creating a large-scale device network. The embodiment of the invention is suitable for being applied to building automation, asset management systems, sensor networks and other solutions of the Internet of things, and can realize large-scale, long-distance, reliable and safe communication among dozens, hundreds or even thousands of devices.

Fig. 7 shows a scanning strategy diagram of a gateway in the prior art. As shown in figure 7, the gateway uses a single BLE chip to poll for three scanning channels. The BLE chip first performs a message scan on a first scan channel (scan channel 37, whose center frequency is 2402MHz), then performs a message scan on a second scan channel (scan channel 38, whose center frequency is 2426MHz), and then performs a message scan on a third scan channel (scan channel 39, whose center frequency is 2480 MHz). Next, the BLE chip repeatedly performs the above scanning process. When scanning the messages on the scanning channels, the time period of each scanning is determined by the scanning interval and the scanning window parameter.

However, when the gateway further includes the 2.4G WIFI module (the gateway of this embodiment includes the 2.4G WIFI module and the 5G WIFI module), the wireless scanning of the 2.4G WIFI module may interfere with one or two of the three scanning channels of the BLE chip, so as to reduce the reliability of data transmission.

In order to solve the above problems, embodiments of the present invention improve the internal configurations of the gateway and the light gateway. Fig. 8 shows a schematic structural diagram of a gateway according to an embodiment of the present invention, and fig. 9 shows a schematic scanning policy diagram of the gateway according to the embodiment of the present invention. In a preferred embodiment of the present invention, referring to fig. 8 and 9, the gateway includes a first bluetooth low energy chip, a second bluetooth low energy chip, a third bluetooth low energy chip, and a processor. The first bluetooth low energy chip performs a message scan on a first scan channel (scan channel 37, whose center frequency is 2402 MHz). The second bluetooth low energy chip performs a message scan on a second scan channel (scan channel 38, centered at 2426 MHz). The third bluetooth low energy chip performs a message scan on a third scan channel (scan channel 39, whose center frequency is 2480 MHz). The processor is in communication connection with the first Bluetooth low-power chip, the second Bluetooth low-power chip and the third Bluetooth low-power chip respectively. The scanning of the first Bluetooth low energy chip on the first scanning channel, the scanning of the second Bluetooth low energy chip on the second scanning channel and the scanning of the third Bluetooth low energy chip on the third scanning channel are carried out simultaneously. And the messages scanned by each Bluetooth low-power chip are transmitted to the processor through the UART interface, and the messages are filtered and processed by the processor. The processor may be a processor such as a CPU. In particular, the first bluetooth low energy chip, the second bluetooth low energy chip, the third bluetooth low energy chip and the processor are integrated on the same printed circuit board.

In this embodiment, since the gateway employs three bluetooth low energy chips, and each bluetooth low energy chip individually scans one scanning channel, compared with the prior art in which a single bluetooth low energy chip is used to poll three scanning channels, the scanning efficiency of this embodiment is increased by several times. In addition, because three scanning channels are scanned simultaneously, the possibility of receiving messages is increased, and the reliability of the whole Bluetooth low-power mesh network is ensured.

In addition, under the condition that the gateway is integrated with a 2.4G WIFI module besides a processor and three Bluetooth low-power chips, the gateway of the embodiment can solve the problem that the 2.4G WIFI module interferes with scanning channels of the Bluetooth low-power chips. Specifically, the channels used by the bluetooth low energy chip scan are typically scan channels 37, 38 and 39. The relevant WIFI interference channels are 1, 3, 4, 5, 13 and 14, so the best solution is to use WIFI channels 2, 6, 7, 8, 9, 10, 11 and 12. 2.4G WIFI will only interfere with 1 to 2 of the first, second and third scan channels. Therefore, under the condition that 3 bluetooth low energy chips work simultaneously, the scanning of at least one bluetooth low energy chip will not receive the influence of WIFI, and this has improved data transmission's reliability. That is, when the 2.4G WIFI module is operating on a certain channel, it only affects a portion of the scan channels of the bluetooth low energy chip. For example, the WIFI channel 2412MHz only affects the first scanning channel 37 (center frequency is 2402MHz) and the second scanning channel 38 (center frequency is 2426MHz), but the WIFI channel 2412MHz does not affect the third scanning channel 39 (center frequency is 2480 MHz). The three Bluetooth low-power chips are used for scanning 3 scanning channels simultaneously, so that the anti-interference capability can be improved, and the network is more reliable.

In a preferred embodiment of the present invention, the light gateway has a configuration structure similar to that of the gateway, and also has three bluetooth low energy chips (a fourth bluetooth low energy chip, a fifth bluetooth low energy chip, and a sixth bluetooth low energy chip). However, the light gateway does not have a processor and a WIFI module. And the fourth Bluetooth low-power chip scans the message on the first scanning channel. And the fifth Bluetooth low-power chip performs message scanning on the second scanning channel. And the sixth Bluetooth low-power chip performs message scanning on the third scanning channel. And the fourth Bluetooth low-power chip, the fifth Bluetooth low-power chip and the sixth Bluetooth low-power chip simultaneously scan messages on respective scanning channels. And the fourth Bluetooth low-power chip, the fifth Bluetooth low-power chip and the sixth Bluetooth low-power chip are integrated on the same printed circuit board.

The configuration principle of the light gateway is the same as that of the gateway, and repeated contents are not described herein again. The configuration of the light gateway in this embodiment can also increase the scanning efficiency by times, thereby improving the possibility of receiving messages, and on the other hand, the light gateway can also improve the anti-interference capability, so that the network is more reliable.

Example four

The present embodiment mainly relates to the subnet configuration method of the bluetooth low energy mesh network of the third embodiment. Fig. 10 shows a flowchart of a subnet configuration method of the bluetooth low energy mesh network of fig. 6. As shown in fig. 10, the subnet configuration method of the present embodiment mainly includes steps S101 to S104.

In step S101, each gateway in the bluetooth low energy mesh network is divided into different subnets.

Specifically, one gateway uniquely corresponds to one subnet. Different gateways are divided into different subnets. Referring to the example in fig. 12, the mesh network includes two gateways GW1 and GW 2. In this case, gateway GW1 is divided into subnet 201 and gateway GW2 is divided into subnet 202.

In step S102, each gateway in the bluetooth low energy mesh network forwards subnet information of a subnet to which the gateway belongs within the mesh network. Here, the subnet information includes a subnet identification code and an information lifetime, and the information lifetime in the subnet information is reduced by 1 each time the subnet information is forwarded.

Specifically, each gateway in the bluetooth low energy mesh network periodically forwards subnet information of the subnet to which the gateway belongs within the mesh network range. The gateway may forward the subnet information in such a way that the subnet information is flooded throughout the mesh network. In order to prevent the information from being forwarded endlessly, the information lifetime in the subnet information is limited.

The detailed description is made with reference to the example in fig. 12. The gateway GW1 outputs subnet information associated with the subnet to which the gateway GW1 belongs. The subnet information includes a subnet identification code and an information lifetime (hereinafter referred to as TTL value, Time to Live value). The subnet identification code is uniquely corresponding to the subnet and is the identity of the subnet. The time to live of information in the subnet information output by gateway GW1 is a default value. In the example shown in fig. 12, the default value of TTL value is 3. The TTL value of the subnet information output from gateway GW1 is 3. The lifetime of the information in the subnet information is reduced by 1 every time the subnet information is forwarded. And after receiving the subnet information with the TTL value of 3, the light gateway subtracts 1 from the TTL value of the subnet information and continuously forwards the subnet information to a subsequent light gateway in communication connection with the light gateway. And when the subnet information is forwarded by the subsequent light gateway once, the TTL of the subnet information is also reduced by 1 by itself until a certain light gateway receives the subnet information with the TTL value of 0. When receiving the subnet information with TTL value of 0, a certain light gateway directly discards the subnet information with TTL value of 0 without forwarding outwards.

In step S103, the light gateway receives subnet information of each subnet, and determines a target subnet according to the subnet information.

Specifically, a method for the light gateway to determine the target subnet according to the subnet information is shown in fig. 11. The method mainly includes steps S1031 to S1034.

In step S1031, the light gateway compares the information lifetime in all the received subnet information.

In step S1032, the light gateway determines whether only one subnet information having the largest information lifetime exists among all the received subnet information.

In step S1033, when it is determined that only one subnet information having the largest information lifetime exists in all the received subnet information, the subnet corresponding to the subnet information having the largest information lifetime is determined as the target subnet.

In this step, the subnet corresponding to only one subnet information having the largest information lifetime is determined as the target subnet.

In step S1034, when it is determined that there is not only one subnet information having the largest information lifetime (i.e., there are a plurality of subnet information having the largest information lifetime), among all the received subnet information, the subnet corresponding to the subnet information having the largest received signal strength indication value among the subnet information having the largest information lifetime is determined as the target subnet.

In this step, when a plurality of information survival times are aligned to be the maximum, the target subnet is determined based on the received signal strength indication value. That is, the received signal strength indication values of the plurality of pieces of subnet information having the largest information lifetime in parallel are compared, and the subnet corresponding to the subnet information having the largest received signal strength indication value among the plurality of pieces of subnet information is determined as the target subnet.

In step S104, the light gateway joins the determined target subnet.

Specifically, after the target subnet is determined in the above manner, the light gateway is added to the target subnet so as to be subordinate to the target subnet.

The method of steps S101 to S104 above is applied to each individual light gateway (i.e. light gateway not belonging to a certain subnet yet) to configure these individual light gateways into the subnet, thereby completing the subnet configuration of the entire bluetooth low energy mesh network. For a light gateway that cannot join a certain subnet using the above steps, it is set that the light gateway belongs to each subnet.

The process of joining a subnet by a light gateway LGW3 is explained with reference to fig. 12. The gateway GW1 transmits subnet information with TTL as default value 3 to the light gateway LGW 3. The gateway GW2 transmits the subnet information with TTL of 1 to the light gateway LGW3 through the two light gateways (the TTL value of the subnet information transmitted by the gateway GW2 is reduced by 1 for every light gateway, and after relaying through the two light gateways, the TTL value is changed from the default value of 3 to 1). Next, the light gateway LGW3 compares TTL values of the subnet information from the gateways GW1 and GW2, and takes the gateway GW1 corresponding to the subnet information whose TTL value (i.e., 3) is large as a target gateway. The light gateway LGW3 then joins the target subnet 201 to which the target gateway GW1 belongs.

The process of joining a subnet by a light gateway LGW4 is explained with reference to fig. 12. The gateway GW1 transmits the subnet information with TTL of 2 to the light gateway LGW4 through one light gateway. The gateway GW2 transmits the subnet information with TTL of 2 to the light gateway LGW4 through a light gateway (the TTL value of the subnet information transmitted by the gateway GW2 is reduced by 1 for every light gateway, and after relaying through a light gateway, the TTL value is changed from the default value of 3 to 2). Next, the light gateway LGW3 compares TTL values of the subnet information from the gateways GW1 and GW2, and when the TTL values of the two subnet information are compared to be the same (both are 2), the gateway GW1 corresponding to the subnet information having a large received signal strength indication value is set as the target gateway. The light gateway LGW4 then joins the target subnet 201 to which the target gateway GW1 belongs.

According to the method, the light gateway can select and join the subnet closest to the light gateway by using the received subnet information of each subnet. The setting of the information survival time can limit the forwarding times of the subnet information of each subnet in the mesh network, and can reduce the network flow.

In addition, in order to solve the problems that in the prior art, when an edge node communicates with a gateway, a message sent in a plain text format can be easily detected by a third party, so that the risk of information leakage is high, and the whole network is easily attacked by a hacker, in a preferred embodiment of the invention, subnet information transmitted in a subnet configuration process is encrypted, then the encrypted subnet information is forwarded within the range of a mesh network, and after receiving the encrypted subnet information, a light gateway decrypts the received encrypted subnet information and determines a target subnet according to the decrypted subnet information. Specifically, the subnet information is encrypted using the AES128 algorithm.

The embodiment can improve the security of the transmission of the subnet information in the mesh network, thereby reducing the leakage risk of the subnet information and the possibility of hacking of the whole network.

EXAMPLE five

The present embodiment mainly relates to a message uploading method of a bluetooth low energy mesh network based on the third embodiment. Fig. 13 is a flowchart illustrating a message uploading method based on the bluetooth low energy mesh network of fig. 6 according to an embodiment of the present invention. As shown in fig. 13, the message uploading method of the present embodiment mainly includes steps S201 to S203.

In step S201, the bluetooth tag broadcasts a message, which includes a message body, a message lifetime, and a message sequence number.

In step S202, the light gateway receives the message broadcasted by the bluetooth tag, and performs flooding transmission on the message in the subnet to which the light gateway belongs, so as to forward the message to the gateway in the subnet.

In step S203, the gateway processes the received message and uploads the processed message to the cloud server.

The method for performing flooding transmission on a message in the subnet to which the light gateway belongs in step S202 is described in detail below with reference to fig. 14.

In this embodiment, the message broadcast by bluetooth includes a message body, a message lifetime, and a message sequence number. The message text is specific data to be uploaded to the cloud server. The message lifetime is similar to the information lifetime mentioned in the fourth embodiment, and is used to limit the number of times of transmission of the message, so as to prevent endless forwarding of the message. The message sequence number is an identification of the message, and each message has a message sequence number uniquely corresponding to it. Here, the earlier the time of the message output by the bluetooth tag is, the smaller the message sequence number of the message is, and the earlier the message output is an old message compared to the message output subsequently.

Referring to fig. 14, the message broadcasted by the bluetooth TAG3 is first received directly by the gateway GW 1. In subnet 201, there are three communication paths associated with bluetooth TAG 4: route one, TAG3- > LGW5- > LGW6- > LGW 7; route two, TAG3- > LGW5- > LGW8- > GW 1; route three, TAG3- > LGW5- > LGW6- > LGW8- > GW 1.

There are two processes involved by the light gateway for relaying messages during message transmission. Firstly, the light gateway executes an updating operation of subtracting 1 from the message lifetime in the received message, and judges whether the message lifetime in the message after the updating operation is 0 or not, if the message lifetime in the message after the updating operation is judged to be 0, the message after the updating operation is discarded, and if the message lifetime in the message after the updating operation is judged to be more than 0, whether the message sequence number with the value more than the message sequence number in the message after the updating operation is stored locally or not is further judged. And under the condition that the message sequence number of the value in the message after the updating operation is judged not to be stored locally, the message sequence number in the message after the updating operation is stored locally and the message after the updating operation is forwarded to a light gateway or a gateway which is in communication connection with the light gateway.

The forwarding process of the message is explained by taking the light gateway LGW6 as an example. After receiving the message with the TTL value of 2 forwarded by the light gateway LGW5, the light gateway LGW6 first determines that the TTL value (2) in the received message is greater than 0, and then the light gateway LGW6 subtracts 1 from the TTL value of the message, and the updated TTL value is 1. Next, the light gateway LGW6 determines whether a message sequence number whose value is greater than or equal to the message sequence number in the message is stored locally, that is, the light gateway LGW6 determines whether a message which is a duplicate message or an old message with respect to the message is stored locally, and the light gateway LGW6 stores the message sequence number in the message locally and forwards the updated message (TTL value is 1) to the light gateway LGW7 and the light gateway LGW8 when determining that the message sequence number whose value is greater than or equal to the message sequence number in the message is not stored locally. Subsequently, the light gateway LGW7 and the light gateway LGW8 also forward the message with the same flow.

According to the above method, in one aspect, a bluetooth low energy mesh network utilizes a flooding method (i.e., a flooding mechanism) in which message transmission is managed (i.e., message lifetime is utilized to limit the number of times a message is forwarded in a subnet) for message propagation in a subnet. Messages can only be forwarded within the subnet range, thus reducing network traffic. It can be seen that the method of the present embodiment is a simple and reliable form of message relaying suitable for low power wireless mesh networks, particularly those handling large amounts of multicast traffic. This makes the method of the present embodiment ideal for applications in the business and industrial markets where stringent reliability, scalability and performance requirements apply. On the other hand, the embodiment can inhibit the situation that the message is repeatedly forwarded by the same light gateway and the situation that the light gateway forwards the old message after forwarding the new message through the message sequence number, so that the repeated message and the old message can be filtered, thereby reducing the repeated service in the network and preventing malicious attacks.

In addition, in order to solve the problems that in the prior art, when an edge node communicates with a gateway, a message sent in a plain text format can be easily detected by a third party, so that the risk of information leakage is high, and the whole network is easily attacked by a hacker, in a preferred embodiment of the present invention, the message transmitted in the message uploading process is encrypted, the encrypted message is then flooded within the subnet, and the light gateway, upon receiving the encrypted message transmitted by the bluetooth tag or other light gateway, decrypting the received encrypted message, judging that the message survival time in the message after the updating operation is more than 0, and in case that the message sequence number whose value is above the message sequence number in the message after the update operation is not locally stored, and encrypting the message after the updating operation, and forwarding the encrypted message to a light gateway or a gateway which is in communication connection with the light gateway. In particular, the AES128 algorithm is used to encrypt the message.

The embodiment can improve the safety of the transmission of the message output by the Bluetooth tag in the subnet, thereby reducing the leakage risk of the message and the possibility that the whole network is attacked by hackers.

EXAMPLE six

The present embodiment mainly relates to a bluetooth tag location determination method based on the bluetooth low energy mesh network of the third embodiment. Fig. 15 is a flowchart illustrating a bluetooth tag location determining method based on a bluetooth low energy mesh network according to a sixth embodiment of the present invention. As shown in fig. 15, the bluetooth tag position determining method of the present embodiment mainly includes step S301 and step S302.

In step S301, the cloud server obtains received signal strength indication values of messages broadcasted by the at least three devices for receiving the bluetooth tag. Here, at least three devices are affiliated with the bluetooth mesh network.

Specifically, after the bluetooth tag broadcasts the message, at least three devices in the bluetooth low energy mesh network can directly receive the message broadcasted by the bluetooth tag. Here, the direct reception means that the device does not receive the message broadcasted by the bluetooth tag via the relay of the other device, but directly scans for the message broadcasted by the bluetooth tag. Each device that directly receives a message records in the message the received signal strength indication value of the received message. The device may be a light gateway or a gateway. In the case where the device is a light gateway, the message recorded with the received signal strength indication value is uploaded to the cloud server via a relay of the gateway (or other light gateways and gateways). And under the condition that the equipment is a gateway, directly uploading the message recorded with the received signal strength indicating value to a cloud server.

In step S302, the cloud server determines location information of the bluetooth tag according to the obtained received signal strength indication value and preset location information of at least three devices.

Specifically, first, for each of at least three devices, a distance between the device and a bluetooth tag is determined according to a received signal strength indication value of a message from the bluetooth tag received by the device. Then, the position information of the Bluetooth tag is determined according to the distance between each of the at least three devices and the Bluetooth tag and the preset position information of the at least three devices.

The distance between the device and the bluetooth tag may be calculated by:

d＝10^((abs(RSSI)-A)/(10*n))

where d denotes a distance between the device and the bluetooth tag, RSSI denotes a received signal strength indication value (negative value) when the device receives a message from the bluetooth tag, a denotes a signal strength when the bluetooth tag and the device are separated by 1 meter, and n denotes an environmental attenuation factor.

After the distance between each device of the at least three devices and the Bluetooth tag is obtained, a circle is drawn by taking each device as the center, and the intersection of the three circles is the position of the Bluetooth tag.

According to the embodiment, the cloud server obtains the position information of the Bluetooth tag by using the geometrical relationship by using the received signal strength indicating values of the messages from the Bluetooth tag, which are received by at least three devices in the Bluetooth mesh network, and combining the position information of the devices which is stored in advance. Therefore, the embodiment provides a reliable positioning method for the bluetooth tag.

Although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method of broadcasting an asset tag, comprising:

2. The method of claim 1, wherein the parameter indicative of the state of movement of the asset is acceleration.

3. The method of claim 2, wherein determining whether the asset is stationary or moving based on the detected acceleration comprises:

4. The method of claim 1, wherein each first broadcast interval includes a broadcast time period and a non-broadcast time period,

5. The method of claim 1, wherein each second broadcast interval includes a broadcast period and a non-broadcast period,

6. The method of claim 1, further comprising:

7. The method according to any one of claims 1 to 6,

a broadcast interval for a broadcast is set by setting a clock chip of the asset tag.

8. The method of any one of claims 1 to 6, further comprising:

9. An asset tag, comprising:

a clock chip;

10. The asset tag of claim 9, wherein the parameter indicative of the state of movement of the asset is acceleration and the detector is an acceleration sensor.