Wireless sensor network system and method based on enhanced mini-slotted threshold aloha protocol

Abstract

A wireless sensor network system includes a base station and at least one sensing device. The base station is configured to receive at least one sensing data packet. The at least one sensing device is configured to collect at least one sensing data and package the at least one sensing data into the at least one sensing data packet. Each sensing device has an age of information and is configured to transmit the at least one sensing data packet to the base station in at least one time slot according to an enhanced mini-slot threshold ALOHA protocol. Each time slot includes a mini-slot and a data sub-slot. The sensing device whose age of information is greater than or equal to a preset age of information threshold transmits at least one transmission request to the base station in the mini-slot at a first transmission probability. The sensing device which receiving a reply message sent back from the base station transmits the at least one sensing data packet to the base station in the data sub-slot.

Description

[Technical Field]

[0001] This invention relates to a wireless sensing network system and method, and more particularly to a wireless sensing network system and method applying the Enhanced Mini Time Slot Threshold ALOHA protocol. [Previous Technology]

[0002] Multiple access control (MAC) protocols provide wireless devices with the ability to access radio channels, and slotted ALOHA protocols are widely used in wireless network applications due to their high transmission efficiency. The age of information (AoI) is defined as the time interval between the point in time the data was generated and the current time, and is often used as an indicator of data transmission performance. Therefore, keeping the average age of information (AAoI) of a wireless network below a certain value is crucial. Slotted ALOHA protocols have further evolved into threshold ALOHA (TA) protocols and mini-slotted threshold ALOHA (MiSTA) protocols to improve the average age of wireless networks. The mini-slotted threshold ALOHA protocol is even more effective at optimizing the average age of information than the threshold ALOHA protocol. Furthermore, based on the mini slot threshold ALOHA, idle slots should be able to be utilized more effectively to provide devices in the wireless network with additional data transmission opportunities, thereby further reducing the average information age of the wireless network. [Summary of the Invention]

[0003] The purpose of this invention is to provide a wireless sensing network system and method that utilizes an improved mini-slotted threshold ALOHA (EMiSTA) protocol to transmit sensing data packets from a sensing device to a base station. By dividing a single time slot into mini-time slots and data sub-time slots, the sensing device in the communication field is given an additional opportunity to transmit sensing data to the base station. This results in a wireless sensing network system implemented with the enhanced mini-slotted threshold ALOHA protocol having a better average information age compared to wireless sensing network systems implemented with conventional time slot ALOHA, threshold ALOHA, or mini-slotted threshold ALOHA protocols.

[0004] One aspect of the present invention is to provide a wireless sensing network system, comprising a base station and at least one sensing device. The base station is configured to receive at least one sensing data packet. The sensing devices are configured to collect at least one sensing data and encapsulate the sensing data into the sensing data packets, wherein each sensing device has an age of information (AoI) and is configured to transmit the sensing data packets to the base station in at least one slot according to the enhanced mini-slot threshold ALOHA (EMiSTA) protocol, wherein each slot includes a mini-slot and a data sub-slot, and wherein the sensing devices whose AoI is greater than or equal to a preset AoI threshold send at least one transmission request to the base station in the mini-slot with a first transmission probability, and the sensing devices that receive a reply message from the base station then transmit the sensing data packets to the base station in the data sub-slot.

[0005] In some embodiments, the base station is further configured to detect the number of transmission requests it receives from these sensing devices.

[0006] In some embodiments, when the base station detects that it has received 0 of these transmission requests, the base station is further configured to broadcast a notification to these sensing devices whose information age is greater than or equal to the information age threshold to transmit these sensing data packets to the base station in the data sub-time slot with a first transmission probability.

[0007] In some embodiments, when the base station detects that it has received more than or equal to 2 of these transmission requests, the base station is further configured to broadcast a notification to these sensing devices whose information age is greater than or equal to the information age threshold to transmit these sensing data packets to the base station in the data sub-time slot with a second transmission probability.

[0008] In some embodiments, the second transmission probability is greater than the first transmission probability.

[0009] Another aspect of the present invention is to provide a wireless sensing network method, comprising the following steps: comparing the information age of each of at least one sensing device with a preset information age threshold; and having the sensing devices whose information age is greater than or equal to the information age threshold send at least one transmission request to the base station in a mini time slot with a first transmission probability, and having one of the sensing devices that receives a reply message from the base station transmit at least one sensing data packet to the base station in a data sub-time slot.

[0010] In some embodiments, the base station is further configured to detect the number of transmission requests it receives from these sensing devices.

[0011] In some embodiments, when the base station detects that the number of such transmission requests it has received is 0, the base station is further configured to broadcast a notification to such sensing devices whose information age is greater than or equal to the information age threshold to transmit such sensing data packets to the base station in the data sub-time slot with a first transmission probability.

[0012] In some embodiments, when the base station detects that it has received more than or equal to 2 of these transmission requests, the base station is further configured to broadcast a notification to these sensing devices whose information age is greater than or equal to the information age threshold to transmit these sensing data packets to the base station in the data sub-time slot with a second transmission probability.

[0013] In some embodiments, the second transmission probability is greater than the first transmission probability.

Implementation Method

[0014] Embodiments of the present invention will be discussed in detail below. It will be understood that the embodiments provide many applicable concepts that can be implemented in a wide variety of specific situations. The embodiments discussed and disclosed are for illustrative purposes only and are not intended to limit the scope of the invention.

[0015] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the claims. Unless otherwise limited, the singular forms of "a" or "the" may also be used to denote the plural forms.

[0016] It is understood that although the terms "first," "second," etc., used herein may be used to describe different elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from others.

[0017] First, it should be noted that the enhanced mini-slot threshold ALOHA (EMiSTA) protocol used in this invention is an improvement upon the mini-slot threshold ALOHA (MiSTA) protocol, which in turn is an improvement upon the threshold ALOHA (TA) protocol, which itself evolved from the slotted ALOHA (SA) protocol. Therefore, before introducing the wireless sensing network system and method based on the enhanced mini-slot threshold ALOHA protocol proposed in this invention, the data exchange methods between the sensing device and the base station regulated by the three protocols—slotted ALOHA, threshold ALOHA, and mini-slot threshold ALOHA—will be explained first.

[0018] In the time-slot ALOHA protocol, all sensing devices within the communication field transmit sensing data to the base station with the same transmission probability (the transmitted sensing data is usually in packet form, i.e., sensing data packets). Wireless sensing network systems designed based on the time-slot ALOHA protocol have the following advantages: First, each sensing device within the communication field does not need to communicate with each other; second, after transmitting sensing data to the base station, the sensing device does not need to spend time waiting for a response from the base station. Conversely, the disadvantage of wireless sensing network systems designed based on the time-slot ALOHA protocol is that the average information age of the wireless sensing network system still has room for improvement.

[0019] To avoid delays in transmitting sensing data collected by certain sensing devices to the base station, thereby lowering the average information age of the entire wireless sensing network system, the slot-based ALOHA protocol can be optimized and evolved into the threshold-based ALOHA protocol. In the threshold-based ALOHA protocol, unlike the data exchange method of the slot-based ALOHA protocol where all sensing devices in the communication field transmit sensing data packets to the base station with the same transmission probability, all sensing devices can be divided into two categories: those with an information age (AoI) greater than or equal to a preset information age threshold, and those with an information age less than the preset information age threshold. Only those sensing devices with an information age greater than or equal to the preset information age threshold are allowed to transmit sensing data to the base station with the same transmission probability. As a result, the average information age of the wireless sensing network system designed based on the threshold-based ALOHA protocol is significantly reduced compared to the average information age of the wireless sensing network system designed based on the slot-based ALOHA protocol.

[0020] Although the threshold ALOHA protocol has improved the average information age of wireless sensor network systems, each slot used for transmitting sensing data is not being utilized most efficiently. In other words, the average information age of wireless sensor network systems designed based on the threshold ALOHA protocol still has room for improvement. In the mini-slot threshold ALOHA protocol, each slot can be further divided into mini-slots and data sub-slots. When a sensing device wants to transmit sensing data to a base station, it first sends a transmission request to the base station in a mini-slot. Only when the base station responds to this transmission request can the sensing device then transmit sensing data to the base station in a data sub-slot.

[0021] In the Mini Time Slot Threshold ALOHA protocol, sensing devices with an information age greater than or equal to a preset information age threshold can send a transmission request to the base station in the mini time slot of each time slot with a first transmission probability. In one embodiment of the Mini Time Slot Threshold ALOHA protocol, when only one sensing device sends a transmission request to the base station in the mini time slot, the base station will send back a reply message to this sensing device, and after receiving the reply message from the base station, this sensing device can directly transmit sensing data to the base station in the data sub-time slot.

[0022] In another embodiment of the mini-slot threshold ALOHA protocol, when two or more sensing devices send transmission requests to the base station in a mini-slot (i.e., the number of transmission requests received by the base station is greater than or equal to 2), since the base station cannot identify which sensing device sent the transmission request, the base station will broadcast a notification to these sensing devices whose information age is greater than or equal to a preset information age threshold to transmit sensing data to the base station in the data sub-slot with a second transmission probability. Further, if only one sensing device transmits sensing data to the base station in the data sub-slot, then this sensing device successfully transmits the sensing data to the base station; if two or more sensing devices still transmit sensing data to the base station in the data sub-slot, then the sensing data of these sensing devices all fail to be transmitted. It should also be noted that the second transmission probability is greater than the first transmission probability.

[0023] As can be seen from the above description of the Mini Time Slot Threshold ALOHA protocol and the corresponding embodiments, since the sensing device has two opportunities to transmit sensing data to the base station within a time slot (the mini time slot and the data sub-time slot each provide one transmission opportunity), the average information age of the wireless sensing network system designed based on the Mini Time Slot Threshold ALOHA protocol can be further reduced compared to the average information age of the wireless sensing network system designed based on the Threshold ALOHA protocol. However, the cost is the information exchange (i.e., the sensing device sends a transmission request message to the base station, and the base station sends a reply message back to the sensing device).

[0024] The above content has explained the sensing data exchange methods between the sensing device and the base station regulated by the three protocols: Time Slot ALOHA, Threshold ALOHA, and Mini Time Slot Threshold ALOHA. The following content will introduce the wireless sensing network system and wireless sensing network method based on the Enhanced Mini Time Slot Threshold ALOHA protocol proposed in this invention.

[0025] Figure 1 is a schematic diagram of a wireless sensing network system 100 applied within a communication range according to an embodiment of the present invention. The wireless sensing network system 100 includes a base station 120 and at least one sensing device 140. The base station 120 is configured to receive one or more sensing data packets. The sensing devices 140 are configured to collect one or more pieces of sensing data and encapsulate the sensing data into one or more sensing data packets. Each sensing device has an information age and is configured to transmit the sensing data packets to the base station 120 in at least one time slot according to the Enhanced Mini Time Slot Threshold ALOHA protocol. Each time slot includes a mini time slot and a data sub-time slot. The sensing devices 140 with an information age greater than or equal to a preset information age threshold send at least one transmission request to the base station 120 in the mini time slot with a first transmission probability. The sensing devices 140 that receive a reply message from the base station 120 then transmit the sensing data packets to the base station 120 in the data sub-time slot. In one embodiment of the invention, the sensing device 140 may be a camera, radar sensor, light detection and ranging (LiDAR) sensor, gyroscope, accelerometer, Hall effect sensor, magnetometer, orientation sensor, proximity sensor, temperature sensor, touch sensor, gesture sensor, biometric sensor, humidity sensor, or a combination of the above elements, but is not limited thereto. In the same or another embodiment of the invention, the base station 120 has a built-in processor or other computing element for receiving and processing one or more sensing data packets from each of the sensing devices 140. The processor built into the base station 120 may be, for example, a central processing unit (CPU), graphics processing unit (GPU), microcontroller unit (MCU), microprocessor, system-on-chip (SoC), digital signal processor (DSP), application-specific integrated circuit (ASIC), programmable logic controller (PLC), or a combination of the above elements, but is not limited thereto.

[0026] In the embodiment illustrated in FIG1, the communication range R includes a base station 120 and a plurality of randomly distributed sensing devices 140 (only one sensing device 140 is marked in FIG1 for illustration). Each of these sensing devices 140 is communicatively connected to the base station 120 within the communication range R divided with the base station 120 as the center.

[0027] The enhanced mini-slot threshold ALOHA protocol used in the wireless sensing network system 100 of the present invention is an improvement upon the mini-slot threshold ALOHA protocol. Therefore, in the enhanced mini-slot threshold ALOHA protocol, each slot is also divided into mini-slots and data sub-slots (refer to Figure 2, which shows a schematic diagram of dividing each slot into mini-slots MS and data sub-slots DSS). When the sensing device 140 wants to transmit sensing data to the base station 120, it first sends a transmission request to the base station 120 in the mini-slot with a first transmission probability. In one embodiment of the enhanced mini-slot threshold ALOHA protocol, when only one sensing device 140 sends a transmission request to the base station 120 in the mini-slot, the base station 120 will send back a reply message to this sensing device 140. After receiving the reply message from the base station 120, this sensing device 140 can directly transmit sensing data to the base station 120 in the data sub-slot.

[0028] In another embodiment of the enhanced mini-time slot threshold ALOHA protocol, when two or more sensing devices 140 send transmission requests to base station 120 in a mini-time slot (i.e., the number of transmission requests received by base station 120 is greater than or equal to 2), since base station 120 cannot determine which sensing device 140 sent the transmission request, base station 120 will broadcast a notification that these sensing devices 140 with an information age greater than or equal to a preset information age threshold will transmit sensing data to base station 120 in a data sub-time slot with a second transmission probability. Further, if only one sensing device 140 transmits sensing data to base station 120 in a data sub-time slot, then this sensing device 140 successfully transmits the sensing data to base station 120; if two or more sensing devices 140 still transmit sensing data to base station 120 in a data sub-time slot, then the sensing data of these sensing devices 140 all fail to transmit. It should also be noted that the second transmission probability is greater than the first transmission probability.

[0029] Although under the mini-slot threshold ALOHA protocol, some sensing devices 140 with information ages greater than or equal to a preset information age threshold can send transmission requests to the base station 120 in a mini-slot, in some cases, no sensing device 140 may send a transmission request to the base station 120 in a mini-slot (i.e., the number of transmission requests received by the base station 120 is 0). As a result, since the benefits of dividing a single time slot into mini-slots and data sub-slots are not fully utilized (i.e., providing sensing devices 140 with two transmission opportunities to transmit sensing data to the base station 120), the mini-slot threshold ALOHA protocol does not have an advantage over the threshold ALOHA protocol in reducing the average information age.

[0030] However, the situation where no sensing device 140 sends a transmission request to the base station 120 in the mini time slot can actually be addressed by the base station 120 detecting at the beginning of each time slot (detecting whether any sensing device 140 sends a transmission request to the base station 120 / detecting the number of transmission requests received by the base station 120 from the sensing device 140).

[0031] Specifically, in another embodiment of the Enhanced Mini-Slot Threshold ALOHA protocol, when the base station 120 detects at the beginning of a certain slot that no sensing device 140 sends a transmission request to the base station 120 in the mini-slot (i.e., the number of transmission requests received by the base station 120 is 0), the base station 120 will broadcast a notification to those sensing devices 140 whose information age is greater than or equal to a preset information age threshold, and to attempt to transmit these sensing data packets to the base station 120 in the data sub-slot with a first transmission probability, so as not to waste the transmission opportunities provided by the data sub-slot as much as possible. It is worth mentioning that other sensing devices 140 whose information age is less than the preset information age threshold will enter a sleep state and will not receive broadcast notifications from the base station 120.

[0032] As can be seen from the above description, the enhanced mini time slot threshold ALOHA protocol proposed in this invention not only provides the sensing devices 140 with information age greater than or equal to the preset information age threshold with two opportunities to transmit sensing data packets to the base station 120, but also solves the problem of no sensing device 140 sending a transmission request to the base station 120 in the mini time slot. Compared with the previous mini time slot threshold ALOHA protocol, it can more effectively utilize the benefits of two data transmission opportunities provided by the mini time slot and data sub-time slot.

[0033] Figure 3 is a schematic diagram comparing the average information age of four protocols (including slotted ALOHA protocol, threshold ALOHA protocol, mini slotted threshold ALOHA protocol, and enhanced mini slotted threshold ALOHA protocol) according to embodiments of the present invention under 140 different sensing devices. In the figure, the diamond curve represents the analysis result of the slotted ALOHA protocol, denoted as L3-1; the triangle curve represents the analysis result of the threshold ALOHA protocol, denoted as L3-2; the square curve represents the analysis result of the mini slotted threshold ALOHA protocol, denoted as L3-3; the cross curve represents the analysis result of the enhanced mini slotted threshold ALOHA protocol, denoted as L3-4; and the circular curve represents the simulation result of the enhanced mini slotted threshold ALOHA protocol, denoted as L3-5. As can be seen from Figure 3, regardless of the number of sensing devices 140, the wireless sensing network system 100 based on the Enhanced Mini Slot Threshold ALOHA protocol has the lowest average information age. Furthermore, as the number of sensing devices 140 increases, the advantage of the wireless sensing network system 100 based on the Enhanced Mini Slot Threshold ALOHA protocol in terms of average information age will further expand compared to wireless sensing network systems implemented with the other three protocols.

[0034] Figure 4 is a schematic diagram comparing the average information age under different mini-slot ratios for four protocols (including slotted ALOHA protocol, threshold ALOHA protocol, mini-slot threshold ALOHA protocol, and enhanced mini-slot threshold ALOHA protocol) according to embodiments of the present invention. The diamond curve represents the analysis result of the slotted ALOHA protocol, denoted as L4-1; the triangle curve represents the analysis result of the threshold ALOHA protocol, denoted as L4-2; the square curve represents the analysis result of the mini-slot threshold ALOHA protocol, denoted as L4-3; and the cross curve represents the analysis result of the enhanced mini-slot threshold ALOHA protocol, denoted as L4-4. It should be noted that the mini-slot ratio is defined as the length ratio between the mini-slot and the data sub-slot. For example, a mini-slot ratio of 0.45 means that the length ratio between the mini-slot and the data sub-slot is 0.45:1. As can be seen from Figure 4, when the length ratio between the mini-time slot and the data sub-time slot exceeds a certain value, the mini-time slot threshold ALOHA protocol and the enhanced mini-time slot threshold ALOHA protocol actually have a higher average information age than the threshold ALOHA protocol. This indicates that in such cases, it is not cost-effective to use the mini-time slot to issue transmission requests; it is better to transmit sensing data packets directly in the data sub-time slot. In one embodiment of the present invention, when the length ratio between the mini-time slot and the data sub-time slot exceeds 0.45, the mini-time slot threshold ALOHA protocol actually has a higher average information age than the threshold ALOHA protocol. In another embodiment of the present invention, when the length ratio between the mini-time slot and the data sub-time slot exceeds 0.75, the enhanced mini-time slot threshold ALOHA protocol actually has a higher average information age than the threshold ALOHA protocol.

[0035] Figure 5 is a schematic diagram comparing the average information age of four protocols (including slotted ALOHA protocol, threshold ALOHA protocol, mini slotted threshold ALOHA protocol, and enhanced mini slotted threshold ALOHA protocol) under different energy consumption limits according to embodiments of the present invention. E1, E2, and E3 represent different energy unit limits, with energy unit E3 being greater than energy unit E2, and energy unit E2 being greater than energy unit E1. In one embodiment of the present invention, energy unit E1 is 0.25, energy unit E2 is 0.5, and energy unit E3 is 0.9. As can be seen from Figure 5, regardless of whether the energy unit limit is large or small, the wireless sensing network system 100 based on the enhanced mini slotted threshold ALOHA protocol has the lowest average information age. Furthermore, as the energy unit limit becomes more stringent (i.e., smaller), the advantage of the wireless sensing network system 100 based on the enhanced mini slotted threshold ALOHA protocol in terms of average information age will further increase compared to wireless sensing network systems implemented with the other three protocols.

[0036] FIG6 is a flowchart of a wireless sensing network method 600 according to an embodiment of the present invention. The wireless sensing network method 600 is applicable to, for example, the communication range R shown in FIG1, and can be used in, for example, the wireless sensing network system 100 of FIG1 including a base station 120 and at least one sensing device 140 or other similar systems. The wireless sensing network method 600 includes steps S610 to S620. The following paragraphs describe the implementation method of each step in conjunction with FIG1 and FIG6.

[0037] Step S610: Compare the information age of the sensing device with the preset information age threshold.

[0038] Step S620: The sensing device whose information age is greater than or equal to the information age threshold sends a transmission request to the base station in the mini time slot with the first transmission probability, and the sensing device that receives the reply message from the base station then transmits the sensing data packet to the base station in the data sub-time slot.

[0039] For an explanation of each step S610-S620, please refer to the operation of each component in the wireless sensing network system 100 shown in Figure 1, for example, and will not be repeated here.

[0040] In summary, the wireless sensing network system and method of the present invention utilizes an improved enhanced mini-slot threshold ALOHA protocol to transmit sensing data packets from the sensing device to the base station. By dividing a single time slot into mini-slots and data sub-slots, the sensing device in the communication field is provided with an additional opportunity to transmit sensing data to the base station. As a result, the wireless sensing network system implemented with the enhanced mini-slot threshold ALOHA protocol has a better average information age compared to wireless sensing network systems implemented with conventional time slot ALOHA, threshold ALOHA, or mini-slot threshold ALOHA protocols.

[0041] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the scope of the present invention. Anyone skilled in the art can make various changes, substitutions and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be defined by the appended claims. [Simplified Explanation of the Diagram]

[0042] To make the above and other objects, features, advantages and embodiments of the present invention more apparent and understandable, the accompanying drawings are described as follows: Figure 1 is a schematic diagram of a wireless sensing network system applied within a communication range according to an embodiment of the present invention; Figure 2 is a schematic diagram of mini time slots and data sub-time slots according to an embodiment of the present invention; Figure 3 is a schematic diagram of comparing the average information age of four protocols under different numbers of sensing devices according to an embodiment of the present invention; Figure 4 is a schematic diagram of comparing the average information age of four protocols under different mini time slot ratios according to an embodiment of the present invention; Figure 5 is a schematic diagram of comparing the average information age of four protocols under different energy consumption limits according to an embodiment of the present invention; and Figure 6 is a flowchart of a wireless sensing network method according to an embodiment of the present invention. [Biomaterial Storage]

[0044] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. A wireless sensing network system, comprising: a base station configured to receive at least one sensing data packet; and at least one sensing device configured to collect at least one sensing data and encapsulate the at least one sensing data into the at least one sensing data packet, wherein each of the at least one sensing device has an age of information (AoI) and is configured to transmit the at least one sensing data packet to the base station in at least one slot according to an enhanced mini-slot threshold ALOHA (EMiSTA) protocol, and wherein each of the at least one slot includes a mini-slot and a data sub-slot. Furthermore, at least one of the sensing devices whose information age is greater than or equal to a preset information age threshold sends at least one transmission request to the base station in the mini time slot with a first transmission probability, and one of the at least one sensing device that receives a reply message from the base station then transmits the at least one sensing data packet to the base station in the data sub-time slot.

2. The wireless sensing network system as described in claim 1, wherein the base station is further configured to detect the number of the at least one transmission request received from the at least one sensing device.

3. The wireless sensing network system as described in claim 2, wherein when the base station detects that the number of the at least one transmission request it has received is 0, the base station is further configured to broadcast a notification to the at least one sensing device whose information age is greater than or equal to the information age threshold to transmit the at least one sensing data packet to the base station in the data sub-time slot with the first transmission probability.

4. The wireless sensing network system as described in claim 2, wherein when the base station detects that it has received at least 2 transmission requests, the base station is further configured to broadcast a notification to the at least one sensing device whose information age is greater than or equal to the information age threshold to transmit the at least one sensing data packet to the base station in the data sub-time slot with a second transmission probability.

5. The wireless sensor network system as described in claim 4, wherein the second transmission probability is greater than the first transmission probability.

6. A wireless sensing network method, comprising: comparing an information age of each of at least one sensing device with a preset information age threshold; and having at least one sensing device whose information age is greater than or equal to the information age threshold send at least one transmission request to a base station in a mini-time slot with a first transmission probability, and having one of the at least one sensing devices that receives a reply message from the base station transmit at least one sensing data packet to the base station in a data sub-time slot.

7. The wireless sensing network method as described in claim 6, wherein the base station is further configured to detect the number of the at least one transmission request received from the at least one sensing device.

8. The wireless sensing network method as described in claim 7, wherein when the base station detects that the number of the at least one transmission request it has received is 0, the base station is further configured to broadcast a notification to the at least one sensing device whose information age is greater than or equal to the information age threshold to transmit the at least one sensing data packet to the base station in the data sub-time slot with the first transmission probability.

9. The wireless sensing network method as described in claim 7, wherein when the base station detects that it has received at least 2 transmission requests, the base station is further configured to broadcast a notification to the at least one sensing device whose information age is greater than or equal to the information age threshold to transmit the at least one sensing data packet to the base station in the data sub-time slot with a second transmission probability.

10. The wireless sensing network method as described in claim 9, wherein the second transmission probability is greater than the first transmission probability.

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