A satellite based IoT communication method and system

Abstract

The communication method according to the present invention is developed for reducing energy consumption of the IoT terminals. The method comprises the process steps of recording and updating the orbital data of the satellite, periodically broadcasting a Beacon signal, determining the coverage area of the next Beacon signal, determining the next passage times of the satellite over the coverage area, determining the next passage of the satellite over the coverage area with an elevation angle above the threshold elevation angle value, transmitting a Beacon signal containing the detected passage data performed by the satellite and the process steps of receiving the Beacon signal, planning transitions between a low-power sleep mode and an awake mode using the passage data performed by the IoT terminals.

Description

[0001] DESCRIPTION

[0002] A SATELLITE BASED IOT COMMUNICATION METHOD AND SYSTEM

[0003] Relevant technical field

[0004] The present invention relates to satellite-based loT systems and, in particular, to an loT communication method and system that enables the reduction of energy consumption of loT terminals. The method in question includes a wake-up algorithm that allows loT terminals to communicate within the communication window created during the satellite's passage and to wait in a sleep mode that provides low power consumption for the rest of the process.

[0005] State of the art loT (Internet of Things) is essentially a communication network that enables loT terminals with data collection and / or activation functions to communicate with each other and with a data center. This allows for remote monitoring and control of various objects. With the advancement of loT technology, its use is rapidly expanding and becoming widespread. Therefore, the number of loT modules requiring data transmission is rapidly increasing, while their distribution across the surface is also becoming much wider. The modules mentioned can be located in residential areas, rural areas, deserts, oceans, and similar areas where terrestrial network access is not possible and can be stationary or mobile. The state of the art includes terrestrial and satellite communication solutions for data exchange with loT terminals. In regions where access to terrestrial networks is not possible, satellite communication applications are gaining importance. As mentioned, loT terminals can be located in areas that are quite remote from residential areas and are difficult to access, and the power they require for communication is provided by a battery within the terminal. Therefore, the lifespan of these terminals is determined by the battery's consumption. Therefore, reducing the amount of energy consumed by loT terminals is crucial.

[0006] In applications developed to address this problem, loT terminals operate in a low-power sleep mode, consuming minimal power as long as they do not need to perform any operations. This also requires planning when the loT terminals will exit sleep mode.

[0007] Applications in the state of the art include orbital prediction algorithms performed by loT terminals. In these applications, each loT terminal must have up to date orbital data related to satellites with which they can exchange data and use this data to predict the satellite’s next pass times. However, for this prediction to be accurate, the orbital data must be up to date, and it is particularly challenging to keep this data up to date for loT terminals located in areas which is hard to access. In patent document CN115406448A, a method is described to prevent prediction errors caused by outdated orbital data in an loT terminal. This method uses a prediction algorithm based on current orbital data. However, this implementation increases the processing load on the loT terminal and only increases the reliability of the prediction to a certain extent.

[0008] Object of the Invention

[0009] The object of the present invention is to develop a satellite-based communication method and system that enables the reduction of energy consumption of loT terminals.

[0010] Another object of the present invention is to develop a satellite-based communication method and system that allows loT terminals to transmit data during the satellite passage period and to wait in a sleep mode with low energy consumption during the other periods.

[0011] Another object of the present invention is to develop a satellite-based communication method and system that shortens the calibration time of loT terminals and provides highly accurate orbital prediction data.

[0012] Description of the invention

[0013] The present invention, developed to solve the above mentioned technical problems, provides a satellite based loT communication method and system.

[0014] It is a computer based communication method for reducing the energy consumption of loT terminals in an loT system that comprises at least one satellite, a plurality of loT terminals with a two-way communication link between them and the satellite, and at least one ground station with a two-way communication link between them and the satellite, comprising the following process steps performed by the satellite: updating the orbital data of the satellite, which is being recorded on the satellite, at regular intervals, periodically broadcasting a Beacon signal, determining the coverage area of the next Beacon signal on the ground surface following each Beacon signal transmission, using the detected coverage area and the satellite's up to date orbital data, determining the next passage times of the satellite over the coverage area in question calculating the elevation angle for detected passages and comparing it with a predetermined threshold elevation angle value which is previously stored on the satellite as a result of the comparison, determining the next passage of the satellite over the coverage area in question with an elevation angle above the threshold elevation angle value generating a Beacon signal containing the detected passage data transmitting the generated Beacon signal and returning to the step of determining the coverage area of the next Beacon signal and the following steps performed by the loT terminals receiving the transmitted Beacon signal planning transitions between a low-power sleep mode and an awake mode using the passage data contained in the Beacon signal.

[0015] In a preferred embodiment of the invention, orbital data of the satellite is broadcast by the ground station, and when the satellite is within the coverage area of any ground station within the system, it receives and records the broadcasted, up to date orbital data. This ensures that the orbital data stored on the satellite is updated. The orbital data mentioned here is preferably digital position data for the satellite, known as TLE (Two Line Elements), which represents its orbital components (Orbital Elements).

[0016] The method in accordance with the present invention enables loT terminals to maintain a wake mode where they can exchange data during satellite passages, and to maintain a low-power sleep mode during the remaining periods. This significantly reduces the energy consumed by loT modules in sleep mode during periods when no satellite passages are taking place. Furthermore, loT terminals can achieve high success rates by knowing in advance the communication time window within which they can transmit data. This increases communication efficiency and, consequently, provides a secondary power saving.

[0017] In a preferred embodiment of the invention, the loT system comprises a constellation of satellites with at least two satellites. The method in accordance with the present invention comprises the process step of recording and updating orbital data for each satellite in the constellation; and for each satellite, to perform the aforementioned process steps using the orbital data of all satellites in the constellation. Each satellite in the constellation broadcasts passage data for the satellite constellation within its next beacon signal. The passage data mentioned here includes information about the satellites that will pass over the coverage area with an elevation angle above the threshold elevation angle value and / or the passage times of these satellites. Therefore, the above mentioned implementation comprises the following process steps: recording the orbital data for all satellites in the constellation on each of the satellites in question and updating this data at regular intervals; and the following process steps performed by each of the satellites in the constellation: periodically broadcasting a Beacon signal following each Beacon signal transmission, determining the time when the next Beacon signal will be transmitted and the Earth's surface coverage area of that Beacon signal using the detected coverage area and the satellites' current orbit data to determine the passage times of satellites that will pass over the coverage area with an elevation angle above the threshold elevation angle value transmitting the passage data for the detected passages via the Beacon signal and returning to the step of determining the coverage area of the next Beacon signal and the following process steps performed by the loT terminals of the system, within the said coverage area: receiving the transmitted Beacon signal and planning the transitions between sleep and wake modes by using the passage data contained in the Beacon signal.

[0018] In an exemplary embodiment of the invention, each satellite in a constellation containing "N" satellites contains orbital data related to both itself and the other satellites in the constellation. The orbital data in question preferably comprises the TLE data of the relevant satellite. Therefore, each satellite has up to date TLE data for “N” satellites. In a preferred embodiment of the invention, orbital data is transmitted to each satellite in the constellation and periodically updated by at least one ground station included in the said loT system. In this embodiment, each satellite falls within the coverage area of the ground stations included in the system during its movement in its orbit. During this process, it receives a data signal transmitted by the ground station containing the up to date orbital information for each satellite in the constellation and stores it in a memory unit. This ensures that each satellite has “up to date orbital data” for all satellites in the constellation. Orbital data is preferably stored and updated in a memory unit contained within each satellite. Each of these satellites transmits a beacon signal periodically, for example, every 30 seconds. The transmitted beacon signal is received by loT terminals within the system that are within the satellite's coverage area and preferably awake at the time. Each satellite transmits data regarding the next pass of all satellites in the constellation over the relevant coverage area and at an elevation angle above the threshold elevation value. In a preferred embodiment of the invention, the passage data transmitted via the beacon signal includes time data for subsequent passes over the coverage area. In another preferred embodiment of the invention, the transmitted data includes the satellite information that will be passing and the time of the pass.

[0019] In an exemplary application, the constellation included in the system comprises satellites named Ui, U2 ... UN. The satellite Us determines the next Beacon transmission time and determines the coverage area it will pass over at the specified Beacon transmission time. It then gets orbital information for the satellites in the constellation from the memory unit. It evaluates the mentioned orbital information to identify the satellites that will pass over the specified coverage area and compares the elevation angle of the identified passes with the pre-stored elevation angle threshold value. For example, as a result of the evaluation, Us can determine that after 1 hour, Ug will pass with an elevation angle of 65 °; after 2 hours, U3 will pass with an elevation angle of 45 °; after 3 hours, U7 will pass with an elevation angle of 30 °; and after 4 hours, it will pass again with an elevation angle of 80 °. In the example application where the threshold elevation angle value is 60°, U7 and U3 passages will be eliminated and the remaining information: “Ug 1 hour later and Us 4 hours later” will be added to the Beacon signal as passage data and transmitted by the satellite Us. The transmitted data will be received by loT terminals within the coverage area and used to plan sleep-awake mode transitions. loT terminals that receive the relevant data can then go into sleep mode and wake up one hour later for the Ug satellite passage. loT units preferably plan the transition between sleep and awake modes by considering the required data transmission frequency, the planning for data collection and other functions, and similar information. Therefore, the passage data received via the beacon signal can be used directly by the loT terminal for power consumption planning or can be stored in a memory unit within the loT terminal for use in planning. The next time the loT terminal enters awake mode, it receives the beacon signal to obtain up to date passage data, thus it can update its planning.

[0020] Preferably, the processing steps specified herein are performed by a processing unit within the satellite. The processing unit performs the relevant processing steps by retrieving current orbital data from the said memory unit, which stores the satellites' orbital information.

[0021] In another preferred implementation of the invention, at least one of the satellites in the constellation broadcasts the aforementioned Beacon signal, which includes the up to date orbital data of each satellite in the constellation, in addition to the aforementioned passage data. This implementation provides a verification function for loT terminals that may be outside the coverage area due to errors in the satellite-calculated passage data or small shifts in the coverage area. Here, loT terminals will evaluate the passage data contained in the broadcast Beacon signal, along with their own previously recorded location data, to make an orbit estimate and to verify the passage data transmitted via the Beacon signal. This implementation increases the accuracy of the transition data.

[0022] The satellite-based loT communication system developed with the present invention comprises: - a satellite constellation comprising at least two satellites, having at least one processing unit configured to perform the aforementioned processing steps and at least one memory unit, and

[0023] - loT terminals, comprising at least one processing unit, configured to evaluate the passage data and / or orbital data received via the beacon signal, to plan for the timing of sleep and awake modes and to ensure the transition between these modes.

Claims

CLAIMS1. A computer based communication method to be performed by an loT system that comprises at least one satellite, a plurality of loT terminals having a two-way communication link between them and the satellite and at least one ground station having a two-way communication link between them and the satellite following process steps: updating the orbital data of the satellite, which is being recorded on the satellite, at regular intervals, periodically broadcasting a Beacon signal, determining the coverage area of the next Beacon signal on the ground surface following each Beacon signal transmission, using the detected coverage area and the satellite's up to date orbital data, determining the next passage times of the satellite over the coverage area in question calculating the elevation angle for detected passages and comparing it with a predetermined threshold elevation angle value which is previously stored on the satellite as a result of the comparison, determining the next passage of the satellite over the coverage area in question with an elevation angle above the threshold elevation angle value generating a Beacon signal containing the detected passage data transmitting the generated Beacon signal and returning to the step of determining the coverage area of the next Beacon signal performed by the said satellite and the following process steps: receiving the transmitted Beacon signal planning transitions between a low-power sleep mode and an awake mode using the passage data contained in the Beacon signal performed by the said loT terminals.

2. A communication method in accordance with Claim 1 comprising the following process steps: orbital data of the satellite is broadcast by the ground station, and when the satellite is within the coverage area of any ground station within the system, it receives and records the broadcasted, up to date orbital data.

3. A communication method in accordance with Claim 1 to be performed by the said loT system having a satellite constellation with at least two satellites comprising the process step of, the orbital data of all of the satellites in the constellation is recorded to each satellite in the constellation and being updated with regular periods; the following process steps performed by each satellite in the constellation: periodically broadcasting a Beacon signal, determining the coverage area of the next Beacon signal on the ground surface following each Beacon signal transmission, using the detected coverage area and the satellite's up to date orbital data, determining the next passage times of the satellites over the coverage area in question with an elevation angle above the threshold elevation angle value transmitting the passage information related to the determined passages with the Beacon signal and returning to the step of determining the coverage area of the next Beacon signal and the following process steps performed by the loT terminals within the coverage area: receiving the transmitted Beacon signal planning transitions between a low-power sleep mode and an awake mode using the passage data contained in the Beacon signal4. A communication method in accordance with Claim 3, comprising the following process steps: orbital data is transmitted to each satellite of the constellation by at least one ground station of the said loT system and updated periodically.

5. A communication method in accordance with any of Claim 3 or 4, comprising the process step of at least one of the satellites in the satellite constellation periodically broadcasting a Beacon signal that includes the up to date orbital data of each of the satellites in the satellite constellation as well as the said passage data.

6. A communication method in accordance with Claim 5; comprising the process step of, loT terminals making an orbit estimation by evaluating the passage data contained in the broadcast Beacon signal together with their own previously recorded location data and applying a control process regarding the passage data transmitted with the Beacon signal using the obtained orbit estimation data.

7. A satellite-based loT communication system comprising, a satellite constellation comprising at least two satellites, having at least one processing unit configured to perform the processing steps in accordance with any of the Claims 3 to 6 and at least one memory unit, loT terminals, comprising at least one processing unit, configured to evaluate the passage data and / or orbital data received via the beacon signal, to plan for the timing of sleep and awake modes and to ensure the transition between these modes.