Packet loss analysis method, base station and mobile terminal

Abstract

According to the packet loss analysis method, the base station and the mobile terminal, after the base station encodes real-time differential global positioning system control information (RTCM) data required by real-time dynamic positioning (RTK) positioning, statistical information used for packet loss analysis is determined, the statistical information is processed into encoding statistical information, the number of data bits used for packet loss analysis is reduced, and the packet loss analysis efficiency is improved. The coding statistical information can be recorded through more than one piece of RTCM data containing the extended field, so that the influence on the data transmission bandwidth is avoided; the method comprises the following steps of: recording coding statistical information by utilizing an extended field of RTCM data, conforming to the regulation of an RTCM standard protocol, and after the RTCM data carrying the coding statistical information is transmitted to a mobile terminal, realizing packet loss analysis by the mobile terminal based on the coding statistical information obtained by analysis; in view of determining the statistical information after encoding the RTK data, the real-time performance of the data for packet loss analysis is ensured, and an information basis is provided for improving the efficiency of troubleshooting the RTCM communication link problem.

Description

Technical Field

[0001] This article relates to satellite navigation technology, particularly a packet loss analysis method, a base station and a mobile terminal. Background Art

[0002] With the advent of technological innovation and the Internet of Things era, people's demand for high-precision positioning has become increasingly strong. The positioning accuracy has been improved from the original meter level to the decimeter level and centimeter level; the application fields of high precision are also becoming more and more abundant, from the initial measurement receiver to the integrated surveying and mapping machine, to drones, intelligent robots represented by lawn mowers, and vehicle-mounted navigation and positioning. Real-time dynamic positioning technology (RTK) positioning is the mainstream technology for high-precision positioning. The mobile terminal uses the received real-time differential global positioning system control information (RTCM) data containing the base station satellite navigation information, and cooperates with the mobile terminal's own satellite navigation information to achieve high-precision RTK positioning.

[0003] The RTCM protocol significantly improves the transmission efficiency of the Global Navigation Satellite System (GNSS) data by optimizing the data format and transmission method, which enables the RTK system to acquire and process satellite data faster, thereby improving positioning speed and accuracy; by using the RTCM protocol, the RTK system can achieve centimeter-level positioning accuracy to meet the needs of high-precision positioning. The RTCM protocol has good compatibility and scalability, and can adapt to different GNSS systems and application scenarios; this allows the RTK system to be widely used in various fields that require high-precision positioning, such as intelligent robots represented by lawn mowers, drones, and vehicle navigation.

[0004] In industry applications, RTCM is mainly transmitted through communication links such as radio, network, and Bluetooth. Regardless of the type of communication link, the quality of RTCM data in the transmission link affects the positioning performance of RTK. Evaluating and confirming the reliability of the RTCM transmission link is an important part of ensuring RTK positioning performance. The method of evaluating and confirming the reliability of the RTCM transmission link in related technologies includes troubleshooting RTCM packet loss. The method of troubleshooting RTCM packet loss includes recording the RTCM data sent by the base station and the RTCM data received by the mobile terminal separately, and then performing post-processing decoding analysis to obtain the packet loss rate and determine which type of RTCM data was lost at each time point. Real-time evaluation is not possible. Moreover, the RTCM data contains satellite navigation information of the location. Due to the confidentiality of satellite navigation information, in many countries and regions, it is not allowed to record and transmit relevant data containing local satellite navigation information, so RTCM packet loss analysis is not possible. Summary of the invention

[0005] The present application provides a packet loss analysis method, including: The base station determines the statistical information for packet loss analysis based on the encoded real-time differential global positioning system control information (RTCM) data required for real-time dynamic positioning technology (RTK) positioning; Processing the determined statistical information at a preset interval to obtain coded statistical information, and carrying it in an extended field of one or more RTCM data; The RTCM data carrying the coded statistical information is sent to the mobile terminal, so that the mobile terminal performs packet loss analysis according to the received RTCM data carrying the coded statistical information and the received statistical information actually obtained by statistics.

[0006] On the other hand, the embodiment of the present application also provides a packet loss analysis method, including: The mobile terminal receives and decodes the RTCM data carrying the coded statistical information from the base station to obtain the coded statistical information; Perform packet loss analysis based on the encoding statistics obtained by decoding and the receiving statistics obtained by actual statistics; The RTCM data is obtained by the base station through compression encoding based on the encoded RTCM data required for RTK positioning and statistical information determined for packet loss analysis, and is carried in an extended field of the RTCM data.

[0007] On the other hand, an embodiment of the present application further provides a base station, comprising: a statistical unit, a compression encoding unit and a sending unit; wherein, The statistical unit is set to: determine statistical information for packet loss analysis according to the encoded real-time differential global positioning system control information RTCM data required for real-time dynamic positioning technology RTK positioning; The compression encoding unit is configured to: process the determined statistical information at a preset interval to obtain encoded statistical information, and carry the encoded statistical information in an extension field of one or more RTCM data; The sending unit is configured to send the RTCM data carrying the coded statistical information to the mobile terminal, so that the mobile terminal performs packet loss analysis according to the decoded RTCM data carrying the coded statistical information and the received statistical information obtained by actual statistics.

[0008] On the other hand, the embodiment of the present application further provides a mobile terminal, comprising: a receiving decoding unit and an analyzing unit; wherein: The receiving and decoding unit is configured to: receive and decode RTCM data carrying coding statistical information from a base station to obtain the coding statistical information; The analysis unit is configured to: perform packet loss analysis based on the encoding statistical information obtained by decoding and the receiving statistical information obtained by actual statistics; The RTCM data is obtained by the base station through compression encoding based on the encoded RTCM data required for RTK positioning and statistical information determined for packet loss analysis, and is carried in an extended field of the RTCM data.

[0009] After the base station of the disclosed embodiment encodes the RTCM data required for RTK positioning, it determines the statistical information used for packet loss analysis, processes the statistical information to obtain the coded statistical information, thereby reducing the number of data bits used for packet loss analysis. The coded statistical information can be recorded through one or more RTCM data records containing extended fields, thereby avoiding the impact on the data transmission bandwidth. The coded statistical information is recorded using the extended fields of the RTCM data, which complies with the provisions of the RTCM standard protocol. After the RTCM data carrying the coded statistical information is transmitted to the mobile terminal, the mobile terminal implements packet loss analysis based on the coded statistical information obtained through parsing. Since the statistical information is determined after the RTK data is encoded, the real-time nature of the data used for packet loss analysis is guaranteed, thereby providing data support for the real-time and accurate evaluation of the RTCM communication link, and providing an information basis for improving the efficiency of troubleshooting RTCM communication link problems.

[0010] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0012] Figure 1 This is a flow chart of a packet loss analysis method according to a first embodiment of the present disclosure; Figure 2 Flow chart of another packet loss analysis method according to an embodiment of the present disclosure Figure 3 is a structural block diagram of a base station according to an embodiment of the present disclosure; Figure 4 It is a structural block diagram of the mobile terminal of the embodiment of the present disclosure. DETAILED DESCRIPTION

[0013] The present application describes multiple embodiments, but the description is exemplary rather than restrictive, and it is obvious to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present application. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0014] The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in the present application may also be combined with any conventional features or elements to form a unique invention scheme. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme. Therefore, it should be understood that any feature shown and / or discussed in the present application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other restrictions. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0015] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps of the specific order described. As will be understood by those of ordinary skill in the art, other sequences of steps are also possible. Therefore, the specific sequence of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps of performing them in the order written, and those skilled in the art can easily understand that these sequences can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0016] Figure 1 Flow chart of a packet loss analysis method according to an embodiment of the present disclosure. Figure 1 As shown, including: Step 101: The base station determines statistical information for packet loss analysis based on encoded real-time differential global positioning system control information (RTCM) data required for real-time kinematic positioning technology (RTK) positioning; Step 102: Process the determined statistical information at a preset interval to obtain coded statistical information, and carry it in an extension field of one or more RTCM data; Step 103: Send the RTCM data carrying the coded statistical information to the mobile terminal, so that the mobile terminal performs packet loss analysis according to the decoded RTCM data carrying the coded statistical information and the received statistical information obtained by actual statistics.

[0017] After the base station of the disclosed embodiment encodes the RTCM data required for RTK positioning, it determines the statistical information used for packet loss analysis, processes the statistical information to obtain the coded statistical information, thereby reducing the number of data bits used for packet loss analysis. The coded statistical information can be recorded through one or more RTCM data records containing extended fields, thereby avoiding the impact on the data transmission bandwidth. The coded statistical information is recorded using the extended fields of the RTCM data, which complies with the provisions of the RTCM standard protocol. After the RTCM data carrying the coded statistical information is transmitted to the mobile terminal, the mobile terminal implements packet loss analysis based on the coded statistical information obtained through parsing. Since the statistical information is determined after the RTK data is encoded, the real-time nature of the data used for packet loss analysis is guaranteed, thereby providing data support for the real-time and accurate evaluation of the RTCM communication link, and providing an information basis for improving the efficiency of troubleshooting RTCM communication link problems.

[0018] The RTCM data required for RTK positioning in the disclosed embodiment may include the following types of RTCM data: RTCM1005: base station information, the length of the entire coded data is fixed; RTCM1006: base station information (including antenna height), the length of the entire coded data is fixed; RTCM1033: base station receiver and antenna description information, the length of the entire coded data is fixed; each RTCM protocol of the MSM2-7 series: base station observation value information, the length of the entire coded data is not fixed, based on the number of observation values, the length of the coded data is dynamically determined, and because of the length limit of the RTCM standard, there is a situation where an observation value RTCM protocol is divided into multiple RTCM coded data packets at the same time point. Taking the Beidou system as an example, in the open environment of the Asia-Pacific region, there are many satellites received, and the Beidou observation value differential RTCM1124 in the MSM4 series will be encoded into 2 or 3 data packets at a certain time point.

[0019] In an exemplary embodiment, the embodiment of the present disclosure is based on the standard RTCM protocol specification, and the base station refers to the relevant technology and uses the GPS system time as the time reference to encode the RTCM data required for the above-mentioned RTK positioning.

[0020] In an exemplary embodiment, the statistical information in the embodiment of the present disclosure includes the following information of the RTCM data required for the encoded RTK positioning: RTCM type, the broadcasting period of RTCM data of each RTCM type, and information of satellite observation values ​​used for packet loss analysis. The information of satellite observation values ​​used for packet loss analysis in the embodiment of the present disclosure includes: the number of satellites and the number of frequency points corresponding to each satellite system.

[0021] The disclosed embodiment can promptly perform the determination and processing of the above statistical information after encoding the RTCM data required for RTK positioning, so as to ensure the real-time nature of the packet loss analysis.

[0022] In an exemplary embodiment, before the determined statistical information is processed at a preset interval to obtain the coded statistical information and carried in an extension field of one or more RTCM data, the method of the embodiment of the present disclosure further includes: Determine the number of bits occupied by each piece of information contained in the coding statistics carried in the extension field.

[0023] In an exemplary embodiment, the number of bits occupied by each piece of information included in the coded statistical information determined by the embodiment of the present disclosure may include: the number of bits for encoding each RTCM type; the number of bits for encoding the broadcast period of each RTCM type; the number of bits for encoding each type of satellite observation value used for packet loss analysis; wherein the number of bits for encoding each type of satellite observation value used for packet loss analysis includes the number of bits for encoding the number of satellites in each satellite system and the number of bits for encoding the number of frequency points in each satellite system. In an exemplary embodiment, the embodiment of the present disclosure may set the value of the preset interval in combination with the change law of the satellite navigation signal, for example, the preset interval may be 60 seconds.

[0024] The disclosed embodiment implements statistical analysis of RTCM packet loss by setting a preset interval to broadcast RTCM data carrying coded statistical information at a low frequency, thereby avoiding impact on system bandwidth.

[0025] In an exemplary embodiment, the embodiment of the present disclosure compresses and encodes the determined statistical information into encoded statistical information at preset intervals, and carries it in an extended field of one or more RTCM data, including: Compress and encode the determined statistical information into coded statistical information at preset intervals, and carry the coded statistical information in an extended field of an RTCM data; or, The determined statistical information is compressed and encoded into coded statistical information at preset intervals, and the coded statistical information is divided into first sub-coded statistical information with a fixed period and second sub-coded statistical information that changes in real time, which are respectively carried in an extended field of an RTCM data.

[0026] In an exemplary embodiment, the embodiment of the present disclosure sends RTCM data carrying coded statistical information to a mobile terminal, including: When the coded statistical information is carried in an extension field of an RTCM data, the RTCM data carrying the coded statistical information is sent according to a first preset period; When the coded statistical information is carried in the extension fields of two RTCM data, the RTCM data containing the second sub-coded statistical information is sent according to the first preset period; the RTCM data containing the first sub-coded statistical information is sent according to the second preset period; The second preset period is greater than the first preset period.

[0027] The disclosed embodiment encodes the first sub-coded statistical information and the second sub-coded statistical information into extended fields of different RTCM types to differentiate the RTCM type periods; the first sub-coded statistical information, for example, uses RTCM1013, because the information contained in it remains unchanged after user configuration, so a long period can be used; the second sub-coded statistical information, for example, uses RTCM1014, because the information contained in it will have real-time changes, so a short period can be used; through the above-mentioned differentiation processing, the disclosed embodiment reduces the amount of output data while ensuring the real-time nature of the packet loss information.

[0028] The disclosed embodiment divides the coding statistical information into first sub-coding statistical information with a fixed period and second sub-coding statistical information with real-time changes, and carries each of the information in an extended field of an RTCM data. Through two RTCM data transmissions, the bandwidth requirements are further reduced, and the bandwidth resource consumption is reduced. Since the data volume of a single RTCM data is reduced, packet loss is reduced.

[0029] In an exemplary instance, the first sub-coded statistical information with a fixed period in the embodiment of the present disclosure may include: the RTCM type and the broadcast period of each RTCM type; the second sub-coded statistical information that changes in real time may include: information on satellite observation values ​​used for packet loss analysis, which may include one or any combination of the following satellite systems, including the number of satellites and the number of frequencies: GPS system and GLONASS system, Galileo system, QZSS system and Beidou system.

[0030] In an exemplary instance, the embodiment of the present disclosure can use the extended field of RTCM1013 to carry the above-mentioned coded statistical information; when distinguishing the first sub-coded statistical information and the second sub-coded statistical information, the extended field of RTCM1013 can be used to carry the above-mentioned second sub-coded statistical information, and RTCM data with fewer extended fields including RTCM1014 can be used, but the number of bits of the extended field meets the requirements for carrying the first sub-coded statistical information; in short, the embodiment of the present disclosure only needs the length of the extended field to support the carrying of coded statistical information; taking RTCM1013 as an example, its extended field is stored in a loop of 12 bits, 1 bit, and 16 bits in sequence; the name of the statistical information of the embodiment of the present disclosure, the number of bits occupied by each component of the coded statistical information, and the description of each statistical information are shown in Table 1.

[0031]

[0032] Table 1 In an exemplary embodiment, the packet loss analysis method of the embodiment of the present disclosure further includes: When the extended field of the RTCM data carries statistical information, distinguishing identification information is added to the extended field to mark that the RTCM encoding contains the encoded statistical information.

[0033] In an exemplary embodiment, for general scenarios, the embodiment of the present disclosure takes the statistical information in Table 1 as an example, and can compress and encode the RTCM type of the statistical RTCM data within the preset interval by fixing 36 bits, and use a bit value of 1 to indicate that the current RTCM data carries the encoded statistical information, and the bit value of 0 indicates that the encoded statistical information is not carried. In the order of GPS, GLONASS, Galileo, QZSS and Beidou satellite systems, the number of satellites and the maximum number of frequency points of the corresponding satellite systems are fixedly stored in sequence; according to the type of valid coding identified in the RTCM similar indication field, the information of the broadcasting period of the corresponding RTCM type data is stored in sequence.

[0034] In an exemplary embodiment, the embodiment of the present disclosure compresses and encodes the determined statistical information into encoded statistical information at preset intervals, and carries it in an extended field of one or more RTCM data, including: The determined statistical information is compressed and encoded into coded statistical information according to preset intervals through preset mapping relationship information, and the coded statistical information is carried in an extended field of one or more RTCM data.

[0035] The disclosed embodiment maps and encapsulates the statistical information through mapping relationship information, and compresses and encodes it into coded statistical information, thereby reducing the occupation of system bandwidth resources by transmitting the coded statistical information and lowering the bandwidth requirement for transmitting the coded statistical information.

[0036] In an exemplary embodiment, the embodiment of the present disclosure compresses and encodes the determined statistical information into encoded statistical information according to a preset interval through preset mapping relationship information, including: According to the pre-set mapping relationship between each RTCM type and the type code, the RTCM type code included in the statistical information is encoded into the corresponding type code; Convert the advertisement period contained in the statistics into the corresponding digital code.

[0037] According to the RTCM types and broadcast cycles commonly used in RTK in major industry applications, the information of the mapping relationship in the embodiment of the present disclosure includes the predetermined number of bits occupied by each broadcast cycle. After compression based on the mapping relationship, the compressed information is encoded into the extension field according to the number of bits occupied by the broadcast cycle.

[0038] The broadcast cycle of RTCM in the embodiment of the present disclosure is in seconds. To reduce the data length, only the broadcast cycles commonly used in industry applications are escaped and stored. For the cycle value range of the RTCM type of the MSM series, 1-60 corresponds to the real value, and the values ​​61-63 can be escaped according to the following corresponding relationship: 61 is converted to 0.1 when decoded on the mobile terminal (i.e., the output interval is 0.1 seconds); 62 is converted to 0.2 when decoded on the mobile terminal (i.e., the output interval is 0.2 seconds); When decoded on the mobile terminal, 63 is converted to 0.5 (which means the output interval is 0.5 seconds).

[0039] The base station of the disclosed embodiment encodes the MSM series RTCM type according to the maximum number of frequencies of all satellites; for example, when the maximum number of frequencies of the Beidou system is 5, the observation value information of satellite No. 1 only has 3 frequencies at a certain point in time, and it must also be encoded according to 5 frequencies. The frequency area not supported by the disclosed embodiment is filled with blank information.

[0040] The disclosed embodiment is based on the RTCM protocol and transmits RTCM data through a communication link; it can support multiple communication links such as radio, Bluetooth, and the Internet.

[0041] Figure 2 FIG. 1 is a flow chart of another packet loss analysis method according to an embodiment of the present disclosure. Figure 2 As shown, including: The mobile terminal receives and decodes the RTCM data carrying the coded statistical information from the base station to obtain the coded statistical information; Perform packet loss analysis based on the encoding statistics obtained by decoding and the receiving statistics obtained by actual statistics; The RTCM data is obtained by the base station through compression encoding based on the RTCM data required for RTK positioning after encoding and determining the statistical information for packet loss analysis, and is carried in the extended field of the RTCM data.

[0042] In an exemplary embodiment, the embodiment of the present disclosure performs packet loss analysis according to the encoding statistical information obtained by decoding and the receiving statistical information obtained by actual statistics, including: The mobile terminal decodes the received RTCM data carrying the coded statistical information to obtain the coded statistical information; Decoding the obtained coding statistical information according to the pre-stored mapping relationship information and the number of occupied bits of each piece of information in the pre-determined coding statistical information to obtain statistical information for packet loss analysis; The mobile terminal counts the RTCM data actually received within a preset interval and required for RTK positioning to obtain reception statistical information; The result of the packet loss analysis is obtained by comparing the statistical information for packet loss analysis obtained by decoding with the receiving statistical information obtained by statistics.

[0043] The disclosed embodiment can use the GPS system time as the time standard to count the above-mentioned reception statistical information; that is, the GPS system time can be used as the time standard to determine the encoding statistical information and reception statistical information at the same time, and the packet loss rate can be calculated by comparing the two.

[0044] In an exemplary embodiment, the packet loss analysis method of the embodiment of the present disclosure further includes: The start time and end time of the packet loss analysis are configured according to the received instruction, so as to perform the packet loss analysis of the RTCM data within the time period according to the configured start time and end time.

[0045] In an exemplary instance, the mobile terminal of the embodiment of the present disclosure can set the start time and end time of the packet loss analysis through configuration instructions, and count the RTCM packet loss rate of the specified time period; for example, the start time and end time can be set through a sliding window, or long-term cumulative statistics can be performed. From a probabilistic perspective, long-term cumulative statistics are more conducive to evaluating the RTCM packet loss situation of the communication link; this function can be implemented in real-time statistics within the positioning module, and there is no need to record data for post-processing analysis. The configuration command of the embodiment of the present disclosure may include a start time point and a statistical duration; if a clear input start time is not specified, the time when the instruction is input is used as the statistical start time; if a clear statistical duration is not specified, statistics are continued until an end statistical instruction is received.

[0046] The embodiment of the present disclosure uses GPS system time as the time standard, determines the encoding statistics at the same time and the reception statistics of the RTCM data actually received and required for RTK positioning, and determines the packet loss information by comparing the results; the following is an explanation through a specific example: The RTCM data types sent by the base station and the corresponding broadcast periods (the corresponding relationship is indicated by - in the middle) are as follows: RTCM1005-10 second interval; RTCM1033-10 second interval; RTCM1013-60 second interval; RTCM1074-1 second interval; RTCM1084-1 second interval; RTCM1094-1 second interval; RTCM1114-1 second interval; RTCM1124-1 second interval.

[0047] In the embodiment of the present disclosure, the positioning module is used as a base station, and the base station antenna is installed on the roof of an office building with coordinates of 40.07898969204, 116.23659499780, 65.9482. At the GPS time point: 2349 (GPS week) 199980 (seconds in GPS week), the positioning module can receive satellite observation values ​​of 22 Beidou satellites and a maximum of 6 frequencies. According to the RTCM coding standard, RTCM1124 is divided into 3 codes; if the time point is a multiple of 60 seconds, the base station will encode and output the RTCM data required for RTK positioning, including: 1 RTCM1005, 1 RTCM1033, 1 RTCM1013, 1 RTCM1074, 1 RTCM1084, 1 RTCM1094, 1 RTCM1114 and 3 RTCM1124; among them, RTCM1013 contains all RTCM types and broadcast cycles (output time interval) of this group of data at this time point, the number of satellites of each satellite system and the maximum number of frequencies, etc.

[0048] The RTCM data required for RTK positioning is transmitted through the radio link. After the mobile terminal receives the RTCM data, it first decodes all the differential data actually received, and then obtains the type and total amount of differential data actually received at GPS time points 2349 and 199980.

[0049] Based on the coding statistics in RTCM1013, the mobile terminal can derive the differential data type and total data volume that should be received at GPS time points 2349 and 199980. For the MSM series RTCM data with non-fixed length, when decoding on the mobile terminal, as long as the number of satellites and the maximum number of frequency points of the corresponding satellite system are parsed, the length of the corresponding RTCM data packet received can be calculated according to the RTCM coding specification, which is convenient for comparison with the MSM series RTCM data of the same type and at the same time actually received.

[0050] Suppose the RTCM data actually decoded and required for RTK positioning are: 1 RTCM1005, 1 RTCM1033, 1 RTCM1013, 1 RTCM1074, 1 RTCM1094, 1 RTCM1114 and 2 RTCM1124.

[0051] By comparison, it was found that one RTCM1084 and one RTCM1124 were missing; the data loss rate can be calculated based on the data volume: RTCM data loss rate = (the amount of data that should have been received - the amount of data actually received) / the amount of data that should have been received.

[0052] Because the frequency of each RTCM type of data sent by the base station is fixed, and the number of satellites and the maximum frequency points of each satellite system change at a low frequency, RTCM1013 can be configured to have a low output frequency, such as a 60-second interval; as long as one message is received and parsed successfully, the last parsed RTCM1013 information can be used to perform packet loss analysis within the actual interval.

[0053] For example, continuing with the above example, at the GPS time point: 2349 (GPS week) 199981 (seconds in GPS week), the RTCM data required for RTK positioning encoded and output by the base station include: 1 RTCM1074, 1 RTCM1084, 1 RTCM1094, 1 RTCM1114 and 3 RTCM1124.

[0054] After the mobile terminal receives and decodes the RTCM data required for RTK positioning, it obtains the information of the RTCM data actually received for RTK positioning. Based on the RTCM1013 received at the last time point, the RTCM data information and data volume that should be received at this time point can be obtained; the same method is used to compare the lost data types and calculate the data loss rate.

[0055] The disclosed embodiments can accurately determine the GPS system time, the packet loss type and the amount of packet loss data of the RTCM at each output moment in real time, and also help to improve the RTK positioning algorithm; in the RTK positioning algorithm, based on the lost differential statistical information, a response strategy is added to improve the reliability of the RTK positioning performance under poor communication link conditions; the disclosed embodiments can be applied to RTK positioning solutions in the direction of lawn mowers, formation drones and vehicle navigation.

[0056] Figure 3 is a structural block diagram of a base station according to an embodiment of the present disclosure, such as Figure 3 As shown, it includes: a statistical unit, a compression encoding unit and a sending unit; wherein, The statistical unit is set to: determine statistical information for packet loss analysis according to the encoded real-time differential global positioning system control information RTCM data required for real-time dynamic positioning technology RTK positioning; The compression encoding unit is configured to: process the determined statistical information at a preset interval to obtain encoded statistical information, and carry the encoded statistical information in an extension field of one or more RTCM data; The sending unit is configured to send the RTCM data carrying the coded statistical information to the mobile terminal, so that the mobile terminal performs packet loss analysis according to the decoded RTCM data carrying the coded statistical information and the received statistical information obtained by actual statistics.

[0057] In an exemplary embodiment, the statistical information in the embodiment of the present disclosure includes the following information of the RTCM data required for the encoded RTK positioning: RTCM type, the broadcast period of RTCM data for each RTCM type, and information about satellite observations used for packet loss analysis.

[0058] In an exemplary embodiment, the base station in the embodiment of the present disclosure further includes a determining unit, which is configured to: Determine the number of bits occupied by each piece of information contained in the coding statistics carried in the extension field.

[0059] In an exemplary embodiment, the compression coding unit of the embodiment of the present disclosure is configured as follows: Compress and encode the determined statistical information into coded statistical information at preset intervals, and carry the coded statistical information in an extended field of an RTCM data; or, The determined statistical information is compressed and encoded into coded statistical information at preset intervals, and the coded statistical information is divided into first sub-coded statistical information with a fixed period and second sub-coded statistical information that changes in real time, which are respectively carried in an extended field of an RTCM data.

[0060] In an exemplary embodiment, the sending unit of the embodiment of the present disclosure is configured as follows: When the coded statistical information is carried in an extension field of an RTCM data, the RTCM data carrying the coded statistical information is sent according to a first preset period; The coding statistical information is divided into first sub-coding statistical information with a fixed period and second sub-coding statistical information with real-time changes. When they are respectively carried in an extension field of an RTCM data, the RTCM data containing the second sub-coding statistical information is sent according to the first preset period; and the RTCM data containing the first sub-coding statistical information is sent according to the second preset period. The second preset period is greater than the first preset period.

[0061] In an exemplary embodiment, the first sub-coded statistical information with a fixed period in the embodiment of the present disclosure includes: RTCM type and the broadcasting period of each RTCM type.

[0062] In an exemplary embodiment, the second sub-coding statistical information that changes in real time in the embodiment of the present disclosure includes: information of satellite observation values ​​used for packet loss analysis.

[0063] In an exemplary embodiment, the compression coding unit of the embodiment of the present disclosure is further configured as follows: When the extended field of the RTCM data carries the coded statistical information, distinguishing identification information is added to the extended field to mark that the RTCM data contains the coded statistical information.

[0064] In an exemplary embodiment, the compression encoding unit of the embodiment of the present disclosure is configured to compress and encode the determined statistical information into encoded statistical information according to a preset interval through preset mapping relationship information, including: According to the pre-set mapping relationship between each RTCM type and the type code, the RTCM type code contained in the statistical information is converted into the corresponding type code; and the broadcasting period contained in the statistical information is converted into the corresponding digital code.

[0065] Figure 4 is a structural block diagram of the mobile terminal of the embodiment of the present disclosure, such as Figure 4 As shown, it includes: a receiving decoding unit and an analyzing unit; wherein, The receiving and decoding unit is configured to: receive and decode RTCM data carrying coding statistical information from a base station to obtain the coding statistical information; The analysis unit is configured to: perform packet loss analysis based on the encoding statistical information obtained by decoding and the receiving statistical information obtained by actual statistics; The RTCM data is obtained by the base station through compression encoding based on the RTCM data required for RTK positioning after encoding and determining the statistical information for packet loss analysis, and is carried in the extended field of the RTCM data.

[0066] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or transient medium). As is known to those skilled in the art, the term "computer storage medium" includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. A packet loss analysis method, characterized in that: include: The base station determines the statistical information used for packet loss analysis based on the encoded real-time differential global positioning system control information RTCM data required for real-time dynamic positioning technology RTK positioning; Processing the determined statistical information at preset intervals to obtain coded statistical information, and carrying the coded statistical information in an extended field of one or more RTCM data; The RTCM data carrying the coding statistical information is sent to the mobile terminal, so that the mobile terminal performs packet loss analysis according to the RTCM data carrying the coding statistical information and the reception statistical information actually obtained by statistics.

2. The packet loss analysis method according to claim 1, characterized in that: The statistical information includes the following information of the RTCM data required for the encoded RTK positioning: RTCM type, the broadcast period of RTCM data for each RTCM type, and information about satellite observations used for packet loss analysis.

3. The packet loss analysis method according to claim 1, characterized in that: Before compressing and encoding the determined statistical information into coded statistical information according to the preset interval and carrying it in the extension field of one or more RTCM data, the method further includes: Determine the number of bits occupied by each piece of information included in the coding statistical information carried in the extension field.

4. The packet loss analysis method according to any one of claims 1 to 3, characterized in that: The processing of the determined statistical information at the preset interval to obtain the coded statistical information, which is carried in the extended field of one or more RTCM data, includes: Compress and encode the determined statistical information into the coded statistical information according to the preset interval, and carry the coded statistical information in an extended field of an RTCM data; or, The determined statistical information is compressed and encoded into the encoded statistical information according to the preset interval, and the encoded statistical information is divided into first sub-encoded statistical information with a fixed period and second sub-encoded statistical information that changes in real time, and each of them is carried in an extended field of an RTCM data.

5. The packet loss analysis method according to claim 4, characterized in that: The sending of RTCM data carrying coded statistical information to the mobile terminal includes: When the coded statistical information is carried in an extension field of a piece of RTCM data, sending the RTCM data carrying the coded statistical information according to a first preset period; The coding statistical information is divided into first sub-coding statistical information with a fixed period and second sub-coding statistical information that changes in real time. When the first sub-coding statistical information is respectively carried in an extension field of an RTCM data, the RTCM data containing the second sub-coding statistical information is sent according to the first preset period; and the RTCM data containing the first sub-coding statistical information is sent according to the second preset period. Wherein, the second preset period is greater than the first preset period.

6. The packet loss analysis method according to claim 5, characterized in that: The first sub-coded statistical information with a fixed period includes: RTCM type and the broadcast period of each RTCM type; The second sub-coding statistical information that changes in real time includes: information of satellite observation values ​​used for packet loss analysis.

7. The packet loss analysis method according to any one of claims 1 to 3, characterized in that: The step of compressing and encoding the determined statistical information into coded statistical information according to the preset intervals through the preset mapping relationship information includes: According to a preset mapping relationship between each RTCM type and the type code, the RTCM type code included in the statistical information is converted into a corresponding type code; The broadcasting period included in the statistical information is converted into a corresponding digital code.

8. A packet loss analysis method, characterized in that: include: The mobile terminal receives and decodes the RTCM data carrying the coded statistical information from the base station to obtain the coded statistical information; Perform packet loss analysis based on the encoding statistical information obtained by decoding and the receiving statistical information obtained by actual statistics; The RTCM data is obtained by the base station through compression encoding based on the encoded RTCM data required for RTK positioning and statistical information determined for packet loss analysis, and is carried in an extended field of the RTCM data.

9. A base station, characterized in that: include: Statistics unit, compression coding unit and sending unit; wherein, The statistical unit is set to: determine statistical information for packet loss analysis according to the encoded real-time differential global positioning system control information RTCM data required for real-time dynamic positioning technology RTK positioning; The compression encoding unit is configured to: process the determined statistical information at a preset interval to obtain encoded statistical information, and carry the encoded statistical information in an extension field of one or more RTCM data; The sending unit is configured to send the RTCM data carrying the coded statistical information to the mobile terminal, so that the mobile terminal performs packet loss analysis according to the decoded RTCM data carrying the coded statistical information and the received statistical information obtained by actual statistics.

10. A mobile terminal, characterized in that: include: A receiving decoding unit and an analyzing unit; wherein, The receiving and decoding unit is configured to: receive and decode RTCM data carrying coding statistical information from a base station to obtain the coding statistical information; The analysis unit is configured to: perform packet loss analysis based on the encoding statistical information obtained by decoding and the receiving statistical information obtained by actual statistics; The RTCM data is obtained by the base station through processing based on the encoded RTCM data required for RTK positioning and statistical information determined for packet loss analysis, and is carried in an extended field of the RTCM data.

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