CN103780348A - DCS satellite link downlink data acknowledgement frame transmission method - Google Patents

Abstract

Translated fromChinese

本发明公开了卫星数据采集系统（DCS）中卫星链路下行数据确认帧格式和传输方法。A.该确认帧格式是一种DCS卫星系统的下行链路传输确认数据帧的可变长帧格式，帧格式由业务标示、比特可变长的卫星标示（ID）位和数据信息字标示组成。B.确认帧传输方法是基于组播与单播混合传输和可变长确认帧格式压缩技术相结合的下行链路确认帧传输方法。当数据采集平台（DCP）物理距离较近，可以将DCP加入同一个组播组里，采用组播模式进行群确认，否则采用单播模式，并对下行链路确认帧进行压缩优化。压缩优化采用由比特压缩、幅度编码、变长压缩编码三种方法组合实现。该可变长帧格式设计灵活，且传输方法实现简单，高效。

The invention discloses a satellite link downlink data confirmation frame format and a transmission method in a satellite data collection system (DCS). A. The confirmation frame format is a variable-length frame format of the downlink transmission confirmation data frame of the DCS satellite system. The frame format is composed of a service label, a variable-length satellite label (ID) bit and a data information word label. . B. The acknowledgment frame transmission method is a downlink acknowledgment frame transmission method based on the combination of multicast and unicast mixed transmission and variable length acknowledgment frame format compression technology. When the physical distance of the data collection platform (DCP) is relatively close, the DCP can be added to the same multicast group, and the multicast mode is used for group confirmation; otherwise, the unicast mode is used, and the downlink confirmation frame is compressed and optimized. Compression optimization is achieved by combining three methods: bit compression, amplitude coding, and variable-length compression coding. The variable length frame format is flexible in design, and the transmission method is simple and efficient.

Description

Translated fromChinese

DCS系统卫星链路下行数据确认帧传输方法DCS system satellite link downlink data confirmation frame transmission method

1技术领域1 technical field

本发明设计到卫星通信领域，涉及在多终端卫星数据采集系统（DCS）卫星数据采集系统。The invention is designed in the field of satellite communication, and relates to a satellite data collection system in a multi-terminal satellite data collection system (DCS).

2背景技术2 background technology

卫星通信中的数据采集系统（DCS）是一种通过远端数据采集平台采集数据或是对数据采集平台进行定位的系统。它采用了航天中的遥测、遥控和遥监等技术，将远端数据采集平台采集的各种监测量经过卫星实时或存储转发后传输到地面接收处理中心，最后由数据处理中心将数据交付给用户使用。虽然几百个乃至几千个数据采集平台在地理位置上是分散的，但通过DCS系统它们被有机地联系在一起，共同协作完成某一监测任务。数据采集平台大多被设计为自动完成数据的采集、发送，而无需人工值守，因此数据采集平台的分布地域广阔，不受环境、地理条件的限制，特别适合安装在人烟稀少或环境恶劣地区，进行野外工作。The data collection system (DCS) in satellite communication is a system that collects data through a remote data collection platform or locates a data collection platform. It adopts the technologies of telemetry, remote control and remote monitoring in aerospace, and transmits various monitoring quantities collected by the remote data acquisition platform to the ground receiving and processing center after real-time or storage and forwarding by satellite, and finally the data processing center delivers the data to user use. Although hundreds or even thousands of data collection platforms are geographically dispersed, they are organically linked through the DCS system and work together to complete a certain monitoring task. Most of the data collection platforms are designed to automatically complete the collection and transmission of data without manual on-duty. Therefore, the data collection platforms are distributed in a wide area and are not limited by environmental and geographical conditions. They are especially suitable for installation in sparsely populated or harsh environments. Work.

但由于DCS中的卫星处理能力有限，其下行速率较低，对有大量DCS终端的系统下行确认帧按照传统一次接收一次确认的方法传输确认信息，大量占用信道资源，这大大限制了单位时间对地面DCP接收数据确认的数量，其通信质量也容易受到信道条件的影响，发生拥塞、丢包重传等现象，所以必须针对其确认信息特侦进行分析，设计适合多终端DCS的数据确认帧格式以及相应的确认方法，进而对DCS数据确认过程进行优化。However, due to the limited processing capacity of satellites in DCS and its low downlink rate, the downlink confirmation frame of a system with a large number of DCS terminals transmits confirmation information according to the traditional method of receiving one confirmation at a time, occupying a large amount of channel resources, which greatly limits the unit time. The number of terrestrial DCP received data confirmation, and its communication quality is also easily affected by channel conditions, such as congestion, packet loss and retransmission, etc., so it is necessary to analyze the special detection of its confirmation information and design a data confirmation frame format suitable for multi-terminal DCS And the corresponding confirmation method, and then optimize the DCS data confirmation process.

对于帧格式的设计，通常需要考虑帧序列号、确认号、头长度、标志位、目的标示（ID）、保留域和校验位等，由于DCS下行链路传输速率小，但其DCP数量众多，在DCS中应尽量在保证下行确认功能完备的基础上设计较短的帧，降低确认帧平均发送时间。For the design of the frame format, it is usually necessary to consider the frame sequence number, confirmation number, header length, flag bit, destination identification (ID), reserved field and parity bit, etc. Due to the low transmission rate of the DCS downlink, the number of DCPs is large , in the DCS, we should try to design shorter frames on the basis of ensuring that the downlink confirmation function is complete, and reduce the average sending time of confirmation frames.

传统确认方法是对地面DCP数据进行依次确认，随着DCP数量的变大，确认时间也呈线性增加，DCS卫星过顶时间大约是20分钟，这限制了地面DCP的数量。针对DCS特点，采用新的下行链路确认方式，降低确认时间。首先设计群确认方案，由于卫星波束覆盖范围大，适合用组播进行群传播传输，对需要确认的DCP信息进行存储，分组确认，设计组播通信模式可以提高一次传输确认信息的DCP。其次设计进一步压缩帧长度的，变长压缩优化技术，压缩优化的方法种类繁多，这里利用DCP ID的信息冗余，能使用一定的编码压缩方法将下行帧进行压缩，减少每一帧传输占用的信道资源。The traditional confirmation method is to confirm the ground DCP data sequentially. As the number of DCPs increases, the confirmation time also increases linearly. The overhead time of DCS satellites is about 20 minutes, which limits the number of ground DCPs. According to the characteristics of DCS, a new downlink confirmation method is adopted to reduce the confirmation time. First, the group confirmation scheme is designed. Due to the large coverage of satellite beams, multicast is suitable for group transmission. The DCP information that needs to be confirmed is stored and confirmed in groups. The design of multicast communication mode can improve the DCP of one transmission confirmation information. Secondly, design the variable length compression optimization technology to further compress the frame length. There are many kinds of compression optimization methods. Here, the information redundancy of DCP ID can be used to compress the downlink frame by using a certain encoding compression method, reducing the time occupied by each frame transmission. channel resources.

3发明内容3 Contents of the invention

本发明设计了一种可变长下行链路确认帧变长编码结构，由业务标示、变长编码方式标示、可变长的DCP标示（ID）位和数据信息字标示组成。The present invention designs a variable-length downlink confirmation frame variable-length coding structure, which is composed of a service mark, a variable-length coding mode mark, a variable-length DCP mark (ID) bit and a data information word mark.

本发明实施提供了一种下行链路确认帧传输方法，能对DCP数据的确认过程进行分组管理，组播、单播结合，提高传输效率，实现简单。The implementation of the present invention provides a downlink confirmation frame transmission method, which can carry out group management on the confirmation process of DCP data, combine multicast and unicast, improve transmission efficiency, and is simple to implement.

本发明实施提供一种由比特压缩、幅度编码、变长压缩编码三种方法联合的下行链路确认帧压缩优化方法，压缩下行链路确认帧长度。The implementation of the present invention provides a downlink acknowledgment frame compression optimization method combining three methods of bit compression, amplitude coding and variable length compression coding to compress the length of the downlink acknowledgment frame.

4附图说明4 Description of drawings

图1为本发明设计的可变长下行数据确认帧格式；Fig. 1 is the variable length downlink data confirmation frame format designed by the present invention;

图2为本发明实现DCS下行数据确认帧传输方案示意图。FIG. 2 is a schematic diagram of a scheme for realizing DCS downlink data acknowledgment frame transmission according to the present invention.

5具体实施方式5 specific implementation

A.下行数据确认帧格式设计A. Downlink data confirmation frame format design

本发明设计了一种可变长下行链路确认帧格式，设计业务标示位标示的含义，设计可变长ID标示位长度以及数据信息字表示位的含义。The present invention designs a variable-length downlink confirmation frame format, designs the meaning of the service flag bit, and designs the length of the variable-length ID flag bit and the meaning of the bit of the data information word.

本发明提出了一种可变长帧结构，一个dcs系统dcp数量m个，则卫星ID标示需要

位。如图1下行链路确认帧结构所示，包括2比特业务标示，2比特变长编码方式标示，0～

比特可变长度卫星ID标示和4比特的数据信息字。假设m为60000个，则可变长度卫星ID标示位为16位。The present invention proposes a variable length frame structure, a dcs system dcp quantity m, then the satellite ID mark needs

bit. As shown in the structure of the downlink confirmation frame in Figure 1, it includes a 2-bit service flag, a 2-bit variable-length code flag, and 0~

1-bit variable-length satellite ID flag and 4-bit data information word. Assuming that m is 60,000, the variable-length satellite ID flag is 16 bits.

业务标志位用于标示单播、广播、组播方式，如最高两位为11，表示后面地址为组播地址；为00，后面的地址为单播地址；为01，所发消息即为广播确认消息等。借鉴IP子网掩码的方式，通过群确认或群查询的方式，提高确认或查询的速率。The service flag bit is used to mark unicast, broadcast, and multicast modes. If the highest two bits are 11, it means that the following address is a multicast address; if it is 00, the following address is a unicast address; if it is 01, the message sent is a broadcast Acknowledgment messages etc. Learn from the method of IP subnet mask, and improve the rate of confirmation or query through group confirmation or group query.

比特变长编码方式标示用于指定对于DCP ID的压缩方法，如果标示为00：去掉ID右边0，标示为01去掉ID左边的0，标示为10去掉ID右边的1，标示为11去掉标示左边的1。Bit variable length encoding mode is used to specify the compression method for DCP ID. If it is marked as 00: remove the 0 on the right side of the ID, mark it as 01 and remove the 0 on the left side of the ID, mark it as 10 and remove the 1 on the right side of the ID, mark it as 11 and remove the left side of the ID 1.

卫星ID标示设计为可变长类型，通过设计的编码优化方法，能够将卫星ID标示的长度压缩在0～16比特之间，这样就将下行链路确认帧的长度压缩。The satellite ID mark is designed as a variable length type. Through the designed coding optimization method, the length of the satellite ID mark can be compressed between 0 and 16 bits, so that the length of the downlink confirmation frame can be compressed.

数据信息字设置为4位，表示卫星对DCP的指令，如0111表示接收完毕，0110表示重传，0101表示同意接入，0110表示拒绝接入，0100表示非紧急业务发送完当前数据后停止接入，0101表示如有空闲信道非紧急业务可以接入，0010表示发送自身状态信息给卫星，最高位为保留位，可用于询问DCP，1001表示要求向卫星发送信息。The data information word is set to 4 bits, indicating the satellite’s instruction to the DCP, such as 0111 means receiving, 0110 means retransmitting, 0101 means agreeing to access, 0110 means rejecting access, 0100 means stop receiving after sending the current data for non-emergency services 0101 means that non-emergency services can be accessed if there is an idle channel, 0010 means sending its own status information to the satellite, the highest bit is a reserved bit, which can be used to query DCP, and 1001 means requesting to send information to the satellite.

B.下行数据确认帧高速传输方案B. Downlink data confirmation frame high-speed transmission scheme

本发明实施提供了一种下行链路确认帧传输方法，能对DCP数据的确认过程进行分组管理，组播、单播结合，并根据编码理论，采取由比特压缩、幅度编码、变长压缩编码三种方法联合的下行链路确认帧压缩优化方法，压缩下行链路确认帧长度。The implementation of the present invention provides a downlink confirmation frame transmission method, which can carry out group management on the confirmation process of DCP data, combine multicast and unicast, and adopt bit compression, amplitude coding and variable length compression coding according to the coding theory The downlink acknowledgment frame compression optimization method combined with the three methods compresses the length of the downlink acknowledgment frame.

引入组播，终端可以通过业务标示识别这是一个组播帧还是一个单播帧，对于编码，则需要在卫星内增加存储和计算单元，当卫星运行到数据采集区域，需要下行传输确认数据帧的时候，首先对于加入组播组中的DCP按照组播传输，然后对其余未在组播中且需要进行数据采集确认的DCP，进行单播传输，并对单播传输的帧进行压缩编码处理。在DCP端，也应引入一定的信号处理单元，使得其能够接收到信号识别组播帧和单播帧，并对单播帧进行译码处理。With the introduction of multicast, the terminal can identify whether it is a multicast frame or a unicast frame through the service label. For encoding, it is necessary to add storage and computing units in the satellite. When the satellite moves to the data collection area, it needs to downlink transmission confirmation data frame At the time, firstly, the DCPs that join the multicast group are transmitted according to the multicast, and then the rest of the DCPs that are not in the multicast and need to be confirmed by data collection are transmitted in unicast, and the frames transmitted by unicast are compressed and encoded. . At the DCP side, a certain signal processing unit should also be introduced so that it can receive signals to identify multicast frames and unicast frames, and decode the unicast frames.

下面结合附图和具体实施例进一步说明本发明的具体实施方案。如图2所示实现DCS下行链路确认帧方案的具体步骤如下：The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings and specific examples. As shown in Figure 2, the specific steps for realizing the DCS downlink confirmation frame scheme are as follows:

步骤201、卫星接收到DCP数据之后，将待确认DCP ID存入ID池中，并对DCP ID按照需要确认的种类例如确认接收完毕、确认重传、确认拒绝接入、确认请求发送等进行分类整理，等待进一步的处理；Step 201, after the satellite receives the DCP data, store the DCP ID to be confirmed in the ID pool, and classify the DCP ID according to the type of confirmation required, such as confirmation of receipt completion, confirmation of retransmission, confirmation of rejection of access, confirmation of request to send, etc. Organize and wait for further processing;

步骤202、以帧长时间为单位，分析当前ID池中适合进行多播还是单播，将适合多播的分为一组，如果暂时未有多播帧需要处理，则进行单播帧的发送。由于多播帧一次确认的DCP数量多，优先发送多播帧；Step 202, taking the frame time as the unit, analyze whether the current ID pool is suitable for multicast or unicast, and group those suitable for multicast into one group, if there is no multicast frame to be processed temporarily, then send the unicast frame . Since the number of DCPs confirmed by a multicast frame is large, the multicast frame is sent first;

步骤203、对适合广播的数据帧进行广播发送，例如要求卫星覆盖范围内所有DCP向卫星发送数据，则启用广播下行链路进行通知确认，当DCP接收到卫星发送数据前2位是01的时候，确认这是一个广播帧，对其数据信息字进行处理；Step 203, broadcast and send data frames suitable for broadcast, for example, if all DCPs within the satellite coverage area are required to send data to the satellite, then enable the broadcast downlink to confirm the notification, when the DCP receives the first 2 digits of the data sent by the satellite is 01 , confirm that this is a broadcast frame, and process its data information word;

步骤204、对适合组播的数据帧进行组播发送，并将业务标示为设置为11，例如在ID标示为16位时，发送：11（组播标示）1111111111111111111000（ID标示）1001（确认字）表示的含义为：需要DCP ID为1111111111111000到1111111111111111的用户向卫星发送信息，也可以采用相同的方式，通过1条指令就可以实现多个信道的确认。DCP接收到帧的时候，如果前两位是11则进入组播过程，根据ID信息判别自己是否在多播组里，如果在则对其数据信息字进行处理；Step 204, send multicast data frames suitable for multicast, and set the service mark as 11, for example, when the ID mark is 16 bits, send: 11 (multicast mark) 1111111111111111111000 (ID mark) 1001 (confirmation word ) The meaning of expressed is: users need to send information from the satellites to the satellite by users who need DCP ID to send information to the satellites to the satellite. The same way can be used to achieve multiple channels confirmed by 1 instruction. When the DCP receives the frame, if the first two digits are 11, it will enter the multicast process, and judge whether it is in the multicast group according to the ID information, and if so, process its data information word;

步骤205、对单播下行链路确认帧进行变长编码，在DCP ID中存在左右两端有多个0和多个1的情况，如果ID右边0比较多，则设置比特变长编码方式标示为00，去掉ID右边的0，如果ID左边0比较多则设置为01，去掉ID左边的0，如果ID右边1比较多则设置为10，去掉ID右边的1，如果ID左边1比较多则设置为11，去掉ID左边的1；Step 205: Perform variable-length coding on the unicast downlink confirmation frame. There are multiple 0s and multiple 1s at the left and right ends of the DCP ID. If there are more 0s on the right side of the ID, set the bit variable-length coding mode to indicate If it is 00, remove the 0 on the right side of the ID. If there are more 0s on the left side of the ID, set it to 01. Remove the 0s on the left side of the ID. If there are more 1s on the right side of the ID, set it to 10. Remove the 1 on the right side of the ID. If there are more 1s on the left side of the ID, then set it to 00. Set it to 11, remove the 1 on the left of the ID;

步骤206、对单播下行链路确认帧进行比特压缩，采用比特压缩的算法将下行数据的比特进行压缩，映射为固定长度较小的二进制值，从而提高数据的传输速率。但是采用比特压缩的方法不能通过算法恢复原来的数据，但是可以通过查表等方法恢复原来的数据。例如，利用哈希算法将任意长度的二进制值映射为固定长度较小的二进制值；Step 206: Carry out bit compression on the unicast downlink confirmation frame, and use a bit compression algorithm to compress the bits of the downlink data and map them to binary values with a fixed length and small size, thereby increasing the data transmission rate. However, the method of bit compression cannot restore the original data through the algorithm, but the original data can be restored through methods such as table lookup. For example, using a hash algorithm to map a binary value of any length to a fixed-length smaller binary value;

步骤207、对单播下行链路确认帧进行幅度编码，将每4位为一组，映射到幅度上。如利用归一化表示：1111表示电压幅度1V，1110表示电压幅度为15/16V，1100表示电压为14/16V，……，0001表示电压为1/16V，0000为表示电压为0V，这样就可以将帧中ID的长度压缩为四分之一。Step 207, perform amplitude coding on the unicast downlink confirmation frame, and map every 4 bits into a group to the amplitude. For example, using normalization to express: 1111 means that the voltage range is 1V, 1110 means that the voltage range is 15/16V, 1100 means that the voltage is 14/16V, ..., 0001 means that the voltage is 1/16V, and 0000 means that the voltage is 0V, so that Can compress the length of the ID in the frame to a quarter.

步骤208、对编码后的确认帧进行调制发送。Step 208: Modulate and send the encoded confirmation frame.

从上述过程可以看出，首先在卫星上建立了待确认DCP ID池，当DCS下行链路确认帧适合群传输的时候，选择组播或者广播进行群传输，可以降低传统卫星下行链路依次确认的时间。设立待确认DCP ID池，对于DCP传输数量大的情况，能更灵活的发送确认消息，降低确认信息因为拥塞造成的丢包率。对于单播中引入的变长编码，在考虑一次传输的ID出现多个0或多个1的情况，用2比特信息就可以替代，实现简单。It can be seen from the above process that the DCP ID pool to be confirmed is first established on the satellite. When the DCS downlink confirmation frame is suitable for group transmission, multicast or broadcast is selected for group transmission, which can reduce the traditional satellite downlink confirmation. time. Set up a DCP ID pool to be confirmed. For the case of a large number of DCP transmissions, the confirmation message can be sent more flexibly, and the packet loss rate caused by the congestion of the confirmation message can be reduced. For the variable-length coding introduced in unicast, considering the situation that there are multiple 0s or multiple 1s in the ID of one transmission, it can be replaced by 2-bit information, which is easy to implement.

本发明在传统DCS下行链路确认技术的基础上，提出了基于多播与单播结合的混合确认模式，并将变长编码、比特压缩与幅度调制相结合提高了DCS下行确认的速率。所有操作均有软件完成，编码实现简单，可行性高。Based on the traditional DCS downlink confirmation technology, the present invention proposes a hybrid confirmation mode based on the combination of multicast and unicast, and combines variable length coding, bit compression and amplitude modulation to improve the rate of DCS downlink confirmation. All operations are completed by software, the coding is simple and the feasibility is high.

Claims (3)

Translated fromChinese

1.一种卫星数据采集系统（DCS）下行数据确认帧传输方案，其特征在于动态调整卫星与地面数据采集平台（DCP）数据确认帧的传输通信模式，该方法包括：1. A satellite data collection system (DCS) downlink data confirmation frame transmission scheme, characterized in that the transmission communication mode of the satellite and ground data collection platform (DCP) data confirmation frame is dynamically adjusted, the method comprising:设计一种适合DCS卫星链路下行数据确认信息的可变长帧格式。Design a variable length frame format suitable for DCS satellite link downlink data confirmation information.设计一种DCS下行确认帧组播与单播并用，比特压缩、幅度编码、变长压缩编码结合压缩帧长的传输方案。Design a DCS downlink confirmation frame multicast and unicast and use, bit compression, amplitude coding, variable length compression coding combined with compressed frame length transmission scheme.2.如权利要求1所述的一种变长下行链路确认帧的设计方案，由可变长帧格式，帧格式由业务标示、比特可变长的卫星标示（ID）位和数据信息字标示组成。2. The design scheme of a variable-length downlink confirmation frame as claimed in claim 1, which has a variable-length frame format, and the frame format is composed of a service mark, a variable-length satellite mark (ID) bit and a data information word Mark composition.3.如权利要求1所述的一种DCS下行确认帧传输方案，其特征在于，卫星接收来自DCP传输的数据，并依据DCP ID和确认信息分组，对DCP进行确认反馈，将DCP的ID信息连续的分为一组，将DCP的ID信息不连续的分为另一组，对其进行分别处理。将DCP的ID信息连续的那一组作为一个子网分组，卫星发送类似子网掩码的卫星ID确认示帧，进行组播传输。否则进行单播传输，单播中对DCP ID信息分散的，采取加入比特压缩、幅度编码、变长压缩编码三种方法组合的编码压缩技术的形式传输。3. A kind of DCS downlink confirmation frame transmission scheme as claimed in claim 1, it is characterized in that, satellite receives the data from DCP transmission, and according to DCP ID and confirmation information grouping, DCP is carried out confirmation feedback, the ID information of DCP The ID information of the DCP is divided into one group continuously, and the ID information of the DCP is divided into another group discontinuously, and they are processed separately. The group with continuous ID information of the DCP is regarded as a subnet group, and the satellite sends a satellite ID confirmation frame similar to the subnet mask for multicast transmission. Otherwise, unicast transmission is carried out. If the DCP ID information is dispersed in unicast, it is transmitted in the form of encoding compression technology combined with bit compression, amplitude encoding, and variable length compression encoding.

Images