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GJB 1198 consists of the following eight parts under the general title Telemetry tracking command and data handling for spacecraft:
——Part 1: PCM telecommand;
——Part 2: PCM telemetry;
——Part 3: Telemetry channel coding;
——Part 4: Ranging;
——Part 5: Radio frequency and modulation;
——Part 6: Packet telemetry;
——Part 7: Packet telecommand;
——Part 8: Onboard data handling interface.
This part is Part 7 of GJB 1198.
This part replaces GJB 1198.7-1991 Telemetry tracking command and data handling for satellite: Packet telecommand.
This part is formulated by reference to the following CCSDS standards, which are consistent in technical content and simplified in text:
——CCSDS 201.0-B-3 2000;
——CCSDS 202.0-B-3 2001;
——CCSDS 202.1-B-2 2001;
——CCSDS 203.0-B-2 2001;
The following main changes have been made in this part with respect to the previous edition:
a) The definition of segmentation layer is extended, and the concepts of telecommand user data unit and telecommand frame data unit are introduced;
b) Among the three command operations procedures, COP-1 is recommended, COP-0 and COP-2 are only briefly described, and a subcategory of urgent service is added;
c) Chinese wording of the control command of the original transfer layer is changed;
d) Randomized processing of telecommand data is added;
e) The tail sequence code image of the command link transmission unit is modified;
f) Support for transfer network datagrams is added;
g) The channel coding block length is fixed at 64bit;
h) The application scope is extended to all spacecrafts.
This part was proposed by China Aerospace Science and Technology Corporation.
This part is under the jurisdiction of China Astronautics Standards Institute.
This part was firstly issued in October, 1991, and firstly revised this time.
Telemetry tracking command and data handling for spacecraft
Part 7: Packet telecommand
1 Scope
This part specifies the data structure, format and necessary operations of packet telecommand system for spacecraft.
This part is applicable to spacecraft telecommand system using packet telecommand system, telecommand interface between corresponding spacecraft and earth station, and interactive support of international space data system in packet telecommand.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this part. For dated reference, subsequent amendments to (excluding any corrigendum), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest editions apply to this part.
GJB 727A-1998 Terms and acronyms of space tracking telemetry and command system
GJB 1198.6A-2004 Telemetry tracking command and data handling for spacecraft - Part 6: Packet telemetry
3 Terms and definitions
For the purposes of this part, the terms and definitions established in GJB 727A-1998 and the following ones apply.
3.1
packet telecommand
open-type PCM telecommand system for multi-source and multi-user telecommand data transmission through layered and dynamic data management in the form of packet
3.2
telecommand user data unit
user data structure of a finite length suitable for transferring telecommand application data from the ground to spacecraft in packet telecommand. It can be a telecommand packet conforming to the format specified in 5.2 of this part, or other user-defined format
3.3
telecommand transfer frame
transfer-oriented standard data structure suitable for transferring telecommand data to spacecraft in packet telecommand. It consists of a frame header, a frame data field and an optional frame error control field, in a format conforming to 7.2 of this part
3.4
telecommand frame data unit
standard data structure that is suitable for being placed in the transfer frame data field in packet telecommand, It can be a telecommand segment in a format conforming to 6.2 of this part, one or more telecommand packets in a format conforming to 5.2 of this part, or a single telecommand user data unit
3.5
command link transmission unit
error control protocol-based standard data structure that is established in packet telecommand and suitable for reliable transmission of telecommand data in noisy channels. It consists of block code block of one or more transfer frames, start sequence and tail sequence, in a format conforming to 8.2 of this part
3.6
virtual channel
dynamic transmission management mechanism that enables multiple sources and users to share the same physical channel. By uniformly allocating the "virtual channel identifier word" which designates the transfer frame header and implementing dynamic management according to the user's needs and the actual situations of the channel, different user application data alternately occupy the physical channel in a time-shared manner, i.e., dividing a single channel into multiple virtual branches
3.7
file of packets
ordered set of relevant telecommand user data units corresponding to a single control function or an independent control process of a spacecraft. It should include three basic characteristics: file name, file size and transmission integrity
3.8
command operations procedure (COP)
closed-loop operation protocol that is used to keep the telecommand sending and receiving ends working synchronously. Depending on this protocol, the correctness, integrity and sequence of telecommand application data transmitted in error channel are guaranteed
3.9
control command
specific telecommand transfer frame, which carries control instruction in its data field, and is used to establish the internal operating parameters required for establishment of the command operations procedures
3.10
command link control word
relevant information of the telecommand receiving end is reported in the packet telemetry transfer layer to the sending end through packet telemetry to support effective command operation. It is a standard format data unit specified for such report information
3.11
multiplexer access point
transmission management mechanism that enables multiple sources and users to share the same virtual channel. By uniformly allocating the "multiplexer access point" which designates the header of the telecommand segment, and implementing transmission management according to different priorities of user’s needs, different user application data alternately occupy the virtual channel in a time-shared manner, i.e., subdividing a single virtual channel into multiple transmission paths
4 General provisions
4.1 Bit sequencing convention
The bit sequencing convention is shown in Figure 1. In an N-bit data field: the first bit transferred (i.e., the most left justified in Figure 1) is defined to be Bit 0 (B0), the following bit is defined to be Bit 1 (B1) and so on up to Bit N-1 (BN-1). When this field is used to express a binary value, the most significant bit shall be the first bit of the field, i.e., Bit 0 (B0).
All fields mentioned in this part are 8-bit words.
Figure 1 Bit sequencing convention
4.2 Data stream of packet telecommand
The information processing process of packet telecommand shall be hierarchical, and the telecommand application data sent from the source side shall be sent to the telecommand user on the spacecraft after five layers of processing and inverse processing, as shown in Figure 2.
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 General provisions 5 Pack layer 6 Segmentation layer 7 Transfer layer 8 Channel coding layer 9 Physical layer
航天器测控和数据管理 第7部分：分包遥控 1 范围 本部分规定了航天器分包遥控系统的数据结构、格式和必要的操作。 本部分适用于采用分包遥控体制的航天器遥控系统，同时适用于相应的航天器与地球站的遥控接口，也适用于国际空间数据系统在分包遥控上的交互支持。 2 规范性引用文件 下列文件中的条款通过本部分的引用而成为本部分的条款。凡是注日期的引用文件，其随后所有的修改单（不包含勘误的内容）或修订版均不适用于本部分，然而，鼓励根据本部分达成协议的各方研究是否可使用这些文件的最新版本。凡是不注日期的引用文件，其最新版本适用于本部分。 GJB 727A－1998 航天测控系统术语与缩略语 GJB 1198.6A－2004 航天器测控和数据管理 第6部分：分包遥测 3 术语和定义 GJB 727A－1998确立的以及下列术语和定义适用于本部分。 3.1 分包遥控 packet telecommand 以分包的方式进行数据分层动态管理，完成多信源多用户遥控数据传输的开放式PCM遥控体制。 3.2 遥控用户数据单元 telecommand user data unit 在分包遥控中适合于从地面向航天器传递遥控应用数据的一种有限长度用户数据结构。它可以是符合本部分5.2所规定格式的遥控包，也可以符合其它由用户自定义的格式。 3.3 遥控传送帧 telecommand transfer frame 在分包遥控中适合于将遥控数据传送到航天器的一种嘶向传送过程的标准数据结构。它是由帧头、帧数据域和可选的帧差错控制域组成，其格式符合本部分7.2规定。 3.4 遥控帧数据单元 telecommand frame data unit 在分包遥控中适合于置放在传送帧数据域的一种标准数据结构。它可以是符合本部分6.2所规定格式的遥控段，也可以是一个或多个符合本部分5.2所规定格式的遥控包，也可以是单个遥控用户数据单元。 3.5 遥控信道传输单元 command link transmission unit 在分包遥控中适合于在有噪声信道中可靠传输遥控数据而建立的一种差错控制协议型标准数据结构。它是由一个或多个传送帧的分组码块加上起始序列和结尾序列而构成的，其格式符合本部分8.2规定。 3.6 虚拟信道 virtual channel 一种使多信源多用户分享同一物理信道的动态传输管理机制。通过统一分配指定传送帧帧头的“虚拟信道识别字”，并按用户需要和信道实际情况实施动态管理，使不同用户应用数据分时交替占有物理信道，相当于把单一信道划分为多个虚拟支路。 3.7 包装文件 file of packets 对应于航天器单一控制功能或独立控制过程的相关遥控用户数据单元的有序集合。作为包装文件应包括三个基本特性：文件名、文件大小和传递的完整性。 3.8 遥控操作步骤 command operations procedure 一种使遥控发送端与接收端保持同步工作状态的闭环操作协议。依靠这种协议保证在有差错信道中传送遥控应用数据的正确性、完整性和序贯性。 3.9 内务命令 control command 一种特定的遥控传送帧，在其数据域内载有控制指令，用来建立遥控操作步骤所需的内部运行参数。 3.10 遥控信道控制字 command link control word 在分包遥控传送层中，通过分包遥测将遥控接收端的有关信息反馈到发送端，以支持有效的遥控操作。对这种反馈信息所规定的一种标准格式数据单元就是遥控信道控制字。 3.11 多路接收地址指针 multiplexer access point 一种使多信源多用户分享同一虚拟信道的传输管理机制。通过统一分配指定遥控段段头的“多路接收地址指针”，并按用户需要的不同优先级实施传输管理，使不同用户应用数据分时交替占有虚拟信道，相当于把单一虚拟信道再划分为多个传输路径。 4 总则 4.1 位序号的约定 位序号的约定如图1所示。一个N位数域中：第一个被传送的比特（图1中最左位）称为位0（B0），接着是位1（B1），……直至位N－1（BN－1）。当这个N位的数域被视为一个二进制数时，首先被传送的位（B0）是最高有效位。 本部分中提到的字节都是8bit。
