空间数据和信息传输系统.空间链路扩展(SLE).回程操作控制场业务

[中文适用范围]： 本推荐标准从抽象的角度定义了ROCF服务，涉及：a)提供服务所需的操作；b)与每个操作相关的参数数据；c)每个操作调用后引起的行为；d)操作及其行为之间的关系和有效序列。它不包括：a)特定的实现或产品；b)实际系统中实体或接口的实现；c)从接收到航天器信号获取遥测帧的方法；d)提供适合通信环境的方法；e)安排、配置和控制ROCF服务所需的管理活动。 本推荐标准为开发实施ROCF服务的实际系统提供了基础。在实际系统中实施ROCF服务还需要通信服务，以在ROCF服务用户和服务提供商之间传递操作调用和返回值。该推荐标准要求此类通信服务必须确保操作调用和返回按顺序传输；完整且无损；不重复；具有流量控制，在发生拥塞时通知应用层；并且在ROCF服务用户与ROCF服务提供商之间的通信中断（可能导致数据丢失）时通知应用层。 本推荐标准的具体目的是以独立于任何特定通信服务、协议或技术的方式定义ROCF服务。 [外文原描述]： The purpose of this document is to define the Space Link Extension (SLE) Return Operational Control Fields (ROCF) service in conformance with the SLE Reference Model (reference [1]). The ROCF service is an SLE transfer service that delivers to a mission user all operational control fields from one master channel or one virtual channel. This document defines, in an abstract manner, the ROCF service in terms of: the operations necessary to provide the service; the parameter data associated with each operation; the behaviors that result from the invocation of each operation; and the relationship between, and the valid sequence of, the operations and resulting behaviors. It does not specify: individual implementations or products; the implementation of entities or interfaces within real systems; the methods or technologies required to acquire telemetry frames from signals received from a spacecraft; the methods or technologies required to provide a suitable environment for communications; or the management activities required to schedule, configure, and control the ROCF service. NOTE – Reference [1] defines the Return Master Channel Operational Control Field (Rtn MC-OCF) service and the Return Virtual Channel Operational Control Field (Rtn VC-OCF) service as two distinct services. Subsequent study has indicated that it is preferable to define one service that provides the functionality of both. The ROCF service defined here does just that. It is anticipated that a future issue of reference [1] will take the same approach, deleting the Rtn MC-OCF and Rtn VC-OCF services and replacing them with the Rtn OCF service.