ISO DIS 26143
Space data and information transfer systems - Space link extension (SLE) - Return operational control fields service specification
|Publication Date:||10 May 2018|
|ICS Code (Space systems and operations):||49.140|
This Recommended Standard defines, in an abstract manner, the ROCF service in terms of:
a) the operations necessary to provide the service;
b) the parameter data associated with each operation;
c) the behaviors that result from the invocation of each operation; and
d) the relationship between, and the valid sequence of, the operations and resulting behaviors.
It does not specify:
a) individual implementations or products;
b) the implementation of entities or interfaces within real systems;
c) the methods or technologies required to acquire telemetry frames from signals received from a spacecraft;
d) the methods or technologies required to provide a suitable environment for communications; or
e) the management activities required to schedule, configure, and control the ROCF service.
PURPOSE OF THIS RECOMMENDED STANDARD
The purpose of this Recommended Standard is to define the Space Link Extension (SLE) Return Operational Control Fields (ROCF) service in conformance with the SLE Reference Model (reference ). 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.
NOTE - Reference  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  will take the same approach, deleting the Rtn MC-OCF and Rtn VC-OCF services and replacing them with the Rtn OCF service.
APPLICABILITY OF THIS RECOMMENDED STANDARD
This Recommended Standard provides a basis for the development of real systems that implement the ROCF service. Implementation of the ROCF service in a real system additionally requires the availability of a communications service to convey invocations and returns of ROCF service operations between ROCF service users and providers. This Recommended Standard requires that such a communications service must ensure that invocations and returns of operations are transferred:
a) in sequence;
b) completely and with integrity;
c) without duplication;
d) with flow control that notifies the application layer in the event of congestion; and
e) with notification to the application layer in the event that communications between the ROCF service user and the ROCF service provider are disrupted, possibly resulting in a loss of data.
It is the specific intent of this Recommended Standard to define the ROCF service in a manner that is independent of any particular communications services, protocols, or technologies