ISO 22671:2007

ISO 22671:2007 defines the communications link transmission unit (CLTU) service in conformance with the transfer services specified in ISO 15396:1998. The forward CLTU service is a space link extension (SLE) transfer service that enables a mission to send communications link transmission units (CLTUs) to a spacecraft. ISO 22671:2007 defines, in an abstract manner, the forward CLTU service in terms of the operations necessary to provide the transfer service;the parameter data associated with each operation;the behaviors that result from the invocation of each operation; andthe 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 radiate data to a spacecraft and to acquire telemetry frames from the signals received from that spacecraft for extraction of the Operational Control Field;the methods or technologies required for communications; orthe management activities necessary to schedule, configure, and control the forward CLTU service.