The Space Link Extension (SLE) Reference Model identifies a set of SLE Transfer Services that enable missions to send forward space link data units to a spacecraft and to receive return space link data units from a spacecraft. A subset of these services is specified by the SLE Transfer Service Recommended Standards.
The SLE Transfer Service Recommended Standards specify:
a) the operations necessary to provide the transfer 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.
