Explanation/Reference:
The Data Movement Layer provides the batch and bulk data handling for the architecture. This layer exists primarily to offload bulk data movement from the upper layers in the architecture. Bulk data movement is a necessary evil in many enterprises, and therefore, the architecture must provide a mechanism to provide this capability in an efficient, controlled manner. Without this layer, the other layers in the architecture might be misused to move large blocks of data, a task for which the other layers are ill suited.
Reference: Oracle Reference Architecture, Service-Oriented Integration, Release 3.0