Another way to look at IICC’s efforts in developing the lab connectivity standard and the roles of our three partner organizations (HL7, IHE and CLSI) is to consider the communication between devices in terms of three layers.

• At the top is the use case layer, which defines the actors (or devices involved in communication), why they need to communicate, what types of messages need to be exchanged and what ambiguity about the context of communication should be eliminated.
• The message layer defines the fields required for each message, the allowable values for each field, a standardized vocabulary for the purpose of eliminating ambiguity, and consideration of other sources of ambiguity and how those can be eliminated.
• The low level layer considers the types of physical transport supported, the kind of handshaking between systems, the level of support for error detection and recovery, and other requirements such as support for compression, encryption or authentication.