IEEE-1394b, Interface Requirements for Military and Aerospace Vehicle Applications, establishes the requirements for the use of IEEE Std 1394™-2008 as a data bus network in military and aerospace vehicles. The portion of IEEE Std 1394™-2008 standard used by AS5643 is referred to as IEEE-1394 Beta (formerly referred to as IEEE-1394b.) It defines the concept of operations and information flow on the network. As discussed in 1.4, this specification contains extensions/restrictions to “off-the-shelf” IEEE-1394 standards and assumes the reader already has a working knowledge of IEEE-1394. This document is referred to as the “base” specification, containing the generic requirements that specify data bus characteristics, data formats, and node operation. It is important to note that this specification is not designed to be stand-alone; several requirements leave the details to the implementations and delegate the actual implementation to be specified by the network architect/integrator for a particular vehicle application. This information is typically contained in a “network profile” slash sheet that is compliant with this base specification. In a similar manner, the electrical characteristics of the bus media, as well as connector information, is contained in a “physical layer” slash sheet that also may be unique to a particular vehicle application. In summary, full understanding of this specification requires knowledge of IEEE Std 1394™-2008 standards and access to the physical layer slash sheets, slash sheets, and handbook for the target application.