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.