Defines the physical layer of the Serial Storage Architecture (SSA). SSA defines a serial interface hierarchy to be used for purposes within its distance and performance characteristics, including, but not limited to, storage subsystems. This standard is intended to be used with an upper layer protocol (e.g., SCSI-2 Protocol (SSA-S2P)) and a transport layer (e.g., SSA Transport Layer 1 (SSA-TL1)). A major goal of the SSA-PH1 standard is to define a physical layer acceptable to device vendors, looking for an evolution from parallel SCSI, and systems inherent to a serial bus.