P_REV=1 was developed under an ANSI standards process with documentation reference J-STD-008. J-STD-008, published in 1995, was only defined for the then-new North American PCS band (Band Class 1, 1900 MHz). The term IS-95 properly refers to P_REV=1, developed under the Telecommunications Industry Association (TIA) standards process, for the North American cellular band (Band Class 0, 800 MHz) under roughly the same time frame. IS-95 offered interoperation (including handoff) with the analog cellular network. For digital operation, IS-95 and J-STD-008 have most technical details in common. The immature style and structure of both documents are highly reflective of the "standardizing" of Qualcomm's internal project.
P_REV=2 is termed Interim Standard 95A (IS-95A). IS-95A was developed for Band Class 0 only, as in incremental improvement over IS-95 in the TIA standards process.
P_REV=3 is termed Technical Services Bulletin 74 (TSB-74). TSB-74 was the next incremental improvement over IS-95A in the TIA standards process.
P_REV=4 is termed Interim Standard 95B (IS-95B) Phase I, and P_REV=5 is termed Interim Standard 95B (IS-95B) Phase II. The IS-95B standards track provided for a merging of the TIA and ANSI standards tracks under the TIA, and was the first document that provided for interoperation of IS-95 mobile handsets in both band classes (dual-band operation). PREV=4 was by far the most popular variant of IS-95, with P_REV=5 only seeing minimal uptake in South Korea.
P_REV=6 and beyond fall under the CDMA2000 umbrella. Besides technical improvements, the IS-2000 documents are much more mature in terms of layout and content. They also provide backwards-compatibility to IS-95.
Now someone else can translate what each revision does or does not do.dancedroid
