Type 1 = Motorola Privacy Plus. 3600 bps single site analog trunking system. Used the concept of fleet maps. Came out in the 80's and has largely been succeeded by other things. I still know of a few SMR's running Type 1, I turned down a Type 1 site last year for a friend as it only had a single customer left on it and the what originated as a 5 channel Startsite eventually whittled itself down to a single functioning Quantro after some 20 years of continuous operation.
Type 2 = Motorola SmartNet. 3600 bps successor to PrivacyPlus. While Type 2 could be backwards compatible with Type 1 by carefully aligning Talk Group IDs with the fleet map, SmartNet introduced some fairly massive new features. Biggest was that of SmartZone...or multi-site systems. Some other interesting tidbits were SmartNet's capability to use digital audio (Motorola's VSLEP based ASTRO at first and then the P25 CAI), the idea of an IntelliRepeater (where the repeaters also function as a site controller) which is still occasionally used to refer to a standalone P25 site (an IR site). SmartNet heavily influenced P25 trunking development in terms of the control signaling protocols.
Most Type 1 systems that are still operational today are SMR's or businesses which have managed to keep them running (3M was still operating a Type 1 system in Austin as recent as 3 years ago that was installed in 1989) as most municipalities/public safety customers long since upgraded to Type 2 or P25. Most Type 2 systems are being phased out for P25 as Motorola ended support for them a few years ago.
P25 Phase 1 = Uses a very similar signaling protocol to Type 2 but it's at 9600 bps instead of 3600 bps. P25 is digital voice only and used a combination of CQPSK (LSM) and C4FM depending on configuration. To program a Phase 1 system in most scanners, all you need to know is the control channels for the site of interest, system ID, and a band plan (if it is not advertised). The scanner will do the rest. P25 radios...depending on how the radio is configured you may only need a bandplan, system ID and WACN or a system ID, WACN and active control channel.
P25 Phase 2 = It's Phase 1 (and backwards compatible) but uses TDMA for voice data instead of CQPSK/C4FM. Allows for additional capacity without the need for additional RF resources. Systems can support Phase 1 & Phase 2 or Phase 2 only. The control channel however, is the same minus a previously null bit in the datastream to signal Phase 2 capable radios that the site is Phase 2 capable (Phase 1 radios simply ignore the bit). Requirements for programming a Phase 2 system are the same as a Phase 1 system. The only difference is the bandplan will have a way to signify that some channels are TDMA.
