I can count on 1 hand how many police dispatches are STILL analog, that I know of. Encryption is creeping into NH as well..
Encryption has been an available feature for a few years; but has had selective use in NH. NHSP almost always uses it on their "Talk 1" car-to-car channel now and depending on the trooper may use it full time on the various troop channels. Places like Nashua use it full time with detectives, but patrol is clear.
As far as a statewide system, there isn't one in place. What has been put in place is a standard channel plan. The Police and Fire/EMS plans are different, but common among their disciplines. In theory, Zone-E, Channel-2 is the same in every Fire Engine and Ambulance in NH. Zone-H is the Interoperability zone and intended to be common in all public safety vehicles, fire, police or EMS.