I'm a volunteer at a small rescue station. We have about 50 members and 500 calls per year. Only 20 to 25% of those calls will be emergent, but we like to have a timely response to all of our calls. Paging out our members can be a time consuming process. Right now, we call our members on their cell phones when a call comes in. This is clearly an inefficient process, but it has proven to be more reliable than commercial pagers which lack coverage in this area. It also allows members to acknowledge that they got the page and are responding to the station. Our membership rotates on-duty shifts when they're required to be either at or within a few minutes of the station. Most of the time they're just up the street, but they're always within a mile or two.
What other options do we have for alerting our membership? We would really like to have a system where members can acknowledge a page, so we know whether or not we have to page another person. Also, the ability to page out individual members is nice. However, for the more urgent calls, we would like to be able to page the entire membership with the press of a button. Finally, it would be nice to be able to remotely control this system over the phone or internet. We're a small department, and our communications center is not staffed full time unless we're on a call. When our call taker gets the call (forward to his or her house) they could initiate a page from wherever they are instead of first responding to the station.
We've considered voice paging, but that would not allow members to acknowledge that they got the page. Most Alpha systems appear to be only one-way, but since our members would only be a mile or two from the station, there might be a two-way industrial paging solution out there that would work. We considered SMS, but there are numerous reliability problems and delays.
There's no urgent need to change our system now. Because we are in a small town, our response times are well within acceptable limits. This system sounds horribly inefficient compared to a voice paging systems, but it allows us to page only who we need. We can call up a full crew in about a minute, but if we could find a new system to simultaneously page out a full crew, that could potentially shave a minute or so off our response time.
I would appreciate any advice on this.

