Your best bet, be it for general use in academic studies, health and safety concerns or simply security, would be to employ a digital two-way radio system, something like the Motorola SL4000. I‚§™m specifically suggesting Motorola because they handle jobs like this all the time, several of which are detailed on their website.
In fact, the Motorola website details a case almost exactly like yours, where this technology was employed to great effect.
According to the site, the Cincinnati State Technical and Community College (CSTCC) was in a situation just like the one you outlined in your email. Here‚§™s the basic issue...
‚§ĹCSTCC is comprised of three campuses and over 1.3 million square feet.¬†Until recently, the college used an all-analog system, components of which¬†were 15 years old.¬† According to Raymond Mirizzi, Director of Facilities atCSTCC, ‚§ĹWe needed to upgrade our whole communications system,‚§ and it¬†was vital that the entire campus be covered with a radio solution that would¬†support very clear, consistent and secure communications‚§.
How a two-way radio network helped the situation is also detailed.
‚§ĹThe three-part campus needed a supervisory channel that would provide the¬†flexibility for critical security officers and related personnel to communicate¬†during times of crisis. Of course, because such emergencies can arise at any¬†time, it was also critically important that the migration from analog to digital¬†proceed smoothly and quickly because even brief downtime could put the¬†campus at risk‚§.
There are lots of companies other than Motorola, of course, but there‚§™s no denying that they are giants in their field, with a long history of customer satisfaction. They are something like The ‚§˜A‚§™ Team in that respect. Still, if your budget doesn‚§™t quite allow for bells and whistles, there are a number of quality independent firms that could do a very good job at a slightly more reasonable rate.
The reality here is that bargains are the exception, not the rule. That‚§™s why we‚§™re always so happy when we get one. By far your best bet is to get an expert to design and implement your faculty‚§™s new communications method. It needn‚§™t be the biggest company, but you want to spend a good amount on communications, as they really do save lives.