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February 2008
Emergency Alerts - Overhead Paging

Schools, and businesses, as well as cities and towns are adopting several approaches to alerting people in emergencies. One challenge is designing systems to reach the most people, whether they use mobile phones, office phones, or email or are located in common areas such as halls, conference rooms or cafeterias. Paging is one approach.

Paging to each telephone’s speaker
Some systems enable designated staff to simultaneously send a voice message to all or most phones equipped with speakers. Although it’s costly, Cisco offers a separate processor that enables simultaneously paging to every phone’s speaker.

Limitations in paging through phones
However, sending a concurrent voice message to each phone is not always feasible:

  1. Some systems have a limit to the number of phones that can be paged at the same time.
  2. All telephones may not have a speaker
  3. Pages may not reach phones forwarded to voicemail or people already on their phone.
  4. These alerts don’t usually reach hallways, common areas such as gyms or outdoor spaces.

Components of Overhead Paging
Overhead paging systems consist of speakers mounted on walls or ceilings that are connected by copper cabling to amplifiers. For the most part, paging systems don’t operate on fiber optic cabling. Amplifiers strengthen voice signals so that they are audible through speakers. Amplifiers are connected to a stand-alone microphone or to a telephone system. Connecting paging systems to the PBX, gives organizations the flexibility to designate which individuals are allowed to broadcast paging messages.

Zones
Because interruptions by irrelevant pages are unproductive and disruptive, many organizations design their paging systems so that some pages reach only designated areas. For example, schools that have special events in their gymnasium may want a zone specifically designed to reach the gym.

The importance of policies
Those of us who worked or went to school in locations where paging was used to routinely reach all classrooms, factory areas or hallways know how annoying it is to hear numerous irrelevant messages over loudspeakers. With today’s technology, it’s possible to allow only a few key individuals to send an overhead-paging message. These few individuals should be at a high enough level in the organization to be aware of conditions and/or be easily reached by key individuals such as console operators or department administrators.


According to Michael Hall, Director of IT at Shady Hill School in Cambridge Mass, "The implementation of our new Voice over IP telephone system had too many details and complexities to smoothly implement without obtaining the kind of expertise and follow-through that Annabel Dodd brought to the project." I can be reached at 508-877-6089, or adodd@doddontheline.com. My Web site, www.doddontheline.com has information about my consulting, training and expert witness services.

What can go wrong?
Designing a paging system for organizations with multi-story buildings, a campus environment or outdoor areas is complex. For example, there may be fiber but not copper cabling connections to all buildings, in which case new cabling runs are required. In addition, longer runs between amplifiers and speakers may require higher grade data quality twisted pair cabling needed for distances of over 1,000 feet.

Finally, not all distributors have the expertise and experience working with complex paging systems to determine the correct number of amplifiers, how to design the paging system for multiple zones, and how to connect the paging system to the telephone system, and then how to program the telephone system correctly. In an ideal world, the paging installers have staff knowledgeable about your telephone system. This goes a long way to avoiding finger pointing.


 


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