A typical MNS includes a central server or control unit, a system adminis-
trative terminal or operating consoles, and a network of notification devices
such as speakers and digital signage. The system may be connected to the
Internet or a cellular service to broadcast notifications via those media. Out-
door systems may include outdoor speakers and sirens providing voice signals
or alarm tones such as Federal Emergency Management Agency (FEMA)
weather warning tones. MNS have now been mandated in all U.S. Department
of Defense facilities (Fig. 9.3).
The MNS server or control unit, along with the administrative terminal, is
used to monitor and control notifications, that is, it generates and sends live or
prerecorded messages. The control unit is typically integrated with the fire
alarm control panel (FACP).
NFPA 72 has specific requirements for MNS and fire alarm systems. As of
this time, details of the design, installation, and testing requirements for MNS
are being developed for incorporation into a new chapter called Emergency
Communications Systems (ECS). The new requirements include risk analysis
of the probability and potential severity of events requiring emergency
response. There is also a requirement for two-way telephone radio communi-
cations service addressing the emergency responders on the ground communi-
cating with those in the building.
IP Paging Systems
Legacy paging systems were typically a separate piece of equipment connected
to a PBX. Speakers were daisy chained in a paging “zone” and connected back
to the paging amplifier. Access to the paging systems was through a micro-
phone or a special call group in the telephone system.
Current systems are built on VoIP-type technology and IP end devices
including IP speakers. The network connectivity allows authorized users to
send and broadcast audio simultaneously to speakers and IP telephones. Some
Figure 9.3 LED signage for emergency notification.
Fire Alarm and Mass Notification Systems 111