Mass Notification System Activation by Web Portal via Satellite
Communications
June 28, 2012
ATI Systems has developed a web based version
of its MassAlert® software. The new software can control system
components with a cloud based application accessible through a web browser
using satellite communications, and without using the central station.
The remote units, such as high powered speaker stations, are equipped with a
satellite modem that allows them to communicate directly to a satellite.
The satellite sends the message to a ground station, which uses the Internet
to connect to the ATI Systems’ MassAlert® Web Portal application server.
The software running in the cloud performs all the same functions as the
software in a central station, including activation and keeping track of the
status of each remote unit.
The diagram above illustrates the
communication pathway for messages between the remote siren & strobe units,
the cloud based MassAlert® application, and the end users.
The Web
Portal can be effectively used for tsunami warning systems that send alert
tones and prerecorded voice messages over a long coastline. It
utilizes the latest advances in cloud computing and satellite technology to
create the most efficient and cost-effective paradigm for controlling a
warning system such as this one that spans hundreds of miles. ATI
Systems’ Web Portal can activate all of the sirens in this system as in the
case of a massive tsunami wave, or only parts of the system as required by
the nature of the emergency. The Web Portal is designed as a web based
version of the ATI’s MassAlert® control software. Its functionalities
include continuous monitoring of the entire system between emergencies,
which eliminates the need for check-up visits to the remote units. The
remote units report their status back to the Web Portal application on a
regular basis, so they only need to be visited for repairs. The remote
units can be tested as well as activated through the Web Portal, and will
immediately report any kind of unauthorized intrusion attempt. The Web
Portal is accessed through a web browser and is secured by a login screen
using encrypted communications to prevent eavesdropping and to securely
identify the web server.
The remote units in this system are ATI’s
High-Powered Outdoor Speaker Stations which can cover the largest area per
unit in community settings. In addition to the speaker station and
satellite modem, each remote unit can have a strobe, all of which can be
powered by solar power with battery backup. This setup insures that they
will be continuously available regardless of any local power failures that
may accompany a tsunami or other emergency. In addition, the remote
units can be placed as required for community notification, independent of
the availability of local power lines. The fact that the system is
controlled by a cloud-based application adds another layer of insulation
against local emergency conditions.
Many remotely controlled systems
use radios for communication, but the signals can become unreliable and
require expensive repeaters when dealing with distances over 20 miles or
about 30 kilometers. In addition to the expense of the additional
equipment, a radio-based system that spanned over hundreds of miles would
require more components and therefore more maintenance work. Other
forms of communication, such as fiber optics, coaxial cable or twisted pair
require building and maintaining large wired networks, or limiting the
system to areas where they already exist. Satellite communication, on
the other hand, is possible from anywhere to anywhere on the planet, as long
as the two points communicating have a line of sight to the communications
satellite.
Communications satellites use a variety of orbits
including geostationary orbit and low Earth orbit. A satellite in a
geostationary orbit appears to be in a fixed position to an earth-based
observer and is the best choice for data communications between fixed points
because ground based antennas, which must be directed toward the satellite,
can operate effectively without the need for expensive equipment to track
the satellite’s motion. Low earth orbit provides shorter lag times
because of the shorter distances, but also results in less reliable data
connections because the satellites are always moving with respect to Earth
positions. For this system, ATI chose to use satellite communications
by the provider Inmarsat, which maintains three geostationary satellites and
can provide the most reliable and cost effective communication with the
remote units for this application. However, ATI’s equipment can
interface with satellite modems from many different providers, as well as
cell modems, for maximum flexibility. It uses industry standards and
state-of-the-art technology which can be integrated with whatever
communications equipment is best suited for the project.
