Security Unleashed
Wireless mesh technology provides Mission residents peace of mind
- By Carla Saavedra
- Oct 01, 2009
For bird enthusiasts, Mission, Texas, is a prime vacation spot. Located
in the Lower Rio Grande Valley, the city of 50,000 is the home of the
World Birding Center, where more than 500 species of birds go to
recharge before heading south for the winter.
Sprawled along 13 miles of the Rio Grande, Mission is a place
where two countries converge. Its Anzalduas International Bridge
provides cross-border commuters entry into and out of the states,
as well as a pedestrian walkway.
With such a large daily influx of human and avian traffic, security
was a high priority for Mission city officials, but its unique
topography made implementing a fiber network cost prohibitive.
“We wanted to purchase something that was very solid, that
had the flexibility to be moved around and that had a multitude
of use,” said Leo Longoria, Mission chief of police, who studied
the different types of security systems on the market for two
years. The city was looking for a system that would provide three
things: video transmission, data transmission and hot spots for
wireless Internet connectivity in residential areas. When Longoria
learned about wireless mesh networks, he knew that he had
found the ideal security system for his city.
From Hot Spots to Hot Zones
Wireless mesh networks build on the concept of Wi-Fi hot spots
and expand it to enable fully wireless hot zones, which provide
buildings and campuses blanket wireless coverage, and even hot
regions, which can cover an entire city. Unlike basic Wi-Fi --
which simply untethers a client from an Ethernet cable -- wireless
mesh liberates an entire network, allowing IT managers and
system integrators the ability to reposition cameras and expand
the network without disturbing the rest of the network.
“The purpose of a security camera is to be able to address
areas that you’re not able to reach at that particular moment,”
Longoria said. “But crime shifts, and you don’t want to be tied
down to a camera that is not giving you what you need.”
Because the technology builds such a large network, bandwidth
is no longer an issue.
“Prior to mesh, municipalities had to use fiber or some other
type of wireline connectivity [for large-bandwidth applications],
which was prohibitive in a lot of cases,” said Bryan Thompson, implement
the wide-area network. “With fiber, you couldn’t put a camera
on a light pole in the middle of a parking lot. Now we can put
up a camera, attach it to a wireless node and very easily take the
information back to a central location.”
A mesh network’s advantages are a result of how it works.
What distinguishes it from hierarchical hub and spoke topology
contained in other infrastructures is the number of times it
interconnects with neighboring nodes throughout the network.
Because each node connects to every other node in the system --
providing a “blanket” of wireless coverage -- implementing it
as a wire or fiber network would be impossible, not to mention
cost prohibitive.
“Typically, the cost of doing an infrastructure mesh versus
doing a fiber installation, just equipment-wise, is usually onetwentieth
of what it costs to lay fiber,” said Bo Larsson, CEO of
Firetide. “And that doesn’t even take into consideration all the
labor, time and repair that is involved with trenching.”
The technology’s interconnectedness produces a self-configuring
network, which, in turn, becomes self-reconfiguring. For an
growing city like Mission, being able to expand its wireless coverage
quickly is critical.
“One of the good things about mesh is that you can put up a
radio, attach a camera to it and attach these to a network very
easily,” Thompson said. “So it can expand without having to use
wireline connectivity.”
Self-reconfiguration makes the entire network self-tuning, allowing
traffic to be rerouted onto optimal paths. Because many
police stations are receiving an enormous amount of data and video,
the network’s self-tuning capabilities prevent it from crashing.
“Firetide’s routing protocol encapsulates a video or data
packet,” said Coffman, explaining that the company’s proprietary
routing protocol is flow-based. “The flows are established
once the data or video packets hit the network, providing one
of the highest throughputs in the industry.” Not only are they
encapsulated, but they are encrypted as well, securing the data
from hackers.
From self-configuration and self-tuning emerges the network’s
self-healing capability. Multiple redundant paths and resiliency
eliminate single points of failure within the mesh.
“If a link goes down, the other nodes maintain backup links,
so they switch traffic without any loss of signal or delay,” said
Ksenia Coffman, marketing manager at Firetide.
Wire-free Wireless
Wireless mesh technology is able to provide a large area with blanket
wireless coverage without the need for wire or fiber because
it uses the existing 802.11 ad-hoc mode standard. Other wireless
technologies, such as Wi-Fi, normally use the 802.11 infrastructure
mode standard, which requires a wireless access point that
is cabled to the network to give clients access to wireless connections,
such as the Internet or a printer. Using this mode to provide
wireless to a large area, however, becomes cost prohibitive as
more and more access points -- and more wiring -- are required to
increase the network’s reach. Ad-hoc mode allows wireless nodes
to directly communicate with each other, eliminating the need for
wireless access points.
Mesh networks also use the 802.11 capability of implementing
multiple spectrums, specifically 2.4 and 5 GHz bands, both
unlicensed frequencies that provide optimal range and minimal
radio interference.
“The Firetide network supports these bands, depending on
customer requirements, so they can mix and match what they
need during deployment,” Coffman said. The company will soon
release a mesh node that will support the 900 MHz non-line-ofsite
frequency as well.
The network makes the ad-hoc mode nodes more robust and
resilient by making its routed traffic control similar to the Interior
Gateway Protocol. With IGP, the mesh is able to perform
point-to-point, multipoint and multicast routing within its own
domain, maintaining full compatibility and interoperability with
external switching and routing protocols.
Integrating with Fiber
Parts of Mission had fiber infrastructure, but the areas of the city
that needed the most surveillance -- parks, residential areas and
the border -- did not. Fortunately, wireless mesh integrates easily
with existing wired infrastructures.
“The wireless mesh becomes a redundancy to the fiber,” Larsson
said. “So even if you have a fiber link break because of construction,
we see that link broken and the mesh network is clever
enough to route traffic to the rest of the system.”
One of Firetide’s clients, the city of Chicago, had been deploying
a fiber infrastructure for years under its virtual shield
operation, but when officials started deploying a city-wide video
surveillance network, they realized they didn’t have fiber in all of
the locations they wanted. They decided to use wireless mesh to
extend the city’s existing fiber infrastructure, saving a significant
sum of money.
Another Set of Eyes
With the wireless mesh network supplementing Mission’s existing
fiber infrastructure, Longoria and his team are able to monitor
areas that had never been monitored before.
“Right now, we have cameras in one of our regional parks,”
Longoria said. “It’s a humungous park, and the idea was to make
it a hot spot.” The city has plans to put cameras along its nearby
military road as well.
City officials of Mission are so satisfied with the new mesh
network that they’ve written it into their yearly budget and have
plans to expand the network’s use.
“We’re going to provide wireless to our mobile control units,
so that they can download camera data into the central command
center,” Longoria said, preventing officers from having to drive
back to the station to upload data. Other future plans include
uploading meter information directly to the city hall database,
making the city more efficient.
Just a week after implementation, a network camera recorded
a car robbery and Mission police were able to catch the suspect
within the same week.
“We were able to play back that video and actually recognized
the suspect in the video,” Longoria said.
Most importantly, the new network has made Mission residents
feel safer. When the local media came out to interview citizens
about the new system, some were proud and others felt more
at ease knowing that there were more cameras.
“In today’s economy, I’m sure there’s some hesitation for a
lot of communities, but I think this is the way to go because it’s
another set of eyes,” Longoria said. “And we want to make sure
that our citizens are comfortable in their own city.”
This article originally appeared in the October 2009 issue of Network-Centric Security.
About the Author
Carla Saavedra is a contributing writer for Network-Centric Security magazine.