Codan Radio Transportable Radio Systems User Guide - Manual (Page 13)

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3.2 Existing Infrastructure Failures
When a catastrophe such as a hurricane, earthquake, or a tsunami hits, existing infrastructure can be damaged or
destroyed. To maintain communications during the emergency and in the post recovery stages, Transportable Radios
play an invaluable role.
A Transportable Radio can be deployed at the site of the existing fi xed infrastructure that was damaged to provide a
rapid replacement for the damaged equipment. In many instances if the Transportable Radio is confi gured identically
to the fi xed site, the replacement appears to operate seamlessly in the network to the fi rst responders.
After catastrophic events like 9/11, Hurricane Katrina and the Asian Tsunami, the strong supporting response from
the fi rst responder community can overwhelm any communications system as the number of radio users is well
beyond that envisioned in the original design of the fi xed infrastructure. To supplement the existing radio network,
Transportable Radios can quickly add additional capacity and coverage during the emergency response.
After 9/11 and Hurricane Katrina, the National Interagency Fire Center http://www.nifc.gov/ in Boise Idaho provided
a network of Transportable Radios to reestablish downed communications sites in both cities. The photo above left
is an example of a Transportable Radio being deployed on the Empire State building, to rebuild the LMR network
in lower Manhattan that was lost, after the main transmitter tower on the World Trade Center was lost. Similarly,
Transportable Radios were deployed throughout New Orleans to replace infrastructure damaged by the hurricane.
3.3 Special Applications
This section examines a number of specialized uses for Transportable Radios where covert and secure communica-
tions are mission critical.
3.3.1 Secure Undercover Operations
Undercover agencies are moving to digital encrypted P25 based body wire microphones (mics) for undercover opera-
tions to prevent certain “groups” under investigation from monitoring the known government channels. Body wire
mics are very low power (~10 mW) with ranges of only a few hundred feet. They require a repeater nearby to extend
RF coverage enabling support teams to keep their distance from the operation. To avoid monitoring, P25 encryption
is essential.
The Bureau of Alcohol Tobacco and Firearms (ATF) http://www.atf.gov/ approached Codan looking for a fully compli-
ant P25 encrypted compact portable repeater for fi eld deployment. The Special Response Teams (SRT) are typically
equipped with P25 body worn surveillance transmitters that operate in the VHF band. For security the transmitters
use P25 AES or DES-OFB encryption.
In their research they found that existing transportable systems are too large, have batteries that are too heavy and
the radio is too complex to operate in the ATF–SRT application. ATF requested a basic P25 encrypted transportable
repeater that was small and easy to disguise. The unit needed to be as compact as possible in size, as the repeater
and battery pack may be carried in a gym bag.
A key requirement for ATF was to have a repeater that used “D” sized batteries and offered an operational life of 3 to
3 ½ hours with a 100% duty cycle (always transmitting). The rationale for “D” size batteries is that it allows a team to
buy, at the last minute, “off the shelf” alkaline type batteries to power the repeater for an operation. This makes last
minute deployment easy since the users only need to install fresh batteries before use.
A P25 encrypted Transportable Radio (6 W transmitter) meeting the above requirements extends the coverage
range of the Body Wire Mic from a few hundred feet to thousands of feet enabling the support team to be a discreet
distance of several city blocks away from the operation; far enough to be undetected, but close enough to lend im-
mediate assistance when needed. This is illustrated in the representative coverage maps below.
Memphis Convention Center — Body Wire/No Repeater Coverage Memphis Convention Center — Body Wire w/ Repeater Coverage