Codan Radio Transportable Radio Systems User Guide - Manual (Page 15)

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3.3.4 Customs Inspection on a Vessel
Temporary communications during marine vessel inspections is increasingly becoming a vital requirement, but is
still a major technical challenge due to all the steel passage ways that inhibit RF propagation onboard. This applies
whether the customs and border agency is inspecting a container ship upon arrival in port or during a hostile board-
ing off the coast of Somalia in pursuit of pirates.
A fully self contained Transportable Radio (radio, battery and antenna) can be quickly set up on the deck of the ship or
carried in a knapsack during the boarding, to enable communications amongst the boarding team once on board, as
well as back to the command center in port or on the supporting naval vessel. Both the Canadian and US Navies have
used Transportable Radios for ship inspections by their boarding teams.
The rugged, compact design enables ease of transportability, ease of operation and long battery life for the duration
of their inspection. P25 encryption ensures security of communications.
The real benefi t the navies discovered was the extensive coverage offered on board a vessel. During trials with the
US Navy it was discovered that a UHF repeater was able to propagate the length of the ship as well as down 4 decks.
This has eliminated the previous communication technology of leaky coaxial cable and also enables rapid deploy-
ment on a vessel to be inspected.
The US Army conducted a trial Transportable Radio deployment in Pearl Harbor to determine RF coverage during a
training exercise. An aircraft carrier was used as the Army’s base of operations for the training exercise. The Army
group tested out the Codan ET-5 tactical Transportable Radio by placing it on the third of ten decks with a 5 dB gain
antenna magnetically mounted to the wall of the ship. Coverage tests showed they had good coverage 4 decks down
on the south end of the ship, 5 decks down on the north end of the ship and through the entire fl ight deck.
Similarly the Canadian Navy has recently tested the same tactical repeater inside a knapsack carried by one of the
boarding team members during hostile ship boarding incidents, to provide communications between the team
members during the boarding as well as back to the Command Center on board the Navy destroyer.
Such a rugged, lightweight and easy to use repeater can now be deployed during training exercises, rescue
conditions, routine inspections as well as by customs and border patrols during inspections of container vessels
or cruise ships.
4. Section 4 – The “Working” Transportable Radio
In this section we will examine the individual pieces of equipment that make up the Transportable Radio system.
Remember, when determining your system components, RELIABILITY is the most important consideration. Quality
equipment is worth the extra cost, especially when a failed piece of equipment could mean the difference between
life and death.
4.1 Features
4.1.1 Analog vs. P25
Codan has developed a P25 Guide www.codanradio.com/lmr that provides an overview of the P25 digital radio stan-
dard and its various interfaces and signals.
P25 Transportable Radios can operate in analog mode supporting all the existing analog control signals such as
CTCSS and DCS. In P25 digital mode signaling such as Network Access Codes (NAC) and Talk Group IDs (TGIDs) are
used to perform the signaling. Transparent passing of these signals is essential to maintain the integrity of the P25
network, especially when encryption is used.
4.1.2 Encryption
In the U.S. there are four general “types” of encryption algorithms. Type 1 is for U.S. classifi ed material (national
security), Type 2 is for general U.S. federal interagency security, Type 3 is interoperable interagency security between
U.S. Federal, State and Local agencies, and Type 4 is for proprietary solutions. P25 documents currently standardize
two different Type 3 encryption processes. One encryption process is the U.S. Data Encryption Standard, or DES algo-
rithm, which uses 64 bit Output Feed Back and is denoted as DES-OFB. Another encryption process is the Advanced
Encryption Standard (AES) which is a 256 bit algorithm. AES and DES-OFB encryption solutions were tested and veri-
fi ed by an accredited National Institute of Science and Technology (NIST) laboratory as compliant with the security
requirements of the Federal Information Processing Standard (FIPS 140-2).
The P25 IMBE™ vocoder produces a digital bit stream for voice messages that is relatively easy to encrypt. Major
advantages of the P25 encryption design are it does not affect speech intelligibility nor does it affect the system’s
usable range. Both of these advantages are major improvements over encryption previously used in analog systems.
Compliant P25 Repeaters (transportable and fi xed) must not change or alter the data that is passing through the
repeater in any way. This includes NAC, TGID, Unit ID, Emergency Indicator and Encryption.
The interface between the receiver and the transmitter inside the repeater must keep this information intact. No
“dual-vocoding” (A/D conversion) is allowed.
Repeater
RX TX