“Several years ago, we proved the feasibility in the
technology, but as you get closer and closer to an end
product that would be used, you want to continue to
improve the design of the system and the reliability of
the components,” he said. “That’s really where our
focus is right now.”
For security reasons, Navy officials declined to discuss encryption and vulnerability to jamming with
regard to Deep Siren.
Under CSD Increment 2, the Navy is requesting proposals for three types of buoy systems for a planned
initial operational capability in fiscal year 2012.
The A2RF Gateway Buoy will be a tetherless, expendable acoustic communications buoy with two operating
modes. One mode is a short-range, medium-data-rate,
two-way communication mode for messaging and data
transfer. The second is a long-range, low-data-rate, one-way acoustic mode for long-range alerts, notification and
paging. The A2RF Gateway Buoy will be launched from
a submarine and use the Iridium satellite.
The Tethered Expendable Communications Buoy-Iridium (TECB-Iridium) and Tethered Expendable
Communications Buoy-Ultra High Frequency (
TECB-UHF) are launched from a submarine and tethered to
it by a fiber-optic line that unspools as the boat maneuvers away from the launch point. The buoys will provide up to 30 minutes of two-way communications.
The TECB-Iridium buoy will be capable of a data rate
of 2. 4 kilobits per second; the TECB-UHF buoy will
communicate through the UHF Follow-On (
narrowband satellite communications) at a data rate close to 32
kilobits per second.
Further out, the Navy is planning CSD Increment 2
to provide a high-data-rate capability for the submarine’s
buoyant towed antenna.
Increment 2 also will feature technologies Starr sees as
having an immediate effect on fleet operations. The proposed improvements include a modular communications buoy with optional payloads — including cameras,
Global Positioning System equipment, electronic surveillance measures, an Iridium satellite link and the
Automated Information System — a shipboard
transponder that transmits and receives discrete identifying information and real-time navigational data from
ships 300 tons or larger. Increment 2 is scheduled for initial operational capability in fiscal year 2015.
Reliability is the main challenge to fielding a CSD
capability and is critical to the program’s success, Starr
said, noting that “if the fleet perceives any system as
unreliable, the systems will not be used.
“Each system must work when launched, since the
submarine cannot recover the buoy or perform intricate
repairs,” he said. “When a TECB is launched with an
urgent message, the submarine does not have the time to
The Navy is evaluating Deep Siren, a tactical paging system developed by Raytheon that uses active sonobuoys,
underwater acoustic communications and global satellite
communications to transmit data one way through the
water to a submarine.
launch two or three buoys to get a message out.”
Starr said that making sure the fiber-optic line of
tethered buoys spools out correctly from a submarine
is one of the technical challenges of the CSD program.
Another is the submarine’s launch vehicle that will
send the buoy to the surface.
Data exchange rates, ranges and system security are
attributes that program officials list as critical to the
program “in order to provide a communications capability that is usable by the fleet in a combat environment, regardless of the level of the threat,” he said.
Although the CSD program is developing systems
that allow a submarine to remain deeper and more
covert, the systems under development all involve
radio transmissions and/or acoustic transmissions that
are potentially vulnerable to electronic interception
and direction-finding by a sophisticated enemy.
One industry executive familiar with submarine
communications technology said the “submarine force
seems to basically want [to have] their cake and eat it,
too. They don’t want to give up their stealth but they
want communications and they haven’t come to grips
with the fact that it’s a continuum.” ■