HYDRA

System Description
The AN/SRC-55 HYDRA Radio System is a digital trunked repeater system that is based on our COTS EDACS technology that supports a maximum of 16,383 users divided between 2,047 user groups. A "trunking system" eliminates the need of a dedicated transceiver for each evolution or user group by switching (trunking) users to available transceivers.

Radios (Basic and Executive)
Low power or standard power (for Damage Control purposes) portables are provided
for use with the HYDRAAN/SRC-55 systems that will operate in digital narrowband mode in the 380-399.9 MHz fre-quency band. These radios consist of our low power portable radios, the M-RK Scan for the “Basic” radio and M-RK II for the “Executive” radio.
These radios are designed to operate in low power between 20-100 mw. Low power operation is ensured by hardware limiting the radio to 100mw. External accessories include high and low noise headsets, speaker mics and other surveillance devices. Radio profiling equipment includes all interfaces (e.g. cables, connectors, adapters, etc.) required to connect portable and fixed radio equipment to a computer for programming and diagnostic testing. This programming software works with standard Windows software. Keyloaders are provided to permit loading DES encryption.

Flight Deck Radios/Flight Deck Helmets
M/A-COM furnishes a MRK portable radio or MPA portable radio that interfaces with the standard Navy issue David Clark Flight Deck helmet for flight deck operations.

Fixed Command Units
M/A-COM has developed fixed command units to support HYDRA communications for use at critical watchstations in command and control spaces. M/A-COM provides two types of fixed command units; Fixed Command Radio stations, and Fixed Standard Radio stations. Both units are Mil Std 901D Grade A shock qualified. Fixed Command Radio stations interface with standard Navy handsets and speakers and use a mobile command display for use in command and control spaces. This unit has an external speaker, an external control head and can work with a standard Navy handset or with a desk microphone. The fixed command radio provides the ability for a watchstander to scan various talk groups as well as communicate with other users of HYDRA. All Fixed Command Radios have an integral UPS which provides 8 hours of UPS protection.

Remote System Monitor
HYDRA (AN/SRC-55) Systems have become critical to everyday operation onboard
a US Navy ship. In order to provide immediate notification of a HYDRA system malfunction, M/A-COM provides a Remote System Monitor. System malfunctions
will be both visually displayed and announced over a prespecified talk group so technicians can take immediate action.

Communications Systems Director
The Communications Systems Director (CSD) provides the ability to monitor and control
the HYDRA System from a computer in the ET shop. The CSD allows the user to define
and maintain databases, adjust system parameters, and monitor system activity. The
CSD utilizes a Windows NT operating system and is driven by a Pentium II processor.

Integrated Ship Board Hydra PCS Interior Commmunication Systems

In 1998, M/A-COM developed and installed the first integrated LMR/PCS system on the USS Rushmore. This system integrated a five channel LMR trunked radio system with a ship wide PCS system. Both systems had full connectivity
with the shipboard PBX and phone system. The system design used on the Rushmore formed the basis for the
systems to be installed on two Ticonderoga class Cruisers and 10 more LSD amphibious ships. The system has been
in continuous service since it was installed in 1998.

PCS System Description
A DCT1900 Freeset PCS system consists of Portable Wireless handsets, Base stations, and a Radio Exchange to
interface with the ship's PBX. The system will operates in the unlicensed PCS band (1920-1930 MHz), and utilizes
TDMA frequency hopping digital technology for its air interface. Since DCT1900 operates in the unlicensed 1900 MHz band (PWT), the user is assured that their system will not interfere with shore based cellular phone systems.

PBX Interface
The PBX interface can be either digital or analog. System on the LSD class ship used the digital interface to connect
to a Definity PBX. Systems on the cruisers used an analog interface to connect to the STC-2 PBX.

Radio Exchange
The Radio Exchange is the interface between the PBX and the Base Stations. All
in coming calls are routed through the Radio Exchange. The unit is mounted in
the cabinet. It contains a CPU card, 2 SLU (Speech Link Unit) cards and either LTU cards for an analog interface or a DTU card to provide a digital T-1 interface. The DTU card supports 48 digital connections, and the LTU card supports 8 analog line connections. Each SLU card supports up to 8 base stations. All base stations are powered using twisted unshielded pairs from the 48 volt DC supply.

Portable Telephone DT 620
The DT 620 Portable Telephone handset contains all the intelligence needed for conversation, roaming, and cell to cell hand over. The
design allows seamless roaming from cell to cell. The Portable
Telephone is equipped with an alphanumeric display to provide the
user with call preferences and call status.

The DT620 Portable Telephone is a small, lightweight handset that contains all the intelligence needed to handle conversation, roaming
and cell to cell handover. All the functions of a wired telephone are available to the Portable Telephone, plus some unique features such
as pre-dialing and display editing.