Guard begins overhaul of distress alert system

Guard begins overhaul of distress alert system

The Coast Guard's National Distress and Response System Modernization project team includes, from left to right, Cmdr. Joe Vojvodich, technical manager; Mary E. Small, contracting officer, and Capt. Ronald Hewitt, project manager.

Digital successor will have more channels, plus encryption

The Coast Guard's maritime 911 system to monitor distress calls from vessels is set for a major upgrade.

The 30-year-old short-range analog communications network monitors distress calls and coordinates search and rescue operations but no longer supports the Coast Guard's communication needs, said Capt. Ronald T. Hewitt, project manager of the National Distress and Response System Modernization Project. Plans for the upgrade were completed last month, and work will begin this fall.

The network also provides communications infrastructure to support other missions that include defense, marine safety and law enforcement.

'It's 1970s technology that is obsolete, difficult and expensive to maintain,' Hewitt said.

The existing system consists of a network of 284 VHF-FM antenna sites with analog transceivers along the East and West coasts.

Each site covers 20 to 30 nautical miles in most areas.

Six frequencies

There are 46 communications centers that monitor the antenna sites. One communications center typically monitors messages received at two to 10 sites, Hewitt said.

The centers use six maritime frequencies, he said. For instance, vessels send distress signals through VHF-FM Channel 16, at 156.8 MHz, and the center uses other channels to manage search and rescue operations.

A major problem with the system is that it can handle only one channel at any given time because the channels do not have enough receiving capacity, Hewitt said.

'Once we try and use a designated frequency, such as Channel 21 or 81, to contact a vessel, then we lose Channel 16 receiving capability and cannot get any distress signals,' Hewitt said.

Also, if two boats try to communicate with a center simultaneously and the signals are of the same strength, the center gets a garbled message and so is unable to capture either call, Hewitt said. If one distress signal is stronger than the other, the weaker signal is lost.

Hewitt said another problem with the system is that it does not cover the entire coastline.

Though the antennas are strategically located, there are about 60 spots where vessels cannot communicate with any center, he said.

The modernization, which includes replacement of the existing system with digital technology, is being carried out in phases, said Mary E. Small, the project's contracting officer.

The $24 million first phase was completed this month.

General Dynamics Decision Systems, formerly Motorola, of Scottsdale, Ariz., Lockheed Martin Corp. and Scientific Applications International Corp. of San Diego designed the new system and surveyed the first sites at which it will be installed.

The Guard released a request for proposals for Phase II Feb. 8. The three contractors will compete against one another to implement the project, Small said. The agency will award the contract in September, she said.

The Guard has budgeted $42 million for the modernization this year and has requested $90 million in fiscal 2003 funding.
During phase II, the Guard will replace the system with two types of digital technology.

By 2006, all vessels will be required to install Digital Selective Calling radios. Each DSC radio will be registered with the Federal Communications Commission, which will assign it a unique nine-digit identification number.

The numbers, known as Maritime Mobile Service Identities, will be entered in the Guard's national distress database.

When a captain sends a distress signal on a DSC radio, the Coast Guard will be able to identify the vessel and use the Defense Department's Global Positioning System to determine its location, Hewitt said.

The digital communications the Coast Guard will employ also will include radios that can encrypt voice signals sent to Guard vessels, he said.

'We perform law enforcement and pass sensitive information such as license number of the boats and medical information, too,' Hewitt said, so secure communication is critical.

The radios will cover communications along the entire coastline and will be able to operate on six channels simultaneously, he said.

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