WASHINGTON
— Emergency responders like those along the U.S. Gulf coast have a new tool for communicating while terrestrial phone lines and cell towers are down: a push-to-talk service that turns their mobile satellite phones into a network of walkie-talkies.

Mobile Satellite Ventures (MSV) of
Reston
,
Va.
, has created regional “talkgroups” among its existing customers, which enables emergency responders to communicate using a push-to-talk button on the side of their handsets. Under the company’s Satellite Mutual Aid Radio Talkgroups (SMART) service, local firefighters conducting a rescue in the same neighborhood as a National Guard unit, for example, can communicate with guard members on their MSV satellite phones without first dialing 10-digit phone numbers.

“What we had before is everyone had their own network as far as satellite phones and radio networks and other communications. It all goes away except the satellite network in a storm,” said David Stone, deputy director of information technology in the
Louisiana
governor’s Office of Homeland Security and Emergency Preparedness.

Stone oversees an MSV talkgroup region, called G-SMART, which includes the
Gulf
Coast
states of
Texas
,
Louisiana
,
Mississippi
,
Alabama
and
Florida
as well as
Puerto Rico
and the
Virgin Islands
.

MSV has launched seven of nine planned regions across the nation and expects the final two regions covering the northeast and southeast
U.S.
states to be activated in September.

Each region is managed by an organization involved in emergency response, such as a state police department or emergency management division. Joining a talkgroup is free to existing MSV customers, but they must apply through the agency serving as regional manager, said Jim Corry, MSV vice president of government solutions and architect of the SMART program.

In
Texas
and
Louisiana
, where hurricanes Gustav and Ike disrupted land-based and cell phone service, the satellite phones were the only way to communicate in recent weeks, Stone said.

Tom Surface, spokesman for MSV, said the company has seen an upturn in purchases of its satellite phone kits since it began activating the regional talkgroups in November 2007. There are more than 1,500 SMART users across the country, and many of the locations have MSV equipment loaded with multiple talkgroups. There are a variety of monthly subscription plans for MSV service, similar to the variety of plans offered by cellular phone services, Surface said.

“We’ve been very busy putting kits on the street and loading customers into talk groups,” he said.

MSV has been unveiling the regional talkgroups one by one, with Stone’s
Gulf
Coast
region going online first in November. In many cases, the talkgroups overlap, allowing one state to join multiple regions. That overlap allows emergency responders from other states to coordinate and communicate with their counterparts at the scene of a disaster, Corry said.

Louisiana
, for example, is at the heart of G-SMART but also will join SE-SMART, the southeastern regional talkgroup, when activated.
Texas
is part of G-SMART and SW-SMART, which includes
Arizona
,
California
,
Colorado
,
Nevada
,
New Mexico
,
Oklahoma
and
Utah
.

The SMART talkgroup is activated when an MSV customer uses the handset to select the talkgroup he or she wants to communicate with and pushes the transmit button, sending up an L-band signal to the MSV-operated MSAT satellite. The satellite sends the transmission via a Ku-band feeder link to a ground station in
Ottawa
,
Canada
, which locates the rest of the talkgroup members and sends the information back to the satellite. The talkgroup is opened, and the originator can begin to use the mobile satellite telephone as a walkie-talkie. Other members of the group can join the conversation by using their push-to-talk option on the handset, Corry said.

The SMART program was launched first in August 2007 for the U.S. Department of Justice and the U.S. Federal Bureau of Investigations. In addition to this J-SMART talkgroup, the Department of Justice’s Wireless Management Office also created an ad hoc, tactical talkgroup called SMART-T.

SMART-T resides on all MSV units operated by the department’s law enforcement agencies. During a joint tactical operation with state and local law enforcement agencies also using MSV equipment, communications can begin on J-SMART, while on-scene federal officials collect the serial numbers of non-Justice Department units. Within minutes, MSV can download specific handsets to SMART-T, so that all officers on the scene can move to the smaller, more private SMART-T. Once the operation is completed, SMART-T is removed from non-Justice Department units for the next operation in a different location, Corry said.

“It allows them to clean the slate,” Corry said.

MSV also is creating other talkgroups among government agencies and emergency responders, including one for public health and medical facilities and for national security, Corry said.