For a long time, establishing a satellite link required the user to stop or pause along the way, and that still remains a valid option today in many instances. However, mobile connectivity when fixed services are impaired, provides greater flexibility, and saves time as the user moves, either in order to arrive at the scene or, in some cases, to relocate a mobile command post or conduct mobile surveillance operations, for example.

Satcom-on-the-move (SOTM) adds another layer of wireless connectivity at critical times when redundancy and reliability cannot be given secondary roles. In the second of our two-part government series, we examine how communications on the move assist in times of crisis.

Earlier this year, the ship Calypso, carrying 462 passengers, issued an urgent call for help while cruising in the English Channel. A fire had broken out in the ship’s engine room, but U.K. firefighters, including several who arrived via a rescue helicopter, respond quickly to calls. The response was the first by the members of the United Kingdom’s new Maritime Incident Response Group (MIRG), which consists of 15 specially trained and satellite phone-equipped Fire and Rescue Service teams that can be rapidly inserted onto the deck of a vessel in distress.

"All MIRG teams have now been supplied with Iridium satellite phones, which will ensure any team mobilized to an at-sea incident will have good communications with the shore," says Fire Officer Mervyn Kettle, Sea of Change Project Manager at the U.K. Maritime and Coastguard Agency. "The Iridium satellite phone enhances the command and control facility of these specialist teams."

Satcom On The Move: A Must Have

Such equipment also has found a market in the United States, with governments in Florida, Georgia, Louisiana, Mississippi, Missouri, South Carolina and Texas having purchased Iridium equipment and services for disaster preparedness, says Iridium spokeswoman Liz DeCastro. A netted Iridium push-to-talk service will be available to all users by 2007, while multi-exchange units — like IDL Corp.’s MXU 2000 — with antennas enable Iridium users to maintain their SOTM link by connecting their Iridium satellite phones via any building’s public branch exchange. "More customers are learning about creative ways to work around the line-of-sight necessity," DeCastro says.

"We have every command vehicle and interoperability van equipped with SOTM," says Jake McHatton, telecommunications chief in the California Office of Emergency Services (OES). "The OES operational readiness plan includes SOTM for key positions that have been identified as must-have communications — no matter what. SOTM supplements our OASIS – Operational Area Satellite Information System – which has two fixed hubs for redundancy, 570 fixed sites to Operational Area Emergency Operations Centers and seven mobile dishes mounted on trailers that provide voice connectivity — soon to be upgraded to include data and video."

Inmarsat’s Broadband Global Area Network (BGAN) service, now available in North America, provides broadband-on-the-move capability. Users are always on the BGAN network but not always transmitting. According to Henrik Norrelykke, president of Thrane & Thrane Inc. in Virginia Beach, Va., the Explorer 527 broadband-on-the-move terminal is a lightweight and easily deployed system that handles inbound data rates up to 492 kilobits per second (kbps), a speed which supports streaming video and also can beam voice imagery to disaster response personnel. "SOTM requirements are changing rapidly as new technologies emerge," Norrelykke says. "VSAT and Ku-band SOTM have emerged with smaller footprint antennae and auto tracking systems. However, the reality is that not one system can be all to everyone. A combination of technologies brings a great deal of capability that was never afforded before."

Thrane & Thrane can provide integrated systems that can combine the BGAN broadband-on-the-move technology with a redundant link via a Ku-band VSAT back at an emergency operations center. "We are using SOTM service provided by Globalstar which splits the bandwidth and supports three satellite phones and Internet access," says Fire Chief Charles Werner of the Charlottesville (Va.) Fire Department. The fire department has installed the equipment in three mobile vehicles, including two command/communications trailers. The satellite commmunications equipment got a live test after Hurricane Katrina, when firefighters from Charlottesville were dispatched to Mississippi to provide responders access to e-mail and satellite phones.

According to Tony Navarra, president of global operations at Globalstar Inc., states like Louisiana, Mississippi, Florida and Alabama have joined a number of federal agencies and departments, including the U.S. Departments of Justice and Homeland Security, in contracting with Globalstar for large bundles of service minutes to be used with mobile handsets, data modems and small transportable multi-channel modem products. During the response to Hurricane Katrina, Globalstar deployed more than 12,000 phones to the Gulf Coast region. "Many offices are now using prepaid or annual service contracts in order to be better prepared and more multimode radios capable of GSM, CDMA and satellite capability," Navarra says. "Applications such as freeze-frame video, graphics and location mapping information, which require speeds of up at 38.4 kbps, are in demand."

Useful On Multiple Platforms

The demand for SOTM-driven airborne video and high data rate transmissions for intelligence, surveillance and reconnaissance via unmanned aerial vehicles (UAVs) and aircraft in homeland security operations is growing quickly. "It certainly appears that way from our conversations with defense and Homeland Security personnel who cite the critical importance of video and teleconference capabilities and the importance of response coordination between federal, state and local governments," says Denis Curtin, chief operating officer at Xtar LLC, a joint venture involving Loral Space & Communications and Spain’s Hisdesat which provides X-band services for government users.

Low profile airborne X-band antennas should be ready towards the end of 2006, and Xtar is looking forward to conducting live demonstrations involving high data rate transmissions from airborne platforms with rates ranging from 3 megabits per second (Mbps) to 10 Mbps, according to Curtin. "Xtar could support three UAVs simultaneously, each operating at 50 megabits per second or one UAV operating at up to 150 megabits per second, enabling simultaneous operations of several different airborne sensors," Curtin says.

The U.S. Coast Guard program known as Fast Boat is the focus of work underway at DRS Codem in the form of a proposed X-Band SOTM demonstration. The dynamic environment and high sea states requires small aperture, stabilized antenna platforms for high bandwidth communications, according to Joe Johnson, vice president of the Antenna and Wireless Division of DRS Codem. DRS Codem recently demonstrated a 3 Mbps Internet Protocol (IP) SOTM link from a moving vehicle over the Xtar-Lant satellite. This is ideally suited for National Guard applications, for example, where SOTM can immediately enhance a wide range of border patrol and disaster response missions, he says. "Homeland security missions require high mobility, dispersed geographic areas and dependence on a large bidirectional flow of information," Johnson says. "As the demand for real-time situational awareness increases, there is a greater need for video and high data rate transmissions to and from the end user." Johnson emphasizes burst type multi-frequency time-division multiple access provides improved bandwidth efficiencies. However, operators must still avoid the unwelcome and expensive possibility of over-provisioned SOTM networks carrying converged IP content including Voice-over-IP and video teleconferencing.

Instant access to Internet-based, real-time information for situational awareness also is a key selling point for SOTM. Additionally, SOTM can push this same real-time data from remote areas to other support personnel in multiple locations simultaneously. "By providing Internet access on the move, personnel can execute their responsibilities without having to be tethered to a desk or building," says Gerald Hopp, director of government sales at Connexion by Boeing, which offers outbound speeds of 256 kbps and data rates up to 5 Mbps inbound.

4G On The Way

Mobile Satellite Ventures LP (MSV) provides satellite-based push-to-talk as well as voice and data connectivity, according to James Corry, MSV’s vice president of government solutions. Boeing Satellite Services is under contract by MSV to initiate the full design and construction of two MSV satellites that will be launched in 2009 or 2010 with an all-IP network core managing both the satellite and terrestrial components.

"We see the use of this equipment not as an option, but as the only way we can move data in New Mexico where traditional methods of communication do not work well due to our large geographical size," says Deputy Chief Randall Bertram of the New Mexico State Police, which is increasing the number of vehicles using MSV technology from the current 282 to 500 by the end of 2006. "We sent 22 officers from New Mexico to help in New Orleans with Hurricane Katrina. We had contact via messaging with our team across several states the entire time they were gone. This system is critical to all future planning for the New Mexico State Police."

MSV’s new MSAT G2 satellite two-way radio and telephone also brings satellite repeater capability enabling the disaster recovery worker to integrate his land mobile radio into the MSAT G2 radio and backhaul his radio traffic to his communications center over the MSV satellite network. "This is critical whenever first responders are working in areas where their radios cannot hit their own repeaters or when their own infrastructure has been compromised," Corry says. "MSV is also able to rapidly configure talk groups."

In most SOTM implementations, small mobile antennas will be added to networks of much larger fixed VSAT antennas. With the constant coding and modulation (CCM) technologies, which are currently available, the hub’s outroute has to be modified in order to close the link to the small SOTM antenna, according to Jim Worley, assistant vice president for Department of Defense Government Systems at Hughes Network Systems in Maryland. "To close the link to the smaller antenna, higher orders of modulation and coding are necessary, which utilize more bandwidth. With CCM, all the terminals see the same outroute, hence the larger antennas within the network are penalized once the small antenna joins them. CCM is an either/or scenario," Worley says.

By embracing DVB-S2 technology that supports adaptive coding and modulation (ACM), users are in effect adopting a more efficient approach. Right now with DVB-S as opposed to DVB-S2, inbound data rates of 5 Mbps using a 20-inch antenna mounted on a SOTM-enabled vehicle are supported with 1 Mbps outbound even at speeds in excess of 75 mph and over very rough terrain, according to Worley. However, the switch to DVB-S2 and ACM boosts link performance to more than 10 Mbps inbound using the same antenna configuration on land whereas at sea — where the antenna size can be larger — higher data rates can be achieved.

"ACM is different and is a critical feature in the implementation of SOTM applications because ACM permits the network’s hub to dynamically change the coding and modulation on a frame- by-frame basis," Worley says. "Hence, less coding and modulation are used when transmitting to larger antennas and higher orders of coding and modulation are used to close the link to smaller SOTM terminals. As a result, unlike CCM technology, there is no spectrum inefficiency when ACM is implemented."

The fact is SOTM cannot be taken for granted. Purchasing and deploying these SOTM solutions is just the first step. Training, constant and regular use along with periodic drills and exercises are going to be necessary so that the SOTM user knows well what the SOTM solution in question can and cannot do. With SOTM, it is a matter of having hands on long before the lights go out.