Satellite radio communications proved essential during Operation Iraqi Freedom as the United States Marine Corps reportedly fought its own more conventional communications systems as much as it battled Saddam's loyalists.

Specifically, Iridium satellite phones provided a highly reliable means for units to maintain contact. This was particularly important at the infantry and battalion levels, given the problems associated with outrunning Enhanced Position Location Reporting System (EPLRS) line-of-sight radio coverage, said Captain Jack Falcone, communications project officer at the USMC's Warfighting Lab in Quantico, Va.

“[Satellite] made us a lot of money at the infantry and battalion level,” Falcone said in a recent interview with Mobile Radio Technology. Translated into civilian-speak, the commercial satellite systems proved invaluable during the course of the conflict.

Every officer from the commanding general of the Marine Expeditionary Force down to infantry battalion commanders used encrypted Iridium phones to communicate. Falcone said the combination of a small omni-directional antenna and the ability to operate on the move made it an “ideal solution for warfighting.”

A demonstration project to expand the usefulness of Iridium is scheduled to take place in fall 2004. General Dynamic Decision Systems, based in Scottsdale, Ariz., will adopt a press-to-talk capability for Iridium, with multiple users on one channel and from 10 to 12 communications networks available for use. Iridium's success in Iraq and in other recent military operations is ironic, considering the company filed for Chapter 11 bankruptcy protection in 2000.

Parent company Motorola had invested $5 billion dollars to put up 66 low-earth orbiting satellites to provide global coverage. At one point during bankruptcy proceedings, Motorola suggested they would let the constellation burn up in the atmosphere. Instead, the constellation and other assets were bought out of bankruptcy at the end of 2000 for $25 million dollars by Iridium Satellite LLC, a small group of private investors.

The success of the satellite-based systems was in direct contrast to other systems, according to an 18-page field report issued in March 2003 by the USMC's Corps System Command Liaison Team.

Interoperability was an issue in all command and armored vehicles, with Marines “overwhelmed” by the different types of equipment they were expected to use. “Routinely, communicators, operations officers and commanders found themselves in information overload as they received information over too many different networks,” the report said.

For example, a Marine in a light armored vehicle might find himself monitoring the vehicle's intercom using its onboard headset, and utilizing two or three other radios to communicate with nearby units, while also monitoring two laptops to keep track of friendly forces.

Higher up the food chain, radios occupied all of the available shelf space in the command vehicles, while seat and floor space was filled by add-in computers on different communications networks, and an Iridium satellite phone tossed in for good measure.

Redundancies of radio networks and communications systems were common, the report said. For example, the Marines used two different computerized systems for tracking U.S. troops to avoid friendly fire incidents and maintain situational awareness on the battlefield — its own Mounted Digital Automated Communications Terminal (MDACT) and the Army-developed MTS-2011 “Blue Force” tracking device (BFT). The Marine Corps deployed 319 MDACTs and 177 BFTs to its units, plus another 47 BFTs to United Kingdom forces.

The MDACT provided a secret and secure location capability for units but was limited by its dependency upon the EPLRS line-of-sight data radio. Because of the rapid advance and wide operating area of Marine units, forces outran the reach of EPLRS and were unable to establish relay sites.

The BFT turned out to be one of the rare bright spots. It used commercial satellite bandwidth and off-the-shelf encryption to provide location information for Army, Marine, and UK units. While the BFT was considered insecure because it hadn't gone through a National Security Agency review process, it was consistently praised for providing reliable communications at all times through the satellite uplink, including an instant messaging capability that proved to be a hit with users. At many times, the BFT was “the only means of communication” for disbursed units, the report said, and was considered very reliable for providing situation reports.

Unfortunately, the MDACT and BFT units were not designed to be interoperable, so Marine commanders often had to monitor both systems to keep track of their own forces as well as neighboring Army and UK troops. Marine units issued one of the systems and needing to communicate with a unit using the other type would have to resort either to a third party or use a courier to deliver a message.

There were a few other successes. Ball Aerospace's OS-302 SATCOM On-The-Move (SOTM) UHF antenna package was praised by users as being “very effective and reliable” despite being “much too big,” the report said.

The 24 × 24 × 6-inch antenna with its associated high-power/low-noise amplifier was mounted on everything from utility vehicles to light armored vehicles to provide satellite communications capability, even with the platform moving at speeds of 50 mph or more.

At the bottom of the food chain, Marine infantry received a rush shipment of the Integrated Intrasquad Radio (ISR), which had been tested at the Quantico Warfighting lab over the past two-and-a-half years. More than 6000 devices were put into the hands of Marine Corps fire team and squad leaders to enable small units to keep in touch during urban warfare operations.

Made by Marconi as the Personal Role Radio (PRR) H4855, the ISR weighs a little more than a pound, including batteries, earpiece, and boom microphone. Using a modified IEEE 802.11 protocol, the device operates in 2.4 GHz with a spread spectrum scheme to provide a low probability of interception and detection.

When used as originally intended, the ISR proved easy to use and rugged enough for tactical use, with an expected range of about 250 square meters in urban environments. Falcone said one radio channel would be assigned per 13-member squad, with a total of four physical radios, three for each of the fire team leaders and one for the squad leader.

However, like their Army counterparts, the Marines tried to stretch the radio equipment beyond its intended use and found the ISR didn't work for platoon-level communications.

At the next level, the Thales AN/PRC-148 Intra-Platoon Radio (IPR) offered both UHF and VHF operations, with the latter being desirable in urban environments. Unlike the ISR, the IPR has on-board encryption. In typical usage, each squad leader would use the IPR to communicate to the platoon leader and other squad leaders. Some squad leaders integrated their IPR and ISR radios with a toggle switch that allowed them to move between the two. One issue with the PRC-148 is its need for AC power to recharge its lithium-ion battery; consequently, DC converters were used to charge them in vehicles.

Other gear winning praise from the field included Harris Corporation's AN/PRC-150 HF/VHF Falcon II pack radio and Raytheon's AN/PSC-5D multi-radio; both units were deployed in small quantities with most earmarked for special forces units.

The digital AN/PRC-150 was described as “very effective” for long-haul communications and Marines wanted more of them, especially if they could get one with a vehicle mount and a way to tie it into the vehicle's intercom system. Able to operate in 1.6 to 60 MHz, the AN/PRC-150 is a software-defined radio that includes embedded encryption, Internet protocol (IP) capability, GPS connectors, and advanced frequency hopping to limit interception.

Weighing less than 10 pounds without batteries in a 10.5 × 3.5 × 13.2-inch package, the radio also is able to transmit data at rates up to 9600 baud. Primarily used by the Navy SEALs, the AN/PSC-5D combines three radios into one for UHF, VHF, and satellite communications.

It also incorporates embedded encryption, operates in 30 to 512 MHz, and the 3.3 × 10.6 × 13-inch package weighs about 11.5 pounds without batteries.

Like their U.S. Army counterparts (“Iraq shows Army radio problems,” Mobile Radio Technology, August 2003), the Marines also encountered their share of power and battery headaches.

Each combat division in Iraq depleted up to 3000 12-volt disposable batteries each day, which were used to power everything from radios to anti-tank missile launchers, according to StrategyPage, a military-news Web site operated by “How to Make War” author Jim Dunnigan.

With the bulk of the designated wartime supply stuck in transit on ships at sea when hostilities commenced, other U.S. units worldwide had to air-freight their stocks into the Iraqi theater. Rechargeable batteries were in limited supply and almost all of them were in use by U.S. forces in Afghanistan.

Consequently, the conversion of radios to generator power was a popular field exercise and a commercial system has been requested for future deployment.

One common-sense suggestion from Marines was to make power converters a standard part of an electrician's equipment so local power could be converted for field use.

For recharging batteries in the field, external auxiliary power units (APUs) could be used, but quieter solutions were desired. Solar trickle panels, which would reduce wear and tear on vehicle power without the noise and heat signature of an APU, are one option. But Dunnigan thinks the better solution to recharging batteries lies in expanded capacity, including the use of fuel cells.

on the web:

For more information on the technology, business and regulatory developments that are shaping the land mobile radio and private wireless markets, check out our Web site: