New Radio Software Promises Improved Access to Military Satellites
The satcom integrated waveform (satcom IW) will ease the burden being placed on overtaxed ultra-high frequency (UHF) satellites, which are the military’s primary means of transmitting secure communications worldwide.
Thales Communications Inc. and Harris Corp., two of the largest providers of radio gear to the U.S. military, are both in the process of receiving certifications to integrate satcom IW software into their respective handheld radios. Raytheon Co. and ViaSat Inc. are among the other vendors working with satcom IW.
Communicating directly with satellites has become more crucial in recent years as the war in Afghanistan has placed dismounted troops in canyons and other areas where line-of-sight communications with ground stations is difficult.
These same troops also want to lighten the amount of equipment they must carry. Thales executives said the waveform, which can be added to the company’s software-defined handheld radios, will result in weight savings.
Currently, dismounted units must carry a separate radio to talk through a satellite, said Walt Hepker, vice president of business development at Thales.
“Now they don’t have to carry that extra 15 pounds,” he said. “Our putting the IW in the handheld radio is lightening the soldier’s load and increasing his capability with the equipment he already knows how to use and has on hand.”
Software defined radios, as opposed to the more common analog communication gear, allow manufacturers to add different functions without having to alter the hardware.
“It’s like adding new applications to a computer, which is an overused analogy because it is nowhere near that simple to port a waveform onto a joint tactical radio system,” Hepker said.
The JTRS program was launched in the late 1990s to bring software-defined communications gear to the military. There are five programs of record, one of which is the handheld, manpack and small form fit class of radios. The military’s ultimate goal is to have devices that will allow it to create ad hoc networks, move encrypted intelligence data such as images around the battlefield, and install new applications into terminals as they come along.
Some of the JTRS terminals have been beset by technical delays. Meanwhile, hundreds of thousands of the single channel ground and airborne radio systems (sincgars) are still being used. Thales executives said sincgars will be in the inventory for several more decades as software defined radios continue to be rolled out. Many of the old terminals are incorporated into vehicles and aircraft and not easily replaced.
Handheld or backpackable radios are easier to swap out, though.
Special operation forces have been pushing for the applications. Commandos must operate behind enemy lines and need to travel light.
“They’ve got unique requirements,” said Lewis E. Johnston, vice president of advanced programs at Thales. “From an acquisition standpoint, they are a lot easier to work with because they will take the 80 percent solution and let you continue to improve that as they go on,” Johnston said.
Other military customers insist on meeting 100 percent of the requirements, which can lead to program delays, he added. “For us, Special Operation Command has been an absolutely wonderful customer. We actively solicit their feedback.”
The JTRS waveforms belong to the U.S. government and are administered by the Defense Information Systems Agency. It began the process of developing satcom IW in 2007 as a replacement for the demand assigned multiple access (DAMA) waveform, which manages access to satellites and ensures that terminals don’t use up too much of a satellite’s limited channel space. Radio manufacturers who are offering hardware to military customers can now add satcom IW to their software-defined radios, if they so choose. Software defined radios can carry several different types of waveforms, including the legacy singcars.
The waveform can also be integrated into radios that have already been fielded, said Chris Martin, product manager for Harris Corp.’s Falcon III manpack line.
Harris has added satcom IW to the AN/PRC-117F, a radio that dismounted troops must carry in a backpack. The approximately 50,000 units that have been fielded since the 1990s can be updated with the new waveform. DISA is rolling satcom IW out in a controlled fashion, a process that includes user operation demonstrations, he said.
“It’s preparing the user community as much as possible for this new capability,” said Martin.
Ground control stations that link the radios to satellites must also be updated, so the new capability will be introduced to different parts of the world at different times, Martin said.
Harris also received certification in September 2010 to integrate satcom IW onto its 117G wideband tactical radio, which is designed to be either carried in a backpack, or installed in a vehicle. The company spent its own research-and-development funds to integrate the waveform on these radios, which number about 10,000 now.
Satcom IW can either be integrated on previously fielded models, or it will be added to new units as they come off the manufacturing line. Harris radios manufactured after January include the new waveform, he added. The 117F and G models both weigh in the eight- to 12-pound range depending on whether they require a battery.
Harris is awaiting certification to add satcom IW to its Falcon III AN/PRC-152 handheld radio, and expects that to happen in the second half of this year, Martin said.
Thales said it will be the first out of the gate with a handheld IW satcom device as it expects certification in March. It will be featured on its AN/PRC-148 JTRS enhanced multiband inter/intra team radio.
The handheld radios will be able to link directly with satellites in some cases, executives for the two companies said. For the most robust communications, they will require an amplifier, which weighs about 5 pounds.
They have the potential to transmit some data such as photos, but they will not be able to send anything on the order of live, streaming videos. Martin likened their throughput to dial-up Internet modems, so still images might be possible, although that would be slow.
“From an end user perspective, the problem is there simply is not enough capacity, particularly for beyond-line-of-sight communications,” said Martin.
The main benefit for satcom IW will be increasing the amount of traffic the U.S. military’s system of UHF satellites can handle. Satcom IW software will allow for more throughput than DAMA, the radio manufacturers said.
“You can double the number of users that can be on the satellite,” said Martin.
That will be key in the coming years because of overloaded channels on the military’s fleets of UHF secure communication satellites.
The series of eight Navy-built UHF Follow-On, or UFO, satellites were built and launched between 1993 and 2000. They are quickly degrading and are at capacity.
The spacecraft intended to replace them, the mobile user objective system (MUOS), also a Navy program, has been mired in technical delays. The Navy has scrambled to look for alternatives such as placing UHF payloads on commercial satellites, but none of their efforts have come to fruition. The latest estimated launch date for the first MUOS spacecraft is late 2011, about three years behind schedule.
There are units in the military that want to use secure satellite communication links, but simply can’t because there are no channels for them, Martin said.