March 5, 2015:   In January the U.S. launched the third (of four) MUOS (Mobile User Objective System) communications satellites. As a result about 70 percent of earth’s surface is now covered by the new MUOS military communications system. MUOS gives military users cell-phone-like capabilities anywhere in the world. Eventually four MUOS communications satellites operating in 36,000 kilometer stationary (geosynchronous) orbits will provide superior satellite phone service worldwide. This will also include encrypted communications that will work despite being in forests or most buildings. In effect, MUOS can replace cell phone towers in any area on the planet once the signals from one of the four satellites are aimed at the area of operations. The complete system is supposed to be active by 2016. The first satellite went up in early 2014. The four ground stations (one for each satellite) are in Sicily, North America, Hawaii, and Australia.

Yet sometimes newer isn’t better. Such was the case with trying to get the infantry to give up their existing PRC-117/150 manpack (carried) radio for the new MUOS compatible PRC-155 radio. “PRC” means “portable radio,” and while the PRC radios have been getting lighter since World War II (when they weighed more than twice as much as the PRC-155), range and interference remained a problem. Thus although the PRC-155 had lots of neat new features field tests brought forth lots of complaints from potential users (infantry who have to carry and use the PRC-155). For starters the PRC-155 weighs 50-100 percent more than the older models. It has less than half the range (three kilometers versus seven) and the batteries last only six hours (versus over 30), The PRC is subject to overheating and the user interface is considered inferior.

The 6.4 kg (14 pounds, one third of that is batteries) PRC-155 radios are used in vehicles and carried by infantry. This is the latest vehicle/manpack radio design and is replacing the PRC-150, which were widely adopted in the last decade, initially by SOCOM (Special Operations Command). The army wants to buy over 50,000 of them. The big selling point for the PRC-155 is MUOS upgrade kits (some additional hardware and software). Most of PRC-155s will have the MUOS add-on kit. With this kit the PRC-155 is equipped to provide Internet-like capabilities on the battlefield and MUOS gives access to a world-wide net. This is a big deal for ground troops because existing radios often had their range greatly reduced by terrain (hills or many tall buildings) or weather (electric disturbances high up). A satellite link eliminates this problem and ground troops have been asking for this for a long time. Sat links are still expensive and a rationed resource.

But when the infantry were asked to try out the PRC-155 many concluded that the negatives were not worth it. Moreover the delays in getting the PRC-155 to the troops forced the military to seek out an off-the-shelf design (the AN/PRC-117G) in the 1990s. This is a 5.45 kg (12 pound) radio that can be carried or installed in vehicles. About a third of its weight is the battery. It has a maximum output of 20 watts and handles FM, UHF, and VHF signals, including satellite based communications. On the ground max range is 20 kilometers (depending on hills and the antenna used). These cost about $40,000 each. There is an improved AN/PRC-117G (the MNVR) that cost $56,000 each. That includes development costs (for the wish list of tweaks and upgrades the military wants). The U.S. has been using the AN/PRC-117 since the late 1990s as an interim radio and found it a solid piece of equipment.

The AN/PRC-117 is based on a commercial design (the Falcon series) that several foreign armed forces and many civilian operations use. The AN/PRC-117 has been regularly upgraded in that time (going from version A to the current G). The upgraded Falcon (PRC-150) appealed to SOCOM (Special Operations Command) which proceeded to buy half a billion dollars' worth of AN/PRC-150 radios. These cost about $2,500 each and all of them were delivered on schedule. The 4.6 kg (ten pounds, without batteries) radios are very flexible (are used in vehicles or backpacks) and are able to use several different types of transmission (including bouncing signals off the ionosphere, for longer range or just to get a signal out of a built up area). Digital transmissions allow for data to get through under poor atmospheric conditions or when in a built up area. The radios also have good encryption and the ability to send and receive all forms of digital data. These radios are also now used by the army.

A similar situation occurred back in the 1990s, when SOCOM realized it needed a new personal radio for its troops and an army “new radio technology” program (JTRS) was supposed to take care of that but did not. Rather than wait SOCOM got together with a radio manufacturer, told them what they needed, and within two years they had MBITR (which soon got official sanction as AN/PRC-148). When the rest of the army saw MBITR many troops bought them with their own money. After Iraq army units began buying the AN/PRC-148 on their own. Soon, over 100,000 MBITR radios were in use.

Some elements of the JTRS (which was cancelled in 2011) survived in the form of radios like the PRC-155. While this radio was acceptable for use in vehicles, it did not make it when troops had to carry it. The military is determined to make the PRC-155 work. By early 2015 about 1,200 PRC-155s have been delivered to the U.S. Army for troop use. Now that three MUOS birds are up there American soldiers in most parts of the world can actually sample the advantages of the PRC-155, along with the disadvantages they already know about.