A combination of line-of-sight and satellite frequencies provides enhanced versatility and interoperability
A new military radio incorporates the capabilities of several different units in a single package. Offering flexible and secure communications in a variety of bands, the lightweight, manportable unit also features an all-digital architecture, allowing for software upgrades and advanced power management.
Providing secure ground-to-ground, ground-to-air and satellite communications, the multiband/multimission radio comes in vehicular, base-station and manpack configurations. It is also interoperable with existing encryption systems and acts as a bridge between radios that otherwise would be incompatible.
Developed by Harris Corporation, Rochester, New York, the AN/PRC-117F is part of the firm’s Falcon II family. However, it differs greatly in mission scope and capability from the others in that group. The radio operates in low-band very high frequency (VHF) for combat network radio, high-band VHF for public safety and ground-to-air communications, and ultra high frequency (UHF) for military ground-to-air and satellite communications. Full use of the frequency spectrum is provided through continuous on-air coverage in the 30 to 512 megahertz range.
Business Development Manager Kevin Kane, Harris Corporation, explains that the AN/PRC-117F covers a number of existing legacy communications systems such as the single channel ground and airborne radio system (SINCGARS). It also features the HAVEQUICK electronic counter-countermeasures system, demand assigned multiple access (DAMA) satellite communications, and all legacy Type I encryption devices.
While the AN/PRC-117F does not make any currently fielded legacy equipment obsolete, Kane notes that it does replace the capabilities of at least three existing radios. It can operate as a PRC-119 SINCGARS radio, which is the standard VHF low-band ground radio in use by the Department of Defense. It also replaces the PRC-113, a UHF amplitude modulation ground-to-air radio using HAVEQUICK frequency hopping and the PS/PSC5 satellite system that incorporates DAMA wave forms.
The AN/PRC-117F also provides cross-band retransmission between different types of radios, effectively acting as a bridge.
Kane offers the example of a forward observer using a ground radio such as a PRC-119. The observer would be able to communicate directly to a 117F radio that would then retransmit the message over a satellite circuit to a command center in the rear.
He believes this is a powerful capability because it can move critical information through the command structure without the need for a relay point. “By being able to do it end to end, you eliminate any kind of delay, and you also ensure that the transmission has been in no way changed, abridged or misinterpreted at any intermediate point.”
The AN/PRC-117F gets its muscle from a digital internal structure it shares with other Harris tactical radios. The heart of the radio is a PowerPC microprocessor, one of several in the product. Using semiconductor chips instead of conventional analog components provides advantages such as reprogrammability, which extends the life of the platform significantly, Kane says. New waveforms can be loaded directly onto the radio’s software without having to return the product or even remove the cover. A built-in test feature can check system performance down to the module level. Because of this ease of maintenance and upgradeability, he predicts the cost of upkeep to extend the life of the radio will be significantly less than that of other platforms.
The radio’s software also allows for additional capabilities such as the full SINCGARS frequency hopping system and complete KY57, KG84 and KY99 Type I encryption capabilities. He adds that Harris engineers have produced an energy-efficient package that reduces the number of batteries soldiers need to carry in the field.
To conserve power, the AN/PRC-117F uses 3.3-volt logic instead of 5-volt logic. Additionally, the radio’s central processor controls all of its internal functions. Instead of powering everything simultaneously, when a device is not in use, it is physically turned off. For example, Kane notes that the radio’s front panel has a backlight that can be turned on or off at the operator’s choice. If the light is left on, it will automatically turn itself off after a few seconds if the panel is not in use.
Another feature unique to the Harris family of radios is the removable front keypad. Kane observes it is a simple, yet innovative, use of design and practicality because other manpack radios have fixed front panels. “You wear the manpack, obviously, on your back,” Kane says of conventional radios. “But in order to change frequencies or do any other control to the radio, you have to stop, put the radio down and look at the front panel in order to change things. This [front keypad] allows you to really operate the radio in front of you.”
Fully compatible with night vision goggles, the keypad also doubles as a crypto-ignition key. This is a fundamental part of the radio’s control of black keys for encryption. Kane explains that this works just like the key on a secure telephone unit III. If the key is taken away, then no encryption can be done. Likewise, if the radio were installed in a vehicle, removing the front panel/keypad renders it inoperable to anyone not authorized to use it, he says.
The AN/PRC-117F also incorporates Fascinator communications security (COMSEC), which is a Type I encryption typically used for VHF handheld radios. The system is reprogrammable from the front panel and can process data on both sides of the Tempest boundary, which separates encrypted from unencrypted data.
Because of these built-in capabilities, the radio also saves troops from having to carry a cryptobox. Kane notes that most radios commonly fielded require an external COMSEC box that also needs its own separate battery. By incorporating them into a single unit, it lends itself to simple ease of use and control.
Up to 100 channels can be programmed into the radio, though Kane sees 10 channels as more realistic for an operator to handle in a field situation. This could include a satellite network and a ground-based low-band VHF network, for example.
According to company officials, two high-speed waveforms are unique to the radio: a 64-kilobit line-of-sight data waveform and a 64-kilobit satellite system. Kane notes that the line-of-sight waveform carries four times more data than the current maximum ground waveform, which is only 16 kilobits. The radio also has a built-in automatic repeat and request protocol, which will resend a message if there are transmission errors.
The ability to move more data continues to be a growing trend in the tactical communications marketplace, Kane observes. “With 16 kilobits, even assuming you’re able to operate, that’s still half as fast or less than what you would have on your typical telephone modem connected to the Internet. So, 64 kilobits at least brings you back to that level.”
This additional data capacity can manifest itself in the form of photographs and graphics, which tend to produce large files, especially if the pictures have quality resolution. The radio has a flexible data interface compatible with RS-232E, MIL-STD-188-114A, or RS-422 guidelines. This connection can support information flow at standard terminal and tactical data rates in synchronous or asynchronous modes.
By bringing more data-hauling capability to the battlefield, Kane explains, the AN/PRC-117F meets a critical mission requirement by being able to move imagery both ways. Kane cites the example of transmitting a map to someone on the front line from a rear area command center.
The radio is a step along the road to meeting the government’s joint tactical radio (JTR) requirements, Kane notes. He is quick to point out that this program has a much broader scope than what has been accomplished to date with this radio. However, he believes Harris is the first company to market a product with a standardized digital architecture that is reprogrammable and has incorporated, in its software, a number of legacy waveforms for existing product interoperability. He adds that the JTR program includes frequency ranges that are not part of the AN/PRC-117F.
Officially launched in May, Harris began shipping some AN/PRC-117Fs to all the services in January.
Kane maintains that the radio’s design will ensure it has an extensive service life. “As new waveforms evolve, we will be able to incorporate them into this radio. So somebody who buys this radio today, I think, can be assured that it will have a long, useful life and be able to stay state of the art for some time,” he concludes.