Communications and networking for US Army airborne forces has taken a step forward following trials of a new architecture that could reduce the hardware burden for airborne forces.
The US Army revealed in late July that the 11th Airborne Division of the 2nd Airborne Infantry Brigade Combat Team (AIBCT) is the first formation in the army to deploy a push-to-talk air-to-air/air-to-ground Enroute Mission Command (EMC) capability. This network was established using L3Harris AN/PRC-158 Very/Ultra High Frequency (V/UHF: 30 megahertz/MHz to 2.5 gigahertz/GHz) multi-channel radios. In a written statement shared with Armada L3Harris described the radio as being the “backbone of this network.”
Links and waveforms supported by the AN/PRC-158 include the Single Channel Ground and Airborne Radio System, better known as SINCGARS. The SINCGARS waveform uses Very High Frequency (VHF) transmissions of 30 megahertz/MHz and 87.975MHz. Also carried by the AN/PRC-158 is the Warrior Robust Enhanced Networking (WREN) waveform. WREN uses VHF and UHF (Ultra High Frequency: 300MHz to three gigahertz) transmissions. Offering bandwidths of between 50 kilohertz to ten megahertz, WREN gives position location information and handles voice traffic, according to the US Army. The waveform is provided in two configurations: WREN TSM enables point-to-point communications at ranges of up to five kilometres (3.1 miles). WREN-NB is a narrowband waveform for use in electromagnetically contested and congested environments. Both waveforms carry traffic across the Integrated Tactical Network discussed in more detail below.
KEN and DAN
The US Army article announcing the news stated that, until now, EMC had needed Key Leader Enroute Node (KEN) and Dependent Airborne Node (DAN) teams to facilitate these communications. The article continued that KEN and DAN teams would be drawn from signals formations outside the army’s AIBCTs. Signallers would need to be accommodated on aircraft supporting the mission, potentially sacrificing space for additional airborne forces and their kit. KEN nodes provide broadband backhaul data and intra-aircraft voice and data communications. These nodes also provide secure video teleconferencing and air-to-air/air-to-ground task force and combatant commander communications. DAN nodes are employed by subordinate commanders for inflight communications to connect with superiors who are using the KEN node.
The adoption of the AN/PRC-158 for these tasks removes the need for KEN and DAN nodes to support the AIBCTs during Joint Forcible Entry Operations (JFEO). The radios connect with standard Satellite Communications (SATCOM) systems used by US Air Force Boeing C-17A Globemaster-III airlifters. C-17As form a key part of the JFEO airborne capability. For example, AN/PRC-158 radios can use the Mobile User Objective System (MUOS) satellite constellation. The MUOS constellation provides UHF (240MHz to 270MHz) narrowband SATCOM. Open sources say that MUOS facilitates voice and data communications at speeds of up to 384 kilobits-per-second. Communications with the MUOS constellation is via the Wideband Code Division Multiple Access (WCDMA) waveform carried by the AN/PRC-158.
The US Army report stated that the AN/PRC-158 radios used the force’s Integrated Tactical Network (ITN) during the EMC experiments. The ITN is a deployable network handling non-classified traffic using military radios and civilian devices, latter including smartphones and tablets. Moving non-classified traffic onto the ITN frees space on other tactical communications networks for secure traffic. As it handles unclassified traffic, ITN can connect US Army units with allied forces during coalition operations.
The new Enroute Mission Command capability was tested during a series of JFEO exercises held recently in Alaska, California and Hawaii over the Pacific Ocean. The architecture was also trialled during a JFEO exercise which commenced in Alaska and finished in Thailand. The adoption of the AN/PRC-158 to support the EMC represents a qualitative enhancement compared to the erstwhile KEN and DAN nodes. Using these transceivers with the army’s ITN shows how this innovative network is finding additional uses beyond the land environment.
by Dr. Thomas Withington
