Going underground – tactical comms
By Andrew White
Since the main assault to retake the City of Mosul from Daesh launched on 17 October 2016, the progress of Iraqi and coalition security forces appears to have been halted as defending forces take the fight into the subterranean environment.
According to US DoD estimates, anywhere between four and ten thousand Daesh fighters remain in Mosul with gains made by the Iraqi Special Operations Forces (ISOF) already being curbed.
USAF Colonel John Dorrian, the DoD spokesperson in Iraq, explained to the media in October, IS or Daesh had started to build tunnels throughout Mosul ahead of the openly planned offensive well before offensive actions were triggered.
Such a tactic, Dorrian conceded, would present ‘unique tactical and operational’ concerns for advancing forces conducting missions to clear miles and miles of subterranean tunnel networks that they use for tactical movement and to hide weapons.
According to Obsidian Technologies’ Charles Cavanagh, communications in subterranean environments present significant challenges for armed forces including different refraction and reflection of signals off wet, dry, tiled and irregular walls; interference from nearby high-power systems; as well as assault teams remaining in close enough contact to maintain relay linkages.
‘This is a multi-faceted problem space. In the cave and tunnel environment, Line of Sight communication is pretty
much absolute and there are added challenges such as multi-path communications; radio discipline; and command and control,’ he explained to Digital Battlespace.
Critical to any military operation is communication and the ability to successfully transmit and receive calls to, from and within the subterranean environment. This is an issue which continues to hound defence forces today, particularly prevalent for Special Operations Forces (SOF) conducting complex counter-terrorism and counter-insurgency operations in urban environments.
Defence sources associated with ISOF explained to Digital Battlespace how Iraqi CT Forces lacked such capability on a grand scale, now required to achieve mature tactical communications connectivity across subterranean environments.
More mature SOF organisations globally have previously relied upon the use of tactical repeater systems which could be cached in sequence throughout underground areas of operation in order to relay communications via Line of Sight to the surface.
However, the market is now witnessing the emergence of specialist standalone technology as well as the development of tailored waveforms capable of being integrated on board Software Defined Radios.
Standalone options revolved around the utility of Through-The-Earth (TTE) communications, capable of penetrating ultra low radio frequency waves (300-3000 Hz) through rock and dirt. Such technology derives from the mining industry where higher frequency signals have traditionally been rebroadcast or relayed through antenna and repeater stations as well as mesh solutions such as the popular Mobile Ad Hoc Networking systems proliferating the defence and security market today.
Additionally, significant attention must be paid to communication headsets with the US DoD selecting Atlantic Signal’s Subterranean Voice Communication System on 19th September 2016.
‘You need a headset and microphone system which can allow you to listen around corners in a very quiet environment. Radio communication needs to be separate to ear canal so some operators can prefer a microphone instead of bone conductor through the ear.
‘On top of that, operations in underground or enclosed spaces can go from very quiet to very noisy so operators need communications headsets with the capability to enhance listening but also actively protect the ears.
Atlantic Signal designed the Dominator II headset which was initially developed in tandem with the US Naval Special Warfare Command.
For more see the feature on Middle East tactical communications developments in the January/February 2017 edition of Digital Battlespace, out now!