An air support signals unit, or ASSU, was a specialised communications organisation that coordinated requests for air support between ground forces and air headquarters. Developed in the Second World War, it used dedicated radio networks and forward detachments at division and brigade headquarters to pass requests quickly to joint command posts. It is the ancestor of what modern forces achieve through air-land integration and joint fires coordination.
From historical unit to modern function
The abbreviation is not a current alliance doctrine term. Today NATO coordinates close air support through tactical air control parties, joint terminal attack controllers and interoperable data links rather than a standing signals unit. The historical British system, with its forward detachments known as tentacles, influenced allied practice, but the capability now lives in networked communications and trained forward controllers rather than a dedicated unit.
Why the coordination problem endures
The core challenge the old unit solved has not gone away: a soldier who needs air support must get an accurate request to an aircraft fast, and the aircraft must strike the right target without hitting friendly forces. Modern systems answer this with digital messaging, precise positioning and shared situational awareness, but the underlying task of linking the ground and the air in near real time is the same one an air support signals unit once handled by radio.
How Canada procures tactical communications
The Department of National Defence defines requirements for tactical communications and air-land integration, and Public Services and Procurement Canada runs the contracting. A central program is the Land Command Support System Life Extension, which modernises tactical vehicle networks and adds satellite communications on the move.
Data links and interoperability
Real-time air-land coordination depends on tactical data links such as Link 16, governed by the defence directive on joint tactical data links. That directive ties Canadian systems to NATO standardisation agreements so that Canadian and allied units can share targeting and situational data.
Scale of the investment
In December 2023 Canada announced a $1.68 billion sustainment package for the army's tactical network, awarded to General Dynamics Mission Systems and described in a federal news release. This is the modern equivalent of the coordination job an air support signals unit once performed, and it shows where communications suppliers can compete. Firms offering radios, waveforms, network integration or data-link software can find a role inside these long-running sustainment and modernisation programs.