All round defence
All-around defense or perimeter defense is a type of defensive fighting position intended to give military units the ability to repel attacks from any direction.
The positioning of the outer defensive fighting positions of a unit, is circular or triangular, from a bird's-eye view.
One version consists of soldiers forming a wide circle around the soldier in charge (and radioman etc.) with a spacing typically of 3–4 metres between each person (on the circle's circumference).
When a group of soldiers relocate as a part of a defensive operation, a perimeter defense can be temporarily maintained without cover.