text: FM 7-100.1________________________________________________________________________________
  Disruption Zone
  9-144. In many cases, dispersed ground ambushing forces and other key as-
  sets in the disruption zone will require point air defense protection. Regular
  infantry, SPF, and affiliated forces operating in the disruption zone should
  have air defense systems as mobile and survivable as the force they are
  protecting. This may require extensive use of man-portable, shoulder-fired
  SAMs. Some forces may rely strictly on C3D for protection from enemy air.
  9-145. Some air defense forces may be deployed in the disruption zone, par-
  ticularly in the form of air defense ambush teams. Their purpose can be to
  deny aerial attack and/or to prevent enemy reconnaissance platforms from
  targeting forces in the disruption zone or battle zone.
  9-146. Area coverage is desirable for protecting the overall disruption force.
  When necessary, the OPFOR will move divisional assets or even OSC assets
  (both normally located in the battle zone) well out into the disruption zone to
  assist in area coverage or to provide early warning for other air defense units.
  Battle Zone
  9-147. Most air defense forces would normally be within the battle zone. In
  order to provide continuous coverage for supported maneuver forces, air de-
  fense systems need to have the mobility to move with those forces. Their
  main role is to allow friendly ground forces the freedom to maneuver as the
  operational situation develops rapidly. Air defense units in a fixing force can
  help prevent enemy aviation from coming to the aid of the enemy formation
  targeted for attack by assault and exploitation forces. Air defense action or
  even an uncertain air defense environment can help create the window of
  opportunity for an attack.
  Support Zone
  9-148. Some air defense units may be deployed in the support zone to help
  keep this zone free of significant air action and thus permit the effective logistics
  and administrative support of forces. Generally, commanders can afford to de-
  fend the support zone with less mobile air defense assets than in the disruption
  and battle zones. Throughout the support zone, the OPFOR makes extensive use
  of passive air defense measures, including C3D, maneuver, and dispersal.
  MOVEMENT
  9-149. The OPFOR anticipates that its units may be subject to air attack
  during movement. Accordingly, units engaged in movement are protected by
  their constituent air defense assets and, in many cases, by additional air de-
  fense assets allocated by their parent unit.
  9-150. When a subordinate tactical unit is conducting tactical movement, an
  operational-level command may order its own air defense assets to provide
  cover for the moving unit. Due to their longer-range systems, operational-
  level air defense units may be able to provide this coverage from their
  original positions or with minimal repositioning. Alternatively, the opera-
  tional command may direct that the subordinate unit conducting movement
  receive air defense coverage from another, adjacent tactical subordinate
  whose air defense assets are within range of the moving unit.