text: Defense
  commander) and battalion and squadron fire support officers,in coordination with the BCT and battalion and
  squadron S-3,S-2,and engineer staff officers. (External to the BCT,fire support planners [division and corps]
  coordinate with the BCT fire support officer and field artillery battalion.) Within the scenario,the IBCT and
  division higher area of interest and area of operations extend far enough beyond forward battalions’forward
  line of own troops that the BCT commander has the time and resources to identify approaching enemy forces,
  assess options,and recommend targets for attack to enable the mission. Fires conducted byjoint fire assets
  or through the provision of mission orders to the division’s attached combat aviation brigade and field
  artillery units at the BCT and division echelons further enable the ability to seize the initiative before the
  advancing enemy makes contact with forward defensive positions. The division JAGIC,in coordination with
  the BCT fire support cell, plans and coordinates joint fires, suppression of enemy air defenses, airspace
  coordination areas, ingress and egress routes, and other airspace requirements to deliver aerial and
  surface-delivered fires simultaneously into a given EAor target area.
  7-149. Before the enemy closes into direct fire EAs,in either the security area or the MBA,the BCT and
  subordinate units direct the initiation of fires. The commander and staff plan to provide the most effective
  fires resources and mitigate the risk of fratricide as the attacking enemy nears the designated EA while
  supporting air conducts army aviation and close air support attacks. During EA development, fire support
  coordination measures, such as TRPs, trigger lines, and final protective fires enable observed fires (see
  ATP3-09.30) and the obstacle plan (see ATP 3-90.8) to force the enemy to use avenues of approach covered
  by friendly EAs. These shaping operations typically focus on enemy HPTs, such as command and control
  nodes,engineer,fire support,and air defense assets and follow-on forces for destruction or disruption.
  7-150. Step 7. Rehearse the execution of operations within the EA. The BCT and subordinate units
  coordinate and rehearse EA actions on the ground, gaining intimate familiarity with the terrain. The
  commander, the S-2, the S-3, engineer planner, and the fire support officer, at a minimum, rehearse the
  sequence of events with the subordinate commanders and separate element leaders for each EA.
  7-151. During rehearsals, the BCT commander confirms designated TRPs, trigger lines, final protective
  fires, EAs, and other direct- and indirect-fire control measures in each EA within the BCT’s area of
  operations. Once in position,the commander may modify subordinate unit positions and preplanned control
  measures during rehearsals to improve defensive capabilities as required. The commander ensures the
  integration of fires by adjusting the planned positions of weapon systems to obtain maximum effectiveness
  against targets in the planned EA. The commander coordinates all fires,including those of supporting Army
  aviation and close air support,used to isolate the targeted enemy force in theplanned EAwhile preventing
  the target’s escape or reinforcement. The BCT and subordinate headquarters rehearse the confliction of fires
  to ensure maximum damage before the enemy can respond. The commander rehearses the actions of the
  reserve and counterattack forces to reinforce fires,add depth,or block,to restore a position by counterattack,
  or to reinforce the destruction of enemy forces within planned EAs.
  7-152. Commanders at each echelon rehearse their planned actions within EAs. Subordinate commanders
  and leaders reconnoiter and identify positions and identify movement or withdrawal routes and revisethem
  as required. Subordinate units rehearse assigned weapon system primary sectors of fire and secondary sectors
  of fire to increase the capability of concentrating fire in certain areas in accordance with established criteria
  and priorities for engagement. Secondary sectors of fire,when there are no targets in the primary sector or
  when commanders need to cover the movement of another friendly element,correspond to another element’s
  primary sector of fire to obtain mutual support. Secondary sectors of fire are rehearsed and confirmed
  depending on the availability of time before execution. Subordinate commanders may impose and rehearse
  additional fire supportcoordinationmeasures as required and as time permits.
  PREPARING AN AREA DEFENSE
  7-153. The BCT uses time available to build the defense and to refine counterattack plans. The commander
  and staff assess unit preparations while maintaining situational awareness of developments in the BCT’s
  areas of interest. Collection activities (see chapter 5) begin soon after receipt of the mission and continue
  throughout preparation and execution. Security operations are conducted aggressively while units occupy
  and prepare assigned positions and rehearse defensive actions. During preparation, surveillance,
  reconnaissance, and intelligence operations help improve understanding of the enemy, terrain, and civil
  considerations.