text: Overview of Signal Support
  ENTRY OPERATIONS
  1-160. The entry of Army and joint forces into a joint operations area or theater of operations may be
  unopposed or opposed (FM 3-0). Being part of an expeditionary force means units deploy on short notice to
  austere locations. Maintaining communications en route to the operational area allows units to refine their
  plans while in transit and arrive in the area of operations with current intelligence estimates ready to
  immediately conduct combat operations.
  1-161. Attaining operational reach often requires gaining and maintaining operational access in the face of
  enemy antiaccess and area denial capabilities and actions. Commanders conduct forcible entry operations to
  seize and hold a military lodgment in the face of armed opposition.
  Early and Initial Entry
  1-162. During the initial phases of an operation, units may not be able to deploy heavy wideband satellite
  communications trailers and nodal systems. Signal leaders need to deploy their communications capabilities
  in phases and build network capacity over time. Initial entry operations may be supported solely with single-
  channel, push-to-talk radios. Commercial cellular networks and devices may augment single-channel radios
  until adequate signal support becomes available in the operational area, but commanders’ risk decisions must
  account for peer threat capabilities to exploit cellular networks for location information and intelligence
  collection. Expeditionary units must be prepared to operate with limited communications capabilities in
  austere locations. Signal planners must effectively deploy the solutions that maximize capabilities within the
  limitations of the situation or environment.
  Forcible Entry
  1-163. Forcible entry is seizing and holding of a military lodgment in the face of armed opposition or
  forcing access into a denied area to allow movement and maneuver to accomplish the mission (JP 3-18).
  Army forces, as part of a joint force, must be capable of deploying and fighting to gain access to geographic
  areas controlled by forces hostile to U.S. national interests to be credible both as a deterrent and as a viable
  military option for policy enforcement (FM 3-0).
  1-164. Forcible entry operations are inherently complex and always joint. Often only hours separate the
  alert from the deployment. The demands of simultaneous deployment and employment create a distinct set
  of dynamics. Operations are carefully planned and rehearsed in training areas and marshalling areas.
  Personnel and equipment are configured for employment upon arrival without reception, staging, onward
  movement, and integration (FM 3-0).
  1-165. Joint interoperability of signal systems enables units to conduct forcible entry operations with joint
  and multinational partners. Interoperable communications allow mission partners to synchronize their efforts
  and share situational awareness to prevent friendly fire.
  1-166. Because communications systems must be built-up at the objective area, some aspects of
  communications support are unique in forcible entry operations. Communications requirements for joint
  forcible entry operations vary with the mission, size, composition, and geographic location of the joint force
  and its senior headquarters. Significant requirements to consider for forcible entry operations are the use of
  intermediate staging bases, en route mission planning, and intelligence sharing.
  1-167. Ground commanders in airlift aircraft may communicate with the chain of command over the Army
  secure en route communications package. Normally, the airlift mission commander and the airborne task
  force commander are in the same aircraft. The senior ground commander can advise embarked ground
  commanders of changes in the ground tactical situation or to the air movement plan (JP 3-18).
  1-168. Forces initially deploy with limited communications capabilities—primarily single-channel radios
  and narrowband (single-channel) satellite communications. As additional units enter the operational area, the
  deployed network becomes more robust to support greater troop strength and associated command posts.
  Refer to JP 3-18 for more information about forcible entry operations.