text: Chapter 1
  Commanders face new challenges in defending capabilities in cyberspace where boundaries are far less
  identifiable. Attacks in cyberspace can originate from, and route through, friendly, neutral, and adversary
  countries.
  1-7. As commanders operate across the range of military operations, signal capabilities must be tailorable
  to meet the commander’s requirements. The way signal formations deliver communications services varies
  based on the mission. Communications requirements during theater security cooperation activities from fixed
  posts, camps, or stations differ from a brigade combat team commander’s requirements during a movement
  to contact mission in large-scale combat operations. Signal staff officers and leaders need to clearly articulate
  to commanders what communications capabilities are available during critical points of an operation and how
  these capabilities support the exercise of command and control.
  1-8. Understanding the operational environment is essential for signal leaders, engineers, planners, system
  operators, and cybersecurity professionals to plan and execute effective signal support. Signal Soldiers must
  understand signal flow from the end user, through the local area network, through the wide-area network,
  and the Department of Defense information network-Army (DODIN-A). The Department of Defense
  information network-Army is an Army-operated enclave of the Department of Defense information network
  that encompasses all Army information capabilities that collect, process, store, display, disseminate, and
  protect information worldwide (ATP 6-02.71). As an example, planners should understand how severe
  weather in Guam may affect satellite communications networks in Korea, or a cyberspace incident in the
  continental United States can quickly traverse the network and affect communications in an operational
  theater.
  INFORMATION ENVIRONMENT
  “There is no better example of the challenge ahead than that of the information
  environment. From moving supplies in the wake of a hurricane disaster to ordering troops
  to the Pacific, or addressing the ever-changing cyber[space] threat, the global dependence
  on information and networks in everyday activities demands our attention now.”
  —General Martin E. Dempsey, former Chairman of the Joint Chiefs of Staff
  1-9. Across the globe, information is increasingly available in near-real time. The DODIN-A provides the
  ability to access this information from anywhere, and at any time. Access to information enables decision
  making, leadership, and combat power. It is also key to seize, gain, and retain the initiative and to consolidate
  gains in the operational environment.
  1-10. U.S. forces seek to dominate the information environment to maintain information advantage. The
  information environment is the aggregate of individuals, organizations, and systems that collect, process,
  disseminate, or act on information (JP 3-13). In modern conflict, controlling the information environment is
  as important as controlling key terrain in the physical domains. The information environment is not separate
  or distinct from the operational environment, but an integral part of it. Any activity that takes place in the
  information environment affects one or more of the warfighting domains.
  1-11. Cyberspace and the electromagnetic spectrum are parts of the information environment. Cyberspace
  is a global domain within the information environment consisting of the interdependent networks of
  information technology infrastructures and resident data, including the Internet, telecommunications
  networks, computer systems, and embedded processors and controllers (JP 3-12). Friendly, enemy,
  adversary, and host-nation networks, communications systems, computers, cellular phone systems, social
  media, and communications infrastructure are all parts of cyberspace.
  1-12. The electromagnetic spectrum is the range of frequencies of electromagnetic radiation from zero to
  infinity. It is divided into 26 alphabetically designated bands (JP 3-13.1). The electromagnetic spectrum
  crosses all domains and provides the vital link between space and cyberspace domains. Cyberspace and the
  electromagnetic spectrum have become increasingly congested and contested, even as their importance to
  successful operations has increased. Army forces must be able to effectively operate in cyberspace and the
  electromagnetic spectrum while controlling the ability of enemies and adversaries to operate.
  1-13. Signal Soldiers install, operate, and secure the DODIN-A in locations where both friendly and enemy
  cyberspace operations occur. Given the high risk to the network, signal operators and information system