Communications and systems development sac

The RCA 474L Ballistic Missile Early Warning System was a United States Air Force Cold War early warning radar, computer, and communications system, for ballistic missile detection.
The network of twelve radars, which was constructed beginning in 1958 and became operational in 1961, was built to detect a mass ballistic missile attack launched on northern approaches [for] 15 to 25 minutes' warning time also provided Project Space Track satellite data.

The ITT 465L Strategic Air Command Control System was a Cold War Big L network of computer and communication systems for command and control of Strategic Air Command combat aircraft, refueling tankers, [and] ballistic missiles.
International Telephone and Telegraph was the prime contractor for Project 465, and SACCS had Cross Tell Links between command posts at Offutt AFB, March AFB, & Barksdale AFB (SACCS also communicated with the Cheyenne Mountain Complex and Air Force command posts.
The 465L System included IBM AN/FSQ-31 SAC Data Processing Systems, Remote and Simplex Remote Communication Systems, SAC Network Control Office, 4-wire, Schedule 4,
Type 4B alternate voice-data operation, and one-way communication with ICBM launch control centers In addition to IBM for the Super SAGE type computers, another of the 6 direct subcontractors was AT&T,

The National Military Command System (NMCS) was the federal government of the United States' Cold War command and control system that consisted of the National Military Command Center (NMCC) at The Pentagon, the Alternate National Military Command Center (NMCC) at Pennsylvania Raven Rock Mountain, 3 National Emergency Airborne Command Post (NEACP) aircraft on 24-hour ground alert, 2 National Emergency Command Post Afloat (NECPA) ships, and interconnecting communications.