Short answers, pulled from the story.
Four communications satellites provided the backbone for the first live multinational television broadcast. Intelsat I nicknamed Early Bird and Intelsat II F-3 known as Canary Bird sat over different parts of the Atlantic Ocean while Intelsat II F-2 called Lani Bird and NASA's ATS-1 orbited above distinct sections of the Pacific Ocean.
The two-hour event took place on Sunday the 25th of June 1967 with worldwide coverage from four geosynchronous orbit satellites. Nine ground stations sent and received signals from these floating mirrors in space to connect North America Europe Tunisia Japan and Australia through a complex web of hardware.
Czechoslovakia East Germany Hungary Poland and the Soviet Union withdrew in protest over Western responses to the Six-Day War four days before the event. Their absence forced a request to the Danish broadcaster which was not originally scheduled and caused the planned section called The Hungry World to disappear from the schedule.
Granada TV documentary shows the Beatles' Our World broadcast segment where they topped the event by debuting All You Need Is Love for the first time during this live global transmission. Friends joined them to create a festive atmosphere including members of the Rolling Stones and Eric Clapton while Marianne Faithfull Keith Moon and Graham Nash all appeared in the chorus of the song.
An estimated audience between 400 million and 700 million people watched the largest television gathering up to that date. Fourteen national broadcasters ultimately transmitted live to twenty-four countries while technical teams monitored and manipulated signals across forty-three control rooms in real time.