Communications

1234567891011
Across
  1. 2. - Silent instructions
  2. 5. systems - online systems
  3. 6. phones - You're always on it
  4. 9. - Old school means of communication
  5. 11. conferencing - talking with video
Down
  1. 1. - Also used by a referee
  2. 3. flares - bright red lights in the sky
  3. 4. - A communication device
  4. 7. - every day post on line
  5. 8. - They beep when you're needed
  6. 10. hailers - really noisy to speak to a crowd