B757 Undifferentiated or Other Model
Air Traffic Control Fully Certified
Communication Breakdown; Situational Awareness
ATC Issue All Types
General None Reported / Taken
Procedure; Human Factors
I was at D2 which the stratum is up to FL350. RX I think had 2 similar sounding call signs Air Carrier ABC and Air Carrier ADC. From what I gather; they were both shipped to RY and when the RY Controller changed the altitude of Air Carrier ADC from FL360 to FL350 when he was in RY's airspace; Air Carrier ABC; who was in RX's airspace took it and descended. At RY; a PVD was quickly put up when RX noticed the Air Carrier descending. We had an aircraft at FL150 deviating; but we were able to turn and descend him just in case because we had no idea why the Air Carrier was descending. Nothing at Sector 2 could have been done different; but every day all the time we have way too many similar sounding call signs in our airspace from the same company; mostly. They depart the same airport; fly almost the same routes and it's very dangerous. They also have routes that converge and we have to call traffic; which can be quite dangerous if one slips on listening. Also; the sectors in our area were completely saturated and were filled with deviations for weather. A little flow into the area would help with so many dangerous situations.
[Narrative #2 held no additional information.]
Enroute Controller described a near separation loss when multiple same company aircraft with similar sounding flight numbers confused instructions/read backs and caused the event.