Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 23
Confusion; Communication Breakdown
ATC Issue All Types; Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance
Airspace Structure
Aircraft X was a photo flight who had been delaying at FL200 for over an hour in Sector 29's and my airspace at Sector 44.  Sector 29 called me and told me that Paradise (NCT) was going to descend Aircraft X to FL190.  I approved this.  I had accepted a handoff on Aircraft Y from Paradise sector (NCT) direct FMG climbing to FL190 who would be in conflict with Aircraft X.  I called Paradise and verified they were descending Aircraft X to FL190.  They said yes.  I instructed Paradise to stop Aircraft Y at 170 for Aircraft X.  Paradise asked if they could turn him and get higher.  I said no; just stop Aircraft Y at 170.  Then Paradise made a request on another aircraft which we worked out a solution for.  Less than a minute later Aircraft X is turning toward Aircraft Y descending to FL190 and Aircraft Y checks on climbing out of 160 to FL190.  I asked Aircraft Y to say again and he again says climbing to FL190.  I stopped Aircraft X at 170. Paradise sector was obviously busy.  If they did not have two people working the sector maybe that would have helped.  Maybe if they had a way to enter altitudes on scope that would have helped.  Paradise probably forgot to stop the Aircraft Y because he was thinking of the other aircraft he coordinated on.  All of this happened right at the boundary where sector 29 owns a shelf of 200 to 230 up against 44's airspace.  If NCT owned up to FL230; like they did in the past; Paradise could have done his plan without having to coordinate with me and Sector 29.  I recommend that NCT's airspace be raised back up to FL230.  This would eliminate this shelf that causes many problems in at least 4 ZOA sectors.
NCT Controller reports of airborne conflict due to another Controller not complying with prior coordination.