Narrative:

Air carrier Y overflt at FL310 came into conflict with air carrier X in descent to nashville. Air carrier X was cleared to an altitude lower than air carrier Y but due to communication failure air carrier X did not receive expedite clearance.

Google
 

Original NASA ASRS Text

Title: ACR X DESCENDED THRU THE ALT OF ACR Y WITH LESS THAN STANDARD SEPARATION. SYSTEM ERROR.

Narrative: ACR Y OVERFLT AT FL310 CAME INTO CONFLICT WITH ACR X IN DSCNT TO NASHVILLE. ACR X WAS CLRED TO AN ALT LOWER THAN ACR Y BUT DUE TO COM FAILURE ACR X DID NOT RECEIVE EXPEDITE CLRNC.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.