1659519c_LTE_Timers___LTE_Guide__Start
[Timer] T320 [Stop] Upon entering RRC_CONNECTED, when PLMN selection is performed on request by NAS, or upon cell (re)selection to another RAT (in which case the timer is carried on to the other RAT). [At expiry] Discard the cell reselection priority information provided by dedicated signalling. [Start] 
Upon receiving t320 or upon cell (re)selection to E-UTRA from another RAT with validity time configured for dedicated priorities (in which case the remaining validity time is applied).
LTE Timers ~ LTE Guide
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