Up link L1/L2 control signalling is divided into two classes in the LTE system
1. Control signalling in absence of up-link data , which is done by PUCCH ( Physical up-link control channel) i.e when the UE is in IDLE Mode and has no dedicated resources allocated to it, only then the control signalling is carried on PUCCH.
1. Control signalling in absence of up-link data , which is done by PUCCH ( Physical up-link control channel) i.e when the UE is in IDLE Mode and has no dedicated resources allocated to it, only then the control signalling is carried on PUCCH.