A method of triggering and reporting traffic statistics in a cellular network is proposed. A UE establishes an RRC connection with a base station. The UE collects traffic statistics upon detecting a trigger event. The traffic statistics comprises packet inter-arrival time. The trigger event may be detected by the UE or by the base station. The UE then determines a representation of the traffic statistics and report the result to the base station. The report may be triggered by the UE or by the base station based on another trigger event. Upon receiving the traffic statistics, the base station determines RRC reconfiguration parameters. In one example, DRX timer values are determined based on intra-burst packet inter-arrival time. In another example, RRC release timer is determined based on inter-burst packet inter-arrival time.