While a transmission time interval (TTI) length of other than 1 ms is in effect for communication between mobile and network nodes, at least one timer related to discontinuous reception (DRX) is implemented according to a rule that defines a time duration of the timer different from a time duration of the same timer implemented when the TTI length is defined as 1 ms. There are a plurality of such DRX-related timers, and in certain embodiments each is associated with one rule of a set of rules for implementing the respective timer when the TTI length is other than 1 ms; and in particular examples the timers are associated with groups for this purpose and all the timers of at least one of the groups is implemented according to the same rule of the set. Thus new DRX parameters need not be sent anytime the TTI length changes.