A flexible Radio Link Control (RLC) protocol for a mobile communication system is provided, whereby a plurality of different RLC functions are defined. These different RLC functions can be combined in a number of different ways to produce a complete and functional, but more flexible RLC protocol than the existing protocol. For example, a new set of rules are provided for determining how and/or when to poll for, or send, a status report for Automatic Repeat Request (ARQ) purposes. As such, for a specific service configuration, one set of the rules can be used, and for a different service configuration, another set of the rules can be used. In this way, the rules can be conformed suitably to the type of service involved.