In one aspect of the disclosed teachings, associating a plurality of contention-based uplink grants with a range of uplink resource blocks allows one contention-based uplink grant message to signal the entire plurality of grants. As an example in the LTE context, the signaling load on the PDCCH is reduced by using a single contention-based uplink grant message to signal a plurality of contention-based uplink grants. The message indicates an allocated set of uplink resource blocks and the number of separate uplink resource grants represented by the set is known or signaled, such that user terminals recognize that separate subsets of uplink resource blocks within the set each correspond to a separate contention-based uplink grant. Information included in the contention-based uplink grant message, or otherwise signaled can be used to control the probability at which the user terminals attempt contention-based uplink transmissions and/or to control the MCS used for such transmissions.