Generating, by a user equipment (UE) of a wireless access network, for a set of contention-based random access occasions of a base station of the network, a random number over an interval. For the generated random number meeting a threshold value within the interval, transmitting, by the UE and to the base station, a random access preamble within one of the random access occasions of the set. For the generated random number not meeting the threshold value, attempting, by the UE, contention-based access to the network within a subsequent set of random access occasions of the base station, the subsequent set of random access occasions occurring after the set of contention-based random access occasions of the base station.