US Patent 10009929 Contention-based random access

Retransmission parameters are determined for a wireless device based on a desired retransmission success rate, that is, a probability that subsequent random access requests transmitted from the wireless device re-initiating a contention-based random access procedure with an access node will reach the access node. The retransmission parameters are determined based on at least a quality of service associated with the wireless device, a distance of the wireless device from the access node, and a cell load of the access node. The retransmission parameters include a retransmission power and a retransmission backoff window size. A product of the power and backoff window is scaled such that it can be equated with a retransmission success rate.