Patent ID: 8718667

Claim:
A method of adapting transmit power levels and repetitions of transmissions from a mobile wireless device to a wireless network, the method comprising: at the mobile wireless device: measuring a downlink signal power level and a downlink signal quality received from a radio access subsystem in the wireless network; receiving one or more transmit parameters from the radio access subsystem; calculating an initial transmit power level for an uplink preamble based on the received transmit parameters and on the measured downlink signal power level; transmitting a series of preambles to the radio access subsystem, each successive preamble having an increasing transmit power level up to and not exceeding a maximum transmit power level, and a number of retransmissions not exceeding a maximum retransmission count; stop transmitting the preamble retransmissions after receiving an ACK or NACK response from the radio access subsystem; when the transmit power level of the preamble equals or exceeds the maximum transmit power level and the measured downlink signal quality falls below a pre-determined threshold, limiting the number of preamble retransmissions to less than the maximum retransmission count; and when the measured downlink signal quality falls below the pre-determined threshold, calculating a minimum number of preamble retransmissions that is less than the maximum number of retransmission count allowed by the wireless network but larger than zero, wherein the minimum number of preamble retransmissions depends on an excess amount between a computed preamble transmit power level and the maximum transmit power level, wherein a higher excess amount decreases the minimum number of preamble retransmissions.