Abstract: There are several kinds of packet types in Bluetooth specification to enhance the data transmission performance in different noisy channels. In this paper, a Bluetooth data transmission mathematical model in noisy environments is presented. The relations between bit error rate and average received signal-to-noise ratio(SNR)in additional white gaussian noise (AWGN) channel are derived for gaussian frequency shift keying (GFSK) modulation and newπ/4-DQPSK and 8DPSK modulations adopted in Bluetooth 2.0+EDR specification. The function expressions of packet retransmission probability and average received SNR of asynchronous connection-oriented (ACL) data packets are put forward. The impact of payload length on Bluetooth data transmission throughput is obtained at last. Simulation results contained in this paper can be severed as a good benchmark against researches on how to enhance Bluetooth data transmission throughput.