US Patent 9531501 Data transfer between electronic devices

During operation in the described embodiments, a transmitting electronic device transmits a first data channel protocol data unit (PDU) with a payload containing data D to a receiving electronic device using a Bluetooth Low Energy (BTLE) interface in a sending window for the transmitting electronic device during a regular event, wherein transmitting the first data channel PDU during the regular event comprises using a first frequency to transmit the first data channel PDU. The transmitting electronic device then transmits a second data channel PDU with a payload containing the same data D to the receiving electronic device using the BTLE interface in a sending window for the transmitting electronic device during a corresponding retransmission event, wherein transmitting the second data channel PDU during the retransmission event comprises using a second frequency to transmit the second data channel PDU.