4.3 Data Transmission

Data transmission between two devices is achieved by calling the following WPAN API,

WPAN_MCPS_Datareq(uint8_t SrcAddrMode, WPAN_AddrSpec_t *DstAddrSpec, uint8_t msduLength, uint8_t *msdu, uint8_t msduHandle, uint8_t TxOptions);

  • In this TxOptions provides the way to initiate direct/indirect/acknowledged/unacknowledged transmission.
  • If the TxOptions parameter specifies that an indirect transmission is required and this primitive is received by the MAC sublayer of a coordinator, the data frame is sent using indirect transmission, that is, the data frame is added to the list of pending transactions stored on the coordinator (indirect queue) and extracted at the discretion of the device concerned.
  • If the TxOption parameter specifies that an acknowledged transmission is required, the MAC sublayer sets the ACK request bit in FCF of MAC frame.
Figure 4-3. Data Transmission Message Sequence