| 摘要 |
In the receiving side MAC layer timestamping approach, the MPDU structure is changed by adding an extra timestamping field. When a MPDU packet is generated, a captured receiving timestamp is written into the MPDU's timestamp field. The MPDU packet is then forwarded from the PHY to the MAC layer of the wireless sensor node. In the MAC layer, the receiving timestamp is further processed and inserted into a corresponding field of the time synchronization message, which is in turn transmitted to a Time Synchronization module. In the sending side MAC layer timestamping approach, the sending timestamp is captured immediately before the time synchronization message is written into TxFIFO.
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