The physical layer service data unit represents the actual framed data handed off by the Media Access Control layer to the physical transmitter. Once the physical layer adds its own preamble and header for radio or cable transmission, the PSDU becomes a Protocol Data Unit. It is a key metric in wireless networking for calculating true data throughput minus the physical overhead.
Heard on the job
The analyzer shows the PSDU length is correct, but the physical preamble is getting corrupted over the air.