PHY Layer Arrival Time -- Time when a packet arrives from MAC Layer and transmission starts

PHY Layer Start Time -- Time when the first byte of the packet reaches the receiver

PHY Layer End Time -- Time when the last byte of the packet reaches the receiver


In general - 


PHY Layer End Time - Phy Layer Start Time = Propagation Delay

PHY Layer Start Time - Phy Layer Arrival Time = Transmission time (plus preamble time in WLAN)


Related articles:

https://support.tetcos.com/en/support/solutions/articles/14000076593-how-do-i-calculate-queuing-delay-transmission-time-and-propagation-delay-from-packet-trace-