Observed Two post transmission pulses on CubCellModule

Currently i’m working on Current Measurement of cubcell module(with ASR6501),
I’ve observed that module is generating 2 post transmission pulses means generating 2 pulses after the transmit pulse can not figure out for what operation device is generating 2 pulses
does any one know for what cube cell is generates 2 pulse after transmit the packet?
Attaching the snapshot for pulses for better idea

looks like the 2 receive windows

Thank you for quick reply, there is also one small pulse between Transmit and First receive window pulse what it could be?