RXPacketTrace doesn't see UL trasmission

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Stefano Biccari

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Jan 12, 2026, 9:51:01 AM (5 days ago) Jan 12

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Hello everyone.

I am writing a simulation in ns3.45 where I need to analyse UL traffic. I have set up the application and everything works fine, but if users are too far away or sometimes after 3 HARQ retransmissions, the GNB stops receiving packets from the user in question. Analysing the NrUePhy logs, I saw that when it should be transmitting, it says it has nothing to transmit, when in fact this is not the case (I put the classic #packets = 0xFFFFFFF for a 2-second simulation, so it definitely does not lack material for transmission).

This only happens in UL. If I analyse the DL traffic, I can place users as far as 10,000 km away from the antenna, but the trace still shows that the packets are being received (although discarded due to the obviously very high SINR).

I would like to ask if anyone knows why this happens, because if I move the users, the signal may degrade, which is not a problem, but it is a problem if the user stops transmitting as a result.