What's the difference between MAX HARQ, HARQ DL or UL?

Hello Experts.

What’s the difference between MAX HARQ, HARQ DL or UL?

What do you mean by max Harq?

Is it maximum number of retransmission or max no. of HARQ process?

  • max retransmission is 4
  • max HARQ process is 16 in NR

So packet loss will happen in max retransmission if it exceeds and packet drop if it goes above 16 in max harq.

Is this the way or am I wrong?

Packet will be dropped after 3 retx → this is for one HARQ process.
16 HARQ process means parallel 16 TB you can process.

But you have set 4 here as example retransmission.

Max retrans is 3 but total transmission count is 4 i.e. 1+3 retx.

So but max threshold can go till 32, no?

1 count for initial transmission.
And 3 retx.

UE and eNode retransmission.
Do you mean rbler in short? If it exceeds 4?

Yes, correct.

But retransmission can be set till 32.
To avoid drops and harq process coming forward.
Throughout wil be comprised but scheduling congestion will happen.
Means till harq process 16 exceeds there will be no drops happening.
Inspite of RLF.
As in NR.
But RLF will happen.

HARQ process doesn’t have any relation with retransmission count.

So if retransmission fails then drop will happen, you mean?

If reTx reaches upto 4 then drop will happen → this is for one HARQ process, which will be completely independent from other HARQ process.

So if drop will happen in one HARQ process then why 16 set if packet is drop?
Then it’s a abnormal release, you mean?
So we can increase retx till 32 to avoid drops.

16 is there because you can send 16 TB parallel.

Multiple HARQ process is introduced because transmitter will send back to back TB instead of waiting for the response of previous TB.

Ok, but what’s the benefit of increasing HARQ?
Will it improves packet drop or packet loss?
To let’s say HARQ process 16 in NR.
Do you mean multiple packet are send so HARQ is used?

Multiple HARQ process are used just to improve Latency of system.

HARQ is used to improve Performance of system.

Ok, so no relation with loss or drop.
So we need to increase retx to avoid drops?

Packet will be dropped only when you have reached maximum retransmission limit.