top button
Flag Notify
    Connect to us
      Site Registration

Site Registration

Why do we need NDI bit in HARQ process?However we have ACK/NACK mechanism then why do we need to NDI?

0 votes
690 views
Why do we need NDI bit in HARQ process?However we have ACK/NACK mechanism then why do we need to NDI?
posted Aug 21, 2017 by Himani

Share this question
Facebook Share Button Twitter Share Button LinkedIn Share Button

2 Answers

+1 vote

as PHICH is not so reliable so, UE trusting only on NDI bit. once NDI bit toggled then only UE release the buffered data.

answer Aug 22, 2017 by Ravinder Kumar
In that case why do you need PHICH, however UE is not considering so you can use only NDI right?
Hello,

it's depend upon which type of HARQ we are using in case of Non adaptive retransmission UE relay only on PHICH. but in adaptive retransmission it also checking NDI bit to clear the buffer.
+1 vote

Harq retransmissions are limited , so if data is not decoded by ue then it will send the nack. Sending nack does not mean next will be retx . So on the basis of ndi, ue will know that it is new or retx.

answer Sep 2, 2017 by Veer Pal Singh Yadav
Similar Questions
+2 votes

Without MAC HARQ configuration how MSG3 is receiving ACK/NACK form ENB , As per my knowledge MAC configuration comes after connection request then how this is possible?

+1 vote

This case will UE accept it as NEW transmission or will it resend the TB?

...