Is it, TTI bundling and DRX in connected mode both should be On/off at same time?

Question

Which messages eNodeB uses to configure connected mode DRX and idle mode DRX for an UE ?

Answer 1

As per my knowledge, TTI bundling is used by UE to send uplink data mainly for VoIP data.
DRX is used to save battery life by just avoiding PDCCH reads per TTI.

If UE can sends either UL or receive DL for each TTI, then "yes" TTI bundling and DRX both should should be on at the same time but this is not the case with off. It may be UE is not using TTI bundling but DRX is on.

TTI bundling will just help to avoid re-transmission of data. When UE at cell edge or has poor channel conditions then TTI bundling will help to UE.

I am not very much comfortable with MAC features. So please correct me if I am wrong anywhere.
Thanks.

Answer 2

Specs doesn't say about it. MAC scheduler is completely proprietary thing.
If you know the concepts of these two then It is implementation which can make it efficient.

For TTI Bundling , UE sendsTB in bundle for 4 consecutive TTI i.e eNB has reconfigured the grant for the UE for these TTIs. So eNB should consider all DRX params . it should make better use of DRX-Inactivity timer