CDRX in ANR in LTE

4G LTE
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1

Hi Experts,

We used to configure CDRX which helps UE to read the CGI and report it to EnodeB.
My question is :
At the time when UE is measuring the CGI info from the Niegbhouring cell,can UE handel
data at that time ?

2

As per my acknowledge reading and reporting CGI of E-UTRAN cells, UTRAN cells and GERAN cells, will be done during long DRX cycle or measurement gap, where during this time UE will not be able to send or receive data , exactly like compressed mode in 3G.

3

Hi @ZCHEMOS … Thanks for your answer

But when you configure long DRX cycle, then you need to configure "onDurationTimer " so in this time enodeb can send data to UE and UE need to process it…So in this case send and receive is possible…
Please let me know your view regarding this

4

Hi @partha_sarathi
yes I agreed because the DRX cycle consist of the following phases:

  • On Duration phase, when the UE is active (can RX or TX data)

  • Opportunity for DRX phase, when the UE is inactive (no RX or TX of data).

b.r

5

UE read CGI in DRX mode, can not receive data during this period. This is one disadvantage of ANR.
So, ANR should be used as an extra tool, help to add missing neighbors but manual configuration should be done first.

6

Hi @Hainm

Thanks for your answer

But when you configure long DRX cycle, then you need to configure "onDurationTimer " also .So in this time enodeb can send data to UE and UE need to process it…So in this case send and receive is possible…
Please let me know your view regarding this

7

DRX for ANR is different with normal C-DRX.
Because reading CGI require long time, so enb configure a long sleep time for UE, about several hundred of ms.

8

As per my knowledge there are only two types of DRX (idle mode DRX and C-DRX)

Idle Mode DRX: It deals with paging and there is no RRC connection during this mode.There is no “ON” or “OFF” duration.
C-DRX: It is connected mode DRX .Here RRC connection will be present but the UE will go for “ON” and “OFF” (sleep and awake) as per the configuration given by the EnodeB.

And in ANR C-DRX will be configured…

1 Like
9

It is recommended that DRX for ANR measurement: DRX cycle parameter be set to a value greater than or equal to 256ms and On Duration timer is at least 80ms to ensure that UE can successfully obtain CGI of a LTE cell.*