How to set the DRX active window?

[xinjiang]

The average current during the nRF9160 test DRX is 2.2mA. The period of DRX is 2.56s. Using a China Mobile IoT card. I am testing on the DK board and have turned off all peripherals. The power consumption in psm is 4.4 uA.

Customers reported that the power consumption during DRX was too high. Mainly because the DRX window time is too long, as much as 300ms(The same IoT card).

Customers use other manufacturers' NB modules for testing, and the window time of DRX is only 30-40ms().

How can I shorten the DRX window time to reduce power consumption.

[Didrik Rokhaug]

Hi,

What application and NCS version are you using?

Are you using LTE-M or NB-IoT?

If you are using the udp sample, could you try to upgrade to the master branch?

Are you using eDRX?

You can also try to request a shorter Paging Time Window (PTW).

You can do that by setting CONFIG_LTE_PTW_VALUE to the request value in your prj.conf, or by using the %XPTW AT command.

Best regards,

Didrik

[xinjiang]

What application and NCS version are you using?

ncs1.3.0

Are you using LTE-M or NB-IoT?

NB-IOT

If you are using the udp sample, could you try to upgrade to the master branch?

I used the at_client routine and turned off the uart peripheral.

Are you using eDRX?

Customers don’t want to use eDRX, they just want to use DRX to maintain real-time.

 The %XPTW AT command just set the window of eDRX. How to set the window time of DRX.

[Didrik Rokhaug]

Are your customer using the same network when they are measuring the power of the other module?

What modem FW version are you using?

I believe the DRX window is decided by the network, but I have asked our modem team to be sure, and to see if they have any other tips for how to lower the power consumption.

I will let you know when I get an answer from them.

[Didrik Rokhaug]

Some more questions:

How is the signal conditions where you are testing?

Do you have good coverage, are there many nearby cells, etc.?

What version of the SiP do you have?

[xinjiang]

Are your customer using the same network when they are measuring the power of the other module?

Yes.

What modem FW version are you using?

1.2.2

How is the signal conditions where you are testing?

The following is the test in our company(The period of DRX is 2.56s. It's just the waveform after the net injection, without any operation):

1、Customer's NB module：

The DRX window will change, and it will shrink when the signal is good.The DRX window measured in the client company is 30-100ms.

2、9160DK：

The DRX window remains at around 332ms.

Do you have good coverage, are there many nearby cells, etc.?

The signal is good, there are other cells around.

What version of the SiP do you have?

I don’t know how to check the SIP version, so I took a photo.

[Didrik Rokhaug]

Thanks.

The modem team suspects that this is because of a high number of paging repetitions per window.

In the next feature update of the modem (v1.3), we will improve this scenario by not listening for all the repetitions if the signal conditions are good enough.

However, until that release, there is not much we can do. The number of repetitions is decided by the network, and not something we can change.