SO_RAI_NO_DATA still does not cause RRC release

[Michal Mühlpachr]

Issue is related to  RE: NRF_SO_RAI_NO_DATA does not cause RRC release in SLM/nrf9160 without send 

Just after AT#XSOCKETOPT=1,50 modem should negotiate RRC Release, but it is not the case.

NCS v2.3 nrf9160_1.3.4

Serial LTE Modem, prj.conf changes:
CONFIG_SLM_START_SLEEP=y
CONFIG_SLM_WAKEUP_PIN=6
CONFIG_SLM_INDICATE_PIN=2
CONFIG_SLM_DATAMODE_URC=y
CONFIG_SLM_EXTERNAL_XTAL=y
CONFIG_NRF_MODEM_LIB_TRACE=y

Modem Trace: trace-2023-03-15T22-56-29.105Z.bin

AT dialogue and PPKII measurements:

[PPK2] DUT Powered, Measurement started
   0.13 <RESET> Wed Mar 15 23:56:33 2023
   1.01 [PPK2] 100k/s AVG   4.02 mA    Max  28.6  mA
   1.25 <INDICATE transition> -> High
   2.03 [PPK2] 100k/s AVG   2.21 mA    Max  29.8  mA
   3.01 [PPK2] 100k/s AVG   0.002mA    Max   0.009mA
   4.02 [PPK2] 100k/s AVG   0.002mA    Max   0.008mA
   4.26 <WAKEUP>
   5.02 [PPK2] 100k/s AVG   1.11 mA    Max  24.5  mA
   5.60     [RX] Ready
   5.60 [TX] AT
   5.61     [RX] OK
   5.61 [TX] AT+CFUN=0
   5.77     [RX] OK
   5.77 [TX] AT%MDMEV=1
   5.78     [RX] OK
   5.78 [TX] AT%XPOFWARN=1,30
   5.80     [RX] OK
   5.80 [TX] AT%XTEMPHIGHLVL=60
   5.81     [RX] OK
   5.81 [TX] AT%HWVERSION
   5.81     [RX] %HWVERSION: nRF9160 SICA BQA
   5.81     [RX] OK
   5.81 [TX] AT%SHORTSWVER
   5.83     [RX] %SHORTSWVER: nrf9160_1.3.4
   5.83     [RX] OK
   5.83 [TX] AT#XSLMVER
   5.83     [RX] #XSLMVER: "2.3.0","2.3.1-8622ee1c632e"
   5.83     [RX] OK
   5.83 [TX] AT%XSYSTEMMODE=0,1,0,0
   5.85     [RX] OK
   5.85 [TX] AT%REL14FEAT=1,1,1,1,0
   5.86     [RX] OK
   5.86 [TX] AT%RAI=1
   5.86     [RX] OK
   5.87 [TX] AT%REDMOB=1
   5.88     [RX] OK
   5.88 [TX] AT%XDATAPRFL=0
   5.89     [RX] OK
   5.89 [TX] AT+CEPPI=1
   5.90     [RX] OK
   5.90 [TX] AT%XNETTIME=1
   5.91     [RX] OK
   5.91 [TX] AT+CNEC=24
   5.92     [RX] OK
   5.92 [TX] AT+CMEE=1
   5.93     [RX] OK
   5.93 [TX] AT%XSIM=1
   5.94     [RX] OK
   5.94 [TX] AT+CEREG=5
   5.95     [RX] OK
   5.95 [TX] AT+CSCON=1
   5.97     [RX] OK
   5.97 [TX] AT+CGEREP=1
   5.97     [RX] OK
   5.97 [TX] AT%XTIME=1
   5.99     [RX] OK
   5.99 [TX] AT%XMODEMSLEEP=1,500,10240
   6.00     [RX] OK
   6.00 [TX] AT+CPSMS=1,,,"00111000","00000000"
   6.00     [RX] %XMODEMSLEEP: 4
   6.00     [RX] OK
   6.01 [TX] AT%XBANDLOCK=1,"0000000000000000000000000000000000000000000000000000000000001000000010000000100010011010"
   6.02 [PPK2] 100k/s AVG   4.64 mA    Max  37.1  mA
   6.02     [RX] OK
   6.03 [TX] AT+COPS=1,2,"23003"
   6.05     [RX] OK
   6.05 [TX] AT+CGDCONT=1,"IP","hardwario.com"
   6.05     [RX] OK
   6.05 [TX] AT+CFUN=1
   6.10     [RX] OK
   6.11     [RX] %XMODEMSLEEP: 4,0
   7.01 [PPK2] 100k/s AVG  27.2  mA    Max  48.0  mA
   7.02     [RX] %XSIM: 1
   7.02 [TX] AT+CGSN
   7.02     [RX] 352656106109476
   7.02     [RX] OK
   7.02 [TX] AT+CIMI
   7.03     [RX] 901288000012723
   7.03     [RX] OK
   8.01 [PPK2] 100k/s AVG  35.5  mA    Max  65.8  mA
   9.00 [PPK2] 100k/s AVG  39.3  mA    Max  66.5  mA
  10.01 [PPK2] 100k/s AVG  19.2  mA    Max  62.9  mA
  11.02 [PPK2] 100k/s AVG   1.89 mA    Max   2.53 mA
  12.03 [PPK2] 100k/s AVG   1.89 mA    Max   2.50 mA
  13.01 [PPK2] 100k/s AVG   1.89 mA    Max   2.51 mA
  13.46     [RX] +CEREG: 2,"AE38","000AC51F",9
  14.01 [PPK2] 100k/s AVG   4.55 mA    Max  55.8  mA
  14.16     [RX] +CSCON: 1
  15.02 [PPK2] 100k/s AVG  33.2  mA    Max 290mA
  16.01 [PPK2] 100k/s AVG  33.6  mA    Max  46.3  mA
  17.01 [PPK2] 100k/s AVG  33.6  mA    Max  46.3  mA
  18.02 [PPK2] 100k/s AVG  33.6  mA    Max  46.1  mA
  19.01 [PPK2] 100k/s AVG  33.1  mA    Max  47.8  mA
  20.01 [PPK2] 100k/s AVG  33.2  mA    Max  46.5  mA
  21.01 [PPK2] 100k/s AVG  33.6  mA    Max  46.3  mA
  22.02 [PPK2] 100k/s AVG  33.6  mA    Max  46.2  mA
  23.02 [PPK2] 100k/s AVG  33.6  mA    Max  46.3  mA
  24.02 [PPK2] 100k/s AVG  33.3  mA    Max  46.1  mA
  24.43     [RX] +CGEV: ME PDN ACT 0,0
  24.43     [RX] +CNEC_ESM: 50,0
  24.43     [RX] %MDMEV: SEARCH STATUS 2
  24.44     [RX] +CEREG: 5,"AE38","000AC51F",9,,,"00000000","00111000"
  24.44 [TX] AT+COPS?
  24.45     [RX] +COPS: 1,2,"23003",9
  24.45     [RX] OK
  24.45 [TX] AT%XCBAND
  24.46     [RX] %XCBAND: 20
  24.46     [RX] OK
  24.46 [TX] AT+CEINFO?
  24.46     [RX] +CEINFO: 0,1,C,8,1,-87,18
  24.46     [RX] OK
  24.46 [TX] AT+CGDCONT?
  24.47     [RX] +CGDCONT: 0,"IP","hardwario.com","10.0.0.157",0,0
  24.48     [RX] +CGDCONT: 1,"IP","hardwario.com","",0,0
  24.48     [RX] OK
  24.48 [TX] AT#XDATACTRL=40
  24.48     [RX] %XTIME: ,"32305122655540",
  24.49     [RX] OK
  24.49 [TX] AT#XSOCKET=1,2,0
  24.49     [RX] #XSOCKET: 0,2,17
  24.50     [RX] OK
  24.50 [TX] AT%CONEVAL
  24.51     [RX] %CONEVAL: 0,1,7,54,24,42,"000AC51F","23003",493,6447,20,0,0,16,2,1,114
  24.51     [RX] OK
  25.00 [PPK2] 100k/s AVG  33.0  mA    Max 148mA
  25.65 [PPK2] ====== SUM: ATTACH   0.157uA/h during  25.6  s ======
  26.73 [TX] AT#XCONNECT="192.168.168.1",20000
  26.73     [RX] #XCONNECT: 1
  26.73     [RX] OK
  26.73 [TX] AT#XSOCKETOPT=1,50
  26.74     [RX] OK
  27.01 [PPK2] 100k/s AVG  33.6  mA    Max  46.2  mA
  28.02 [PPK2] 100k/s AVG  33.6  mA    Max  46.3  mA
  29.00 [PPK2] 100k/s AVG  33.4  mA    Max  46.3  mA
  30.01 [PPK2] 100k/s AVG  33.0  mA    Max  46.2  mA
  31.01 [PPK2] 100k/s AVG  33.6  mA    Max  46.3  mA
  32.01 [PPK2] 100k/s AVG  33.6  mA    Max  46.1  mA
  33.01 [PPK2] 100k/s AVG  33.6  mA    Max  46.1  mA
  34.01 [PPK2] 100k/s AVG  33.5  mA    Max  46.4  mA
  35.02 [PPK2] 100k/s AVG  32.8  mA    Max  46.3  mA
  36.00 [PPK2] 100k/s AVG  33.6  mA    Max  46.2  mA
  37.01 [PPK2] 100k/s AVG  33.6  mA    Max  46.2  mA
  38.02 [PPK2] 100k/s AVG  33.6  mA    Max  46.1  mA
  39.01 [PPK2] 100k/s AVG  33.6  mA    Max  46.5  mA
  40.00 [PPK2] 100k/s AVG  32.6  mA    Max  46.0  mA
  41.01 [PPK2] 100k/s AVG  33.7  mA    Max  46.1  mA
  42.02 [PPK2] 100k/s AVG  33.6  mA    Max  46.2  mA
  43.02 [PPK2] 100k/s AVG  33.6  mA    Max  46.6  mA
  44.02 [PPK2] 100k/s AVG  33.7  mA    Max  48.2  mA
  45.02 [PPK2] 100k/s AVG  32.7  mA    Max  45.9  mA
  45.49     [RX] +CSCON: 0
  45.49     [RX] %XMODEMSLEEP: 1,86399999
  45.49 [TX] AT#XSLEEP=2
  45.49     [RX] OK
  46.00 [PPK2] 100k/s AVG  16.5  mA    Max 194mA
  47.02 [PPK2] 100k/s AVG   0.017mA    Max   0.023mA
  48.01 [PPK2] 100k/s AVG   0.017mA    Max   0.023mA
  49.03 [PPK2] 100k/s AVG   0.017mA    Max   0.023mA
  50.02 [PPK2] 100k/s AVG   0.017mA    Max   0.023mA

[Achim Kraus]

Maybe, it's easier to use SO_RAI_LAST and a own "empty message".

At least in the past versions, the idea with SO_RAI_NO_DATA seems to be the same, sending a last empty message with NO_RESPONSE. Therefore you have to "connect" the udp socket in order to tell the stack, where to send this injected empty message.

Just because you use a 90128 SIM:

Do you know the HPPLMN search interval of your SIM card? Not that you get too surprised by some additional power consumption from that function (see HPPLMN search - reason unknown , it explains, why Nordic will always search for such a 9xxxx network.) By the way, did your modem ever report that 90128 network (see nRF9160 - who's device has seen/reports a network with a global PLMN starting with 9 ).

[Michal Mühlpachr]

SO_RAI_LAST and an own "empty message" works as workaround.
But SO_RAI_NO_DATA should still be fixed.

As you can see from AT dialogue, UDP socket is "connected" (without any IP traffic).
As you can see from modem trace, stack is not sending any empty message after SO_RAI_NO_DATA.

HPPLMN search does not apply because Vodafone CZ uses 90128 for home NB IoT (all Vodafone CZ NB IoT SIMs are 90128 - i.e. "roaming"), so it is the highest priority PLMN already.

Since SO_RAI_NO_DATA  and SO_RAI_ONE_RESP work reliably like a charm, I see no reason why SO_RAI_LAST should struggle with  HPPLMN search  or another corner strange causes. You can see from LTE RRC/NAS signaling (Modem Trace) that it is not the case also.

[Michal Mühlpachr]

I am sorry, correction:
Since SO_RAI_LAST and SO_RAI_ONE_RESP work reliably like a charm, I see no reason why SO_RAI_NO_DATA  should struggle with  HPPLMN search  or another corner strange causes. You can see from LTE RRC/NAS signaling (Modem Trace) that it is not the case also.

[Achim Kraus]

Sorry, my writing was misleading. 

The topic SO_RAI_NO_DATA or SO_RAI_LAST is separated from the HPPLMN search.

Last year I also wasn't able to get SO_RAI_NO_DATA working. I read "somewhere", that the implementation of SO_RAI_NO_DATA will use "SO_RAI_LAST with an injected/additional empty message", but that may be wrong. We will see, if it works once upon a day.

> HPPLMN search does not apply because Vodafone CZ uses 90128 for home NB IoT (all Vodafone CZ NB IoT SIMs are 90128 - i.e. "roaming"), so it is the highest priority PLMN already.

"COPS?" reports in your log PLMN 23003, and not 90123. I understand of course your writing and your interpretation, I share that. But, if you read carefully the link to the other discussion I provided, you will see, Nordic has a different interpretation! Since mfw 1.3.2 Nordic DOES a HPPLMN search for the "90123", because "23003" is not the same. It depends now mainly on your search interval, how often that happen. And you select the bands, so the search may be faster. But again, Nordic decided with mfw 1.3.2 to search for the "90123", if "23003" is reported as PLMN.

My IMSI starts with 90140 and my reported PLMN was 26201. With a search interval of 2h, I can see such a HPPLMN search every 2h. Unfortunately, you don't get events for that, you only see the larger power consumption and the "sleep event" is delayed (in my case about 60s).

 

[dejans]

Hi,

I have made an internal inquiry related to SO_RAI_NO_DATA to our developers. I will get back to you when I get more information.

Best regards,
Dejan

[dejans]

Hi,

Unless Release-14 RAI is supported by the network and enabled by the device the "immediate release" does not take place. In your case, the network did not activate AS-RAI. In addition, eNB did not request form UE to provide its capabilities. Therefore, UE did not get an opportunity to notify eNB about its support for R14 AS-RAI.

Best regards,
Dejan

[Achim Kraus]

So, if AS-RAI is not supported by the network operator, SO_RAI_LAST is working, but SO_RAI_NO_DATA not?