@HaraldNaumann Yes, but when we want the exact numbers you tell us to buy your cookbook or attend your webinar. So how can we be educated then?
Posts made by Stefan de Lange
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RE: What is the difference of NB-IoT and LTE-M?
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RE: RRC inactivity timer duration for NB-IoT and LTE-M
Is the inactivity timer always containing C-DRX cycles like in the picture?
It should. Unless C-DRX is disabled by the network, which appears to be the case. This is strange because it saves power. Have you tried to activate PSM and CSCON URC’s? That would help you in debugging.
From here you can see the DRX cycles after the connection mode. This is why I’m thinking that the inactivity timer is contained between the actual data transmission (spikes on the right) and the beginning of the DRX cycles
Yes I think so as well. You can get a lot more info if you enable aforementioned URC’s and hook up the serial debug port to the otii serial input.
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RE: RRC inactivity timer duration for NB-IoT and LTE-M
@Alessandro-Parmigiani Do you have the same picture including time/current scale? It would be very helpful to figure out what is going on
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RE: RRC inactivity timer duration for NB-IoT and LTE-M
@Alessandro-Parmigiani said in RRC inactivity timer duration for NB-IoT and LTE-M:
- From your experience, is the RRC inactivation time related to the number of LTE frames, in this case 5 s ~ 5.12 s, therefore 512 frames or can it also be uncorrelated?
I do not know. The module normally does not expose such details. You would need to have a network simulator or a module which supports extensive tracing on L1/L2/L3 (like the Sequans for example).
- Is the RRC inactivation time ending where the spikes on the right begin? Or is the transition to idle mode also included?
I believe the large spikes on the right signal RRC release. The very low power level afterwards suggests PSM mode. Your module also seems to be skipping the C-DRX phase, according to power consumption it is continuously in receive mode… I wonder why that is?
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RE: RRC inactivity timer duration for NB-IoT and LTE-M
@Alessandro-Parmigiani Hi Alessandro. I have experimented a lot with this on various networks/modules and in general my experience is that RRC inactivity cannot be controlled by the device. The only succesful way I have found to circumvent the RRC inactivity period is to use Release Assist.
However, release assist has some downsides. I have found that it only works on NB-IoT, I have not found any LTE-M modules/networks that support it. The implementation also highly depends on which module you are using. Release assist does lead to significant power saving, in some specific cases (like uplink only nodes) more than 90% of power can be saved.
In general it is very hard to visualize the RRC timer. The best method I found is to activate the +CSCON URC. This will tell you when the modem has left RRC connected state.
However, I do not know the specifics for the T-Mobile network. I am just a user
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RE: Arduino MKR NB1500: lukt niet om te verbinden.
@Crowdsourcer I don’t know. BQ24195 is pretty solid. Probe it if you need to.
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RE: Arduino MKR NB1500: lukt niet om te verbinden.
@Crowdsourcer That can be many things. Maybe the LiPo is bad, has too little charge or has too low capacity/current capability? I would suggest to test using a bench power supply and try to steadily lower the voltage. If that also doesn’t work then perhaps the module is faulty
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RE: Using NB-IOT for citizen-science
@bertrik Hi,
My perspective:
- No, for powerconsumption the amount of data doesn’t matter at all. I have sent KB’s in one go and the change in power consumption vs a payload of a few bytes was practically 0, although it does get worse under poor signal conditions. The overhead of signalling with the basestation will consume the majority of the power. I believe you can send up to 512 bytes in a single packet…
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RE: Downlink API dataformat
@Lauwie007 I don’t know sorry. Maybe t-mobile knows
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RE: Downlink API dataformat
@Lauwie007 so basically, you want binary data transfers?
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RE: Downlink API dataformat
@Roalnd-Baldin 01AB uses twice the amount of data as hi if it’s received as ASCII
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RE: Ack message from server
@David-Netten I don’t think CoAP is supported. Here it says not before february: https://forum.iotcreators.com/topic/633/when-are-we-getting-non-neulmessenger-coap
On N211 I believe you can use the neul messenger version of CoAP, which does support acknowledgements. Look for the command AT+NMGS. General tip, try not to build your own acknowledge system.
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RE: quectel nb-iot modem is activated every hour - why? (psm is 10 hours)
@lorenz I checked the PSM timers and everything looks good to me. You request a TAU timer of 10 hours and it is also assigned as per the correct response of +CEREG. So I cannot explain why it doesn’t follow the set timers, it is very strange.
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RE: quectel nb-iot modem is activated every hour - why? (psm is 10 hours)
@lorenz Hi Lorenz, can you show the output of AT+CPSMS?
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RE: QUECTEL BC95-B8 not connecting to Network
@jonasled I got mine through a supplier. So try asking the company you bought the devkit from. I do not like how quectel handles this, it is very inconvenient and old fashioned…
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RE: QUECTEL BC95-B8 not connecting to Network
@jonasled “EMM_CAUSE_UNKNOWN” is hard to diagnose. Any time I have seen this error it could either be some operator issue, a SIM issue or a modem FW related issue. So I would suggest to update the FW first and then try again
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RE: QUECTEL BC95-B8 not connecting to Network
@jonasled You can enable more verbose error reporting with AT+CMEE=2. That will tell you what kind of error you have.
Quectel usually has their own version for every command so SARA N211 commands will not work.
What I can think of:
- Make sure you have the latest firmware
- Make sure the SIM works (try with a different module?)
- Make sure the antenna is properly connected
- Make sure you are in range of a network (scan with AT+COPS=?)
- Make sure you have a proper powersupply/cable (especially some USB supplies can be bad)
- Make sure you have the correct LTE bands enabled
- It should autoconnect to an available network but if it doesn’t you can force it with AT+COPS
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RE: QUECTEL BC95-B8 not connecting to Network
@jonasled Can you check if you have a working SIM card? Try AT+CPIN?
It should return OK
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RE: NB-IoT network and DNS
@Artur-S As far as I am aware all NB-IoT connections are limited to the internal network only. The only reachable endpoint is the CDP so reaching your API endpoint directly is not possible. Maybe that LTE-M does offer this option. Someone from T-Mobile can comment on this
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RE: NB-IoT network and DNS
@Artur-S I don’t think so. And since your device can’t access open internet anyway it doesn’t make much sense to do it. Interested to hear why you need DNS
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RE: When are we getting non-NeulMessenger CoAP?
@Sopwafel I agree, regular CoAP is awesome. The Neul Messenger protocol is only usable with a very limited number of modems
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RE: How long does it take that the network detects a dead IP connection?
@Roalnd-Baldin
The 2 hours is probably related to the 3GPP TAU timer, if it expires the device is implicitly released from the network I believe. Which is bad if you have a device that wants to sleep for more than 2 hours. So usually you set this value to whatever is the greatest the network accepts. You can run AT+CEREG=5, AT+CEREG? and check the returned values. It will tell you the timers that are used.