Anyone using a SIM800 module? Does it still work?

Forums › Gadgets, robotics, home automation, electronics (including wearables) › Anyone using a SIM800 module? Does it still work?

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Linux

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#3304653 3-Nov-2024 08:49

RunningMan:

Linux:

You import a unit that does not work in the GSM900Mhz band and only the EGSM900Mhz that is your problem

Is EGSM 900 not a superset of GSM 900? i.e. an extra 10MHz of bandwidth at the lower end of the spectrum? Which would mean that any EGSM device would also work on GSM?

@RunningMan Looks like the SIM800 unit only supports the EGSM part of the GSM900Mhz frequency

I am still not 100% sure even if a change was made in this part of the spectrum but I suspect it was

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Linux

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#3304654 3-Nov-2024 08:51

Hwale:

Linux:

Hwale: If the EGSM band has been re-farmed, that's still MY problem, but MY problem is that this portion of the GSM band is no longer available. Furthermore, there was no forewarning or even any knowledge on the provider's part that it was going to happen despite the fact that many devices still use this band which OneNZ would be well aware of. MY problem is with the network, because the network has changed.

Yes it is 150% your problem and OneNZ do not need to notify you as ' YOU ' decided to purchase a ' product ' that does not actually support all of the 2G 900Mhz band only part of it

You don't own the spectrum that the carriers have rights to so if they want to make changes to it they are allowed to

The 2G / GPRS network is still up and running

You're still sperging.

EGSM is an ITU designated GSM band in its own right, you don't just switch it off arbitrarily.

Who said they switched it off? I am not commenting further till I hear back from my contact in OneNZ and then we will have an answer

I am not saying I am 100% correct I could be incorrect and it is something else

RunningMan

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#3304655 3-Nov-2024 08:59

Spec sheet is here.

Frequency Receive Transmit

EGSM900 925 ～ 960MHz 880 ～ 915MHz

Excuse the formatting, but that says it supports the entire EGSM band which includes the original GSM band, not just the additional 10MHz at the bottom of the send and receive spectrum.

I think GSM 900 uses 890-915MHz to send information and 935-960MHz to receive and EGSM uses 880-915 MHz and 925-960MHz.

Essentially, the SIM800l covers the entire GSM900 band + the extra 10MHz of the EGSM900, so assuming GSM900 is operating in the OP's geographical area, then shutting down some of the 900 band should not be the issue.

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#3304656 3-Nov-2024 09:03

RunningMan:

Spec sheet is here.

Frequency Receive Transmit

EGSM900 925 ～ 960MHz 880 ～ 915MHz

Excuse the formatting, but that says it supports the entire EGSM band which includes the original GSM band, not just the additional 10MHz at the bottom of the send and receive spectrum.

I think GSM 900 uses 890-915MHz to send information and 935-960MHz to receive and EGSM uses 880-915 MHz and 925-960MHz.

Essentially, the SIM800l covers the entire GSM900 band + the extra 10MHz of the EGSM900, so assuming GSM900 is operating in the OP's geographical area, then shutting down some of the 900 band should not be the issue.

@RunningMan Correct if it supports the complete band then the issue is 100% something else

Hwale

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#3304663 3-Nov-2024 09:11

RunningMan:

Spec sheet is here.

Frequency Receive Transmit

EGSM900 925 ～ 960MHz 880 ～ 915MHz

Excuse the formatting, but that says it supports the entire EGSM band which includes the original GSM band, not just the additional 10MHz at the bottom of the send and receive spectrum.

I think GSM 900 uses 890-915MHz to send information and 935-960MHz to receive and EGSM uses 880-915 MHz and 925-960MHz.

Essentially, the SIM800l covers the entire GSM900 band + the extra 10MHz of the EGSM900, so assuming GSM900 is operating in the OP's geographical area, then shutting down some of the 900 band should not be the issue.

Good point and I think you're right. I took Linux's word on this because he says he has 17 years experience.....

EGSM900 is PGSM900 (primary GSM900, now deprecated) extended at both ends. So the SIM800 should have no trouble.

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#3304664 3-Nov-2024 09:19

I could be incorrect I only saw EGSM at a quick glance but network changes 99% of the time are done early hours of the morning

I will have further information this week about any changes done in the 900Mhz spectrum

Was the IMEI range of these devices blacklisted? I would be surprised if it was

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#3304665 3-Nov-2024 09:26

Hwale: [snip] EGSM900 is PGSM900 (primary GSM900, now deprecated) extended at both ends.

Not quite. It's only extended at the lower end by 10MHz on each of the send and receive bands. Either way, EGSM is a superset of GSM, not an entirely different band.

Bear in mind that module doesn't just operate on 900MHz, it's got 3 other bands too, hence why it would have been good to have the historical data as to what it was connecting to up until recently.

RunningMan

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#3304666 3-Nov-2024 09:27

For completeness, the full operating frequency table from the spec sheet:

Frequency. Receive Transmit
GSM850 869 ～ 894MHz 824 ～ 849MHz
EGSM900 925 ～ 960MHz 880 ～ 915MHz
DCS1800 1805 ～ 1880MHz 1710 ～ 1785MHz
PCS1900 1930 ～ 1990MHz 1850 ～ 1910MHz

Hwale

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#3305341 4-Nov-2024 22:12

So OneNZ must have kicked off a bunch of SIMs being used in non-approved devices because both the SIMs worked in the modules again after re-registering them using a handset. I've never had to do this before. Odd that they were both 'de-registered' at the same time.

I'm now wondering how long until I have to do this again, or if this was some kind of error.

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#3305342 4-Nov-2024 22:14

What do you mean "de-registered"? What did you have to do to get it working again? Did they keep the same number as before?

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Hwale

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#3305343 4-Nov-2024 22:24

Neither SIM would connect to the network in the SIM800 modules, all AT commands would return a network available, adequate signal strength, everything working fine but the SIM would just never register, i.e. AT+CREG? would always return 0,0.

Putting the SIM in a mobile and selecting 2G would result in an automatic connection after a short delay - the SIM would immediately work again in the SIM800 module afterwards.

The fact that both SIMs disconnected permanently from the network at the same time several days ago before requiring this process to 're-register' them suggests this was something done on the network provider's end on the morning of the 30th.

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#3305454 5-Nov-2024 09:03

I haven't read the previous thread, so I'm just going to ask here - what troubleshooting steps did you actually undertake?

Did you power cycle the devices, or reseat the SIM cards to see if that resolved, prior to putting them in a 2G mobile?

Anything I say is the ramblings of an ill informed, opinionated so-and-so, and not representative of any of my past, present or future employers, and is also probably best disregarded.

Hwale

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#3305752 5-Nov-2024 23:38

toejam316:

I haven't read the previous thread, so I'm just going to ask here - what troubleshooting steps did you actually undertake?

Did you power cycle the devices, or reseat the SIM cards to see if that resolved, prior to putting them in a 2G mobile?

Probably everything you can think of including power cycles, re-seating the SIM, various diagnostic tests with the modules via AT commands etc. By the time I got to testing the second module the first one was working again and I kind of suspected what had fixed it so I did all the tests on the second module before re-connecting the SIM with a handset and sure enough it worked.

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