SIM7600G-H Module and Optus/Testra 3G closure

Hi,

I purchased the “Global” version of the SIM7600 from here a little while ago, in anticipation of the 3G shutdown.

The dates are now firm - Telstra by the end of June this year, followed by Optus in September.

I am with Optus, and despite using this module, they are frequently sending me emails saying “I have a device that may be affected by the shutdown”. This is ramping up now.

I only use the module for alarm system control using SMS - no Voice (which requires VoLTE be set up for the device to be supported), so am wondering if the unit will continue to function after June/September.

Has anyone got any experience with this and the upcoming closures?

I am sending sms using the basic commands (AT+CMGS etc), and not creating any deliberate data connections. I can confirm the device uses Optus B28, which will be required after September, but I am not explicitly configuring the device to force use it.

SMS functionality is typically not affected by network shutdowns, as SMS operates on the control channel of the network. Your alarm system should still be able to send and receive SMS messages even after the 3G shutdown.

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We purchased the same and are getting the same notification from Optus. We use it for data and SMS. Will we really be affected?

Hi there,

From September 2024, we’ll be switching off our 3G network. We’re reaching out as we’ve determined that your business has one or more impacted devices that relies on 3G, which will either stop working or will have significantly reduced coverage from this date.

This includes the inability to:

Make calls
Make emergency calls to Triple Zero (000) on the Optus network
Send or receive messages
Use data or connect to the internet

Hi @Huda213747 , welcome to the forums!

Similar to what @lia262073 has said, I think this should be ok. The SIM7600G-H communication module seems to support both 3G and 4G, so that message should be taken from more of a ‘you may need to upgrade your device’ standpoint.

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Optus seem to know the exact phone numbers affected here tho - one is our router with backup (big deal - i’ll upgrade), the other is the SIM module. The router occasionally sends me SMS’s - wondering if this will also break.

Does anyone know how Optus are working out whether they “suspect” your device will be impacted? A big part of 4G is that calls will now happen over Voice over LTE (VoLTE) - perhaps they have a way to try and make a call to your device, and see if it rings, or is negotiated somehow.

I have not set up any VoLTE functionality on the SIMCOM - its probably a pain in the arse to do, requires setting up a TCP/IP stack and other shenanigans - curious if there are any Optus Insiders who know more on the test being conducted here.

Given that the exact band shutdown for both networks is 850 and 900 mhz, is there a command to tell the module to stop using these as an early test?

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So… Digging a little deeper as a preventative measure…

I’ve looked at the SIMCOM 7600 manual, other forums suggest setting CNMP=38 to use LTE only - so i’ve added this to my init string.

It was previously set to 2 (Auto).

Other settings from the manual:

Will see if this stops Optus bugging me (I suspect not).

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That’s a deep dive @Mal56281 and i’m sure the community will appreciate hearing about your response.

As for whether Optus get the message - I suspect their system does a match for certain profiles of SIM card + plan that you originally subscribed to.

If any layer would become affected it is likely you will receive the alerts, regardless of whether you’ve disabled that function as the end user.

I think you’ve made the right move switching to LTE only and am curious to see how things go after the cutover. One would expect you should have a graceful swap over and it sounds like you’re already operational on LTE… I guess time will tell.

Thanks for taking the time to document the proactive countermeasures you took. These SIM7600 tech issues can get quite esoteric so it’s really valuable to the community.

Best of luck, please keep us updated.

One week left to shutdown (unless extended even more). Getting excited :wink:

Reviving the thread in anticipation!

I’ve had some early “scares” in the last few weeks - the module appeared to completely stop sending/receiving sms a few times around 7-8pm, but a quick check between regular mobile phones showed it was actually Optus that seemed to be “fiddling”, and had completely broken SMS for a few hours each time (Telstra still worked).

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Great time to revive this thread. I’m sure there will be some people caught off guard next week.

Hello everyone,

I am working with the SIM7600G-H module on a Raspberry Pi 4 and facing issues connecting to the internet using Jio and Vi SIM cards. However, when I use an Airtel SIM, the internet works perfectly fine.

What I Have Tried:
Changed network mode to LTE-only and GSM-only.
Adjusted settings like pidswitch and lanmode.
Tested multiple Jio and Vi SIM cards.
Tried different locations to rule out network coverage issues.

Despite these efforts, I am unable to get internet access with Jio or Vi SIMs. If anyone has successfully configured the SIM7600G-H module to work with these networks, please share your insights or solutions.

Any help would be greatly appreciated! Thanks in advance.

Hi @Krishna288965

Welcome to the forum!

Potentially those service providers only support a certain band in your area, you may need to set a specific band to be used by the unit.