When will RW support Samsung S9 on CDMA network?

I want to upgrade my old RW Moto X1 to a new Samsung S9, but I live in a poor cell service area for all 4 national networks. Several visitors with T-Mobile service have reported no connectivity, but Sprint at least delivers 1 bar and can provide emergency cell service when my WiFi is offline due to power failures or other technical issues. Since RW already supports the S8 on both CDMA and GSM, and the S9 also supports both CDMA and GSM, why the delay? I won’t upgrade to the S9 until RW supports it for CDMA.

Hi @ericf.p52ay1,

Thanks for your interest in upgrading and staying with Republic Wireless! The delay is due to emerging technology that requires yet another type of SIM card. The SIM cards we are currently able to provide are not compatible with the S9 for Republic service on Sprint’s network.

We are diligently working with all the parties involved to bring this new SIM card into production. Although I do not have any sort of estimated date of availibility, if you’d like, I’ll make a note to follow up with you just as soon as it is available.

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Interesting that the S9 is technically that different from the S8, yet 1) the S9 still supports RW’s current GSM SIM, and 2) both of the national CDMA Network Operators currently provide SIMs that work on an unlocked S9.

I’m eager to upgrade to the S9. While I won’t hold my breath, I would very much appreciate a follow-up when it’s finally available for CDMA. Many thanks.

Just in case you want the background:
GSM SIMs have been the same for quite a while. In the meantime, SIMs for LTE on CDMA networks have been evolving, largely with the goal of making CDMA activations more like GSM activations. By name, these evolutions have been CSIM, ISIM and now SIMOTA. Republic doesn’t take just the carrier SIM and slap their logo on it, there is actually some secret sauce, involving the SIM, that is part of Republic’s blending of the VoIP Bandwidth network and the carrier partner. Because of this, it isn’t as simple as the phone supporting the SIM type, Republic needs to work with the partner when the new SIM type comes out to make the secret sauce work.


As a software CTO, I appreciate technology and thank you for the detailed explanation. I’m going to do some digging into the differences between CSIM, ISIM, and SIMOTA.

Frankly, I would prefer a GSM solution to a CDMA one if signal coverage weren’t a roadblock. Perhaps the GSM SIM’s coverage in the S9 unit will be sufficient here, but I’m reluctant to make that bet until falling back to the known CDMA coverage becomes an available option.

As technology, I’ve always preferred GSM to CDMA. BY design, GSM has always supported the concept of unlocked phones and moving service among phones by moving a SIM. CDMA originally didn’t account for unlocked phones and ties service to the phone itself. CDMA didn’t even use SIMs until the emergence of 4G LTE (which is arguably an evolution of GSM rather than CDMA). CSIM was the first effort and still ties service to the phone. Likewise ISIM ties service to the phone but accounts for VoLTE. SIMOTA appears to be an attempt to make CDMA more GSM like in not tying service to the phone but we shall see.

Meanwhile, you might consider acquisition of a far less expensive Republic compatible GSM phone and try a Republic GSM SIM as a test. Alternatively, if you have access to pretty much any unlocked GSM phone, you might acquire a SIM form Republic’s GSM partner directly to test that network’s coverage in your area.

I’ve already tried visitors’ lesser T-Mobile phones here and received little or no signal strength. Perhaps the S9’s radio circuitry is enough better that it will be able to work with the weak T-Mobile signal, but that’s an expensive experiment. That’s why I’m unwilling to move forward with an S9 purchase until the CDMA option becomes available.


Unless the phone you used didn’t have access to Band 12 or you happen to be in an area where B71 is deployed, the S9 won’t really improve coverage.


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