serpens

I need to plead ignorance here; I'm not familiar with the jargon and I'm afraid of miscommunication. When I said I had used it overseas, I meant that I had had an eSIM (Airalo, in my case) and that I made local calls to USA using what I understood to be IMS (not connected to hotel or other Wi-Fi but still able to make a call using a physical SIM that had no roaming partner in the area). If there is something more to it, I must ask for a pointer to a web page I can try to understand.

Wikipedia is my go-to reference, but it didn't return anything for Dual SIM Dual Standby. It had Dual SIM Standby (one SIM active at a time) and Dual SIM Dual Active (both SIMs receiving calls), but neither seemed to be what we're discussing. It also didn't have IMS. Usually it serves me well, but not in this case.

Based on having used a Consumer Cellular SIM with no overseas service to make a phone call to USA with no Wi-Fi connection (but with an Airalo SIM with local non-voice service), I assumed I could accomplish the same thing with US Mobile.

TGarza

The iPhone SE 2020 is dual sim dual standby see discussion on the Apple forum. This model supports one physical sim and one esim. The 2022 SE supports 2 active esims.

draver

Thank you TGarza.

I think the confusion lies in the fact that the dual sim, dual standby became active on TWO ESIMS with the 2021 model iPhones. I believe the IMS function actually was available around 2019 or so with iOS 13. My first dual sim phone was the iPhone XR from late 2018. I was able to install an esim in Dec. that year in addition to the SIM card.
Initially there was a lot of speculation about setup and requirements for this to function. I found some notes on another forum from Jan. 2020 I made for this setup.

Anyhoo, I’m still satisfied that the US Mobile $10 “Warp” line is well worth the money for traveling. Having a worldwide voice line available for calling while keeping the cheap or included data roaming in place is awesome. And having a second network with voice & 2Gb of data easily justifies the cost for me while in the US. Great customer support is also present, with the reps active on the Reddit US Mobile subforum.

serpens

Thank you for the confirmation and the citation. However...

The answer on the Apple discussion page you cited appears not to answer the asked question. In particular, the technical specifications page does not seem to be for the SE 2nd generation. (The image has a discrepancy when I compare it to my iPhone SE 2, and when I finally located an Apple tech spec page for the iPhone SE 2, it was not the same page.) Also, the terminology is not consistent, with a question about dual standby network and an answer about Dual SIM Dual Standby, with a reference to a page about Using Dual SIM with an eSIM (that mentions neither dual standby network nor Dual SIM Dual Standby). This might be clear to those in the know, but it serves to confuse me.

What convinced me that my phone will perform as desired is past history (as I said earlier, I used a pSIM and an eSIM to make calls from overseas to USA in a manner consistent with descriptions of IMS) and the previews from the Wikipedia article that indicate that iPhone XR and XS (the article cited in the answer to the question and another article both refer to XR or XS or newer, although that second article does not clearly apply) are 12th generation and the iPhone SE 2 is 13th generation.

In any event, thank you TGarza and draver for your help.

freecia

2022 SE is one physical sim and one esim which supports 5G and two active sims. 2020 supports up to LTE.
https://www.gsmarena.com/apple_iphon...022)-11410.php

Tiny but important distinction for those looking to get pSIM capable iPhone in the US as US models stopped offering a pSim from the iPhone 14 onwards. My main US Mobile Warp/Verizon sim is an esim but I have a pool GSM T Mobile psim which I could also use in other phones. The sim packet is inexpensive on Amazon.

They've been working on a "Network Bounce" self service transfer number between networks feature https://www.reddit.com/r/USMobile/co...our_attention/
and enabling native roaming voice + sms, no data, on Warp esims internationally
https://www.reddit.com/r/USMobile/co...aming_updates/
https://www.reddit.com/r/USMobile/co...t=share_button
Feature may be enabled in April https://www.reddit.com/r/USMobile/co...rap_5g_native/ but they do like to have teaser announcements so actual delivery may vary.

If they come through with Warp 5G esim international roaming with voice + sms, I probably would opt to just use my main Warp eSim and get my own data only travel esim. I've read there is battery drain when using Warp internationally since it keeps searching for signal but perhaps a setting was missed https://www.reddit.com/r/USMobile/co...cellular_data/

I want to be able to receive sms internationally. Many 2FA sms use short codes and some local travel apps/wifi portals require a phone number or e-mail (which requires internet access to receive said e-mail). That info mining/meh privacy is also why a second phone number and Apple hide my email iCloud subscription feature comes in handy.

TGarza

The SE 2022 has a pSIM tray but US cell companies shipped and activated the phones eSIM only. The 2022 SE can use 2 eSIMs without requiring a pSIM. This was a feature many users requested since the previous iPhones could have several eSIMs but only 1 active eSIM.

Apple confirms 2 active eSMs iPhone 13, SE 2022 and newer

freecia

The eSIM + eSIM dual is definitely news to me! Happened to have purchased one last year. I activated it, carrier locked, with a Verizon MVNO pSIM. Waited for unlock, tested with a T-Mo MVNO pSIM, and currently maintain service on an AT&T MVNO eSIM. Specs page lists both combinations https://www.apple.com/iphone-se/
Makes sense as that follows the international sku sim setups like iPhone 15 offered in JP https://www.apple.com/jp/iphone-15/specs/

Non-US iPhone 15's might need to run through a Verizon IMEI check before trying to activate a USM Warp/Verizon eSIM https://www.reddit.com/r/USMobile/co..._global_model/

BigFlyer

Now that US Mobile is offering roaming do you have to get them to turn off roaming on your line, as IMS is dependent on the SIM for calls not roaming.

Also, have you ever tried IMS using a T-mobile SIM with roaming turned off? There is a setting online that supposedly blocks all roaming.

draver

I am on a Warp/Verizon Shared Data plan (@$10 mo.) that does not have international roaming included. It has no option for data roaming, so the basic plan cannot roam. Therefore it defaults to “Using Cellular Data” with or without data roaming On or OFF. A minor consideration is, you can only get the IMS feature with WiFi calling enabled. That can only be enabled while in the US. If it falls off due to a carrier fault or reset, you will lose the feature until you are back in the States to reset it. I chatted with support and asked if a US based VPN could be used, and he was unsure if it would connect to set that up. They did however enable my WiFi calling remotely for my Warp line once, so if you ask nicely it is possible.

draver

That is a good question about the T-Mobile website switch regarding a roaming block. Here is what the ON/OFF switch labeling describes. The switch appears in the TM web app under: Account-Profile-International, then individual line.

“Block International Roaming (including Charged International Roaming)

Blocks International Roaming for the selected line, except when in Canada and Mexico. If you select this service you will no longer be able to call, text or use data for these lines while roaming internationally; Canada and Mexico excluded. You can use Wi-Fi for calls and text; additional charges may apply.

Charges will include taxes and fees for customers on tax inclusive rate plans.”

This sounds like it could be a shortcut for IMS setup by eliminating the hunt for non roaming voice line carriers. I would test this, but I will not be at a roaming location for the next 10 days, then back to the US.

draver

I actually have been able to test the “Block International Roaming” switch today when in the Bahamas. This did activate IMS service and it’s simulated WiFi on my voice line for free US calling. Texting was reliable on the voice line also. This eliminates the non roaming carrier hunt to trigger “Using Cellular Data”.

I plan on posting a summary of my experiments in a single post for those interested in free US number voice service with native Dual Sim, Dual Standby phones. A US Mobile line will give free voice calling to international numbers while roaming on dual sim phones. Also, those on T-Mobile should be able to easily set up their dual sim phones for free calling to & from US numbers while roaming.

docbert

Given that US Mobile have dropped their $5 plan (cheapest now is $10 unless you want to sign up for a year), another option would be https://hellomobile.com/ who have a $5 unlimited minutes/txt (including some interational), 500MB plan. I haven't tried them as I'm still grandfathered on the US Mobile $5 plan, but they are on T-Mobile so things should work pretty much exactly the same as the US Mobile GSM5G plans.

BigFlyer

I just did a quick look at the Hello Mobile website - and see no reference to wifi calling. I believe wifi calling is a prerequisite for IMS to work.

sobore

I have US Mobile on my travel phone, all works great within the US. Since I am on the light plan, I believe there is no international roaming natively on this plan.
I assume when I leave the US, I would not have any service? Again, this is using the phone as-is, no ESIM.
Thanks.

docbert

Correct - except for if you enable Wifi calling, in which case you'll get full service when you're connected to (most) wifi networks.