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One interesting thing that eSIMs enable is geographical arbitrage by the carriers. When I was visiting South Korea last year, the (cheap enough) eSIM I got fro
by klausa 3y ago
One interesting thing that eSIMs enable is geographical arbitrage by the carriers.
When I was visiting South Korea last year, the (cheap enough) eSIM I got from one of those "buy sims for your travel!" services was actually from a carrier from Hong Kong.
Similarly, when I visited Japan this year, the eSIM I got was from a South Korean carrier.
Can't do that if you need a physical SIM!
- dzhiurgis 3y ago“Wifi calling” is pretty cool if your operator supports and you got 2 sims.
- hattmall 3y agoCan you explain what you mean by this?
- lozenge 3y agoWifi calling sends calls (sent and received) over the Internet as UDP packets. So you can call somebody in your home country using your home country SIM, but the data is actually using your holiday SIM's data allowance. As roaming and "international" rates are crazy.
- NoZebra120vClip 3y agoJust to clarify: WiFi calling uses an 802.11 connection nearby, instead of a cell tower, and sends UDP packets over the WiFi network. (I don't know how far they transit the Internet; I assumed that they went to your mobile provider and entered the PSTN there.) https://en.wikipedia.org/wiki/Generic_Access_Network https://en.wikipedia.org/wiki/Generic_Access_Network In this scenario, your "home country SIM" is providing you a phone number and provider's authorization to activate and use WiFi calling, but your voice calls aren't actually using the SIM or a cell tower. Neither is your "holiday SIM" using data for this call: you're free to use that data allowance for browsing, streaming, general Internet use; it won't be taken up by phone calls.
- fatfingerd 3y agoIt's not really just WIFI calling. A data network and a WiFi network are all the same to a UDP packet and your phone can have settings to prefer one or the other so that you can use the data plan you want as if the WIFI were setup.
- hx833001 3y agoYeah, an iPhone will use a secondary esim data connection to route “wifi” calls while abroad.
- joecool1029 3y agoHaving wifi calling on your home carrier means you can use the data of a cheap international carrier while you're traveling to make calls with your home carrier and not incur roaming charges. This is because your home carrier basically VPN's to your home carrier's network over whatever data connection it has, so it's just using the cheap international data off the second card to make a VOIP call.
- smallerfish 3y agoActually you can. My "published" phone number is parked at a voip firm, and I get calls on that number over data (fairly few real ones, since my friends tend to mostly use whatsapp to arrange social stuff.) When I travel, I buy a 25GB-for-a-month physical sim from 3UK, sold on the US Amazon site. The only downside is that you can't top up the data using the same pricing unless you're physically in the UK, so I have to get a new sim each trip.
- daveoc64 3y agoThis is actually quite common with physical SIMs aimed at travellers or those where multi-country or multi-network support is required. A company will partner with a carrier in country X that has roaming agreements with carriers all over the world.