Roaming Report – Part 4 – When the SIM card talks to the Internet

Here’s a quick follow-up to my recent blog post on using an eSIM when roaming in the US: After I installed the eSIM, I noticed with my trace tools that whenever my smartphone connected to an LTE network, the phone would, in addition to the LTE PDU session for Internet connectivity, request another PDU session with another APN (Access Point Name). This was not configured anywhere in the device. The PDU session just lived for a few seconds and was then terminated again. I was a bit puzzled at first but soon had a suspect… the SIM card.

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Roaming Report – Part 3 – Airalo – 5 Minutes to the eSIM

After a bit of a disappointing prepaid eSIM (non-) experience directly from US network operators, I switched to plan B and had a look if I could get an eSIM for use in the US from one of the global eSIM roaming platforms. Two years ago, I checked out Airalo when I was roaming in Europe, and was quite happy with the result.

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Roaming Report – Part 2 – Getting a Local US eSIM – How Hard Can it Be?

While I was in the US, I was using my German SIM card to roam through the different networks. When using a German SIM card, however, all IP data traffic goes back from the US to Germany and from there to the Internet. As the servers for my self-hosted services are in Europe, that’s not much of a problem. However, I also wanted to test some of the US specific features / limitations of mobile Internet access, and was prepared to spend some money to get a Prepaid eSIM from one of the US network operators. Prices in the US are significantly higher than in most countries in Europe, but it would not have kept me away. It turned out, however, that getting a prepaid eSIM from US network operators is not straight forward.

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Roaming Report – Part 1 – Roaming with Verizon – A First!

It’s March 2024 and for the first time in 5 years (thank you Covid pandemic), I was in the US again. So far, so good, but there is one significant difference this time, at least from a technical point of view: For the first time ever, I’m roaming with Verizon!

Most travelers won’t even notice, but until recently, Verizon in the US could not be an international roaming partner for most travelers, because their 2G and 3G CDMA networks were incompatible with the majority of international networks. Even with the introduction of LTE, this did not change. This was because for GSM/UMTS/LTE/5G network operators, international roaming depended on the 2G/3G circuit switched voice core and the CS-fallback mechanism from LTE/5G to GSM or UMTS. And this is what Verizon could not offer to international operators. But finally, VoLTE roaming is on the rise and it seems my home operator has made a roaming agreement with Verizon. Agreed, most people use Internet based voice calling apps these days, including me, but VoLTE roaming support in devices and networks is still crucial for emergency calling and calls to people that don’t share the same messenger / calling app.

So here we go, one of those rare ‘firsts’! And as the title indicates, I made good use of my time in North America and had a look at a lot of other things while roaming. So stay tuned for more posts to come!

Sony WF-1000XM5 In-Ear Headset – Review

In my life there is a time before noise cancellation headsets and the time ever since, as noise cancellation has brought so much more silence, peace and concentration when I’m in noisy city, home and office environments. As my current first generation Bose in-ear noise cancellation headset I’ve had for many years are showing signs of battery fatigue and charger connector problems, it was time to look for something new. After shopping around a bit, the two contenders for my refresh where either the latest generation Bose in-ear Bluetooth headset, or the latest Sony variant. In the end, I decided to go for the Sony WF-1000XM5 and I’ve been using them for around 2 weeks now. Was it a good choice? I’m not so sure…

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Some Thoughts on the 6 GHz Band for Wi-Fi and Cellular

Back in December 2023 a number of interesting decisions were made at the World Radio Conference (WRC) in Dubai. One of the most important bands for which a number of decisions were made was the 6 GHz band. Today, spectrum in this band is already used for Wi-Fi, and it is pretty much the only remaining additional spectrum for cellular networks in the next 10 years. The decisions reached for this band make it look like all players took a big gamble.

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Internet Access on Planes in Europe – 2024 Update

In the past two months, I’ve flown form Germany to Spain twice. With a flight time of over 2 hours, it’s actually worthwhile to jump through the hoops and connect to the in-flight Internet over Wifi. I can’t quite believe it, but my last post on in-flight Internet access in Europe is already back from 2018. Yes, Covid got in the way. So let’s have a look at how the system worked for me this time around.

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