Month: November 2018

Back in the mid 1980’s I’ve visited my uncle at the ETH Zürich and I still remember what he showed to me that day: A Cray-1 supercomputer. There I was, a teenager with a Commodore 64 at home standing right next to one of the fastest computers on earth at the time. The very fact that I still remember the visit is a strong indication that it had a long lasting effect on me and certainly influenced my future. Now, 30 years later, I thought it was time to revisit this piece of my past and learn a bit more about it.

Continue reading Book Review: The Supermen – The Story of Seymour Cray

I’m using OpenVPN for many years now and while in the past the uplink speed of my DSL connection at home was the limiting  factor when it came to throughput, this might not be the case anymore. I was therefore keen to check if my current OpenVPN setup in a virtual machine on an Intel i3 based server can still handle the theoretical maximum throughput of 35-40 Mbit/s, which is the uplink speed of my vectorized VDSL line.

Continue reading OpenVPN Throughput Revisited

While in Europe, most network operators have the 3.x GHz band in mind when thinking about 5G deployments. Some network operators in the US, however, want to launch 5G in the mmWave bands in the 20-50 GHz range. So how will antennas in mobile devices look like for these bands?

Continue reading 5G – How do mmWave Antennas Look Like?

Once upon a time, it was still necessary to tweak a number of init files and the .htaccess file in the Owncloud/Nextcloud folder to increase the maximum file size the system would handle beyond the default, which is just a few hundred MB. But it looks like the manual tweaking is not necessary anymore.

Continue reading Increasing Nextcloud’s File Size Limit

Back in 2014 I noticed for the first time that different devices charge at different rates on the same charger. At the time I had a Samsung charger that could supply 5 V and 2 A and even then, devices such as the Samsung Galaxy S4 made good use of it by drawing 1.6 A. A bit down the road, a new device I bought came with a power adapter that could either supply 2 A at 5 V or 1,67 A at 9 V. So do devices I have actually make use of this?

Continue reading Power Charging Investigations

10 years ago, most people would have deduced from the headline of this post that I would probably want to talk about prices for voice calls while roaming. Today in 2018, I’m pretty sure most people will think about Internet access first. And indeed, I am in the US at the moment and I have noticed that my German network operator of choice has a new data roaming offer for North America that goes beyond what was available so far. This inspired me to have a look at how things have evolved over the past decade.

Continue reading Evolution of International Roaming Prices

Every now and then I get the question why virtually all network operators that want to offer 5G mobile service go for the non-standalone setup first that requires LTE as the anchor instead of going directly to a standalone setup. There are a number of reasons for this but I guess that spectrum availability is the main reason.

Continue reading Why Not Standalone 5G From The Beginning?