If you are interested in how a 5G EN-DC Option 3 connection is set-up between the mobile device and different components in the network the best but also the hardest way is to look up the procedures in a number of different 3GPP specifications. 3GPP TS 37.340 is a good starting point for EN-DC. Another interesting source that I have just discovered is over at EventHelix.com. On the page, there are a number of links to call flow diagrams that aggregate a lot of information from different 3GPP specs and to a blog post with some more details and a video at the end. Interesting stuff!
Windows Subsystem For Linux – Part 2 – Graphical Stuff
In the previous post I’ve been looking at Windows Subsystem For Linux (WSL) being a potential solution of how I could remotely administer and support a Windows box with tools and processes I use for supporting remote Linux machines. As it turned out this works great in practice. So how about using WSL and FOSS tools to do things locally on a Windows box with Linux tools for which there are no tools that I would rate as equivalent?
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Windows Subsystem For Linux – Part 1 – Remote Stuff
While all PCs and notebooks I personally own run on Linux, I can still not totally escape Windows on other machines. Apart from not being FOSS, the other thing that bothers me when I have to use or support a Windows machine is that the tools and programs for local and remote maintenance and backup are entirely different. But perhaps there is hope now… In 2016, Microsoft announced what is now known as the ‘Windows Subsystem for Linux‘ or WSL for short, which emulates a Linux kernel API so Linux binaries can run on Windows as well. Kind of a reverse-Wine. So how well does this work and could I use this to remotely administer Windows boxes in the same way as Linux boxes?
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5G Spectrum For Germany – How Much For Whom?
Speaking about how much spectrum is needed by a network operator to make a difference with 5G, I had a closer look at how the German telco regulator wants to go forward with the auction of spectrum in the 3.6 GHz band. The spectrum auction is scheduled to take place in 2019 and the details about which part of the 3.6 GHz band shall be used for which purpose can be found in German here and in English here.
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Book Review: The Supermen – The Story of Seymour Cray
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.
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OpenVPN Throughput Revisited
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.
5G – How do mmWave Antennas Look Like?
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?
Increasing Nextcloud’s File Size Limit
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.
5G – How Much Spectrum Do You Need To Make A Difference?
The current situation around 5G reminds me a bit of how things were a decade ago when first 4G LTE networks came on air. Network operators in the US launched LTE with 10 MHz of spectrum and overall, their LTE networks where not much faster, if at all, compared to 3G UMTS/HSPA in Europe that could aggregate two 5 MHz carriers. So will things be different now that we are moving from 4G to 5G? Or, in other words, how much spectrum do you need for 5G to make a difference for users?
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Power Charging Investigations
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?