5G EN-DC – Split Bearer In Downlink Only

In most situations the limiting factor when transmitting data over the air between a mobile device and a network is the uplink transmission power of the mobile device. In practice that means that when the mobile device is unable to increase its transmission power any further, it can still focus the transmission power on a narrower 4G channel and thus increase its range. But how will this work in early 5G networks that will use the dual connectivity (EN-DC) approach in which data can flow over 4G and 5G simultaneously?

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Evolution of International Roaming Prices

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.

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Book Review: The Time Machine

I like to read literary classics every now and then but recently, I’ve been somewhat hindered by Project Gutenberg completely blocking German visitors after a German court has ruled that they must not make certain works available in Germany. Shame on the S. Fisher publishing house and I will certainly never buy anything from them again.

In any case, there are ways around the embargo, so when a short vacation came up, I made good use of the platform and downloaded a couple of books, including H. G. Wells’s ‘The Time Machine’.

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LineageOS on a Samsung Galaxy S9

Over the years, I’ve used LineageOS and its predecessor CyanogenMod on my personal devices such as the Samsung Galaxy S4 and, for the past few years, on the Samsung S5. But my S5 is aging so I was looking for a replacement. There is a LineageOS port for the Galaxy S6 but it seems to be quite experimental, I kept having power drain issues due to some system task starting to run wild after a few days. There’s also a version for the Galaxy S7 which is already kind of hard to get on the market but a version for the S8 is missing. The more surprised I was to see that there is a version for the relatively recent Galaxy S9.

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At the VCFB This Wekkend!


While I’m typing this I’m sitting in the train from Cologne to Berlin, on my way to this year’s Vintage Computer Festival Berlin (VCFB). It’s beautiful sunny weather, unlike last year, when an autumn storm turned my train trip into a nightmare.

Like last year, I have brought a little exhibit with me again, this time about GEOS, a graphical user interface for the masses that was very popular in the second half of the 1980s. In addition, I’ve spent the last few weeks collecting my thoughts and pictures about the evolution of wireless networks and mobile data communication in the past decades. I will present the result in a 90 minute talk tomorrow, Saturday, 12 October. The talk will be recorded and perhaps also live streamed in case you are interested. I intend to hold the talk in German but there will surely opportunities in the future to record an English version as well.

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Android Opens Links With GPS Coordinates in Osmand

Open with OsmandSometimes it is just a lot more convenient to do a map search on the PC rather than on the phone. Nevertheless I still want to have the result in Osmand (OpenStreetMap for Android) on my smartphone for later use, e.g. for car navigation. So my approach so far was to first search the location on the PC and once I knew where it is I would manually locate and bookmark it on the smartphone again. Far from ideal… However, I just found out a much simpler way to do this by accident:

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Backbone Bottlenecks

backbone congestionAfter upgrading to VDSL vectoring with a 100 Mbit/s downlink and 40 Mbit/s uplink in Cologne recently, I soon figured out what to do with the additional uplink speed: Advanced synchronization with my network behind a fiber line in Paris. Equally soon I noticed that no longer is my access link the bottleneck but rather under-dimensioned backbone links. So I had to find a way to creatively route my traffic around the problem.

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