Author: Martin

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?

Continue reading 5G – How Much Spectrum Do You Need To Make A Difference?

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

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?

Continue reading 5G EN-DC – Split Bearer In Downlink Only

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?

I’ve been running LineageOS on a Samsung Galaxy S9 for a few weeks now and I have come away very impressed indeed. Actually I have only found three issues since I’ve started using it.

Continue reading A Cross-Decade Comparison: The Nokia N95 vs. the Samsung S9

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’.

Continue reading Book Review: The Time Machine

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.

Continue reading LineageOS on a Samsung Galaxy S9

The weekend is almost over and before I board the train back to Cologne, I thought I’ll do a quick post on my talk about the history of mobile networks and mobile data communication in the past 30 years at the Vintage Computer Festival Berlin this year.

Continue reading My Talk About Mobile History @ VCFB 2018

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.

Continue reading At the VCFB This Wekkend!