I’ve been using virtualization on my notebook and in the cloud for many years now on a daily basis and as all of it has so far been on x86 based platforms so I was a bit surprised when I read about Virtualization on ARM last year in this Ericsson research paper. On second thought I should not have been, though, as virtualization is obviously a generic concept not tied to a specific processor architecture.
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The Day The Routers Died
758k views and a decade later I must be one of the few who have not yet seen and heard the video of the song about “The Day The Routers Died” from the RIPE 55 meeting back in 2007. Back then, public IPv4 address depletion was already a big topic and sets the state for the song. If you also haven’t seen it yet, head over and cheer up!
The Digital Divide Starts in Rennes
When I recently traveled on a high speed train in France to the coast I experienced what the ‘digital divide’ really means. For the first one and a half hours of the trip on the 350 km long TGV line from Paris to Rennes, LTE coverage along the route was excellent. I don’t know if the train had on-board RF signal repeaters but since the signal was usually excellent I suspect so. Not only was the signal coverage good but I also managed to get quite some work done with web based services at 300 km/h. Upload and Download data rates were in the region of several megabits a second and I didn’t notice coverage holes that would have impeded with my work. That’s how it should be.
Where Did those 50 GB Go On My Backup Drive?
When recently an rsync backup failed due to a full destination drive I had a closer look at the ext4 formatted partition and noticed that despite the disk being reported as full, 50 GB were unused. While this was not the reason for rsync to fail, I nevertheless wanted the 50 GB back.
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How Does An LTE eNB Signal A Co-Located 5G Cell?
In the previous post I looked at 3GPP TS 23.401 and how the UE, the RAN and the LTE core network signal their 5G capabilities. TS 23.401 states that the LTE eNodeB signals a locally connected 5G gNB to the UE. But how does it actually do that?
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LTE Core Network Enhancements for 5G EN-DC
In many cases 5G will come to smartphones, tablets and other devices in the form of 4G-5G dual-connectivity, also referred to as EN-DC (E-UTRAN New Radio – Dual Connectivity). While the mobile is in Idle state it will camp on a 4G LTE cell. A 5G NR cell is only added by the network once the device enters the RRC Connected state. Interesting conundrums that now present itself are for example if and how the mobile device can indicate to the user that it is ‘connected’ to 5G even while in Idle state and thus only really connected to a 4G cell!? Also, how does an LTE eNodeB know whether a 5G NR cell should be added when a mobile transfers to RRC connected state!? After all, network operators could decide that not all of their subscribers should have access to 5G. These problems do not exist today as the situation that a device talks to more than just one RAT (Radio Access Technology) is new. Some answers can now be found in the LTE core network specification 3GPP TS 23.401.
IoT Failures With Network Impact
With hundreds of thousands of IoT devices in mobile networks it seems that every now and then, bad behavior in failure scenarios on the application level leads to, well lets say, interesting behaviors on the network layer. While most network operators keep such incidents to themselves, Annex A of GSMA TS.34 (IoT Connectivity Guidelines about which I’ve already written here) contains a number of interesting scenarios that mobile network operators have been willing to share with IoT implementors in the hope that they think a bit before deploying their devices.
Dual Boot: Ubuntu and Windows 10 + Bitlocker
When I recently got a new notebook on which I had to have a Windows 10 partition I had a bit of a fun time to make an Ubuntu / Windows 10 Dual Boot system out of it because Bitlocker wasn’t really happy about the change in the boot sequence. As I took quite some precautions before installing Ubuntu alongside Windows, I was able to wiggle out of the situation. Read on for a fun story how how to get dual boot right.
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Book Review – Isaac Asimov – The Caves of Steel
After reading ‘Ready Player One’, a science fiction novel written not long ago, playing in the near future I thought I’d pick up something entirely different and have a look at a classic science fiction crime story, Isaac Asimov’s ‘The Caves of Steel’. Written in the 1950s and playing in the distant future, the contrast to today’s science fiction is remarkable, striking, interesting and fun while the the issues underlying the plot could just be out of today’s world as well!
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eCall over IMS
This month an EU directive that seems to have been in the making for a decade will finally come into effect and require all new cars and trucks in the EU to embed an emergency call device that automatically calls an emergency call center when it senses a crash. Basically, the technology is based on stone age circuit switched voice telephony and consequently, crash information, location data and other stuff is sent in-band in the speech channel. For an introduction, have a look at this post I wrote two years ago.
To be prepared (perhaps in 10 years time <sarcasm off>) an IMS based eCall solution has now been specified in 3GPP Release 14 which will allow the migration towards something a bit more modern, at least from today’s point of view once circuit switched voice is no longer available in mobile networks.