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?
Continue reading How Does An LTE eNB Signal A Co-Located 5G Cell?
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.
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.
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.
Continue reading Dual Boot: Ubuntu and Windows 10 + Bitlocker
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!
Continue reading Book Review – Isaac Asimov – The Caves of Steel
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.
From 2011 to 2013 I provided Wifi Internet connectivity with backhaul over LTE or 3G at quite a number of meetings for 50 to 100 people in hotels (see my reports from back then here and here). In those days the hotel Wifi networks could often not handle the load and the number of Wifi devices and at some point would simply crash or run out of DHCP leases. At some point things improved somewhat so I no longer had to do this. Recently, however, I hosted a meeting myself at a location where I was not quite certain that the in-house network would meet my expectations so I decided to provide Internet connectivity myself again. Things went very well and it was quite interesting to see the differences to 5 years ago.
Continue reading Providing Internet Connectivity To A Meeting Over LTE Backhaul
I take my personal privacy seriously which is why I like open source software and hosting my own servers at home. When I recently used Outlook (for work, non-personal…), I noticed that when a search for a specific email came up empty handed the following text was shown: ‘We didn’t find anything to show here.‘ I find such a response rather creepy because who is ‘We’? I always thought the software on the computer or the server was doing the search but ‘we’ is plural…
Even in the first version of the LTE standards (3GPP Release 8) the specs contained a device category referred to as Category-1 (CAT-1). This category was envisioned for computationally restricted devices with a maximum throughput of 10 Mbit/s. This was little compared to CAT-3 devices which was the lowest class used for smartphones, tables, USB dongles, etc. that had to support a downlink throughput of 100 Mbit/s. Nothing ever came of Cat-1 until a few years ago, when some manufacturers started producing wearable such as watches, i.e. very small devices with small batteries and little space for advanced LTE features.
Even before I started reading Artemis, I listened to an interview of Andy Weir who recommended ‘Ready Player One’ by Ernest Klein as a must read. Spielberg must have thought so, too, because he’s doing a movie on the book which is coming out this April. But I’m not a great fan of movie adaptations, too much good stuff has to be left out which I thought was another good reason to read the book right now. The story is about a dystopian future, not one of my favorites topic to read about, about computer games, also not my favorite topic, I’m not a gamer, and about the 1980s – now we start talking! So despite some skepticism and a lot speaking against it I started reading… Continue reading Book Review: Ready Player One