When it comes to investigative reporting in the telecommunication domain, German telecoms news website Teltarif certainly is at the forefront. Recently they noticed that the public network coverage maps of one of the network operators in Germany now show that in many cities, they have deployed LTE in three different frequency bands.
Continue reading One German LTE Network Operator Now On-Air with 50 MHz
I’ve been using SSDs for many years now and I’m more than happy as the speed difference on a notebook compared to hard disks is just like day and night. Unfortunately I use a one terabyte Samsung 840 Evo in my notebook that has now bitten me for the second time.
Yes, I’m a comparatively late convert to Open Source as I’ve only installed Linux on a production machine I used for everyday work back in 2009. At the time there wasn’t a lot of discussion about using a 64 bit version of Linux on x86, the mainstream was still on 32 bit at the time. Not a big problem, most computers only came with 2 GB RAM at most so there were only few advantages of using a 64 bit OS if the processor supported it. In the meantime a lot has happened and I decided that it’s time for me to finally make the move.
Recently I read this very interesting post that analyzed how many users can be connected to an LTE eNodeB simultaneously. As the author says in the article there is no single answer to this as many factors are playing into the game. From a pure uplink signaling point of view there can be well over 1000 users simultaneously in RRC-Connected state. In practice I wouldn’t be surprised if networks set that number way lower as that number is far too high to give anyone a halfway decent speed experience. So how many might there be connected simultaneously to a base station today? Let’s play with some numbers.
Continue reading LTE And The Number Of Simultaneously Connected Users
When I first heard about the news of a serious security vulnerability in glibc I thought that I would soon see a lot of programs of my Linux distributions being updated. That’s because I faintly remember that I once read somewhere that in Linux, libraries are often compiled into the application instead of dynamically linked at runtime. But I guess that was not quite true, at least not for glibc anyway. So far I’ve only seen an update of the glibc library itself. Since then no other programs have been updated due to statically linking that library. So if that holds true we might have been luckier than I thought. Would be nice for a change!
Wifi 802.11ac with 80 MHz channels (Wave 1) have been on the market for some time now and high end notebooks and smartphones have started supporting the new standards. I’m still stuck with 802.11n on 5 GHz with 40 MHz channels but I do have an 802.11ac capable access point. So while I can’t use the functionality for the moment with my notebook I decided I could at least have a look at the Access Point’s 802.11ac capabilities by doing a Layer 2 Trace and capturing a Beacon Frame.
When I recently wanted to do a quick Wi-Fi Layer 2 trace on a machine running Ubuntu 15.10 I couldn’t get it working anymore. I was quite surprised because I’ve used this machine many times before for the purpose. Grudgingly I started to investigate…
Continue reading Ubuntu Has Lost It’s Wifi Tracing Capabilities
The Internet of Things (IoT) that some are also calling the “Internet of Targets” is currently one of the hot topics in wireless. One flavor of IoT is Cellular-IoT for devices that for some reason can’t be connected to a local area network and only infrequently transmit small amounts of data.
Continue reading Which Personal Devices Would I Connect To Cellular-IoT?
In a previous post I had a look at the possible downlink speeds of my current WiFi setup at home. The exercise clearly showed that my current 5 GHz WiFi with a 40 MHz channel in combination with an Intel Centrino 6205 card in my notebook and a Fritzbox 7490 VDSL router can easily cope with the 50 MBit/s downlink speed of my current Internet backhaul. In the uplink direction, my current line offers 10 MBit/s so also no problem there. One thing I noticed though when transferring files to a local server was that uplink speeds were nowhere near the speed reached when downloading the same file to the server.
After recently upgrading my VDSL line at home, it was also time to upgrade my Wi-Fi equipment to support the higher speeds. When doing some speed tests after the upgrade I noticed to my satisfaction that my Wi-Fi connectivity now easily supports the 50 MBit/s VDSL line. I also noticed, however that downloading a file from a local web server at 100 MBit/s takes a heavy toll on my CPU, it’s almost completely maxed out. At first I suspected the Wi-Fi driver to cause the high load but I soon found out that Firefox is the actual culprit.
Continue reading Forget About Using Firefox When Testing Network Throughput