Things That Moved Me In 2016 – Part 1: Networks

Like every year, time has flown and it is already end of December and thus time to look back at what has happened this year that has literally ‘moved’ me. This year I have three categories: Networks, Linux & General computing and Miscellaneous Other Things. Let’s start with a look back at my year in the network section:

LTE – Legacy but Cool!

LTE networks are hardly anything new anymore and in 3GPP, LTE is almost considered ‘legacy technology’ now that a lot of effort is spent on 5G, i.e. ‘New Radio’ and the ‘Next Generation Core Network’. There is not yet too much to report about 5G from a practical point of view, so that’s perhaps something for next year. On the LTE side, however, quite a number of things have happened in practice. In Germany and other countries, many network operators have started to massively deploy Carrier Aggregation. In Germany, for example, one network operator is now on air with 50 MHz.

Getting Into QAM Modulation

One thing that was always a bit blurry to me was how Quadrature Amplitude Modulation (QAM) that is used in LTE and other fixed line and wireless systems can best be described without going too far into the maths. I finally came up with this blog post which I think describes it pretty neatly. Suddenly, the baseband with it’s I and Q inputs and outputs makes a lot more sense.

VoLTE and VoWifi

Moving up the protocol stack, 2016 has definitely been the year of VoLTE and VoWifi. Not because they were brand new, the IMS has been specified for over a decade. However, Voice over LTE has finally made it into live networks on a bigger scale. I’ve had quite a number of posts on the topic over the year, too many to link them here. If you are interested in some of the SIP and bearer details, just search for VoLTE by using the search box in the left sidebar of this website. Voice over Wifi and handover of an ongoing call between LTE and Wifi has also made it into live networks this year (well, already last year in some countries). To me, VoWifi is not only a tremendously useful extension to VoLTE but a general evolution of the traditional mobile network operator voice service to fixed line networks as well. I know the term ‘convergence’ is old and tried but it fits what is happening here.

Delay, Jitter and Loss Experiments

With a suitable Wi-fi access point, VoWifi can also serve as an interesting basis for experiments with delay and packet loss. A Raspberry Pi and Wi-Fi dongle is pretty much all that is needed to see how much delay, jitter and packet loss can be artificially introduced without perceptible loss of speech quality and shows nicely what happens when this threshold is crossed.

Analyzing Wireshark Traces

Wireshark is probably running more often on my notebook than LibreOffice Writer as it’s and indispensable tool for my daily work. For repetitive tasks, I’ve now found a way to analyze Wireshark dissected packets with Python programs. Sounds complicated to setup but it’s actually quite straight forward.

IPv6 At Home

IPv6 has been coming for years now but the sad truth is that still only a few percentage of the traffic coming to this website is via IPv6. My fixed line network operator at home seems to be one of the few who’s deployed IPv4v6 dual stack. 2016 has thus been the year for me in which I’ve set up my first server at home that is reachable over IPv6, despite a daily changing prefix. Quite a lot of things had to be put into place to update the DNS server entry when the prefix changes and to configure the DSL router to forward incoming IPv6 TCP connection requests to the right box in my home network. While it was some work I’m glad about the experience I’ve gained. A summary with links to detailed blog entries can be found here.


Another interesting topic I’ve researched in-depth this year is how Eduroam works across the world and how it enables students to use their student credentials to gain Internet access at all universities, research institutions and even airports that have Eduroam Wi-Fi access points on air. Interestingly enough, my article on how to set-up Eduroam securely on Ubuntu is in the top-5 accessed blog posts of this site even months after I’ve written the post.

EU Roaming

A lot has happened in 2016 when it comes to EU roaming charges. Lots has been reported by the not so tech-savy magazines so I decided to comment what was going on and why some things are not so easy as they seem. By and large the only thing that is still missing now is that the EU parliament and the EU commission agree on a wholesale price for inter-operator IP data but that should happen any day now. After that one can only wait until roaming charges are finally removed for everyone in the EU by mid-2017.

NB-IoT Questions

On the other end of the scale, the Internet of Things (IoT) and in particular Narrowband-IoT has been on the agenda of this blog quite a number of times. In 10 blog entries, I’ve been going through quite a number of subjects on the topic ranging from a look at the new air interface to a discussion of the envisaged 10 years battery life and whether it really is such a good idea for IoT devices to have an IP address.

Wi-Fi Speed Speed Speed

An finally, Wi-Fi has also had a couple of surprises for me this year. In October, for example, I ran a speed test with an 802.11ac capable notebook running Ubuntu with an 802.11ac capable access point at home. The results were quite breathtaking.

A year full of interesting topics and I’m just getting started. In two follow up posts I’ll have a look at what’s happened for me in Linux & general computing and miscellaneous other things. So stay tuned…