Category: Uncategorized

A few weeks ago I updated from Ubuntu 14.04 to Ubuntu 16.04 on my notebook. Was it worth the effort?

Continue reading Upgrading to Ubuntu 16.04 – Is It Worth The Effort?

Continuing my mini-series on how VoLTE works in practice I’ve recently taken a closer look at how DTMF tones are transported over IMS. You might argue that DTMF tones are old technology but they are still used a lot today. Examples are entering the PIN to your voicemail system from the phone or sending a conference bridge ID and password over an established connection. In ‘good old’ analog telephone networks DTMF tones were generated by the phone itself and sent as an audible tone over the speech channel. In GSM and UMTS networks things changed and DTMF start and stop indications were transmitted as signaling messages to be interpreted and converted into a real tone in the network. In VoLTE, things have again been implemented differently.

Continue reading VoLTE – Some Thoughts on DTMF

If you are often dialing into conference call bridges I’m sure you have also more than once wished the ID and participant code would dial themselves automatically. I’ve done this by hand for years and have only recently found out that there’s actually a simple way to fully automate the process.

Continue reading Auto-Dial Conference Call IDs and Participant Codes

I recently had one of those moments again when I realized that what I was able to do just then would have been impossible just a year ago. When I was recently able to download a massive 3 GB file over LTE I needed urgently at 40 Mbit/s while roaming abroad I realized that it was just such a moment.

Continue reading The Power of 40 MBit/s LTE Roaming

I’m quite fascinated by Bitcoins and in a previous post I’ve started to tell what I have learned by taking theory into practice. In the second part I continue the story as there is still a bit to tell about Bitcoin exchanges, market volatility, limitations of the system and how bad guys might be using the system to their advantage. Read on for the details. Continue reading Bitcoin Experiences – Part 2

For me, Bitcoins are a fascinating phenomena. For one thing nobody really knows who created the Bitcoin system initially, it’s a big mystery. Regularly someone claiming to be the inventor of the system comes forward or is suggested by the media but so far nothing was ever proven. A major idea behind the Bitcoin system is to have a method of payment that is independent of state governments. The idea is great and more and more shops have started accepting Bitcoins as a method of payment. Unfortunately, Bitcoins are also used by criminals which receives quite some attention in the press as well. However, in this respect it is no different from any other currency.

While every now and then I’ve read about the theory of Bitcoins I never actually owned or used Bitcoins to pay for anything. With the time of the year coming up at which I make donations to a number of open source projects I decided to put theory into practice and donate to them using Bitcoins if it is offered as a payment method. So here’s the story of what I found out in the process, from practical payment experience to insight into how anonymous the system really is and and why and how crypto trojans can potentially misuse Bitcoins.

Continue reading Bitcoin Experiences – Part 1

Yesterday I was in the Netherlands for a day and by chance it was just the day when they had a trial run of their NL-Alert system at noon that broadcast a test message to all mobiles in the country. I was quite surprised I got the message with my non-Dutch CyanogenMod Android device so I had a quick look at the technical details to find out more.

Continue reading I Had An NL-Alert Yesterday – Some Technical Details

In part 4 of my mini-series about 3GPPs Internet of Things standardisation for cellular networks I’ve given an overview of the currents state of the NB-IoT standardization in 3GPP. Most of what I’ve written in there is based on a 3GPP Technical Report that summarizes the different options that were studied and RP-151621 which contains the Work Item Description for NB-IoT in which the resulting compromise was detailed. But where in the 3GPP Specs is NB-IoT now actually specified?

Continue reading Cellular IoT – How to find out more about NB-IoT in 3GPP – Part 5

In the three previous parts (here, here and here) on the Internet of Things and 3GPP, I’ve described Cat-1, Cat-0 and Cat-M1 devices. In this post we get down to the really interesting development in 3GPP on this topic: Narrow Band Internet of Things (NB-IoT) and Cat-NB1 devices (previously referred to as Cat M2 devices).

Continue reading Cellular IoT – The Dust Slowly Settles – Part 4 – Cat-NB1 Devices