We are quite a bit into January 2018 already and I still haven’t come around to reflect which things from back in 2017 ‘moved’ me. But finally here we go this is my 2017 round up from cellular to history.
Let’s start with LTE
At some point in 2017, I don’t quite remember exactly when anymore, my wireless network operator of choice activated the use of the EVS (Evolved Voice Services) speech codec in its VoLTE network. I didn’t expect that it could really improve over WB-AMR much but I was very positively surprised that speech and especially music sounds even better. Since then a lot of devices support the EVS codec such as all the latest devices from Samsung, Apple, Sony and others. Really stunning and its a really disappointing feeling now to call someone in another network and being stuck with the old Narrowband Speech codec.
While VoLTE, which is based on the IMS (IP Multimedia Subsystem) is a relatively new service in mobile networks, IMS has been deployed in many fixed line networks for quite some years now. So far I always assumed that one could only use it with DSL or cable modems supplied by the network operator but in 2017 I found out that it can also be used with open source software running on the PC.
One thing that always helps when debugging things on devices or the network is real-time tracing with Wireshark. On mobile devices with root permission real-time Wireshark tracing is possible over USB as described in this post.
When it comes to speed, LTE networks go from record to record. I live in the center of Cologne and my wireless network operator of choice has LTE deployed there with a combined channel bandwidth of 65 MHz. With the right device I can get a sustained data rate of 170 Mbit/s and I was wondering at some point ‘how much air’ is still left for LTE until we run out of licensed spectrum. Not to much I’m afraid. Also I noticed Free using the still somewhat exotic LTE 700 MHz band (band 28) in Paris. To make data transfers even smother when running out of LTE coverage my mobile network operator of choice now uses LTE to UMTS handover instead of the slower release with redirect mechanism. I only wished that UMTS to LTE handover was also in the network already but that had to remain on my wish list for 2018. And my final LTE nugget of 2017 is that I learnt how to use the GSM timing advance to find out the location of a co-located LTE cell.
Still a bit of a phantom in the wireless industry is the eSIM, i.e. an embedded version of the SIM card that can be provisioned over the air. It is slowly gaining ground so it was time to cover the technology in a 7 parts series.
As I’m always quite interested in the number of devices that are currently using a cell or Wifi access point I noticed that professional access points have an information element in which they broadcast the number of connected devices.
Vacation is a nice thing but without Internet connectivity it can be hard for some people. This is why I experimented a bit with a ‘Freifunk’ Wifi setup and provided Internet connectivity for others while being at a castle in Germany for a week in summer and using the nearby LTE cell as backhaul.
Another really important issue for me on the mobile device side is that I have an open source operating system running there on which I have root. CyanogenMod is no more and LineageOS is the new black. At some point in 2017 I moved to LineageOS on my Samsung Galaxy S5 and it has been working well ever since I made the switch.
Oh yes, another important thing in 2017 was the launch of the latest edition of my book on wireless networks. Now in it’s third edition it’s fully up to data again with the current state of wireless networks in practice.
While 5G is still quite a bit away from being deployed, 2017 was the beginning of the 5G frenzy and I wrote quite a number of technical posts on the topic to demystify a bit what is going on. For details have a look here.
Like the eSIM, the cellular Internet of Things was still more of a mythical creature in 2017 than really deployed in real networks. But it is slowly coming and I wrote quite a number of articles about different technologies such as Sigfox (see here) and about NB-IoT and OneM2M (here and here).
International Roaming
I travel a lot so roaming fees and being able to connect to the Internet for a reasonable price is very important to me. At the beginning of the year I was in Korea for a week and thanks to good preparation I could pick up a local SIM card right at the airport and enjoy unlimited data over LTE for the week for a reasonable price. Good preparation is necessary as there are also offers which take several hours to activate.
In the EU, 2017 saw the introduction of ‘roam-like-home’ and with some restrictions and lots of legal text behind it there are no roaming charges for voice and data anymore in the EU. Well, almost. My current subscription also includes the US, Canada and a few other non-EU destinations in my 3 GB data and unlimited voice bundle and having been in the US several times I made good use of it. A bit shocking is the different prices for cellular Internet connectivity in different countries in the EU and I dug into the topic in this post.
Internet and Web Stuff
Coming to the web and the (non-wireless specific) Internet domain I figured out how to use Let’s Encrypt SSL certificates on a Raspberry Pi web server at home and I was recommended Volumio as a Raspberry Pi based audio server for home which I have been using with great delight since then. The multi-hop SSH functionality which I also discovered in 2017 makes it much easier for me now to connected to devices at home via SSH without having to expose all of them directly to the Internet. And the final Internet topic I have for this 2017 summary is a blog post on how I used a virtual desktop in a virtual machine to access my company email from far away.
My History Track
In 2017 I had a lot of fun again with my Busch 2090, a computer from the 1980s for which I built a cassette interface emulator and an assembler so I could program it on the PC in a much nicer way then typing in hex values on the small keypad. For all the details see here, here, here and here.
While on vacation I did some research of how computing evolved from teletypes to touchscreens and you can find my essay about it here. Also in 2017 I attended a vintage computer festival for the first time in Berlin and exhibited my Busch 2090 and the work I was talking about above. An amazing experience about which I should have written on this blog but never quite came around to do it. A real shame I’ll try harder next time. I’ve also been to the Computer History Museum in Silicon Valley for a day and learnt a lot about computers having to be ‘earthed’ in the Centre for Computing History in Cambridge.
And that’s pretty much 2017, except for the many books I’ve read and reviewed on this site as well. It’s been a great 2017!