Category: Uncategorized

At the beginning of 2013, Google announced that they would shut down their Google Reader RSS service in June and so they did. Many were not amused, including me at first, but it was an incentive to make myself independent of yet another one of the few centralized cloud services I used – by setting up my own RSS server at home. After looking around I opted for Selfoss as it looked easy to use and had all the functions I required.

Some things come and go, but Selfoss has stayed. Except for a small hiccup once it keeps doing its job marvelously and even when I'm somewhere without 3G or LTE coverage and have to fall back to GPRS/EDGE, the posts remain perfectly readable as images in the posts are only loaded if a button is pressed.

Thanks Tobias (Zeising), an excellent program I can fully recommend!

Back in May, I've bought a GSM enabled power socket to be able to reset my homecloud from abroad should something become stuck. Since then everything has been extremely stable and I didn't need it once. But then while I was abroad on vacation recently there was a power failure, quite a rare event and the first one this year. I noticed it quite quickly of course because my RSS server stopped responding.

What I found odd was that I didn't get a warning SMS from the GSM power socket as I've tested the functionality in the past and it was working then. There are a number of explanations for this, one of them being that the power outage was a bit more widespread and the GSM base station was also affected. I then sent a status query which was not answered. That had me worried for a bit. But at least I got an sms immediately after power was restored 50 minutes later.

The figure on the left shows how I queried the power status when I noticed that something was wrong and got no answer at first. The following two messages were then received once power was restored together with an answer to my initial status query that was stored in the SMS service center in the network an delievered once power was restored.

Hm, perhaps I should start thinking about buying a USV now. But even if my homecloud at home stays up I wonder where the DSLAM in the street gets its power from… There are some things that are just out of your hands…

Believe it or not but I am still using an 802.11g access point at home because the 802.11n access point that is part of my high end VDSL router at home is just crap. In most cases the 20 Mbit/s I can get out of it through two walls is good enough for my purposes. But my VDLS line gives me 25 Mbit/s so this is hardly a state I can tolerate much longer.

I do have another Wi-Fi access point at home who's 802.11n implementation works a lot better and I get around 70-80 Mbit/s out of it at close range in the 5 GHz band and around 50 Mbit/s through my walls. Next time I manage to be at home for more than just a few days I'll try to port my VPN server configuration from my 802.11g OpenWRT router to this box that also runs on OpenWRT and if it is as stable as my current setup it will be my configuration for the foreseeable future.

Time has moved on, however, and 802.11ac products are already on the market. The recent 1/2014 issue of the German C't computer magazine has an interesting benchmark test with real life scenarios. Speeds measured are between 700 Mbit/s at very close range between a 3×3 MIMO capable 802.11ac access point and a PCI Express card in a PC with three external antennas. But that's rather an exception.

802.11ac USB sticks are only 2×2 MIMO capable and according to the magazine, up to 200 Mbit/s are possible at very close range. In their 20 m + walls scenario the throughput is cut down to 100 Mbit/s. Quite far away from the 700 Mbit/s above but still respectable. In most other combinations that make use of 3×3 MIMO, speeds were in the 350 Mbit/s category at close range (same room but at some distance) to 150-170 Mbit/s in their 20 m + walls scenario.

Interesting numbers to be kept in mind when seeing advertisements of 1300 Mbit/s capable routers (which stands for 3×3 MIMO in the 5 GHz range). Some even advertise their routers as AC1800 because they add the theoretical maximum of 450 Mbit/s of 802.11n in the 2.4 GHz band to the 1300 Mbit/s in the 5 GHz band of 802.11ac. That's what I guess is called creative marketing.

When I first wanted to learn about the ins and outs of Wi-Fi many years ago I discovered what I consider the bible on the topic, '802.11 Wireless Networks – The Definite Guide' by Matthew Gast. It has since held a prime spot in my bookshelf but obviously it is now a bit outdated as it doesn't include information on 802.11n and the current latest and greatest 802.11ac standard. So when I recently wanted to deep dive into 11ac I had a look around on the web and discovered Matthew's '802.11ac survival guide'. After reading it I can very much recommend it because the level of detail and writing style was just what I've been looking for.

While it can be read on it's own if you have some background on how Wi-Fi works, newbies are better advised to first read the general chapters of his original book and then jump into the 11ac survival guide. Both books and his 802.11n survival guide are available as ebooks. If you buy directly from O'Reilly you can download it it in various formats and all of them are DRM free. I'm glad I looked before I bought the DRM protected Kindle edition over at Amazon.

To get a first impression I can also recommend this video on Youtube where he gives a talk about 11ac.

The year is drawing to a close and I had some time over Christmas to reflect what has been going on this year and I found quite a number of defining moments on the technology front. Here's my personal top 10 list of things that mattered to me personally in technology in 2013

1. LTE goes Mainstream

While first networks were deployed already in 2009, this year has been the year of LTE in the mass market. There is a myriad of LTE smartphones in the market now, and I use it myself day in and day out over Wi-Fi tethering to acccess the Internet. Actually, from a daily duration perspective, I access the Internet more over LTE than over my VDSL line at home. Also, 2013 saw circuit switched fallback (CSFB) delays significantly shrinking in some networks and it has thus become usuable on a smartphone as well and not only for PC tethering.

2. Raspberry Pi

A breakthrough on many fronts came when I bought my first Raspberry Pi this year. In one sentence I would say that the Raspi opens the world to inexpensive computing with Linux and Internet connectivity and bridges the gap (which is perhaps only in my mind) between standard desktop computing, embedded computing , and mobile devices such as smartphones. Hallo of them (can) have a Linux kernel today and are programmed in the same way and with the same tools.

3. Owncloud

Cloud services have become popular in the past few years for file sharing, backup, synchronization of calendar and address books between devices, etc. One thing that kept me away from cloud services over the years was that I would have had to put my private data at the mercy of huge companies and I was not willing to do that. And then I discovered Owncloud which which I could finally benefit from cloud services and have everything stored on my own hardware in my own place. Running Owncloud on a Raspberry Pi completed the setup for me and I'm not only in the cloud now, I'm in heaven. Finally the cloud makes sense to me.

4. The PRISM shock

In the global scale, Edward Snowdon's revelations that started with the PRISM scandal had me shocked beyond imagination and I'm still not sure I'm out of it. In the aftermath I've written many blog posts on how I further tightened the security and secrecy of my online communication with Owncloud only being one part of the puzzle. I started using TOR for sensitive web browsing, I've protected my Owncloud setup with a real SSL certificate, instant messaging communication between familiy members now runs of my own Messaging server at home, I have a VPN server at home to tunnel all Internet traffic via my VDLS line at home while I'm not there, I've experimented with email encryption etc. etc. And the PRISM shock has altered my voting behavior in the general elections as the party I wanted to vote for was in a constant denial of the state of things and unfortunately still is. Lots more could be said about this but I let my many posts on the topic speak for themselves.

5. Busch 2090

On the history track I discovered my first computer I always wanted to have but never got, the Busch 2090 experimental kit. It inspired my to have a closer look at electronics tinkering again and I managed to get an original via ebay.

6. Finding Out How a CPU works

The Busch 2090 that lead me down the history trail also made me starting thinking again how a CPU works. I had a rough idea but the big mystery was how the control unit worked. I finally found two resources that explained the concept of a hard wired control unit and a microcode based control unit and in only a few hours I could finally understand what had remained a mystery so far. For me it was the last piece in the puzzle between digital electronics and a working computer.

7. Data Roaming in Europe becomes affordable

2013 has been the year in which data roaming became cheap enough in Europe so I no longer had to  get local SIM cards in many cases. I still did in other places such as Hong Kong and South Korea but not in Europe anymore.

8. OpenStreetMap and Osmand – Google Mapping Independence

Another liberator has been OpenStreetMap and the corresponding Android Application, 'Osmand'. Finally I no longer have to tell Google, Yahoo or Microsoft where I am when looking at maps, it can remain private now. Also, Osmand is offline capable and it can navigate perfectly with maps downloaded to a smartphone. Very important when roaming as despite reduced data roaming prices, navigation and map downloading remains expensive in Europe and not affordable in the rest of the world. Privacy and offline maps, a great combination!

9. Bye Bye Symbian – Shedding Tears

2013 has also been the year in which I had to say good-bye to Symbian. For me it was THE smarpthone operating system that brought the breakthrough for the Internet on mobile devices. I would have loved to migrate to Meego but that was not to be due to the unfortunate events at Nokia. It makes me sad as Nokia was the last European mobile device manufacturer. So I replaced Symbian with Android as it was the least bad of the available alternatives for me. But looking ahead things look brighter with activities around Meego's successor 'Sailfish' and other projects such as Ubuntu on smartphones that might restore my need for privacy again that Google's Android can't give me.

10. Bye Bye Windows – Not Sheeding Tears

And finally, one thing I won't shed tears about is that I got rid of the last Windows computer at home. Not only mine but alll PCs and notebooks at home are now running Linux which puts me at great ease as open source now reigns at home.

So those were my personal 2013 technology highlights paving the way for an interesting 2014!

Yesterday, the 30th Chaos Communication Congress (30C3) has started in Hamburg Germany and here are some interesting links to peek into the event:

A couple of weeks ago I had a post on the 100 Gbit/s link the congress had to the outside world for participants to stay connected during the event. Here's a link to a page that shows some live stats on bandwidth utilization, amount of data transferred, number of Wi-Fi clients, on-site GSM use and more. When I looked in the evening of the first day, bandwidth utilization was around 12% in the uplink and 6% in the downlink. In other words more data got sent out of the congress than in. The percentages might seem low but 12% means a data rate of 12 gigabits per second… Another staggering number is the 4000 Wi-Fi clients using the system.

For those who can't be there in person here's the schedule and a link to a fast proxy of the raw video streamdumps of the sessions for quick downloads right after the talks are over. Live video and audio streams are also available as well as cut and edited versions of each session. Google will help you for those links.

Four years ago I put down my notes in a blog post on how to use Ubuntu on a notebook to trace Wi-Fi in combination with Wireshark so I could see the Wi-Fi management frames and also the Wi-Fi portion of each Ethernet frame. Amazingly enough, it still works the same way as it did four years ago so I thought I'd write a quick post and link to the original entry as information about how this is done is not widespread. So here's link to the original post.

Tracing this way is a bit more complicated than the approach with the mini-Wi-Fi-Access point that backhauls its traffic via Ethernet as described in this post from back in November. However, this approach is only good for tracing Ethernet frames and gives no insight into the wireless part. But sometimes that is not necessary anyway, it really depends on what one is looking for.

Back in November I had a post in which I wrote that my next device would be a Fairphone (which has now started shipping). Not because it has revolutionary new features or because it's especially high end, which it is not, but for a number of other reasons.

First of all, I like the idea that people think about how a smartphone can be produced in a fair(er) way for the people and the environment. Also, I like the fact that it is done by a small company and that they are very open about the way the phone is designed and produced. I can identify with their ideas and their motives and that's another important thing that has been missing for me ever since Nokia threw itself (or was thrown?) into Microsoft's grip of death.

Before continuing on the Fairphone, a quick look back to former times: Back in the 2006+ timeframe I could identify with Nokia devices because it was pretty much 'the' company at the time for me that innovated the most around bringing the Internet to mobile devices. At the time, social media was also a new concept and to me their approach appeared to be honest. Sure it was driven by a marketing department but the whole thing was so novel that it was still possible to get engaged with the people there. This interaction got lost on both sides over time as the original people left and as things just became too main stream.

These days, the Internet on mobile devices has gone mainstream so the issue is solved. Sure, there is still innovation but by and large the Internet is mobile now. I'm not mainstream and so wasn't Nokia when they pushed the idea of Internet on mobile so it's difficult for me to identify with large and anonymous corporations spitting out devices in the tens of millions today.

With the Fairphone, to come back on topic, it's different. The company has faces and although I only know all of them but one from their website it's a much more personal approach. Also, I'm happy that I could contribute a bit to the project, by paying up front in November for one thing and having been part of the testing and bug fixing effort for another.

And last but not least the Fairphone, on the technology side, has some features I don't get in any other device in that combination such as dual-SIM capability in combination with a good screen resolution, fast processor and an almost stock Android with root rights so I can tame what Google is doing. I haven't tried yet but I hope this still works.

Thanks for that, Fairphone, I'm sure it will become even more exciting as the story continues.

Recently, a German consumer telecoms magazine published their annual network testing results for network operators in Austria, Switzerland and Germany. If you are interested, P3 has a PDF of the article here. Sorry, it's in German only but even if you don't speak the language, the result tables should nevertheless be discernible.

It's good to see that 80% of their drive route in Germany was covered by LTE networks of two carriers and top speeds of beyond 90 Mbit/s were measured. Also it's interesting that network operators now have the tools to minimize call setup times when a fallback from LTE is necessary. While two network operators still have several seconds of additional delay, one network operator has managed to cut that down to a mere 0.2 seconds as I've already noticed myself back in July.

So far, so good. However, when I was recently on a 10 hour train trip through Germany and Austria I was painfully reminded that network coverage along many rail lines is still very far from perfect. This was made even worse by the train not being a high speed train with 2G/3G repeaters inside and unfortunately insulating windows that do not only keep out the heat or cold but also the wireless networks.

So perhaps it would be time to include train trips through the three countries as another testing criteria in such network tests in 2014 to get an idea as a consumer how well different railway lines are covered and what to expect on trains with/without repeaters and insulating windows. Perhaps this would encourage network operators that want to provide quality coverage to do something about the current state of affairs. And trains are usually full of people being bored and wanting to use their mobile devices so it's a strong sales argument!

In my series on my renewed enthusiasm about Bluetooth (see here and here) I can surprisingly add another entry: Even though it is every now and then amusing to listen to advertisement on the radio I do get bored and annoyed after a while. When recently renting a car for a day and driving overland I got to this point quite quickly. But then I noticed that the car was equipped with a Bluetooth interface for music streaming and telephony. The pairing procedure was not for the faint hearted and one should deny the car's request to access the phone's address book but once done I could stream my music from the phone to the on-board audio system – without advertisement interruptions. Excellent! Voice telephony was also integrated in the system as incoming calls were alerted over the car's loudspeakers.