Category: Uncategorized

Being a Linux and open source fan I always like to see when and where it is used. So despite something having evidently gone wrong in the picture on the left, it's good to know that technology wise, the Basilica in Montreal has gone the Linux way for its advertisement. Seen on a recent field trip to Canada.

Continuing my stream of thoughts on networks and communication in Shanghai I noticed that even with Opera Mini I could not access Facebook service despite the browser tunneling all traffic in an encrypted form to a gateway. A closer look revealed that OperaMini when used over Wi-Fi on my phone selected a gateway in China which explains this behavior.

Then I thought let's deacivate Wi-Fi, restart the phone and try again over cellular. In this setup, the GGSN is in my home country so I am assigned a German IP address and DNS server. As a result, Opera Mini should then connect to a European gateway. But strangely enough that was not the case. Despite the German IP address used for my phone (which I verified), it was still a Chinese gateway that was used!? Not only could I still not access that social networking site but each IP packet traversed from Shanghai to Germany back to the Chinese gateway and then back to Europe or the US to other websites. And the incurred delay and the websites not accessible are quite noticeable.

Recently, I've been in Shanghai for a conference and as it was my first time in China, I was looking quite forward to see how GSM, UMTS, Internet connectivity, speed and access of resources at home through VPN tunnels would work from there.

Cellular Networks

On the cellular front, GSM and UMTS are working fine for me, but a few times when establishing a PDP context, no data would flow afterwards. After tearing it down and reestablishing it, everything was fine. Data transfer speeds don't seem to be very snappy back to Europe, but it doesn't matter much as prices are so prohibitive anyway, that I only use connectivity for downloading emails without attachments and for web browsing by using Opera Mini which does a fair amount of data compression.

Encryption and Tunneling

I am using mandatory encryption for sending (SMTP) and receiving (POP3) emails via servers back in Europe and both over cellular (with a German SIM) and the Internet at the hotel that works just fine. In other words, that's not blocked in any way. Also, my company VPN to Germany works just fine over the hotel Wi-Fi. After all of this working so well I was a bit surprised that the VPN product I use on my private PC would not connect to any gateway around the world, it seems to be blocked. A quick chat with the online support of the company, however, gave me a workaround within 5 minutes and I managed to get a VPN tunnel working to a gateway in the US.

Speed, speed, speed

When accessing servers in China from Europe I always have the impression that things are rather slow. Perhaps, I always thought, this was due to generally limited connectivity to Europe? But when bringing the Internet connectivity for the conference online I got a steady 10 MBit/s in the downlink direction and 10 MBit/s in the uplink direction to servers back in the US and Europe. So, no, it could not have been the transit links that were previously slow. Another thing demystified.

 

A quick thought on small hotels, Internet an Wi-Fi since I've just come across one of those: Like bigger chain hotels the staff also has no clue on how things work or what to do when things don't work around Internet connectivity. The big difference, however, is that it's not so hard to find the Wi-Fi router and the repeaters and get permission to restart them. After that, things work better than in bigger hotels 🙂 Yes, I know, I usually get a local SIM card for 3G Internet access but I didn't this time (in Canada) and was promptly confronted again with mediocre (at best) hotel Wi-Fi in 3 hotels. Back to the local SIMs then.

I've been doing a lot of e-book reading lately in a number of different forms and shapes and thought I'd write down some thoughts about my experiences here.

One form of e-book reading that I find quite useful and fun is on my mobile phone while commuting and also in the evening before going to bed. In both situations the tablet is too large and heavy and while the display is much larger and thus perhaps better for reading I prefer the mobile phone in such situations. Especially for text books where formatting changes are not an issue it works perfectly for me. And by the way there are many ebook reader apps available free of charge as are the books via Project Gutenberg which has huge amounts of classic novels converted to ebooks available. A great service so I made a donation, Paypal makes that quick and painless.

On the commercial side I have given the Kindle app on an Android based phone and an Android based tablet a try.  Again, I like the experience and books bought in the Kindle app or on the PC via the Amazon website are transferred to the device in a number of seconds. In particular I read a technical book with this solution, sometimes on the mobile, sometimes on the tablet and the Kindle app makes it easy to keep my bookmarks and last read page synchronized across devices. Very good! The downside of reading a technical book in electronic version becomes apparent when there is a need to quickly jump between different parts of the book. In a real "paper" book that works much nicer and faster than on a tablet. An advantage of the electronic version on the other hand however, is that it is searchable when one doesn't know the exact place of that piece of information in the book.

So while I like the experience I'm not totally converted. The argument that wins me over for most of my reading, however, is that I can have books with me anytime anywhere without extra space required or extra weight to be carried, both of which are precious commodities during commuting and traveling.

 

I have to admit that the diverse nature of spectrum holdings and wireless technologies used by mobile network operators in the US keeps me mystified and it's not easy to find out who has what kind of spectrum available. Back in 2011 I did a bands comparison between the US and Europe (see here) and came to the conclusion that there is pretty much the same amount of spectrum available for cellular on both continents. But this post tells little about which company owned which parts in each band. This is where these two posts (see here and here) provide some very interesting background information.

If (or when?) someone starts deploying LTE in the PCS 1900 MHz band, it would be one of the few bands worldwide in which four technologies are deployed simultaneously, GSM, UTMS, CDMA and LTE. Needless to say that manufacturing devices for the US (and for other continents with roaming capabilities) that can be used on more than one network in the US is getting more and more difficult. Also there is some talk of two carriers combining their surplus PCS resources for a common LTE network. Again very interesting from a device perspective as for one carrier such a device would have to support CDMA in addition to LTE while devices for the other carrier would have to support GSM/HSPA + LTE.

It must be happy days for Qualcomm who seems to be the only chipset maker so far that produces basebands that can do GSM, CDMA, HSPA and LTE simultaneously. Oh how I love the spectrum simplicity in other parts of the world 🙂

The title of this post might be a bit confusing but let's do the following thought experiment to compare prices for mobile Internet access with prices for circuit switched voice calling in terms of amount of data transferred:

A GSM voice call requires a constant data rate of about 25 kbit/s in both uplink and downlink direction (22.8 kbit/s with GSM channel coding to be exact), i.e. an aggregated 50 kbit/s. This includes overhead for coding and error protection in case you are wondering why I am not calculating with the nominal 12.2 kbit/s of the codec itself. So 50 kbit/s that is 3000 kbit/minute which is 375 kbytes per minute or 22.5 Mbyte per hour. The same amount of data goes over the air interface on the terminating side as well, so together that's 45 Mbyte per hour.

So how much are you charged for this amount of telephony "data"? Here things start to get difficult because prices vary per operator, country, contract, etc. So let's take a few examples. In Germany, prepaid calls are around 9 cents a minute. That is 5 euros 40 per hour, i.e. 5.40 euros for 45 MByte of data transferred. When staying in the same network, there are offers out there for 3 cents a minute, which would be 1.80 euros an hour. And if you take an on-net flatrate for 10 euros a month and then use it for 20 hours, that's 0.5 euros per hour, i.e. 1 euro for 90 Mbyte. To summarize the price for the 45 Mbyte of data transferred ranges from 0.5 euros to 5.40 euros.

Now let's look at the data side. A typical prepaid offer in Germany for 500 MB of data is 10 euros a month. In other words that's 50 MB for 1 euro and that is pretty much twice the amount as the cheapest voice example above. Let's go to the other end of the spectrum 20 GB for 90 euros a month. That is 222 MB per euro if used fully of course or 0.2 euros for the 45 MB. In other words, the cost for the data is about half of that of the cheapest voice call offer above in terms of amount of data transferred through the network.

So what's the point I am trying to make here? There is the perception in the industry that mobile data takes up much more network capacity than voice calls and brings in less money so voice calls must (still) be a much better source of income for network operators. But when looking at the calculations above that is not really the case.

Just as I am on my morning 30 minute train ride I am seeing ever more people who are using their mobile devices not only for voice calls (few) or SMS (quite some) but also for browsing the web, checking their email or using an IM program of some sort to communicate (quite many). On this particular train, the network coverage of the network I use is excellent except for in one spot where I loose the network for a minute. And already that is annoying. My experience on other train routes is not so favorable. So I can't help but wonder if in the future an even better way to differentiate from other network operators than in the past when mobile use was lower is to have good coverage along railway lines for those millions of daily commuters? I can see many commuters changing mobile networks when they see that others seem to have a much better experience. I wonder if those people making the decisions of where to expand network coverage do a daily commute on a train?

I recently reviewed the qualities of a entry level Android phone available at less than 150 euros and overall came away quite impressed. Here's a quick follow up on how image quality compares to one of the best camera smartphones, the Nokia N8. I've included two comparisons in this post one image taken at close range and the other showing more distant objects. It's of course not surprising that the image quality is lightyears away from the N8, even when only zooming into the image up to the resolution allowed by the 3 megapixel camera. But I don't think that's the point I want to make here. Have a look at image quality of a picture taken with a high end 600 Euro smartphone from back in 2002 (the Nokia 7650) and then come back and re-evaluate the entry level 3 megapixel camera quality 🙂

O.k., so if I could decide what to change about current Android phones so I could fully embrace the platform once my current Nokia N8 needs to be replaced it's actually not hard to come up with a long list. Not that I don't like Android at all, quite the contrary, it's just that there are still a couple of fundamental things that still don't work well for me. So here we go:

1. Fix Multitasking: This point would actually get at least 5 places on my list because this is my top grievance with Android. Much better than other platforms in this regard it is still nowhere near Symbian's multitasking capabilities. Even Android 4 – Ice Cream Sandwitch on a flagship device with lots of RAM keeps closing apps such as the browser after a while. So Google, repeat 5 times and say it out loudly: IMPROVE MULTITASKING!
2. Camera & Xenon Flash: The N8 has been out there for ages now and no other device has come close to the camera and Xenon flash performance of the device. Is it really that hard?
3. Offline Maps application: I am traveling a lot and I need a street and navigation app that works with preloaded apps. Sure, there are third party apps that do that but they are not part of the overall package and surely not with worldwide maps. But at least there's a solution today, even if it comes at a price.
4. Better privacy protection: I understand that Google wants to get a return for their investment by hording my private data on their servers. And I would even give them some but definitely not all Android sends home by default. So I'd wish that instead of the per default data export once a user is logged in I'd really like Google to ask me twice before exporting data.
5. USB storage connectivity: Some vendors have removed the USB mass storage option that emulates a drive on the PC. Can I please have that back? SMB over a file manager is an alternative but sometimes the cable is just more convenient.
6. Lock by SMS: Android manufacturers have some interesting schemes how to lock and wipe the device remotely when it is lost or stolen. But it can be done much simpler with an SMS from any phone at any time with a secret user definable password inside. The phone sends an SMS back that it is locked and you are done. Straight forward, simple, easy. Can I have that on Android, too, please? I know there are third party apps but I am a bit weary to loading an app that is allowed to send and receive SMS messages without knowing the author and without having seen the source code. Trust is the important thing here.
7. Smaller display: Bigger is better they say but from my point of view, display sizes have reached ridiculous levels. So please, a high end phone with a reasonable display size, say iPhone dimensions?
8. Cellular Radio Stuff: Yes, I want a high end device so please toss in HSPA dual carrier for improved cell edge reception. And as I travel a lot I value penta-band HSPA for worldwide use a lot. I don't necessarily need LTE in my smartphone if it increases power consumption, call setup times and if reduces the number of supported bands for HSPA. LTE is nice for my tablet and USB dongle for the netbook but on my smartphone I have different preferences.
9. And last but not least: Why on earth can only Nokia do a decent lock/unlock slider button on the side of a device?. Lock in a fraction of a second, unlock in a fraction of a second. No button presses, swiping over the display, waiting for the nice animation to fade away, just lock, unlock, lock, unlock, really fast. Timing is crucial, just like with my multitasking wish above. Which kind of nicely closes the circle.

Non of these things are really difficult to do and I hope by the time Android becomes the OS of my main phone I get at least my first wish plus perhaps a couple of the others. What do you think?