Category: Uncategorized

Wi-Fi tethering has been in Android and other mobile operating systems for quite some time now and as of late I've become quite fond of it, having exchanged my 3G dongle with Wi-Fi connectivity to a phone or tablet. It seems, however, that for the moment, I am pretty much alone with this approach on my daily commute as I don't see any other Wi-Fi hotspots with a strong signal in the train in which, by the way, the carriages are openly connected, i.e. my PC could see any Wi-Fi signal from at least 4 or 5 carriages. Just a note on the blog for a moment so I can come back to it over time should this change in the future.

Every now and then there is a note in the press about the success of mobile TV in Asian countries such as Japan and Korea in combination with bewilderment of how it could have taken off there while it wasn't a success at all elsewhere.

In retrospect I can confirm this. When I was in Korea recently, I noticed that all phones of Samsung I know from Europe as well look very much the same, BUT, they have a retractable antenna for television reception at the top. One doesn't see it at first as it's nicely integrated in the design but it is there. And I think the big difference to the approach tried in Europe, for example, is that TV reception on the mobile phone seems to be free. No extra monthly charge, who could say no?

I am not sure if they receive the normal TV program on their mobile or if it is special content, however. From a technical point of view I wonder if there's a separate chip for TV reception or if that is integrated somehow in one of the other chips? And I wonder what the motivation is for manufacturers to put this into the Korean version of their devices? If it's not revenue generating it must be quite popular as otherwise I am sure the companies wouldn't go the extra mile and extra expense to include it. As usual one question answered, several new ones being raised 🙂

In most countries in Europe, there are four mobile networks for customers to choose from. To me from a consumer point of view it seems to be the "lucky" number as in countries with fewer network operators, real competition often doesn't get a chance and network quality and prices are not where they are in other countries.

A case in point is France, where until last year there were only three network operators served the market with pretty much the same prices. Not a lot of competition as could have been clearly seen in the prepaid market which was one of the most unattractive ones in Europe, with validity dates of only 1-3 months for top-ups. 

A lot has happened in the 12 months since Free has started, however, and prices have come down quite considerably to a more "European" average level. Lots of complaints could have been heard in the time since, including parliamentary hearings, etc. And it seems feelings are still running high, according to the following quote from Stephane Roussel, SFR's CEO:

'The number of mobile operators in France is clearly excessive,
unreasonable in my opinion.’

I find the words "excessive" and "unreasonable" quite interesting. So the situation in a lot of other countries, in which the four network operator system works quite well is clearly excessive and unreasonable? Further, in his opinion, to quote the article linked to above, three network operators would be ideal. Hm, for the network operators or for the customers?

In my previous post I’ve been using the SunSpider JavaScript test in an attempt to get a feeling for the performance of smartphones compared to PCs. On my PC I am using quite a number of virtual machines and guest operating systems for various purposes. Using the SunSpider test is also quite revealing of how virtualization impacts performance of the guest OS.

My hypervisor of choice is VirtualBox and it seems that the operating system it handles best as far as CPU performance is concerned as a guest OS is Windows XP. On the host system running Ubuntu 12.04 the SunSpider benchmark results in a score of around 420 ms with Firefox 16.0.2. Running the same test with the same browser in the virtualized Windows XP results in a score of 455 ms, i.e. only slightly slower.

On a Windows 7 guest OS, however, the score drops to 604 ms, quite a bit slower. And finally, an Ubuntu 12.04 guest also only reaches a score of 607 ms.  In other words, while the Windows XP guest almost incurs no slowdown, Windows 7 and Ubuntu are 50% slower. That is very strange and I haven’t figured out the reason for this yet.

Also, I can rule out that the SunSpider tests gives different results in different operating systems running natively. On another computer I have Windows Vista and Ubuntu 12.04 installed natively and the SunSpider results with Firefox 16.02 give almost exactly the same value.

ARM based smartphone CPUs are getting more and more powerful but so far I found it difficult to compare their performance to notebooks in a meaningful way. But now I found SunSpider, a benchmark available on pretty much any platform that will help in this quest. In essence, the SunSpider test benchmarks the JavaScript execution speed and can be used for various things, such as for example comparing the JavaScript implementation of different web browsers running on the same machine or to compare different devices running the same web browser.

When comparing smartphones with notebooks both the device and the web browser implementation changes which is not ideal. However, when testing the JavaScript engines of Firefox and Chrome on a PC and Opera Mobile and the native Android browser, their results only differed in the order of 10%. That's an indication that highly optimized JavaScript engines of different browsers do not have a significant impact on the general result when comparing smartphones with PCs this way. The following list shows the result of running SunSpider 0.9.1 on different devices:

• 175 ms, Notebook, Intel i5-2520M CPU, 2.5 GHz, Firefox 16.0.2, Windows XP, (2012)

• 266 ms, Notebook, Intel Centrino 2, Firefox 16.0.2, Ubuntu 12.04, (2009)
• 269 ms, Notebook, Intel Centrino 2, Firefox 16.0.2, Windows Vista (2009)
  

• 301 ms, Notebook, Intel Core 2 Duo, Firefox 16.0.2, Windows 7, (2009)

• 410 ms, Notebook, Intel i3 2367M, 1.4 GHz, Firefox 16.0.2, Ubuntu 12.04, (2012)

• 690 ms, Netbook, ARM, Exynos 5 Dual 1.7GHz, Chrome OS (result from here), (2012)

• 914 ms, iPhone5, ARM, (result from here), (2012)
  

• 1034 ms, Netbook, Intel Atom N570, second generation, 1.66GHz, Chrome OS (result from here), (2011)

• 1194 ms , Android 4.0 based high end Smartphone, ARM, native browser (2012)
  

• 1266 ms, Netbook,  Intel Atom N270 (first generation), 1.6 GHz, Firefox 16.0.2, Ubuntu 12.04, (2009)
  

• 1279 ms, Lava X900, Android smartphone, Intel Atom based (result from here), (2012)

• 1400 ms, Samsung Galaxy S-III International, ARM, native browser (result from here), (2012)

• 2000 ms, Android 3.0 based tablet, native browser, ARM, (2011)

• 6100 ms, Legacy Android based high end smartphone, native browser, ARM, (2010)

• 11062 ms, Nokia N8, Opera Mobile browser, (2010)
  

(approx. device release date in brackets)

When comparing the results there are a number of interesting conclusions that can be drawn:

First, my current Intel i3 based notebook is significantly faster than the Intel Atom based notebook I used for my daily work while traveling until only recently. No surprise here, one can feel the difference.

Second, the latest iPhone's CPU single core performance is better than that of my 3 year old netbook running the latest Ubuntu and latest Firefox browser. They are still sort of in the same ballpark when it comes to performance and I wouldn't want to exchange my i3 based notebook with my netbook again. However, the point is that the latest smartphone processing power is in the area of first generation Atom based notebooks.

Third, the latest Chrome OS netbook (the XE 303) uses an ARM processor and while the performance is not quite the same as that of my Intel i3 based notebook, it is still twice as fast as my 3 year old Atom based netbook. It comes close enough to my current notebook, however, that I'd really like to try it with an Ubuntu installation once there's an ARM version that supports that device.

Fourth, Heat: Notebooks used to get pretty hot. But even my Intel i3 based notebook remains surprisingly cool (with a fan running).

In summary, the list shows clearly how close ARM processors have come in the SunSpider performance test to Intel based devices and the performance difference between low power desktop devices and smartphones is getting smaller. In another two or three years, perhaps even sooner, slim tablets will have enough processing power and acceptably low heat creation for that amount of procesing power that they are fast enough to become full desktop replacements with operating systems that have desktop like functionality when needed.

One year after the first version of my experimental Android Program – Cell Logger – I have published version 2.0 with one major addition: It now uses the GPS receiver to also track the location of signal strength and cell changes. You might remember this and this blog post where I ran some tests with it in Germany and Korea.

If you are interested, you can download the APK for a direct install on the device via this link. The source code is available via this link. In Google Play, you'll find the app by searching for "Cell Logger 2".

Independently from installing directly or via Google play, it's a good idea to download the source zip file from this page as well as there's an extra folder inside that contains some useful information on how to use the generated KML/XML file for offline analysis with Google Maps or Openstreetmap.

And after the jump, some more detailed info. Agreed, as always with experimental projects, documentation etc. could be better 🙂 Nevertheless, enjoy.

License

Cell Logger is available as Open Source Android app using the GPL 2 or later version license. For details see the source code.

What does it do?

Cell Logger records date and time of signal strength changes, the cell's Location Area ID, Cell-ID and, if available, the GPS coordinates where a cell change from one cell to a new cell that has never been observed occurs. GPS coordinates will not be recorded for cell changes between cells that have already been observed to prevent ping-pong handovers in certain situations to be counted as real cell changes. On the display of the device all this information is shown real time including counters on the number of cell changes and the number of unique cell changes (i.e. without ping-pong).

Whenever a cell change occurs data is written to a file in the main directory on the mass storage partition of the device. The file name used for this is “cell-log-data.txt” and data is appended until the file is removed. The file output is buffered in memory until 2k of data have accumulated to prevent frequent write access to Flash memory. The file buffer is also written to the file when the app is moved to the background.

This document is accompanied by an Excel file that gives a description on the fields of the .txt file described above. For analysis it often makes sense to copy and past the data contained in the text file into the Excel spreadsheet.  Auto filters for each column have also been added for easy data evaluation.

When a unique cell change occurs and GPS information is available, the event will be logged into a separate file, “cell-change-log.kml”. The format is text/xml and can be used for import to Google maps (http://maps.google.com). A Google account is needed to use the “import” functionality on the website. As the app has no control when logging starts and stops, the XML header and footer need to be inserted after copying the file to a PC before data is imported to Google maps. The file “header-footer.kml” that accompanies this document contains the required XML structures for easy copy/paste to the KML file that is used for the maps import.

The Network Type that is recorded in each line is a number as given by Google's API. Here are some numbers and their meanings:

2 = GSM/GPRS/EDGE
3 = UMTS
8 and 15 = HSPA (some networks switch between 3 (idle) and 8/15 (DCH)
13 = LTE

The KML file uses three different styles to indicate the use of different network types. The numbers given by the Google IP are mapped as follows:

1,2=GSM is mapped to STYLE 2 and is then mapped to blue ballons in the KML header file.

3=LTE is mapped to STYLE3 and is then mapped to yellow balloons in the KML header file.

Everything else is mapped to STYLE 1 and is then mapped to red balloons in the KML header file

It is important to let the app run in the foreground at all times. It prevents the device to go to sleep mode, i.e. the display is always on to ensure it is supplied with location and cell information from the baseband processor. If put to the background (e.g. when going to the idle screen), GPS location tracking is disabled by the app and no cell information is recorded. Recording continues once the application is brought back to the foreground again.

After many years of using a 3G stick for my notebook on my daily commute I've finally made the switch to Wi-Fi tethering, either to an Android smartphone or an Android tablet, whatever I carry on a particular day. For the moment, it seems more convenient as that 3G stick requires some extra space which is at a premium in trains.

That makes me wonder if 3G sticks will have a future or if their will be completely replaced by Wi-Fi tethering, even more so because a 3G stick needs a separate SIM card which is usually a hassle and which often costs extra money. The few megabytes I use during my daily commute can easily be absorbed by my smartphone plan that does not exclude tethering use.

Speed wise I have not seen a difference between a 3G stick and smartphone tethering. Over both connections I can easily reach speeds well over 6 MBit/s, depending of course on cellular signal quality. Sure, dual-carrier sticks can go far beyond this speed but LTE smartphones with tethering capabilities are now on the market, taking away this advantage as well.

I've also noticed interesting Wi-Fi power saving mechanisms. While the ping round trip delay times are quite normal when tethering to my smartphone, they are around 300ms when tethering to the tablet. However, when I transfer more data over the tablet than just the ping packets, round trip delay times are down to the usual 60 ms again during the transfer and return immediately to 300 ms afterwards. This rules out cellular power saving schemes like Cell-FACH and Cell-PCH which take a much longer time to get activated. No disadvantage but I was a bit surprised when I saw the 300ms for the first time and initially thought something was wrong.

One thing that is an advantage as much as a disadvantage is that the smartphone or tablet runs on a battery vs. the 3G stick that takes the power from the notebook. On the positive side my PC runs a lot longer on a charge. My Lenovo Thinkpad requires about 12 Watts without the stick and an additional 3-4 Watts with the stick (depending on the type of 3G stick). This cuts the operation time by at least one and a half hours.

On the negative side I have to remember to activate/deactivate the Wi-Fi hotspot option on my smartphone once I arrive at work or at home. I wonder when we'll see an option to switch off the Wi-Fi hotspot functionality after a configurable time when no clients are active anymore.I faintly remember of already having seen such an option in a device but it deactivated the hotspot immediately after the last client had left. Not good for my train scenario in which every now and then suspend the notebook for a minute by closing the lid to answer a call or to show my ticket.

But even when switching off the Wi-Fi hotspot functionality after use the smartphone probably doesn't last a full day when using it for other tings, too, as a Wi-Fi/3G bridge for an hour a day with frequent data transfers requires quite some power. The tablet's got an advantage here due to its much bigger battery.

Another downside of the tethering solution is that in other scenarios such as libraries or at Starbucks two power sockets are required, one for the PC and one for the smartphone/tablet. Usually one is lucky if there is even one socket available.

But tethering is often cheaper than having an extra SIM for a 3G dongle which is why I think most people will not mind the drawbacks in some situations.

When it comes to cellular networks, Austria is one of the most advanced countries concerning network ubiquity, speed and low prices. To see how things evolve, a German mobile communication magazine together with a test house does an anual in-depth test of networks in Germany, Austria and Switzerland. Their reports of these activities are usually quite insightful. Here's a link to the ENGLISH version of the 2012 report for Austria. An interesting read that shows what's possible, even in a country where for around 20 euros a month there's so many voice minutes included and so much data that it's hard to hit the limit (read: usage is high).

The Internet is great for freedom of choice, freedom of use, freedom of expression, freedom of speech. I really like that I'm able to post things on my blog that can be read anywhere in the world where the open Internet is available. I equally like that there are search engines that let me find documents and information no matter where they are stored and I like small companies that are offering videos, podcasts and other content on niche topics that would never make it to the mainstream media.

So all of these things are great and do not match the title of this post at all. However, the Internet is now more and more also used to restrict the freedom we used to have. Here are some examples: Companies such as Apple, Google, Microsoft and Amazon have great products that are used and enjoyed by people around the world including the author of this post. But more and more these companies are trying to build silos by offering software and hardware that is tightly controlled by them. Third parties offering services and content independently are unwanted. A few examples: Apps can only be downloaded to the iPhone from the Apple store, Amazon's kindle only accept apps from Amazon's store and also Microsoft wants to go down that road with Windows 8, as metro apps can only be installed from Microsoft's web store.

Why such limitations and why now? The second part is answered easily, it's because it's possible to do it now. 10 years ago, restricting devices to a particular web store was not feasible as many PCs were not yet connected to the Internet and hence, installation of new programs from disks and CDs was the norm rather than the exception. Nobody would have accepted to only be able to install programs that had a Microsoft certificate. This has significantly changed as most devices are now connected to the Internet and the ease of use of exclusive web stores make many people blind to the fact that they are giving up a freedom they used to have. Giving up this freedom means that those who do are subjecting themselves to the values that a company thinks are the right ones rather than your own.

The first question of why this limit is imposed is often answered by saying that this protects users from badly designed or even malicious programs and that it's in the user's own good. To a certain extent that is of course true as programs go through a centralized audit. But I am a grown up and responsible person and I want to decide for my own. Someone else deciding what is good for me or not, no, thanks, I like my freedom. Google is using a somewhat different approach for Android. By default, downloading and installing apps from third party sources, e.g. from this web site or via sideloading from an SD card is blocked. However, the user is informed that if he really wishes to do that, it can be enabled in the settings. From my point of view that is a fair middle ground. It protects users from accidental installs of malware but still allows to open the door to freedom for those who want it. Also it is an incentive for users to buy software and content from the company that built the device or the operating system which is, by the way, the main reason for companies going down that road. Company interets and freedom do not have to be at odds with each other if done the right way.

One should also keep in mind that malicious programs are not the only way for a device to get infected by malware. Zero day exploits in web browsers that can inject malicous code that downloads keyloggers, scareware and other nasty programs are still frequently found. Web browser plugins such as Flash and Java leave the barn door wide open as well. Also, documents in email attachments that exploit weaknesses in office programs and files looking like documents but being executables are also able to infect systems and are very common today. A centralized and exclusive app store does not help against any of that. So the security argument might even backfire as it creates a false sense of safety.

Unfortunately, the anti-freedom effect the Internet has these days doesn't stop here. More and more, ubiquitous Internet access is also used for location and usage tracking, and only media pressure has so far prevented some excessive forms from becoming the norm. Anyone remember the "Carrier IQ" row from only last year? Yes, people forget quickly… Oblivion is the enemy of freedom.

Let also think about cloud services, freedom and privacy for a moment. Have a look at the terms and conditions of your favorite cloud service company. Is the data you store there, be it emails, documents, pictures, etc. really still yours or have you, by uploading them to that cloud service given the owner of the cloud service usage and redistribution rights to your data? You don't know? Well better check it out and ask yourself if this is acceptable to you or not. Note that I am not saying that all cloud services are bad. I use cloud storage for example but only with encrypted containers and the key is under my control and never ends up in the cloud. I also use email, obviously, one of the first cloud services and I am quite aware that I have no control over who sees what on the way from me to the recipient. And I act accordingly.

No, not everything is bad and if one is aware of these things one can act accordingly. My desktop is free, I am using a Linux distribution and I can install whatever software I like. Yes, it's not the only choice for a free desktop today, but companies are working hard to make it the only choice in the future. I use a VPN solution to protect my Internet connectivity when I travel and to prevent unwanted interference with the data I exchange such as unwanted network side compression or VoIP blocking. On the mobile side I use an operating system that lets me install any third party software I want and I only use cloud services to store unencrypted data I don't consider private, personal or my own. All of that takes effort, another enemy of freedom.

Freedom is not given it has to be struggled for.

For years, I've been collecting information from all around the web about which mobile network operator has how much bandwidth in which bands. Such information is quite helpful when it comes to understanding strategies and arguments in debates. No need to do that anymore as CEPT has just released a very comprehensive document giving an overview of spectrum owners for all European countries for the 800 MHz digital dividend band, the 900 MHz GSM/UMTS band, the 1800 MHz GSM/LTE band, the 2100 MHz UMTS band and the 2600 MHz LTE band. Here's the link to the page and here a link directly to the document ('ECO Report 03'), enjoy!