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An international roaming thought today: While in the past I used manual network selection while roaming mainly to reduce the number of unwanted welcome SMS messages I have recently found another good use for it: As I am usually always connected to the packet side of the network, using manual network selection and thus locking the mobile to a particular foreign network prevents the PDP context from dropping every time there's a coverage hole and the mobile phone searching and attaching to another network. Quite a nasty thing if you are billed extra for each context activation or in big increments. But I would certainly trade manual network selection for affordable data roaming prices…

Back in 2007 I wrote a post about why I think that the 'Average Revenue per User' (ARPU) has become totally meaningless and needs to be replaced by another measure. Three years later, not much has changed on the reporting front, but I think in terms of definition, the general ARPU is even more meaningless now as back then. In fact I think the lower the ARPU reported by a network operator is today when compared to other national operators and operators in comparable countries, the better it is for the network operator.

The lower, the better!? Look at it this way: The lower the ARPU, the more subscribers have been won over by the network operator to use the network that do not spend as much as subscribers that use the network more. But even though those subscribers spend less, they are by no means less valuable to have. Also, there's a growing trend of people owning more than one SIM card for various reasons such as making cheaper calls to other networks with a second SIM card (hello Dual-SIM phones), an additional subscription for business, a 3G stick for business use, a 3G stick for private use, additional 3G enabled gadgets such as the iPad, 3G enabled netbooks, etc., etc.. All require a separate SIM and hence a separate prepaid or postpaid subscription that generates its own ARPU.

From this point of view I generate at least 5 separate ARPUs today and even more if you count the various prepaid SIMs I occasionally use for test purposes. So the PU "Per User" part of the ARPU is far from reality today. It's really time for a new measure…

Interesting self observation: I regularly use two computers, one notebook at home that remains on the desk 99% of the time and is fully wired to the local infrastructure (mouse, printer, scanner, power supply, etc.) and a netbook I use a lot while traveling and commuting. One of my printers has a Wi-Fi interface while the other one only has a USB connector. So while I use both printers from the notebook that is always on the desk as it is connected to both permanently anyway, I only use the Wi-Fi enabled printer from the netbook.

Not that it is a lot of effort to unplug the USB cable of the other printer and plug it into the netbook but it is really very inconvenient compared to just clicking on the 'print' button on the netbook and the page magically appears on the printer without any further action. And I can even print from another room if I happen to use the netbook somewhere else for a change. Also, I use a wireless mouse with the netbook so there's no fumbling with the cable of the mouse when I get the netbook out of the bag.

As Internet connectivity runs over Wi-Fi, too, the only cable that remains for the moment is the power cable. Some early solutions for this are also in sight with induction based chargers that are now sold for mobile phones (e.g. the Touchstone for Palm Pre) and currently standardized in the Qi Wireless Power Consortium. I'd really like to have that for my netbook as well. Just put it on the table when coming home and it magically recharges without any further action to be taken.

About five years ago (November 2005 to be exact) I started this blog as a bit of an experiment to figure out what to do with this new 'blogging' thing and to see if it could be of use to me and others. Now in 2010, more than 1100 blog posts and 2000 comments later, I have found it to be an incredibly useful tool to gather my thoughts, share them with a wider audience, ask for your opinions and to meet others in this industry either virtually over the net or in real life. I have learnt a lot by writing the posts and from reading and responding to your comments. A couple of days ago, the blog has passed the one millionth page view. To me that's an incredible number and another sign that the information an my opinions on this blog are useful. Thanks to all of you, that's great additional encouragement to keep writing and developing the site!

I always find it interesting how public Wi-Fi hotspots deny access in some form or another for some services. The free public Wi-Fi hotspot at an Avia gas station in France I recently encountered gets the prize for the most innovative blocking I have seen so far. Encrypted POP3 and SMTP are blocked so no e-mail. On top, SSL VPNs are blocked so also no privacy here. The blocking is actually quite intricate when taking a closer look:

As I can use port 443 for https, which works, I was wondering how they could let https go through while the VPN is blocked. With Wireshark, I could determine that the TCP sync packet gets a response from the VPN server, so these packets pass their filter, while all further packets are discarded. So it looks like they don't only filter on a port basis but in addition do some deep packet inspection to determine if a TCP session establishment over port 443 contains certain SSL header elements for HTTPS. Hm, time for a HTTPS emulation for my VPN then…

Most of the time I use a 3G stick when out and about to connect to the Internet. It's just very convenient, you plug it in, hit the connect button and that's it. But there are also occasions when a Wi-Fi hotspot has its advantages if it wasn't for the manual login process and the manual activation of a VPN for privacy and security afterwards. In the past I've found some good advice on the net on how to automate the hotspot login for T-Mobile hotspots in Germany via a bookmark in the browser. That works great but there are still two manual tasks to be done before the connection is in place. So I recently decided to automate the procedure on my netbook running Ubuntu. Here's how it works:

Once Ubuntu has detected the T-Mobile hotspot and has automatically attached, I execute a bash script that does the following:

First it performs a login into the hotspot system so I get internet access. The link above shows how that is done with a bookmark in the browser. In effect, the login is performed with a HTTPS request that contains the username and password (original tip from here). In a script the HTTPS request can be sent with the following command:

wget –output-document=/dev/null "https://hotspot.t-mobile.net/wlan/index.do?username=USERNAME@t-mobile.de&password=PASSWORD&strHinweis=Zahlungsbedingungen&strAGB=AGB"

The wget command sends the request and receives the result page from the login server which is discarded to the NULL device because I don't really care about it. Next I start OpenVPN to connect to a Witopia VPN gateway:

cd /path/openvpn
sudo /usr/sbin/openvpn –config myvpnscript.ovpn &

Note that the Witopia ovpn files contain a line at the end that the openvpn executable above can't interpret and hence stops execution with an error. Just comment it out and you are good. And now comes the tricky part: Unfortunately, openvpn does not change the DNS server entry. So once the tunnel is established the OS can't resolve names to IP addresses anymore. To counter this I start openvpn in the background (&) and the script continues. I let openvpn do its initialization by waiting 5 seconds and then change the DNS server configuration with the following commands:

sleep 5
sudo cp /path/scripts/resolv.conf /etc/resolv.conf

The resolv.conf in the script's directory contains an original resove.conf from /etc in which I have put the DNS server used by Witopia which is reachable through the VPN tunnel. A bit of a kludge but it works. If you know how to do this in a more elegant way, let me know.

After that, the tunnel is established and I halt the script with the read command to wait for user input. This way, I can tear down the VPN tunnel once it is no longer needed. After the user presses a key, the openvpn tunnel is torn down. One could now also restore the original DNS entry but its not really necessary as Witopia's DNS server is reachable over the public Internet as well. 

read nothing
sudo killall -9 openvpn

There we go, not quite straight forward to come up with but once the script is in place it works like a charm. As with everything there are of course also disadvantages:

• The network icon in the taskbar doesn't show that the VPN tunnel is established like it would if you active the VPN tunnel via the Gnome menu.
• The script requires you to type in the root password as activating the tunnel device for the VPN link requires elevated rights.

Any idea what is happening with Bluetooth out there these days? The Bluetooth SIG keeps including ever more features in the Bluetooth specification, now at version 4.0 with Ultra Low Power enhancements. However, there are few if any products on the market these days that even only implement the security enhancements introduced back in 2007 with version 2.1 of the specification!?

Nokia and Samsung seem to include Bluetooth 3.0 in the feature set of their latest phones but they don't go into the details of what that actually measns!? Is it the Wi-Fi transport layer for fast Bluetooth transmissions that was introduced with version 3.0 or just some minor improvements over the 2.1 standard? Bluetooth is used a lot today for wireless headphones, wireless keyboards, etc. but I don't see it in new applications, at least not when it comes to mass market adoption. So I wonder if the technology has reached a plateau from which it is going to be difficult to escape? As always, your thoughts are welcome.

One and a half years ago, I was very impressed with download speeds of 5.76 MBit/s as measured by a German computer magazine in life networks. These days I have upgraded by equipment a bit and now have a stick that outpaces this value by far. At home, without any special setup, no external antenna, just the plain basic setup, I now get downlink speeds in excess of 11 MBit/s over HSPA. Have a look at the picture on the left where the speed shown as 1.4 MByte/s (around 11 MBit/s). Also interesting how stable the curve is with only small variations, i.e. no wild oscillations, etc. Very impressive and surely not the end point in the race for every faster and better wireless networks.

Another cross company meeting observation today: It's good to see how choice works when the network doesn't. When In a recent meeting the Wi-Fi connectivity for the participants acted up, about half the participants just got our their 3G USB sticks and used the various 3G macro networks to get back online. Probably inexpensive for the local residents, a bit more expensive for the foreign participants. Shame on the Wi-Fi network not working as it should, but then, if the meeting is not underground there is a now a good alternative when you have a local 3G SIM or can afford the roaming charges.

Every now and then I see something that reminds me in an impressive way of how quickly the mobile industry is changing. Not too long ago, even electronic stores sold mobile phones (the word 'phone' used intentionally here) in a way where you would have to ask an assistant to give you the box of a phone you wanted to buy out of a locked shelf. Usually the store had a couple or a few dozen of each model in stock. These days are over. Take a look at the picture on the right (click on it to enlarge). Low end phones are sold from the rummage table now. Just take a box for 29 euros and stick in a SIM card of your choice inside. Even higher priced touch phones up to about 110 Euros were sold in the store this way. Incredible, I think the word 'mass market' is not quite adequate anymore to describe how pervasive mobile communication has become in everyday life now.