Category: Uncategorized

O.k., here are some follow-up thoughts after my previous post on background applications that generate keep-alive IP packets which have a negative effect on radio interface efficiency. The “efficiency” issue here is that the ratio between the amount of data transferred and air interface radio signaling is very unfavorable for small bursts of data, especially in cellular broadband networks such as UMTS. So Dan asks in a comment to the post why mobile e-mail (push or pull) could be counted in the “wasteful” category. All right, here we go, this is my take on it:

There are two kinds of mobile e-mail delivery:

The first is push e-mail to mobiles, such as on the Blackberry. Here the server is likely to only communicate with the mobile device when there is an e-mail to deliver. I haven't tested it personally yet so I don't make a definite statement here. But I assume even if some keep-alive messaging is necessary, for example in cases when no e-mails are delivered for some time, it should not be that much. Also, IMAP push which is supported by more and more phones these days should also not generate keep-alive messaging.

Second is pull e-mail, which I use for example as I don't like the IMAP (push) implementation of my e-mail program. My polling timer is set to 10 minutes, so my N95 checks for e-mail 6 times per hour. Definitely more wasteful than push if there are less than 6 e-mail per hour. In case you receive more e-mails per hour however, it can even be more efficient than push.

So is mobile e-mail wasting air interface resources? I guess that depends on the definition. If the definition is that an application is wasteful that only transfers little data per radio bearer setup, then I guess the answer is yes. But then, small screen web browsing, like for example with Opera Mini, would have to be categorized as quite wasteful, too. Many pages I view are compressed to less than 20 kB. Ouch, that hurts, as it's one of my favorite applications…

So my own definition of “wasteful” would be:

Exchange of IP packets for frequent keep-alive messaging that do not contain data.

That excludes e-mail push, Opera Mini use and, depending on configuration and number of emails per hour, e-mail pull.

That still leaves us with a lot of other applications, especially when connecting the PC to the cellular network, that keep babbling away and provoke lots of bearer reconfigurations. But as I said in the previous post on this topic: For battery driven devices, always-on applications are quite likely to be optimized over time to talk less to increase the battery lifetime.

I've had my new netbook for about a month now (see here and here) so it's time now for an update on how things turned out. I was a bit skeptical at first whether I would keep Ubuntu Linux on the machine or revert back to the original Windows XP. A month later, I am pretty much convinced that Ubuntu is the right thing for me on the machine.

One of the most important things for me with is the startup time of the operating system and the applications. In both categories, Ubuntu does extremely well. Booting the system takes just around 60 seconds. Going to suspend mode and waking up again just takes 6 seconds. That's almost instantaneous and helps a lot if you just want do something quickly, like looking something up on Wikipedia for example.

The applications I use most are Firefox, Thunderbird, Open Office, GIMP, Pidgin (for IM) and Skype. Even when compared to my full notebook with Windows XP, most of them launch much quicker. Sometimes I even catch myself thinking that the netbook is faster than the notebook…

Some things especially noteworthy I haven't mentioned so far:

• No drivers are needed for 3G phones or USB sticks. Both my Nokia N95 phone and the Huawei E220 3G USB stick worked right away. Not quite perfect as reported in part two, but it's a huge plus not having to install third party software, which often does more harm than good.

• HP went out of their way to produce Linux drivers for their multifunction printers. The package is called HPLib and makes using my printer / scanner / fax over Wi-Fi very easy. I even dare say the software is much quicker than the PC version, especially the scanning part. No waiting for the next dialog box, no long program startup times, the scanner just jumps into action when the scan button is pressed. Conversion to JPEG and PDF works out of the box, too, very nice!

But where there is light, there is shadow, too. Here are the things that required under the hood tweaking to get it working:

• The fixed line Ethernet chip was not detected automatically so I had to install the driver manually. It's not very complicated but for the average user compiling a driver is not a straight forward thing.

• There seems to be a WPA2 problem with the Wi-Fi driver as I get lots of packet retransmissions. I've tried with several access points but the result is always the same. When going back to WPA encryption, everything is fine. I've searched the forums but haven't found anyone reporting this. Under Windows XP, WPA2 is working fine so it seems to be a driver issue.

• The built-in video camera made some problems. I got it working for a while but it stopped once I've experimented with the screen resolution of the external VGA port and a second monitor. It seems the graphics driver can't handle advanced functions with a higher screen resolution. Also, desktop effects like windows zooming in and out when they are minimized only worked with the lower resolution. Getting the effects back requires manual intervention in the xorg.conf file as described here.

• Automatic suspend when closing the lid did not work at first. Even worse, the processor utilization went to 100% and the netbook kept running. The root cause seems to have been a BIOS issue. After upgrading the Bios of my Acer Aspire One D250 to V1.07, suspend when closing the lid now works.

So even though it required some tweaking I've got a fully functional Ubuntu netbook now and I am very happy with the performance.

Back in 2007, network operator '3' in the UK announced that they are no longer asking for roaming charges for voice or data between their networks worldwide. A great offer even though the times I tried, their interconnection was hopelessly overburdened. Looks like the offer is no more as they 3UK has started introducing international roaming charges again since July. A great pity… Strangely though, '3 Like Home' is still offered by 3 Austria!?

This might seem obvious to most but I just realized these days how important the battery is for the mobile experience. I recently bought a netbook (see here and here) and while most experiences are positive, a battery lifetime of only 2 hours just doesn't do for me in many cases especially when I am traveling. Even if it is enough, connecting the netbook back to the mains all the time for recharging is also a hassle. So I bought an extension battery pack which gives me 6 hours of autonomy in addition to the 2 hours of the standard battery. An incomparable experience! Now even while traveling for a whole day, sitting in the train, waiting at the airport and on the plane, I don't have to worry about the netbook running out of power. Very nice!

Back in October 2008, I wrote about a blog post of David Wood, who is part of the Symbian leadership team, where he said that while smartphones only account for 10-15% of sales units, the sales revenue is between 20-25% and profits may even exceed 40%. Now Moco News reported similar numbers being given by Deutsche Bank analyst Brian Modoff in an article in the Wall Street Journal.

His numbers are as follows:

• Apple and RIM together only have 3% of the mobile phone market share but make 35% of the total profits.

• Nokia manufactured 46% of the mobile phones sold last year (I heard 38% somewhere else) and made 55% of the profits. Note: It would have been interesting to see the split in profits between their smartphones and the rest of the phones they produce. Do they give these numbers in their quarterly reports?

That makes me wonder why there is so much profit in smartphones vs. the rest!? Granted, their price is much higher than that of ordinary phones and thus if the profit percentage is similar, the profit per device is also higher. However, that can't explain it all. Less competition then maybe? Also a bit doubtful as the smartphone market seems to be quite competitive with manufacturers like Nokia, Apple, RIM, HTC (G-phone, WinMob), etc. vying for market share. What do you think?

Every now and then I get an interesting comment for which a typekey id was used as a commenter id instead of an e-mail address. While that is perfectly all right in theory it unfortunately doesn't allow me in practice to reply to you by e-mail in addition to leaving a comment of my own below the poast. That's a bit unfortunate as most people probably won't check back on the blog to see if I have left a response. Therefore, dear readers, please put an e-mail address in the id section of the post if you would like to receive a response in case I have any 🙂 The e-mail address is only shown to me so there is no need to worry about spam. Thanks!

Here's a quick update on my experience with my netbook, Ubuntu and 3G connectivity. As reported previously, the 3G connectivity manager built into Ubuntu works (most of the time) but doesn't have some important administrative functions included such as network and network type selection and some general observational functions such as current network name and signal strength indications.

At least the later functions are included in the Linux 3G Dashboard from Vodafone Betavine, which works great with my Huawei E220 USB 3G stick. The screenshot on the left shows how signal strength and the network name is displayed in the lower left corner of the dashboard. Nicely done!

What's still missing is a network selection dialogue and to be able to lock the USB stick to 3G, which sometimes helps to stay connected in bad signal conditions. It would be nice to see this in a future version. Also, having the possibility to select a different connection profile on the main screen would also be nice, especially for people (like me) who travel a lot.

To install the dashboard go to this Vodafone Betavine project page, and download and install all packages from the download section.

Back in April I ran some tests in London to see how many 3G frequencies were used by the carriers there to get a feeling of how much capacity is offered today. To my great surprise, only one of the network operators had deployed more than one 5 MHz carrier frequency. Recently, I was in Vienna and since the country has many affordable 3G Internet offers that lots of people already use, I was wondering if the situation was different.

It turned out that the situation was pretty similar. Except for T-Mobile, who had two 3G carriers deployed in the center of Vienna, all other operators only used one carrier frequency. Network throughput during the day and in the evening in the A1 network were always good (above 1.5 MBit/s) so the current low capacity build-out from an available carrier perspective can handle the traffic well. To me, that sounds like good news!

As standardized today, LTE does not have built in SMS capabilities. In a recent webinar on VOLGA (Voice over LTE via GAN), Franz Seiser of Deutsche Telekom (formerly T-Mobile International) argued that this might be a significant issue in the future for a number of reasons.

First, he said, there are a lot of systems in the network that rely on SMS such as SIM card provisioning, for updating the roaming operator list and other data on the SIM card for example, SMS subscription to activate/deactivate add-ons, etc.

Second is the EU mandated SMS user interaction while roaming. Introduced during the first wave of roaming regulation, operators are obliged to inform their subscribers by SMS about roaming costs when they start using a network abroad. In the future, notification to prevent "bill shock" (e.g. when using mobile data abroad) might also be based on SMS.

While the roaming tariff SMS announcements for voice and SMS are probably meaningless for LTE networks that do not support voice and SMS, the notification about bill shock might very well apply to LTE as well. Unless of course, the same tariff applies abroad like at home. Unlikely I would say…

So I quite agree with Franz, if a network allows VOLGA roaming in the future, the SMS solution already comes included at no extra price.

Another option is using SMS as part of the CS fallback (CSFB) feature that is already standardized. However, if the roaming country does not support CSFB and the mobile device is mostly data centric, then the SMS can't be delivered. While it's pretty obvious that a USB data dongle is a data centric device, I wonder what an iPhone or an N97 qualifies as.

And then there is SMS over IMS. However, I doubt we will see IMS and mobile IMS clients anytime soon.

Here's a picture of my new netbook, a 10.1" Acer Aspire One D250 side by side with my first notebook I bought 15 years ago. Sizes are quite similar but the interior is quite different. 1 GB of RAM vs. 8 MB, 160 GB hard drive vs. 20 MB, 386 processor running at a couple of MHz against an Intel Atom running at over 1 GHz. About two orders of magnitude apart from each other. Of course, 15 years ago it wasn't called a netbook, even though my 14.4 kbit/s Modem (external) was start of the art then. Surprisingly, the 15 year old notebook still works. MS-DOS and Windows 3.1 boot in a matter of seconds, out of the 8 MB of memory, 5 MB are free once the OS is loaded and Microsoft Word loads faster than anything I have seen in the past decade. Sounds all nice but I don't want to go back. It's just a bit more comfortable today and I am not sure the old Compaq could handle a 6 MBit/s DSL line. After all, at that speed the hard drive would be full in less than a minute 🙂