My Mobiles

Recently, I had an email conversation with a reader and he sent me a list of mobile phones he had in the past. Interesting memories coming up. I doubt my list is equally long but I think it is time to make my own so I won't forget. Here we go:

  • I started with a Bosch 738 (I am German, the French will get the irony)
  • A Siemens S25 (my first color phone)
  • A Ericsson T39 (my first GPRS phone (!), could only do static assignment, only worked in one network)
  • A Siemens S45i (GPRS worked well after a couple of software upgrades)
  • A Siemens S55 (browser, color screen, a couple of hundred KB of flash memory with file system!)
  • A Sony-Ericsson V800 (my first UMTS phone)
  • A Nokia 6630 (only used as a modem at the time)
  • A Nokia 6680 (First phone on which I discovered the power of S60)
  • A Nokia N70 (Natural evolution from the 6680)
  • A Nokia N93 (Bought because of the camera and the twist) 
  • A Motorola V3xx (initially used as an HSPA modem, today also as backup phone)
  • A Nokia N800 Internet tablet (o.k. not quite a mobile phone)
  • A Nokia N95 (my main phone today in 2009, bought because, well, because of everything 🙂
  • A Nokia N82
  • A Nokia 5000 (low end with color screen, used as phone and to test apps on an entry level platform)

And in addition:

  • I had a Palm 3, and two HP PDA's, discontinued to use them when I bought the N70, as I could do all the calendar stuff, etc. on the mobile phone
  • A Sierra Wireless 850 1.8 MBit/s cat 12 HSDPA PC-card modem
  • 2x Huawei E220 3G USB dongles (3.6 MBit/s cat 6 HSDPA) for Internet access. In use today. They might be a bit clunky by today's standards, but they just work in all networks I have used so far, which can't be said of other 3G sticks I tried.

There we go, the list is already longer than I thought 🙂

The Digital Dividend, LTE, HSPA, TV Stations and Wireless Microphones

Over the past days there have been reports in the press that Vodafone Germany will trial LTE in the 800 MHz digital dividend band to collect experience how this frequency band can be used for rural broadband Internet coverage. The reports also mentioned that a TV station (the WDR) will also take part in the trial. A TV station?

Why, I wondered at first, as all but Unstrung did not go into the details of why a TV station is part of the trial. So, according to Unstrung, the TV station is part of the trial as they are interested, or a bit worried, that using spectrum in the 800 MHz band for broadband Internet could have an impact on their TV broadcasts in an adjacent band. Further, wireless microphones are using the digital dividend band today and it seems it is not quite clear of what can be done about that in the future (see here and here).

So the outcome of this part of the trial will be quite important to figure out if or how all of the 72 MHz foreseen to be assigned in the 800 MHz band for mobile broadband systems can be used without generating too much interference for TV broadcasts. An interesting topic to follow.

Crop Insurance in Kenya – Via SMS

And another follow up post on the University of Oxford's Future Technology Conference: During on of the many "socializing breaks" I met Eric Seuret of 3SMobile and he told me about the crop insurance via SMS application for farmers in Kenya he has developed for Syngenta, a large global agriculture company. The concept is so elegant, simple and has the potential to improve the lives of many people, so I asked Eric to send me some more details about how the service works. Here are the details:

The weather insurance solution via SMS helps protect small holder farmers against the risk of drought.  When a farmer purchases certain Syngenta seeds and crop protection products he obtains special insurance stickers.  When he has collected a certain number of stickers he gets an ID number which entitles him to 1 acre of free weather insurance for that season. To obtain the insurance he does not need to fill out any forms or contracts.  All he needs need to do is SMS a unique insurance code ID to a local number. The system then verifies that the insurance code is valid and confirms the farmer's insurance status.  If the farmer has a larger plot of land he can obtain multiple cards and insurance policies.

Throughout the course of the year the farmer is kept informed of major weather issues that are related to the policy via SMS.  At the end of the season the historical weather data is used to determine which farmers are entitled to a payout based on their region.  In the case of a payout the farmer is notified via SMS and they can go to the stockist to obtain the payout.

It is the first time that insurance has been made available to small holder farmers in Kenya with 1 acre or less of land.  This has only been possible through the use of mobile technologies were the solution finally became cost effective.  Mobile phones were used to simplify the administration, reduce costs, enable immediate registrations, and to help form a direct link to the end customer. In many cases the mobile phone represent the only way to reach the farmers without physically visiting the remote villages.  The innovative solution is currently running as a pilot project and is so far proving to be very successful.

The insurance concept and solution was designed by Rose Goslinga and Fritz Brugger for the Syngenta Foundation for Sustainable Development and developed by Eric Seuret.

Early Beta of Nokia Point & Find

Except for Japan, 2D barcodes haven't really made it into the consumer world so far. Maybe we can jump right to the next step in the evolution with Nokia's Point & Find early prototype that does not rely on a barcode to identify something and then get some more information from the internet but instead does image recognition? Below is a video of how it works in the context of getting more information about a movie by pointing the camera phone at a movie poster.

Personally, I can also imagine to use the application for sightseeing. No more tracing through a tourist guide, just point your phone at that church, castle, monument, etc., and you get background information on it. I'd really like that.

The web page for the new application contains some further information in PDF files but doesn't go into the details of exactly how it works, like for example if a picture is taken and uploaded for analysis or if  information is downloaded before and then analyzed locally).

In any case, I think there's great potential behind this, especially because individual companies can create their own Point & Find worlds. If Nokia allows some sort of billing for world downloads, I can imagine it might be an interesting application for companies working on tourist guides (to come back to my example above) to create an enhanced electronic version of their printed guides. Free point and find world downloads would be good for other purposes, like the movie industry, who could promote their movies this way in the hope users buy a ticket online or later on rather than charging for general use.

What happened to 3GPP’s Earthquake and Tsunami Warning System?

Over the weekend, I wanted to take a closer look at the 3GPP Earthquake and Tsunami Warning System (ETWS) for GSM, UTMS and LTE. I was expecting to find proper stage 1, 2 and 3 documents in place by now so implementations could follow soon. It turns that of the three documents, only stage 1 (3GPP TS 22.168) has made it so far into Release 8. However, it seems that the specification might have been withdrawn at SP-43 in Biarritz in March 2009. 

The same applies for the stage 2 documentation 3GPP TS 23.168, it's current state is "withdrawn". There is a pointer to Technical Report (not a specification!) TR 23.828 which gives an overview of the different options analyzed and the proposal at the end to go for solution 5. Solution 5 would be to send a first warning to the mobiles via a special paging message with further details right afterwards in a cell broadcast message. For GSM mobiles already engaged in a voice call, the BTS would create a special SMS and sent it over the slow associated signaling channel while the call is in progress. In UMTS, paging messages can also be received during a call. What's not mentioned is how mobiles currently having a GPRS TBF established would receive the notification as there is no associated circuit switched signaling channel and pagings would not be received over the paging channel. But for the moment, that is beside the pont, since both stage 1 and stage 2 of the specification was withdrawn.

However, there is a link to 3GPP TS 22.268, a stage 1 specification for a much more generalized public warning system (PWS). No stage 2 specification exists so far, so this one is also at the beginning. It's an interesting document as it shows how much time there is to warn the public about an earthquake or a tsunami. Very challenging!

I am a bit puzzled!? Looks like ETWS was already quite well on it's way but now seems to be suddenly stopped? Did it fall short of the requirements? If you know more, please leave a comment below.

LTE: Default vs. Dedicated Bearer

One of the big changes brought about by LTE is that when the mobile device connects to the network it also implicitly gets an IP address. This is called "Default EPS Bearer Activation". What seems to be a trivial change at first is actually a whole new way of thinking compared GSM and UMTS.

In 2G and 3G systems, the mobile registers to the network first and in order to get an IP address, a "PDP context activation procedure" has to follow. This is also what is known as establishing a "packet call". I never very much liked the term "packet call" which was probably created because of the still mainly circuit switched thinking at the time. So with the default bearer activated right from the start, the "packet call" and all the legacy behind it has become history.

To build on the default bearer there is also a procedure in LTE called "Dedicated EPS Bearer Activation" which is initiated for the network. But what is it needed for, most people ask at first, the mobile already has an IP address!? True, the mobile already has an IP address but the default bearer comes without any quality of service guarantees. For VoIP, IMS, VoLGA and other real time streaming applications, it would be good to have some QoS, especially on the air interface. This ensures that the base station and other network components deliver IP packets for those applications with a higher priority. Also on the mobile side, such IP packets should get a higher priority than other packets, especially when the bandwidth is limited. And that's what is done with a dedicated bearer.

In the network, the dedicated bearer is connected to a Traffic Flow Template (TFT), a concept that already exists in GSM and UMTS. In this template, think of it as a list of ip addresses and tcp/udp port combinations, describes which IP packets should be given a higher priority. The TFT is also forwarded to the mobile during the dedicated bearer activation and it helps the protocol stack to put the IP packets to or from a specific TCP/UDP port and/or IP addresses into a special QoS queue that is treated with a higher priority.

No need for the mobile to have an extra IP address for this higher priority traffic, as the protocol stack uses the Traffic Flow Template information to decide what to do with each IP packet. In other words for those who are familiar with GSM and UMTS, a dedicated bearer activation is pretty similar to a Secondary PDP context activation in 2G and 3G that can be used by the IMS for example to ensure real time data is delivered promptly.

For the details have a look at 3GPP TS 24.301, chapter 6.4 and table 8.3.3.1 a bit further down for the message details.

Finding Dormant Cells

Having stayed a bit outside of Barcelona for a couple of days before the Mobile World Congress back in February, I ran across a phenomenon again that I call the "Dormant Cell" issue. While a "dormant" cell seems to be up and running for both the mobile devices and the RAN control center, it is somehow locked up internally and is not functioning properly. In my case outside Barcelona it was a UMTS cell and the signalling to establish an Internet connection worked just fine. However, subsequent data transfers did not work at all. A kilometer or so away things worked again as the mobile selected a different base station.

One would think operators would detect such cells quite quickly and reset them. However, it seems that in practice cells sometimes do not send alarms to the operation center so the personnel is oblivious to the issue. In my case the situation remained that way over three days. Now try to report such a behavior to the operator's first line support staff…

To catch such issues, some operators run statistical counter analysis like for example to compare daily data transmission volume per cell. If suddenly a cell shows abnormally low values the analysis program generates an alarm so the network operation center can take a closer look. Unfortunately, not everyone seems to do that or at least not very often, like the operator of the network I used in Spain.

Agreed, it's quite a number crunching effort when you have several thousands of cells in your network and requires a big database to compare current counter values against those measured in the past. But benefits of such analysis go far beyond just finding dormant cells. This way, it's also possible, to give just one example, to follow rising use of certain cells in your network and to predict when it will run out of capacity. That way the network can be upgraded before the cell runs into saturation. The principle does not only apply for Internet access but also for voice calls.

I picked the Barcelona incident to start the post but quite frankly, it is not the first time I've seen such behavior and not only in a single country. Looks like this is a general phenomenon experienced not only with a single RAN vendor.

The Making of the N97

O.k., I'll play along with Nokia marketing for the N97 today for three reasons:

  • I can't wait for the N97 to be launched so I can finally get one after months and months of waiting.
  • I hope they made good use of the time and have a usable firmware version by now.
  • I like the N97 "making of" video embedded below. O.k., it's marketing, but well done and it reflects my passion for mobile communication.

Nuff said, here's the video, switch to HD, full screen and enjoy!

Telecom and the Green Planet

Greentv Over at TelcomTV, a video series has been started on the impact of the Information and Telecommunication Industry on CO2 emissions, energy consumption and how to reduce the impact as we go forward. One episode is published per week together with lots of background information. A very interesting project sponsored by Ericsson and Juniper and I'll be surely watching it over the coming weeks. There's also an RSS feed on the page so you don't have to remember going back to the page once a week for the latest update.