100% Compatible?

SFR has just told me in an unsolicited email advertisement that in case I go for their "generous" 3G USB stick offer, 100% of all computers are compatible. In the fine print, they say they have drivers for Windows and Macs. Hello, haven't you forgotten something? Yes, I am using Ubuntu Linux, I guess that's the 0% you've been missing… But good news for you, your stick looks like a Huawei E169 and that should run just fine under Ubuntu as well, there are not even drivers required for it…

OperaMini on Android – A Quick Review

I've been looking around a bit for a future replacement for my aging Nokia N95. One thing that definitely has to work on the new phone is OperaMini as I am often in situation an places without fast and affordable 3G Internet access. I've noticed that OperaMini is available for the Android platform so I gave it a try on one of the new Android devices.

The Good Stuff

The Mini implementation on Android is great! Pages are loaded in a flash and the touch interface works very well for following links or selecting a page to go to from the bookmarks. The browser also doesn't have to stand back when directly compared with the native Android browser. The kinetic scrolling is not as smooth as with the native browser but on the other hand, pages are loaded much faster due to the network side compression. Also, unlike with the native browser, I can go back several pages very quickly as those pages are still in the cache and thus do not trigger a reload. Another important point: Copying/pasting of links works in the same (clunky) way as on the N95 by bookmarking a page, selecting and copying the URL in the process, aborting the task and using the URL for example in the e-mail application. Not very elegant, but it works.

The "Not So Good" Stuff

The one thing I didn't like: Either Android is not fully multitasking or the amount of RAM was not sufficient as whenever I went to the home screen and started another application OperaMini was closed and I had to start from scratch again when going back. The program loads very quickly but the previous pages were no longer in the cache. That's a pity as it works much better on my current N95, where the browser stays in memory no matter how many other applications are open at the same time.

LTE Tracking Area Update vs. UMTS Location/Routing Area Update

Here's an interesting piece of technical insight I gained this week when going through 3GPP TS 23.401 concerning tracking area updates that I haven't seen when I went through the spec for my SAE review posts back in February (part 1, part 2 and part 3):

In UMTS, location area and routing area udpates are only done when the mobile is in idle state, i.e. no physical link is established on the high speed shared-, dedicated- or forward access channel. This makes sense as in these states the RNC in the access network is aware of the location anyway and can report location changes to the core network when necessary. Only once the mobile goes to idle state and the mobile makes the decision to go to another cell on its own without reporting back, routing and location area updates come into play if the new cell is outside the current area.

In LTE, the corresponding procedure is called a tracking area update. The first difference to the LAU and RAU of UMTS is that the mobile can have a list of several valid tracking areas and an update only has to be made if the new cell is in a tracking area that is not part of that list. So far so good. TS 23.401 chapter 5.3.3.0 says, however, that a tracking area update is made in both idle and connected state. Quite a surprise to me so I wondered why an update is necessary in the connected state!?

The answer to that question can be found in the message sequence charts for handovers. For example: during an X2 handover, which is directly negotiated between two base stations, the Mobility Management Entity (MME) in core network is only informed of the handover after it has taken place. Also, there's no direct communication between the MME and the mobile device during the handover procedure. That means that in case the new cell is in a new tracking area, the mobile has to update its tracking area list as that information was not contained in the handover messaging.

From a logical point of view that also makes sense. Traking areas are administered by the core network (by the Non Access Stratum) while handovers are performed by the access network. Also, the signaling does not interrupt the user data transfer so there are no side effects of performing this procedure in connected mode and while transferring data.

More LTE technical tidbits this week also over at Wired n' Wireless.

How Much in The 3GPP Specs is Deprecated or Will Never Be Used?

I know I won't get a real good answer for this one but I was just wondering of how much in the current set of 3GPP specs is no longer used at all anymore and, even more interesting, how many features and options specified over many years never made it to real networks!? With tons of features specified in each new release and only a few really used, I assume it should be a sizable percentage.

Why I care? Well, when reading the specs it's often not only difficult to interpret what is written but also if what you are just trying to figure out already is or will be used on day. Is this the price to pay for having one system to which (almost) everyone contributes to? What do you think?

3G Price Models

I've recently had a chat with a friend on different 3G price models and I thought I'd write down a little overview to document the diversity of the tariff landscape in Europe today:

Let's start with examples from Germany: Here, a popular post-paid model is a fair use all you can eat plan with a volume cap, for example 5 GB, after which the bandwidth is throttled down to 64 kbit/s for the rest of the month. While staying within the bucket, speed is only limited by the device, network capability and radio conditions. Prices for such plans range between €30 and €40. Other volume caps also exist.

In the pre-paid sector, there are many offers for small screen devices billed per MB. Prices range between 20 to 40 euro cents per MB. Great for low to medium use with OperaMini and e-mail without attachment download. Some operators are also offering prepaid plans for notebooks with volume caps of a couple of hundred MB to a couple of GB for prices anywhere between €20 and €40. Vodafone and others have offers based on time, for example 24h access for €5 and a week for €10 with a volume cap at 1GB. If you dig a bit deeper the weekly package can also be had from a reseller for €6.99.

Finland: Here, Saunalathi Saunalahti offers unlimited bundles and charges based on maximum throughput. Prices range from €9.80 with a speed cap of 384 kbit/s up to €34.90 for a throughput of up to 5 MBit/s Gbit/s.

Austria: The el dorado land when it comes to mobile. Drei (Hutchison 3) sells 15 gigabytes a month for €15on a postpaid contract. Prepaid contracts are available as well, like for example those of Mobilkom and One, where €20 buy one gigabyte that can be used over 12 months. Maybe not very attractive from a price per GB point of view but for occasional users it's an unbeatable monthly price.

France: Here, clocks are still ticking differently compared to pretty much the rest of Europe. Orange for example offers 1 GB of traffic on a post-paid basis for €39.90 after which the bandwidth is throttled. 4 GB are offered for €79.90. Prepaid packages are only available on a time basis. 20 minutes go away for €3, an hour can be had for €8, six hours cost €25 and if you want to be connected for 12 hours over the duration of one month, you have to invest a staggering €35. Nothing really for always on connectivity fans.

Feel free to add to the list if you know of yet another variation.

Update: Orange in the Metro

Back in September I noticed that the speed when browsing the web in the Paris Metro with OperaMini has significantly improved using France Telecom's / Orange network. At the time I was wondering if this improvement over a previous massive slowdown was only temporary due to the vacation period or if something has really changed. This Saturday I took a hopelessly overcrowded Metro 4 through the city center and it's good to see that there was enough network capacity for my Opera Mini browser to fly from one page to the next. Thanks Orange, it's usable again now!

HSPA Cat 8 in Practice

Almost exactly 2 years ago, I've first seen a demonstration of a cat Cat 7/8 HSDPA device and went away very impressed after seeing downlink speeds of 4.2 MBit/s. Now I've finally gotten my hands on one myself and tested it in Vodafone's network in Germany. On the 6th floor of a building, the base station pretty close by (I assume) and my download speeds easily exceeded 5 MBit/s (= 700 kbyte/s) consistently over several days and at different times of the day. Wow, that's twice as fast as my ADSL line. But that's not the end of the line, a few operators have already rolled out HSPA+ with 21 MBit/s. Examples are Mobilkom Austria in Vienna and Telstra in Australia.

Base Station Throttling Revisited

A couple of weeks ago I posted my thoughts around doing throttling of heavy users directly at the base station so the current load can be taken into account as well. No need to throttle heavy users if nobody else is using the cell. While it was just a "Gedankenexperiment" a reader pointed my to this paper in which Ericsson actually describes just such an approach and says it has already implemented it in their RAN. Very interesting! The paper unfortunately doesn't contain a lot of information of how this is done from a technical point of view, i.e. how is the base station informed which users to prefer over others. If you know more, if this is not a state secret and some information about the feature is publicly available, please let me know!

Mobile Notification for Parcel Deliveries from DHL

Here's an innovative mobile service from the German Postal Service (Deutsche Post, DHL) I think I will use more often from now on: My big problem when getting things via mail is that I am usually not at home when the parcels are delivered. That leaves me with guessing when the parcels arrive, go home early to pick up the delivery failure notice and then drop by the post office before it closes in the evening. But now there's a better solution for it: Close to my office there's a so called "Packstation" to which my parcel can be delivered. Once it's there I automatically get an e-mail or SMS to inform me that I can pick it up. Great, I just have to walk over, insert my customer card, type in the PIN and the parcel is mine. Great mobile service, that's how I like it!

Web Browsing over DSL and 3G Compared Side by Side

Web surfing over 3G must be slower than over DSL, right? To see if this statement is correct, I used two computers side by side, one connected to to Internet over a 3 Mbit/s DSL line and the other one over a 3G dongle. The 3G network of choice was that of Vodafone Germany in Cologne with the base station at least supporting HSDPA category 8 (7.2 Mbit/s) devices.

For the first web browsing test I used a Huawei E220 3G dongle with a somewhat older but very reliable HSDPA category 6 software load. Computer screens side side by side I simultaneously clicked on links to load web pages, both visited and never visited before, to see on which computer the pages displayed first. The result: In this test, the web pages took around one second longer to be first displayed on the 3G connected computer but the difference was quite minor. Definitely less than what I expected.

In a second test, I used an HSDPA category 8 + HSUPA capable E176 which has been available on the market already for a little while. Definitely not the latest and greatest anymore but still good hardware. With this setup the side by side comparison showed no difference anymore, pages on both computers showed up almost instantly. Sometimes, the page would show on the DSL connected computer a fraction of a second earlier, sometimes it would be loaded a bit quicker over the 3G connection. Fantastic!

A little caveat: At the time of the test the network was only slightly loaded so one of these days I have to find a time at which it is a bit busier and repeat the test to see if that makes a big difference.