Author: Martin

Ericsson says 1GB can be had for 1 Euro

Here's an interesting article from Ericsson on the business case of mobile broadband. Taking CAPEX, OPEX for both access and core network into account, the article comes to the conclusion that once an economy of scale is reached in terms of the number of broadband subscribers, the network can deliver 1GB of data for one Euro.

While this is the main outcome of the paper, there are a number of other pieces of information in there on which the calculation is based which are quite interesting. Here are some which I noted:

  • 20% of the cells carry 50% of the traffic. I've heard of similar numbers before and I think it's a good thing because the network operator can focus on upgrading a subset of all cells rather than having to work on the whole network simultaneously.
  • 3-5% of the cells carry very heavy load. The article doesn't say where such cells are usually located. It would be interesting if this load is mostly generated in-house, for example in shopping centers, train stations, airports, etc. and if femtos would provide a cheap future capacity extension for those places.
  • The technical evolution of 3G networks is all about keeping pace with higher user demand for capacity. Fully agree to that.
  • Going from 7.2 MBit/s to 21 MBit/s adds a cost of around 10-15% but increases capacity around 70%. An interesting statement because 7.2 -> 21 MBit/s is about a 3x theoretical speedup while from a practical point of view it is much less. The article says its 70% or 0.7x.
  • 70% of overall CAPEX is spent on base stations.
  • 50% of overall OPEX is spent on base stations.
  • The €1 per GB seems to be a number over a 5 year period. At the end of the article it is stated that the networks that Ericsson looked at for the study are not quite there yet. However, the first network, after 2 years of operation, reported that they have reached €2 per GB.
  • For the study, a base station price of €40k was assumed. Looks like they have gotten quite a bit cheaper than what was calculated with just a couple of years ago.

And just to get a bit more aggressive, this Ericsson presentation states that mobile broadband is even cheaper than DSL (cp slide 13 ff.). I assume that leaves IPTV delivery out of the equation, but still it's an interesting way of looking at things.

Spectrum Use Today of Wi-Fi and 3G Compared

Here's an interesting comparison of how much spectrum is used today for 3G vs. Wi-Fi. In Europe, UMTS/HSPAS is assigned a 60 MHz uplink + 60 MHz downlink = 120 MHz. Out of that only 20+20 = 40 MHz are in active use today even in dense urban areas except for a few exemptions. For details, see here and here. In the future, the digital dividend band in the 800 MHz band (2×35 MHz), and the IMT extension band in 2.6 GHz (2×70 MHz) will be added.

Wi-Fi 802.11b and g use the 2.4 GHz band spanning 80 MHz. Especially in dense urban areas, I'd say that's already used quite intensively these days. In addition, some 802.11n kit can also use the 5 GHz band, where almost 400 MHz is allocated for Wi-Fi and other short range wireless systems. It's probably still not used a lot but with more and more 5 GHz band enabled equipment appearing that will certainly change.

So, what's the message here? There are several. 3G only uses a fraction of the spectrum that is already allocated today without suffering massive bandwidth bottlenecks. The same applies to Wi-Fi although the original 2.4 GHz band is already quite busy. But if your gut feeling told you that cellular networks probably had much more spectrum available than Wi-Fi, then that was not quite accurate.

I Need Opera Mini for the N900

Yes, like many others, I am waiting for the release of the Nokia N900 and I have lots of good reasons for it. But there's one thing I really need on that device before I can use it: Opera Mini. True, in all the videos, the browser looks great. However, try using the browser with EDGE and frequent loss of signal. Quite a different experience under such circumstances.

I've used Opera Mini for years now and just under such circumstances, which happen more often than not when traveling, it really excels. But I am afraid that with the N900 we have to wait a bit for the browser as it is a Java ME application, an environment the N900 does not support (yet). So anyone heard of Java ME being added to the N900 software repository or Opera working on a port of their Mini for Maemo Linux?

HSDPA now with 28 Categories and Speeds up to 84 Mbit/s

Hsdpa categories Almost exactly two years ago, I wrote a post in which I reported my first sighting of new HSPA+ device categories. The top at the time were category 14 and 16 with 64-QAM modulation and MIMO respectively and speeds up to 28 Mbit/s. This was Release 8 of the 3GPP standards. Now in Release 9, 28 device categories are listed in 3GPP TS 25.306 (see table 5.1a) with top speeds under ideal radio coverage of up to 84 Mbit/s if everything is combined, i.e. 64-QAM, MIMO and Dual Carrier. For almost every combination of options there's a category now. Breathtaking…

As I found no good overview of which device category goes up to which speed, I took the liberty of updating the HSDPA article on Wikipedia and add device classes 16-28 in the table. A screenshot of it can be seen on the left.

Now where can I get a Category 28 device and a suitable network please? 🙂

P.S. 1 – Important: Note that all indicated speeds are top speeds under ideal signal conditions. See here for further details and a reality check!

P.S. 2 – I left out cat 17 and 18 as they are a bit special and I am not sure that they will be relevant. If you have an opinion on this one, please let me know. Also, feel free to add them to the table on the Wiki yourself and while you are at it, have a go at the coding rates for the higher categories as well.

The 1000ms SIP Delay Mystery

Here's a mystery I can't quite figure out so I thought I'd write about it to see what you think: There are a number of VoIP services I use frequently over a DSL link and they all work well. Over a 3G wireless connection, however, SIP via Sipgate.de isn't working as it should. While there is almost no noticeable delay in the speech path in downlink direction, the uplink speech path has a delay of almost 1000 ms!

One might argue, that's a 3G issue, but it definitely is not, as the delay in Skype in both directions is just fine. O.k. so maybe it's a combination of the mobile device I use for my SIP calls, a Nokia N95, and the 3G router that's causing this. No, I can rule that out, too, since I've tried it with a Huawei D100 3G router as well as with my Fritzbox DSL/3G router from AVM. I also use the Fritzbox over DSL and the N95 works well over that backhaul link, so that can't be the issue either.

My final idea: Maybe something is done in the network!? Possible but unlikely as the behavior is the same in Vodafone's network in Germany, the Mobilkom A1 network in Austria and Wind's network in Italy.

Other ideas, anyone?

The Economist on Mobile Banking in Africa

Here's an interesting article I've recently discovered in The Economist on mobile banking solutions in Africa and Asia such as MPesa and others. In my opinion the article contains good information on how such services work, how people benefit from them and the issues encountered with the local banking system and regulators. Also quite interesting are the many comments which contain quite different points of view so be sure to check them out as well.

Mobile vs. Newspaper @ Breakfast

Self observation today: How is the daily morning news best consumed during breakfast? From a mobile device, TV or a plain good old newspaper? I guess the answer depends on whom you ask but I strongly prefer a mobile device for a simple reason: I can get to the news that interests me quickly, i.e. I decide, and it can be easily held and navigated on with one hand while the other hand takes care of breakfast.

With news on the TV I am not in charge so that's a no-go for me. And with the newspaper, I need both hands and my table is just not big enough so I can put it down. Sure it can be folded etc. but that won't help much as each time you are done with half a page both hands need to come back into action to "navigate" to the next page. There we go, my preference. How do you consume the morning news?

ARPU is Out, Market Share and Revenues is In

Average Revenue Per User, or ARPU, is a measure often used when discussing financial results of mobile network operators. But in this day and age, ARPU has become pretty much irrelevant as discussed here. Still it is used a lot. Finally, I've recently seen a refreshingly different approach being used by the London Times. Instead of reporting ARPU, network operator performance was assessed in market share and revenue terms. That makes a lot of sense to me!

All network operators need to build a nationwide network to compete. So comparing the market share between operators makes sense to me because each network operator has a similar network to build and support. How thoroughly and thin-meshed that network is built is another matter. That distorts the market share picture a bit. So maybe one should add the number of base stations into the equation?

As always, comments are welcome!

When Linux runs the Wi-Fi card better than the original

Ubuntu keeps surprising me positiviely! A few days ago I installed the OS on my somewhat older desktop computer as well, not really hoping that I could reuse the PCI Wi-Fi card inside. That was because I thought the card was broken as under Windows and the native driver it always stopped working after a while and would only come back after a reboot.

Surprise surprise with Ubuntu! Not only did it recognize the card instantly without the need to install an extra driver it is also rock solid and hasn’t stopped working after hours of using it. Looks like it wasn’t the hardware after all but just a crappy Windows driver installation by the manufacturer of the card. Incredible! While the manufacturer has long given up on the card, it works like a charm under the free OS and is much more stable. What more can you want?