WirelessMoves

Power Consumption in 2G/3G Connected State

Some years ago, when I tested how long the battery of a mobile phone would last when a mobile device was connected to a 2G or 3G network (PDP context established) but not transferring any data for most of the time. At the time, the result was quite clear: I could almost watch almost in real time how the battery level decreased. Looks like things have changed pretty much in the meantime.

When repeating the test these days with a Nokia N95 and a Nokia N82, one being connected to an EDGE network and the other to a UMTS network over the course of the day while transferring almost no data, there seems no difference anymore to the device not being connected throughout the day. The picture on the left shows a screenshot of my N95 that was connected to an EDGE network throughout the day. Note that at the time the screenshot was taken, the mobile was also connected to a Wireless LAN network (i.e. some applications used the EDGE connection, others the Wifi connection). The same test with the N82 that was connected to a 3G network showed the same result.

Very good, one thing less to be concerned about! No more advice about disconnecting from the network due to the fear of running the battery into the ground quickly.

Mobile Devices Are Getting Ahead of the Networks

I still remember that in the early days of GPRS, the main problem was to get mobile devices that could actually make use of the new network service. The story repeated itself with UMTS where where things became even worse. When UMTS first started, there were lots of networks around but no or only clunky mobile phones available for at least a year or so.

In the meantime it looks like the situation has reversed. Quite a number of 7.2 MBit/s HSPA devices are available, but only few networks yet support ten simultaneous downlink spreading codes and have the required backhaul capacity to the base station. With HSUPA it is quite similar. A number of devices, mainly USB sticks, are available on the market today, but most networks still lack support. And it's not only in UMTS, where devices are far more capable then most networks today.

Even 2G mobiles now support features that most networks are lacking. The AMR (Adaptive Multi Rate) speech codec is a good example. Widely supported in handsets today, but only used in few networks today, despite the potential capacity increases the feature offers to operators. Or take DTM (Dual Transfer Mode), which enables simultaneous voice calls and Internet connectivity for GSM/GPRS/EDGE devices. Again, many mobiles support this today and it could be put into good use especially with feature phones. However, I haven't seen a single network that supports it in practice.

A worrying trend. Are the standards bodies specifying too much?

Nokia and Open Source

Stefan Constantinescu over at Intomobile made me aware of an interesting podcast with Ari Jaaksi he must have given recently at an open source developer conference (not sure which one).  In the podcast, Ari talks about Nokia's involvement and interest in Open Source for their Internet tablet and for the open source based applications on their S60 platform (e.g. the Webkit browser).

It's interesting to compare Nokia's Open Source involvement with that of Google/Android: Nokia uses Open Source software to create their own (hardware) products. This is good for them because they can build products quicker, it's good for the open source community as the contribute back to the community, and it's good for application developers as they have a reasonably open platform for which they can develop their applications.

Google's approach with Android, however, is quite different. Their interest is creating a platform for themselves and others so that hopefully many companies develop devices and software based on Android.

In the short term, Nokia's concept works quite well as the Internet tablets they have built around their Maemo platform are great and there is not yet much competition. In the mid- and long term, however, I see their approach sidelined a bit once Linux in general and Google/Android in particular become more widespread in the mobile world. And Intel is pushing with their Mobile Internet Devices, too, likely to become a nice hardware platform in the future for new device manufacturers which then need to look for an open OS. Nokia's Maemo is then just one of many Linux based partly/fully open operating system but limited to Nokia products while other Linux based OS'es will run on more devices.

What do you think, might there be a point when Nokia opens up Maemo for third party devices?

Resources:

• Ari's podcast
• Slides

T-Mobile And The Asus eeePC

At the CeBIT kick-off press conference today, T-Mobile Germany and Asus announced an interesting cooperation: T-Mobile will start selling the eeePC in Germany and Austria with access to their Wifi and 3G networks. The 3G offer will include an HSPA USB stick. I've just recently bought an eeePC myself and time will tell how often it will be preferred over taking a full notebook with me. But I think chances are fairly high since it nicely fits into a bag and weighs almost nothing compared to the notebook.

For those who prefer using their mobile phone as a 3G "modem" for the eeePC (like me) instead of being locked to a single operator, here's a link that explains how to do this as well. I tried with an N95, a Nokia 6680 and a Motorola V3xx and they all worked fine.

The Dangers of Going SIM-Less

Dean Bubley over at the Disruptive Analysis Blog has published an interesting post about the advantages of going SIM-less for next generation connected mobile devices. In essence he argues that today, SIM cards lock users to a single operator and complicate using the device in other networks, locally or abroad. He comes to the conclusion that SIM-less mobile devices are better because users then have control which networks they want to use. While I agree with his arguments, I think there are many ways for operators to deal with SIM-less devices today. It is therefore by no means certain that a device without a SIM gives a greater choice to the user.

When I look at the status quo, SIM-less devices give users much less freedom of choice than devices with SIM cards. The best example are CDMA networks, mostly used in the U.S. Here, devices have no SIM cards and are locked by default to a single operator. Using the device with other networks is not possible and when roaming, users can not use a local SIM card to reduce their costs. Switching local operators is also not possible with the device since it can only be used in one network. And finally, mobile phones can only be bought directly from an operator, so there is no competition and hence prices are unlikely to be very competitive. This approach also gives mobile operators a great degree of freedom to lock handsets down by removing VoIP, Bluetooth and Wifi capabilities that have become very popular on devices which are not locked down to the operator. In short, such a SIM-less world is far from desirable.

So while I think Dean makes some important points I am actually quite happy that the GSM standard uses SIM cards. Here are some examples of what is possible if only the SIM card belongs to an operator while the mobile device belongs to the user:

• Voice Competition: Germany, for example, has become a very competitive MVNO (Mobile Virtual Network Operator) market and prices for prepaid communication have come down over the past two years from 60 Euro cents a minute down to 9 cents or even less. MVNOs basically only sell a SIM card and users just put them into the phone they already have. If there is a better offer and the current MVNO does not adapt, his SIM card is quickly replaced. Great for competition!

• Data Competition: The same applies for prepaid mobile data. If the network coverage is bad or if prices are not competitive, the device can be quickly used with another operator or network by simply exchanging the SIM card.

• Roaming: When I go abroad I usually use a local SIM card because data charges when roaming are still ridiculously expensive. Granted, it is sometimes not convenient to get a local SIM card but if you stay abroad for more than just a day there is a quick return on investment.

• Handset prices: Today I have several choices when I want to buy a new phone: I go to the operator to get a bundle, I go to an electronics store and get a bundle, or I go to one of many online stores and just get a phone. Then I go to the next supermarket, buy a SIM card and I am set. This has had a significant effect on handset prices. Let me give you a recent example: In operator shops, an N95 is currently available for 250 Euros if taken with a 24 month subscription with a basic fee between 10 and 20 Euros a month. I can get the same mobile with the same terms and conditions for 1 euro in most electronic stores today which are not related with the network operator. In addition, the phone is usually not locked down to an operator specific software version with crippeld VoIP and other niceties. And if I don't want it with a SIM card at all I buy it for 450 euros but without a 10-20 euros a month fee and it becomes even cheaper if you calculate the costs over 2 years. There's no way of doing that with a SIM-less device with the current model.

So in order for users to benefit from SIM-less devices, a number of additional things need to be in place:

• Location of the certificate server: WiMAX devices are unlikely to use SIM cards from what I hear at the moment. Instead they will use built in or user loadable certificates. The important point is who issues those certificates. If they are issued by a mobile operator, then the user is stuck to one network. This is the same as the current CDMA approach. Therefore, I hope that there will also be certificates issued by an independent certificate authority. When establishing a connection the network would then have to verify the user's credential with an external certificate authority.

• Networks using external certificate servers: The best external certificate server is of no use if networks only use internal servers. Hopefully competition will prevent this scenario as most network operators are probably happy to get additional revenue from national and international roamers.

In practice I can see networks using both internal and external certificate servers. This would allow the operator to sell devices which are locked to his network and to his control while roaming in exchange for a device subsidy. At the same time users would have the freedom to buy a device with an "open" certificate they could use in any network. They would then have the choice to pay per use, similar to the hotspot model today, or to get a subscription with an operator without being locked in.

Summary

Going SIM-less with WiMAX and other systems is a double bladed sword. If authentication is not "open", we will end up in a situation similarly to what we can observe with CDMA operators today: Users and devices are locked to a single network instead of having a greater choice. While some operators would surely prefer a "closed" authentication solution I think it would do great harm not only to users but also to the industry as it reduces competition among network operators, keeps prices up, and reduces attractiveness for users to go wireless.

OMAP - The Chipset of Nokia Phones

A note today for those who wonder what kind of chipset is working in their Nokia Nseries or Internet Tablet. According to here and here, Nokia uses th Texas Instruments OMAP 2420 platform for a wide variety of their high end devices. The specs of the chipset are quite impressive. An ARM-11 CPU clocked at 330+ MHz, 2D/3G graphics booster, built in MPEG en/decoder and direct external interfaces for just about any functionality you could wish for on a mobile device. And the next generation of OMAP chipsets is just around the corner. OMAP 34xx chipsets will push beyond clock rates of 500 MHz with a processor speedup due to enhanced superscalarity of 2-3 times compared to the current generation, support cameras of up to 12 megapixels, hardware support for full DVD video quality en/decoding, etc. etc. Now translate that into next generation Nokia devices and you get a feeling for what you will have in your hands in 2 years time.

Jazelle: Executing Java ME Bytecode in Hardware

From time to time I have wondered before why current mobile phones are able to execute Java ME applications so well and with good performance. To me this was a bit surprising to me since Java ME programs are not compiled for a specific hardware platform but instead into a machine independent 'byte code'. This enables Java applications to run on a wide variety of Java enabled handsets. To execute machine independent byte code a Java Virtual Machine (JVM) is required. On the PC for example, JVM's are implemented in software. On mobile devices, however, I found out today that ARM for example offers a CPU operating mode referred to as Jazelle which executes Java byte code in hardware. This way Java applications can be executed much faster as if a software JVM interprets the byte code. Pretty slick! For details see the Wikipedia entry on ARM processor and ARM's description of Jazelle.

P.S.: A long time ago Sun, the inventor of Java, tried hard to push JAVA CPU's for desktop machines but never really succeeded. Now, a decade later, there are indeed Java CPU's, just for a slightly different purpose. Looks like there were a bit ahead of the time.

When ARM and Intel meet on Mobile Devices

Interesting times ahead in the mobile hardware world. Today, most mobile, wireless and embedded devices are based on a chip with a processor design from ARM. Although many companies such as Texas Instruments, Marvell, STM, VLSI etc. design and produce chips for small devices, most are based on a CPU core licensed from ARM. On the desktop and PC world, things are equally clear with Intel's x86 design dominating. With both architectures now targeting powerful mobile devices, these two worlds are about to collide.

The ARM design was initially targeted at ultra low power embedded devices. As technology evolved so did ARM's design of their processors and it is estimated that an ARM processor core is used in 95% of mid- to high-end mobile phones today. The current ARM-11 high-end platform for example is used in devices such as Nokia's N-series phones like the N95 and in Internet tables like for example the Nokia N800 and N810. The ARM-11 platform is the result of a bottom-up approach, as it has evolved from earlier platforms for simpler devices. According to ARM's web page all phones of mobile giants such as Sony Ericcson, Nokia, LG, Samsung, etc. are ARM powered. This shows how flexible the ARM architecture is today since requirements range from voice telephony with ultra ultra low power requirements to full blown multimedia devices. Today, a lot of operating systems support the ARM architecture. Examples are fully embedded operating systems of low-end to mid-range mobile devices to operating systems for smartphones like Symbian, Windows Mobile and these days also Linux. Linux is about to become popular in the mobile device world e.g. with Nokia's Internet tablets and in the future with devices built around Google's Android OS. The advantage of using Linux on mobile devices is the wide variety of available software from the Linux desktop world, which often only has to be slightly adapted and recompiled for the ARM processor architecture.

On the other end there is Intel who seems to be keen to enter the mobile space with it's x86 processor line. A couple of years ago they tried to get a foothold in the mobile space by licensing ARM technology and building a product line around that. However, they have since abandoned this approach and are now tuning their x86 architecture for low power consumption and ultra small packaging. This is kind of a top-down approach, i.e. streamlining a desktop processor architecture for smaller devices. Their advantage: No or few adaptations are required to run applications written for the desktop. Adaptation is usually only required for smaller screen sizes, mobile device specific desktop environments and less disk and memory capacity. In theory, Microsoft Windows can also run on x86 based devices but in practice it is too resource hungry.  On the downside, Intel's platform for Mobile Internet Devices (MIDs) and Ultra Mobile PCs (UMPCs) does not have a native cellular interface like ARM has. Thus, device manufacturers have to look around for additional chips in case they want to put 3G connectivity into their devices. Intel, however, will surely use their mobile platform to combine it with their own WiMAX chips.

For the moment, Intel and ARM have not made contact yet. Intel's design is still too heavy for most mobile devices but they have gained a lot of ground lately. ARMs architecture on the other hand keeps pushing forward with increased processing power and additional functionality embedded in the main chip. Give it another 12-18 months, however, and I think they will have similar offers for mobile devices. Expect heavy architecture competition.

Further resources:

• Wikipedia: ARM Architecture
• Engadget: Intel explains MID vs. UMPC
• C-Net: ARM says it's ready for the iPhone