mobile hardware – WirelessMoves

Android and Huawei + T-Mobile and Prepaid

Android, Huawei, T-Mobile and prepaid, a very interesting combination! T-Mobile has just announced in the UK and also in Germany that they will ship Huawei's first Android smartphone in October. That's interesting from a number of different angles and the press release contains a couple of other interesting points:

First, Huawei has tried for some time to enter the mobile phone business with very mixed results to say the least. With Android they are launching another attempt and have found a mighty ally in their quest, T-Mobile. Announced back in February 2009 at the Mobile World Congress, Huawei seems to have pretty much met their projected release date. With T-Mobile going public, that probably means that both hardware and software must be well on their way, otherwise T-Mobile wouldn't push it that strongly.

Second is the price point: T-Mobile UK has announced that it will sell it in a prepaid bundle (no strings attached, no monthly contract) for 179 pounds, which is around 215 euros at the current exchange rate. For a smartphone with large display and touch screen, that sounds like an ultra-competitive price. It even undercuts Nokias 5800 low price touch phone, which currently sells for around 290 euros. Let's see how processor speed, camera and other features work out at this price point. And that's only the initial price. I'd say it's quite likely the price will drop over time. Also interesting that T-Mobile UK announces the phone together with a prepaid offer. Definitely not targeted at the high-end market then.

Third is the data option: The post linked to above quotes the T-Mobile UK representative saying that an all you can eat data option for the device is 5 pounds a month. I guess they won't allow tethering but even without, the price is quite stunning and only a third of the current rate described here. 5 pounds a month on a prepaid SIM will probably make mobile Internet access interesting for even more people.

Multitasking on the Bicycle

As a tech-savvy person I used to carry a lot of gadgets when going on a bicycle ride for fun: A mobile phone, a photo camera, a paper map, a GPS, an MP3 player and a PDA to surf the Internet and to check my e-mail. Yes, I know what you want to say now, that was a couple of years ago (but not too many ago when you think about it) and today, all these devices have shrunken into a single smartphone.

It's a strange feeling, my backpack is now almost empty with only my N95, the sun glasses, the door key and some money in it. And who knows, the door key and the money might just be included in the mobile phone in a couple of years as well with an RFID chip for mobile payment and a Bluetooth solution to open my apartment door.

It's amazing how many things the phone now does simultaneously while being in my pocket:

It runs the MP3 and podcast player so I am entertained while enjoying the ride

The camera application is always ready and while I take a picture, all other applications keep running in the background

Nokia Sports Tracker runs in the background and uses the GPS chip to record the trip and upload my position in real time to the Internet. Once back home the program looks for pictures I have taken during the ride and the songs I have listened to and uploads them as well. For example, here's the data from the bike trip I reflect on in this post.

I've uploaded some of the pictures I have taken in full resolution to Flickr with the help of Shozu on the phone, which also accesses the GPS information to geo-tag the pictures. To save cost, I've configured Shozu to only upload the pictures when it detects my Wi-Fi network at home. No manual intervention necessary.

In the pictures you might have noticed a little camouflaged box. That's a geocache which I found with the help of a Geocaching application using the GPS chip in the phone. An interesting and healthy hide and seek game and sometimes motivation not to stay at home sticking my nose into books or working on new projects.

In case I get lost, I can fire up Nokia Maps which also uses the GPS chip. Note that all programs can access the location data simultaneously. Very nice!

Needless to say that my e-mail program (Profimail) was also running in the background to alert me of incoming mail.

And for the quick information fix, Opera Mini is by default always lingerning in the background. Very helpful to get quick information from Wikipedia, often replacing the tourist guide on paper.

And everyone of course takes for granted that incoming voice calls and text messages are also treated. That's two separate tasks running in the background as well.

With all of these things running, the impact on the battery is quite significant. After four or five hours the battery is empty. So for longer trips, that spare battery adds a couple of grams to the weight of the backpack. Acceptable I would say.

So what else could be improved in the future? While the N95 8GB already has quite a big screen, I think I am ready now for the higher resolution and size of the screen of the N97. Hello Nokia, how long do we still have to wait? Also, the touch screen should be great for some applications like the built in web browser, which in itself can still be improved. There are still some pages I don't go to on the mobile because they take too long to load because the processor is not powerful enough to render them as quickly as on the PC. A higher capacity battery at the same size and weight of today would obviously also be good. On the software side I am waiting for that geo-info application that lets me take a picture of something, combines it with the GPS coordinates, goes to the Internet and comes back with a Wikipedia entry on it. Nokia's CTO has mused about such a program in the past but so far I haven't seen one.

So, what's missing for you when you take your smartphone for a walk or a bike ride?

Verizon’s first Draft Specification for LTE Devices

Unstrung has an interesting pointer to Verizon's first draft spec (v0.9) which details what they want devices to be capable of to allow them on their future LTE network. While they are mainly referring to relevant 3GPP specification documents, there are some nuggets of information in there that took my attention:

The 700 MHz band they intend to use seems to be band 13 in 3GPP talk. I wonder if that encompasses the complete 700 MHz band in the US or just a part for it!? In other words, will band 13 devices also be usable in other LTE networks (e.g. that of AT&T)? According to this post on Gigaohm, the total bandwidth of the 700 MHz that was auctioned off was 18 MHz per direction (uplink/downlink), so the answer is probably yes.

The channel bandwidth they will use: 10 MHz (double that of HSPA today but short of the theoretically possible 20 MHz as per the standard. Again, by looking at the link above, that's obvious because that's all there is available.

Devices must have RF connectors for testing purposes for all antennas. Haven't seen that in years on mobile devices. RF designers will have fun…

Devices will be assigned an IPv6 address when attaching to the network. IPv4 addresses shall be requested by the device if an application requests an IPv4 connection. The IPv4 address shall be released once no applications are executed on the device that require it. Interesting requirement, looks like an IPv4 address is not initially assigned to the mobile device by the network. This should not be a big deal, S60 for example already has a dual IPv4/IPv6 stack today.

Mobile device timer for moving from Connected to Idle state: The document says that the LTE standards say that the move from Connected to Idle state (on the radio layer, this has nothing to do with the IP address assignment) is controlled by the network. The standard leaves it open for the mobile to also initiate such a state change, for example if the device detects (by whatever means) that no applications currently wants to send and receive data. At this point, however, Verizon does not mandate devices to implement this. An interesting side note: Today, HSPA only knows a network initiated state change in the standards. In practice, however, there seem to be some devices that also trigger it from the devices side with a bit of an unorthodox signalling message exchange. Looks like standards people have learnt from that and included this feature in the LTE specs from day one.

No mention is made of dual mode CDMA/LTE capabilities. I wonder if that means that they expect that first devices will be LTE only? That wouldn't make a lot of sense to me. I can't imagine people would be very happy using a CDMA USB dongle and a separate LTE dongle, depending on where they are.

Verizon expects that first devices are data only, no voice capabilities. A pity, but who knows, they might yet discover the benefits of VOLGA.

Note that the current version is only a draft, there are still many unfinished chapters.

Radio and Baseband Now Integrated in a Single Chip

With the number of functionalities that require dedicated hardware in mobile phones rising and rising, it's important to integrate as many of them as possible on a single chip to save space and power. In the past mobile devices used a classic radio chain: A receiver/power amplifier, an analog modem chip and a baseband (CPU and DSL) chip. These days it has become possible to integrate the analog modem chip and the baseband chip on a single die and products such as the Broadcom BCM21331GSM/EDGE chip are now used by major phone manufacturers such as Samsung and Nokia for their 2G GSM/EDGE phones. I've looked a bit around and I haven't seen a similar product for combined 2G/3G phones yet. But that might just be a matter of time now. Maybe the current Qualcomm Snapdragon platform goes into that direction!? If I understand correctly, though, this platform still needs an external transciever chip, something that Broadcom has built into their single chip solution already.

If you have further info on that, please leave a comment, I'd be interested to lean more.

How To Secure The BarackBerry

Some sources have started speculating if the secret service lets President Barack Obama continue to use some sort of Blackberry. The latest speculations are that he might get a Sectra Edge, a ruggedized and secured Palm Treo 750. You can find the specs here but while they are interesting, they don't (of course?) go into the details of how things are secured in practice. Tomi Ahonen over at Communities dominate brands has a good post on possible angles of attacks. I think these are quite possible for someone with time, monetary resources and a couple of infiltrators. Tomi suggests a couple of countermeasures which I think are quite interesting and I've come up with some of my own while commuting today that I thought I'd share here:

Phone identification and targeting

The first thing that needs to be done is to ensure anonymity. Today, there are two IDs in GSM/UMTS systems that can be exploited if somebody knows them and can get access to the core of the mobile network to find out the current location of the phone up to the level of the radio tower. These IDs are the International Mobile Subscriber Identity (IMSI) on the SIM card and the International Mobile Equipment ID (IMEI) of the mobile phone itself. Also, knowledge of one of the two values can also be used by someone who has access to the core of the mobile mobile network to intercept non end-to-end encrypted voice calls and Internet traffic.

To ensure anonymity these IDs should be changed in regular intervals. If I were the secret service I would get a large number of IMSI's of several network operators, get the SIM card vendor on board and devise a scheme to change the IMSI on the SIM card on a regular basis. Concerning the IMEI a changing random number would do.

Another thing I would do is to use the pool of IMSI's not only for the president but also give similar phones to his aides and other people in the government that need to communicate with him and others securely. This ensures encrypted communication. At the same time more than one IMSI of the pool is active, so its fruitless to get hold of the IMSIs of the pool as the attacker still wouldn't know which one is currently used for the president's phone.

Changing IMSI's on a regular basis has one big disadvantage: Whenever an IMSI is used for the first time it is transmitted in clear over the network. In all subsequent communication establishment requests a changing temporary id (the TMSI and the P-TMSI) is used. So an attacker could use this to try finding the president's phone by scanning the air interface for those rare IMSI based connection establishments. In addition the scanner used would have to be near the location of the phone (i.e. in the same cell) and the attacker would need the list of IMSI's used for the purpose. A very remote possibility and the attacker could not do a lot with the info anyway. A countermeasure would be to have many such phones around the president (e.g. those of his aides) doing the same thing.

Outgoing Voice calls

Both network encrypted and end-to-end encrypted calls could be directly connected to the destination. However, I would put a gateway in the middle to which all calls are sent and which then forwards them over a secured link to a second gateway which brings it back into the public network again. This way the current phone number of the president linked to the IMSI could not be seen at the other end and could also not be tracedby someone having access to the public network.

Incoming Voice calls

A bit more tricky as other persons don't know the presidents current phone number. Again, a gateway would help which knows the current number of the president. It could be informed via an encrypted data connection by the phone itself of the current phone number (see below).

Getting to the Microphone and Camera

Every now and then one can find reports that hackers can get access to the microphone of a phone by giving it a secret hidden call. It might work or not with some public phones but not with one that was inspected by the NSA. Also, frequently changing IMSI's should prevent anyone from knowing which number to call.

GPS Positioning

By controlling the operating system itself and the applications that run on the smartphone it can be ensured that even if the phone has a GPS the coordinates are not smuggled out. Not a big issue here.

Internet connection

I'd only allow a "full tunnel" solution, i.e. everything goes through an encrypted tunnel to a gateway and only from there to the Internet. The tunnel termination on the network side must be well protected, of course, but I think the people working at Ford Meade know how to do that.

Smartphone viruses

With a customized OS version I would ensure that applications can't be installed and that all applications running on the phone have no hidden weaknesses and backdoors. Not trivial but I am sure it could be done with a tiny fraction of the NSA's budget.

E-Mail

The e-mail client must of course be able to use strong end-to-end authentication and encryption, and authentication and encryption for transmission to the server itself. Needless to say that the server should be well secured.

Web surfing

To prevent bad things in web pages harming the smartphone I would run all communications via a secured and monitored web proxy. No direct contact with the Internet for the web browser. Another benefit of the proxy is to anonymize the traffic.

And the rest

I'd block all other Internet traffic from or to the phone to ensure that the e-mail client and the web browser are the only applications that can communicate with the outside world. Also, I'd give the TCP/IP stack a very hard look to ensure no buffer overflows from malformed packets can cause any harm.

Lot's of stuff to be done to secure such a phone, no question about that. But I guess the president of the United States is not the only person requiring air tight security so the cost can be split. Also I would be very surprised if a lot of this infrastructure is not already in place. Like all security measures, securing the BarackBerry is a cat and mouse game and not a one shot operation. I am sure the list above is far from complete. Further ideas?

3G Network Stability: 8h of Continuous Voice, IM and Remote Desktop

This week, I've ventured far beyond my 'normal' 3G use by giving remote support to someone being connected with a notebook over a 3G link for over 8h at a time. During that time, we had a Skype voice session established with excellent audio quality, used Instant Messaging and e-mail to send and receive documents and I had a remote desktop session open to see what is going on and to directly lend a hand when necessary. All sessions were open simultaneously and there was not a single glitch with a single application or the 3G connection.

That's what I call network stability! During that time, around 300 Mbyte of data were exchanged. It's impressive to see that both networks and devices have matured to such a level. On the network side, Mobilkom Austria (A1) has to be congratulated for the stability and performance of their HSPA network and for offering Internet access with prepaid SIMs. On the terminal side, the Huawei E220 modem did it's part. Congratulations to all companies involved, it was a truely great experience!

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:

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.