LTE and the SMS Question

As standardized today, LTE does not have built in SMS capabilities. In a recent webinar on VOLGA (Voice over LTE via GAN), Franz Seiser of Deutsche Telekom (formerly T-Mobile International) argued that this might be a significant issue in the future for a number of reasons.

First, he said, there are a lot of systems in the network that rely on SMS such as SIM card provisioning, for updating the roaming operator list and other data on the SIM card for example, SMS subscription to activate/deactivate add-ons, etc.

Second is the EU mandated SMS user interaction while roaming. Introduced during the first wave of roaming regulation, operators are obliged to inform their subscribers by SMS about roaming costs when they start using a network abroad. In the future, notification to prevent "bill shock" (e.g. when using mobile data abroad) might also be based on SMS.

While the roaming tariff SMS announcements for voice and SMS are probably meaningless for LTE networks that do not support voice and SMS, the notification about bill shock might very well apply to LTE as well. Unless of course, the same tariff applies abroad like at home. Unlikely I would say…

So I quite agree with Franz, if a network allows VOLGA roaming in the future, the SMS solution already comes included at no extra price.

Another option is using SMS as part of the CS fallback (CSFB) feature that is already standardized. However, if the roaming country does not support CSFB and the mobile device is mostly data centric, then the SMS can't be delivered. While it's pretty obvious that a USB data dongle is a data centric device, I wonder what an iPhone or an N97 qualifies as.

And then there is SMS over IMS. However, I doubt we will see IMS and mobile IMS clients anytime soon.

My Netbook…. 15 Years Ago

Netbook 15 years ago Here's a picture of my new netbook, a 10.1" Acer Aspire One D250 side by side with my first notebook I bought 15 years ago. Sizes are quite similar but the interior is quite different. 1 GB of RAM vs. 8 MB, 160 GB hard drive vs. 20 MB, 386 processor running at a couple of MHz against an Intel Atom running at over 1 GHz. About two orders of magnitude apart from each other. Of course, 15 years ago it wasn't called a netbook, even though my 14.4 kbit/s Modem (external) was start of the art then. Surprisingly, the 15 year old notebook still works. MS-DOS and Windows 3.1 boot in a matter of seconds, out of the 8 MB of memory, 5 MB are free once the OS is loaded and Microsoft Word loads faster than anything I have seen in the past decade. Sounds all nice but I don't want to go back. It's just a bit more comfortable today and I am not sure the old Compaq could handle a 6 MBit/s DSL line. After all, at that speed the hard drive would be full in less than a minute 🙂

First Vodafone Femtocell User Review

Vodafone UK has recently launched their first Femtocell product which they call the 'Vodafone Access Gateway'. Andrew Grill over at 'London Calling' is probably one of the first in the UK to get one to test and use at home.
An interesting report about clueless shop managers, setup procedure,
femto features and performance at home. Thanks Andrew, very insightful

Nokia N97 Review Part 4 – eMail

One of the most important applications on my mobile device is e-mail. The built in Nokia e-mail client is a bit to light weight for my purposes so I've been using Profimail the past couple of years. In this part of the review, I'll have a quick look at both.

The Natvie e-Mail Client

For the newcomer, the functionality and usability of the built in e-mail client might just be ok so I concentrated on how easy it is to create a new e-mail account with the creation wizard. It turns out that just a couple of steps are necessary to get an Ovi mail account (name@ovi.com), assuming general access to the Internet has been set-up already. The account creation wizard asks for your name and a new password, makes a couple of suggestions for how the e-mail address can look like and then sets-up the account and configures the phone. Nicely done even if the web based wizard was not yet optimized for the screen size of the N97.

My first attempts to send an e-mail to the newly created account failed but after half an hour or so the server configuration seemed to be working and e-mails were delivered promptly afterwards. Another plus is that e-mail attachments are not automatically downloaded as that is  mostly unnecessary anyway. New e-mails are notified by an audio alert, by vibration and by changing the blinking of the light behind the menu button.  The blinking, however, is hardly noticeable, I would have wished they would have done something more visible. There's a small white LED next to the USB / power port which which could be put to good use. Next software version, maybe? Downloading and opening a PDF attachment worked fine while doing the same with a word document repeatedly resulted in a "server error" and a subsequent automatic closing of the e-mail client.

Profimail

Now over to Profimail. I've been using it for a number of years now and I am a huge fan. With it's own UI layout it's more efficient in displaying information and it's also more customizable. So no doubt I want it on the N97, too. The installation worked flawlessly and the program has even been adapted for touch input. The style and size of the menu and the soft keys are just the right size for me, not too big to take too much of the visible space and not too small for touch input. Scrolling through the e-mails with a finger on the touch display also works great and the big screen of the N97 makes e-mail reading even better than before. All the rest works as on the non-touch N95 so definitely two thumbs up for the N97 implementation. What I found a bit more difficult is writing an e-mail. The QUERTY keypad of the N97 is good for short replies but for longer texts I reverted to the on-screen T9 input. While typing works ok, the very limited space available for showing the text in this mode is not as comfortable as on the N95 where all of the screen is used for showing the text. Also, for some strange reason, typing a space character sometimes resulted in a new line. So the learning curve for typing text is not as smooth as I hoped for.

In summary, the e-mail experience on the N97 with Profimail works for me and I guess that with a bit of practice, I could manage to work with the different text input modes that are available. Well done Nokia and Profimail!

LTE and HSPA Uplink Power Control in Comparison

And here's my LTE thought of the day:

One of the fascinating things about the 3G/WCDMA/HSPA uplink is the 1500 power control commands per second to ensure all devices transmitting at the same time are received with a similar power level. This is necessary as only this way the base stations can retrieve the individual data streams that are stacked on each other in the code/power domain. 

With LTE, however, such a fast power control is no longer required as each mobile sends at a different time or uses different subcarriers (i.e. different time / frequency domains). While it is still necessary that all transmitting devices are received by the base station with "more or less" the same power in order not to overload the A/D converters it is by no means as essential as before. A lot less work and signaling involved that way.

VOLGA Forum Publishes Stage 2 Specification For Voice Over LTE

Regular readers of this blog probably remember that I'm a fan of Voice over LTE via GAN (VOLGA). For those who don't, have a look here on more details on why I think it has a good chance of becoming THE voice solution for LTE. It's amazing how fast the Volga-Forum is pushing out the specifications. In May, they published the stage 1 specification document, which contains a high level architecture and the requirements. Now only a month later, a first version of the stage 2 specification is available. Stage 2 specifications as per 3GPP contain a detailed architecture description and all procedures required from connecting to the network, originating and terminating calls, doing handovers, etc.

While their speed is incredible, maybe it should not be that surprising, because VOLGA is based on the already existing 3GPP GAN (Generic Access Network, i.e. GSM over Wi-Fi) specification. That's a good thing because that means that VOLGA could thus be developed quite quickly as it's likely that existing products can be modified instead of being designed from scratch. In addition, this should also mean that the first version of the standard is already quite mature as many areas were already verified during implementation and rollout of GAN in current networks.

I did a quick comparison between the two stage 2 specs and as I expected, many parts are very similar. While the GAN stage 2 specification has 126 pages, the current VOLGA stage 2 specification has 87 pages. This is probably because VOLGA is simpler than GAN. There are fewer handover procedures and most of the handover details are part of the 3GPP Single Radio Voice Call Continuity (SR-VCC) specification (for IMS) so they don't have to be included in the VOLGA spec. In addition to fewer handover scenarios, handovers are a bit more simple with LTE from a VOLGA perspective, as the network takes care of it unlike with GAN, where the mobile has to force the network into a handover. Also, there's no need to support the packet switched part of the network which also significantly lowers the complexity.

Well done, I am looking forward to the stage 3 specification which will contain the details on all messages and information elements used.

Nokia N97 Review Part 3 – Text Input and the Bluetooth Keyboard

In part three of my N97 review I'll focus on how the various text input methods work for me.

Both the on-screen and built-in keyboard work great for me. I am a quick T9 user and the virtual keyboard on the touch screen works very nicely. I can type almost as fast as on the real keyboard of an N95 for example and the haptic feedback helps a lot with the experience (the phone vibrates when pressing a key). In silent mode there is no haptic feedback which is also great in some situations where even a short vibration for every key press would disturb. In that respect, it's better than the N95 which makes a mechanical sound when a button is pressed. And: T9 can be used with a single hand on the N97 just like on the N95, another important feature for me!

Typing in usernames and passwords with T9 is often a bit difficult as especially passwords are usually just a combination of characters and letters so it is necessary to deactivate T9 first. That's where the three-row hardware keyboard comes in for me. It works great for usernames and passwords! For longer texts, however, I prefer the T9 input especially when I can't use my Bluetooth keyboard, e.g. while standing in line or with very restricted space like in the metro.

One of the most important features of Nokia S60 phones is the support
of Bluetooth keyboards as I sometimes write lengthy e-mails or blog
entries. For The N97, there is currently no supported driver for
Nokia's SU-8W keyboard. However, the S60 3rd
edition driver works on the N97 and installation is quick and smooth. After updating the device's firmware from version 10.x to 11.x, however, the
driver always crashed and I had to re-install it to get it working
again. It would be nice to get an officially supported driver where these things don't happen.

So much for today. Next stop: e-mail

Unlocked 3G Dongles in the Supermarket

Recently, Aldi supermarkets in Germany have started selling unlocked 3G USB dongles for €59. Yes, unlocked, which means that the buyer is free to either use them with a SIM card that can also be bought in the supermarket or with a SIM card of a different operator. For the details see here (while the link leads somewhere).

The SIM card offered by Aldi is for the German E-Plus network, which unfortunately is quite patchy and not upgraded to HSPA yet. I wonder if it might be the last non-HSPA 3G network left in Europe!? Prices for daily use are €1.99 with a traffic limit of 1 GB or €15 for 30 days with a traffic limit of 5 GB. Stunning prices but don't ask for high speeds.

I am glad to finally see this happening in Germany, after it has pretty much become common practice in Austria for a year or two now already. To my knowledge, Germany is only the second country so far where unlocked 3G dongles can be bought in supermarkets. If you are aware of any other countries except Austria, please let me know.

Let's hope that similarly as in Austria this move will stimulate competition around pre-paid offers where the SIM card for Internet access can be bought independently from the 3G dongle. After all, I feel a bit silly to buy a locked dongle in countries I travel to just to get the SIM card.

Some prepaid offers without a dongle are already available in Germany for some time now and you can find out more on the Prepaid Wireless Internet Access Wiki here. There's information about lots of other countries there as well in case you want to find out what's going on in your country. Have fun!

Mobile Terminating Roaming Retry Call

While doing some background reading I stumbled over the following optional Mobile Terminated Call procedure for a race condition:

The scenario: Just when the mobile network receives an incoming call for a user, the user's mobile changes to a cell which is controlled by a different mobile switching center. This results in a race condition, i.e. the previous MSC receives the call while the mobile is already performing a location update via the new MSC. If this is not treated, the mobile will not see the paging in the old cell and the call establishment fails.

This is where the "Mobile Terminating Roaming Retry Call" feature comes into play: If implemented, the previous MSC which has sent out the paging message to contact the mobile is informed of the location update by a "Cancel Location" message from the HLR. This is standard practice so far. However, instead of failing the paging procedure, e.g. after a timeout, the Cancel Location message is used as a trigger to signal to the Gateway MSC that the subscriber is no longer with this MSC. The Gateway MSC then releases the speech path to the previous MSC, runs another subscriber location search with the Home Location Register and then forwards the call to the new MSC. All quite elegant.

For details see 3GPP TS 23.018, chapter 5.2.1

I wonder, if this feature is widely implemented and used today? If you know, please let me know.

Nokia N97 Review Part 2 – No SIP – No Skype

Part one of my N97 review series focused on the touch based web browsing experience with Opera Mini. Today, I'll take a look at the Voice over IP, presence and instant messaging experience on the N97.

Unfortunately, there is not much to focus on at the moment. What I very much like on my (current) N95 is the integration of SIP telephony. Whenever I come home the N95 detects my Wi-Fi and automatically registers to my SIP VoIP provider sipgate and the phone becomes a combined cellular / cordless phone with a fixed line phone number and a cellular phone number. One would expect to find the same functionality in Nokia's latest flagship product but TO MY GREAT DISAPPOINTMENT the functionality was removed. The configuration menus are still present but the UI for making SIP phone calls from the phonebook or by typing in the phone number and then selecting "Internet Call" from the menu have been removed.

But what about the much touted Skype integration Nokia announced during the Mobile World Congress in Barcelona earlier this year? Again, a blank, no Skype to be seen anywhere on the phone. It made for good publicity then but if no actions follow, that kind of undermines credibility.

While it was one thump up in the last post, this post definitely ends with two thumbs down, my expectations for VoIP integration (based on the N95) were greatly disappointed. I don't really feel that connected anymore with the N97 🙁