Author: Martin

LTE and the Voice Gap

A recent report I read about the future rivalery between HSPA and LTE has made me think about an important difference between the two technologies: Voice. While UMTS / HSPA intrinsically supports voice calls in the radio and core network, LTE requires the IP Multimedia Subsystem (IMS) for voice calls. So what will happen to LTE if IMS doesn’t take off? I know, many in the industry believe even asking such a question is close to heresy but who can promisse today that IMS will be a success?

The trouble with IMS and to some extent with mobile VoIP is not that it’s a young technology, standardization has been going on for many years and books about it are going into their third edition. However, there are still no IMS systems out there today that have come out of the trial phase, and I have yet to see a mobile device with an IMS client which is nicely integrated and simply works. Also, the IMS standard is getting more complicated by the day which doesn’t make life easier. Another main issue with VoIP and consequently IMS is power consumption. I use VoIP over Wifi a lot on my Nokia N95 and can nicely observe how the phone slightly heats up during a long phone call. Also the non-IMS but SIP compliant Nokia VoIP client in the phone, which by the way is nicely integrated, sends keep alive messages to the SIP server in the network several times a minute. This is necessary mainly due to Network Address Translation (NAT). While this doesn’t require a lot of power over Wifi, power consumption skyrockets as soon as I configure VoIP for use over 3G. I can almost watch the power level of the battery drop as the network now constantly keeps a communication channel open to the device. So there are two problems here: VoIP calls cause a much higher processor load during a call, i.e. the VoIP talk time is much shorter than the 2G or 3G talk time and the standby time is significantly reduced. Add to that the missing handover capability to 2G and 3G networks (yes, I know there is VCC in theory) and you have a prefect package for a very bad user experience.

So the big question is if all of these things can be fixed, say over the next 5 years!? I have my doubts…

If not, then LTE has a big problem. Will network operators accept running GSM or HSPA alongside LTE until the problems are fixed? The choice is this and accepting that LTE is for Internet access and some niche VoIP applications on devices such as notebooks or to decide sticking to HSPA(+) until things are fixed.

In case LTE is deployed and LTE – IMS devices are not ready it’s likely that a device can’t be attached to several radio networks simultaneously. So how do you inform a device attached to LTE about an incoming voice call? It looks like the people in standards bodies are looking at different solutions:

– Send a paging message for an incoming circuit switched voice call via LTE to the device. You can do this on the IP layer or on the radio network signalling layer. The device them switches radio technologies and accepts the call.

– Some people have started thinking about extending LTE with a circuit switching emulation. This could be handled on the lower layers of the protocol stack and the software on top would not notice if the call uses GSM, UMTS or LTE. This one is easier said than done because I don’t think this concept will fly without a seamless handover to a 2G or 3G network. If such a solution ever gets into mobile phones, it would make life for IMS even harder. Who would need it then?

Are there any other initiatives I have missed so far to fix the LTE voice issue?

When The Small Screen Becomes Big

Judging by the advantages of printed newspapers and magazines in terms of better readability compared to the small screen Internet, it’s likely that they won’t be going away anytime soon. However, just recently, I noticed just how much I personally prefer reading the news and tech articles on my mobile phone in many situations especially when I am out and about. Some examples:

  • When going to the train station recently to exchange a train ticket (no in France that is mostly still not possible online…) I took along a magazine I wanted to read while waiting in line. On the way there, I noticed that I didn’t like carrying the magazine. Not that it was heavy and bulky but it restricted my movements because one hand was no longer free. I was close to dumping it on the way home.
  • In the metro there is usually no place to unfold a magazine or newspaper and usually also no place to open the backpack to get it in the first place.

In both circumstances reading the same content on the mobile phone is much more convenient. Sure, the screen size is a lot smaller and one has much less overview over the content. However:

  • The mobile can be taken out of the pocket immediately. No extra space is required for this and its possible even in a very crowded metro.
  • I can read even in the most crowded places.
  • When being distracted I can easily resume reading where I was interrupted because the passage is still on the screen.

So in those situations the small screen Internet is definitely the winner. And I am sure the iPhone 3G will help to increase awareness, even though in my opinion downloading full web pages is much inferior to using OperaMini.

What are your experiences?

Sunrise Switzerland Starts Marketing Prepaid Internet

It’s good to see Sunrise Switzerland starting to offer mobile Internet access for notebooks via a prepaid SIM. With their TakeAway Prepaid product, 3G Internet access is billed at 3 Swiss francs per hour, about 1.86 euros. While I would personally have preferred a volume based offer I think it is nevertheless an interesting offer to consider for vacations in Switzerland or for the time spent at Zurich airport 🙂 For details see the corresponding page on the Prepaid Wireless Internet Wiki.

Via teltarif.de

Orange Internet Max – The Port 25 Trap

Here’s a blog entry about something that leaves me quite speechless: A couple of months ago, Orange France started to offer mobile Internet access via their prepaid Mobicarte SIMs. For 9 euros a month, Orange says they grant full access to the Internet (no, not the Web, the Internet!) from mobile phones with their Internet Max offer. The fine print says may limit the speed after 500 MB a month. Further they say that eMail via SMTP, IMAP and POP3 is limited to 10 MB per month. And finally they say that VoIP, Peer to Peer and Newsgroups are not allowed. Tethering to PCs is also not allowed and will be billed separately. No word about how much is charged separately or what happens after the 10 MB per month eMail limitation. 

So I activated the option on my prepaid SIM and have used it for a couple of weeks now. As per the description, all the services I use on my mobile phone such as web browsing with OperaMini, the default web browser, eMail (POP3 and SMTP), A-GPS ephemeris lookup, etc. work well.

Then recently, I discovered that every now and then my prepaid account seems to leak a few cents. But why? After experimenting a bit I found out that every time I send an eMail via SMTP some cents vanish. To verify I repeatedly sent eMails over the course of several days, deactivated and activated TLS encryption, but each time the result was the same. Sending an eMail with a 200 kb file attachment resulted in a charge of 3.50 euros!!!? Did I pass that 10 MB boundary? Unlikely, since I only sent and received few eMails from activation time until I first noticed the behavior. And even if that is the reason, why did the system not send an SMS to warn me? It can bill me but it can’t send me a warning?

This sort of service behavior is one of the reasons that keep users from using the Internet on their phones. Imagine I had used a post paid SIM with the offer and would only have discovered this behavior a month later.

Hello dear readers at Orange France! If you read this and have any idea why this is happening I’d be very interested to hear from you. Or maybe this is an issue of the billing system? In that case I am sure there is someone who could fix it. Could I also get reimbursed please?

Carnival of the Mobilists 133 at Vision Mobile

This week I am probably the fastest Carnival of the Mobilists reader, as I was traveling  at 300+ km/h with the high speed train from Avignon to Paris while reading the posts on my Nokia N95 with OperaMini. The carnival this week is about as fast paced as was that train, so make sure to check it out at the Vision Mobile Blog. There’s definitely no better place to find out what happend in the mobile space in the previous seven days. Enjoy!

Uplink Downlink Ratios

I’ve observed my network usage over the past couple of days to see how much data I would transmit and receive over the course of a week while traveling. I’ve noted that there is a big difference between PC and mobile device use in terms of uplink/downlink ratio. With the PC, which I mostly use to access my eMail and for web based services, the ratio is about 10:1. The ratio on my N95, however, is close to 1:1 as I upload pictures, blog posts and eMails. Especially picture uploading with Shozu has a major impact on the ratio.

Other statistics say that 90% of the data traffic in mobile networks is from PC’s and I think that also reflects my behavior. As a consequence, the uplink traffic generated by mobile devices is still an order of a magnitude smaller compared to overall downlink data traffic.

With faster uplink speeds becoming available the ratio could change once it becomes feasible to upload high quality video material from mobile devices in a reasonable time. That’s about the only application I can imagine that could have a real impact on uplink use. Until then, however, the uplink will remain rather unused.

Place and Cost

I am at the European Telecommunication Standards Institute (ETSI) in Southern France this week and every now and then I have to give a call to some experts back in Germany. Interesting how a 5 minute call to the same number is priced depending on which calling option I use:

  • Using my French SIM card in my N95: € 3.50 (70 cents a minute)
  • Using my German SIM card in my N95: € 2.90 (58 cents a minute)
  • Using the N95 VoIP function via the Wifi network: € 0.09 (1.79 cents a minute)
  • Using the VoIP client on my PC via Wifi: € 0.00 (call is VoIP end to End)

In the end I mostly use the N95 VoIP option over Wifi as for some calls some privacy is needed which is not not provided in the meeting room where the PC is located. I could move the PC but the € 0.09 is a good tradeoff for the convenience.

I titled this post “place and cost” because it shows how cost dramatically drops when different access methods are available and compete with each other. In places with less competition like the car, the countryside, etc.) mobile operators take over and option 3 and 4 are no longer possible. Unless of course, the operator offers a reasonable 3G data plan which make VoIP calls affordable again. One might argue it is more expensive to operate nationwide mobile networks with good coverage compared to DSL networks but I doubt the difference is € 0.09 to € 3.50.

S60 As A Platform

Recent news that Nokia would buy Symbian and put it together with its own S60 user interface into the new Symbian Foundation has sparked quite some interest. One reason for this move is that the operating system and the user interface is more and more seen as a platform which is better to distribute to as many players as possible than to use it as a differentiator. Differentiation should come from the applications running on the platform.

Recently, due to a one day outage of ProfiMail on my N95, I became aware of just how dependant I have become on my N95 from software that is not directly from Nokia, i.e. that didn’t come in the box when I bought the device. Together with OperaMini, Profimail are the main applications I use on my mobile device. Should both companies decide to leave the business (o.k. very unlikely but just imagine for a moment) I would be without a real alternative since both programs communicate with the mothership in order to function.

Sure, there are other browsers and other eMail clients but these two are definitely unique and I couldn’t replace them easily with others for my purposes. On the one hand this is good news for Nokia since third party programs have become a strong pillar in the overall value chain and thus promote the versatility of their platform. But on the other hand there is also a certain vulnerability as their own products are not where the competition is in a number of important areas, at least for my purposes.

The Mobilized Internet and the Mainstream

This week, the winning post of ‘krisse’ in the Carnival of the Mobilists has spawned some interesting thoughts over here. In the post, ‘krisse’ reports about entry level phones such as the Nokia 5000, which are around 100 euros without a contract, now come with OperaMini pre-installed. With a screen resolution of 320×240 pixels, the viewing experience is as good as with much more expensive feature phones. He didn’t say anything about how fast the browser runs on the phone but I assume processors have become fast enough even on S40 phones for the purpose.

So while Nseries devices and the iPhone might push the mobilized Internet revolution from the top, they won’t bring the real breakthrough as they are too expensive for a broad audience. But with phones for 100 euros now supporting feature rich mobile web browsers, that’s a different thing entirely. I would say that such phones are used by the majority of people in Europe, North America and many Asian countries.

From a hardware price point of view, mobile Internet access for the masses is now possible. Problem solved. From a software point of view, Opera Mini and other browsers have also reached a level of maturity that make them mass market usable. Hardware and software, however, is not all that it takes. In addition, I think the following things need to be put in place:

  • Prepaid data plans, either ‘fair use’ or a reasonable price per megabyte. Such plans are in place now in many countries now, but one can argue about the many ‘if’s, ‘buts’ and ‘must nots’ though. If marketed well and if they are simple enough to understand without a law and computer science degree, such offers should reduce the fear of only knowing one month later what mobile browsing sessions have cost.
  • Training of sales people: Absolutely essential! The average normob (normal mobile user) doesn’t want to figure it out himself. Currently, most sales people in shops are just clueless. This has to change.
  • Autoconfiguration / Pre-configuration: Devices must work out of the box, normob’s don’t configure anything. Again, a chance for operators to stay valuable in the value chain. 
  • Advertise compelling services: Also, good progress seen here nowadays with Vodafone and others advertising Facebook, Google and eBay on mobile devices.

Any other requirements I have missed for mass market mobilization of the Internet?

Carnival of the Mobilists Over At The Mippin Blog

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I was a bit sad over the weekend when I cleaned out my my RSS feeds as about half the blogs I’ve been reading over the past year have gone quiet. Hope you guys are coming back at some point. On the positive side other people are setting up new blogs to post to the world. And the best place to find both long timers and newcommers is the Carnival of the Mobilists, a compilation of the best writing around mobile of the past week. This week, the Carnival has stopped at the Mippin Blog. So head over and enjoy!