IMT-Advanced (4G) Submission and Evaluation Process

News from the ITU (International Telecommunication Union) on 4G, aka IMT-Advanced: In a recent meeting it was decided that technology has now moved sufficiently beyond enhanced 3G systems (such as UMTS HSPA, WiMAX, CDMA1xEvDo also called ‘enhanced IMT-2000 systems’ in ITU terms) that the selection process of suitable technologies for 4G can now begin. In a paper, the ITU describes the steps that will now follow and the time frame they see for the process:

  • 2008 – beginning of 2009: Companies can submit proposal for candidate technologies. I guess 3GPP’s LTE Advanced and IEEE’s WiMAX 802.16m are hot candidates. Let’s see who else will come up with something.
  • Up to 2010: Evaluation of the proposed technologies
  • Mid-2010: Decision will be made which systems will get the IMT-Advanced stamp

A further interesting note is that the new documents now published by the ITU do not specify any new technical details concerning the properties of future 4G systems. Instead, they just reference ITU-R M.1465, which has been around for some time now, which calls for data rates of 100 MBit/s while moving and 1 GBit/s while stationary.

Via LTE Watch

Wi-fi Hotspots Are Spreading But Network Management Is Not Keeping Up

It’s rare that I use public Wi-Fi hotspots since for me, mobile Internet access via a cellular 3G network is usually a cheaper and more flexible alternative. But every now and then I just log on to them to see how much users are charged for connectivity. These days, however, more often than not, the Wi-Fi hotspots I log on to are not working as they should. Either I don’t get an IP address (in one instance Wireshark showed that the DHCP server returns failure messages because the IP address pool is exhausted), the portal page fails loading which probably means the backhaul link is broken or the speed is so abysmally slow (for whatever reason) that any meaningful use of the service is not possible. Yes, I am complaining! Or is it just something specific of the countries I travel to? Not that the reliability of 3G wireless networks is beyond complaint but I can still count the instances a network didn’t work on a single hand (and I travel to many countries in Europe).

Why They Should Cover This Office Building?

There is this new office quarter in a Paris suburb to which I go every now and then. 2G and 3G coverage is o.k. while being on the street but as soon as I enter one of the office buildings, signal levels of all networks drop like a stone in the water and in many meeting rooms I have little or now network coverage. Which network I receive depends on the part of the building I am in.

Well, this quarter is not so new anymore, operators had more than two years now to improve the situation. I am really puzzled why they haven’t done so!? There are tens of thousands of people working there and many must feel disappointed by the wireless network coverage they have at their desk. I guess many have in the meantime made the decision for which operator to go on their private phones depending on which network they can receive at their desk. And always living in fear of having to move to a new desk…

A bizzare situation. So listen up, dear network carriers, a lot of potential new clients are just waiting for that new antenna that gives them better coverage in the building they spend the major part of their time. A strong argument you don’t have to work very hard for next time that contract runs out… And if that is not enough, think of all the additional SMS messages, eMails and phone calls these people will use their mobile phones for once they can do so.

Vikuiti: To Be Seen Or Not To Be Seen

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3G networks offering me mobile Internet access at most places I go has definitely changed the way I work and where I work. Yet, there is also one big disadvantage: In some places people next to me can look at the screen of my notebook and see what is sometimes is not really for their eyes. Privacy is definitely an issue sometimes. A couple of weeks go, I thus bought a Vikuiti display filter from 3M that restricts the viewing angle. Since then, nobody is looking anymore and I get questions like “is your notebook turned on”? Very nice 🙂 The picture on the left proves my point. More resources:

  • Here’s a video of how it works on YouTube. Thanks 3M, not cheap, but very usueful.
  • And here’s a link to a recent 3GPP meeting with an interesting picture on the right. You can see who’s using a filter and who is not 🙂

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!