Author: Martin

HSDPA backhaul over ADSL

Kevin Evans has put a post on his blog on HSDPA backhaul over ADSL. At first, it seems like a pretty good idea he says but has some second thoughts:

Kevin says Internet Service Providers (ISP) would probably be less than happy to connect HSDPA ADSL links to their  backbone. I agree! Cells where HSDPA is used heavily will pretty much use most of the bandwidth of an ADSL link for a considerable time per day. Consequently, such links would substantially increase the load of the ISPs ADSL backbone.

He then goes on to say that the alternative for mobile operators is to do their own ADSL backhauling. He thinks this is also not a good idea due to having to build an overlay network for backhauling next to the E-1s currently used for real time voice traffic. But why is it such a bad idea for operators to put their own ‘mini’ DSLAMs in central offices and have a little fiber there for backhauling? There is cost whatever you do, E-1, microwave, etc. so why not ADSL?

Some operators might have already decided to do this (speculation on my part). O2 Germany for example has said that they want to become an integrated fixed- and mobile telecommunication company, providing both high speed fixed line Internet access via DSL and high speed mobile Internet access via HSDPA. If they decide to build their own ADSL network, they can use it for both purposes.

As an alternative, Kevin suggests to use Ethernet for carrying both real time voice traffic and non real time background and streaming traffic generated by web browsing, podcast downloads, etc. But what about the distance you can cover with commercial Ethernet equipment today over phone cables?

When I first read about HSDPA over ADSL backhaul it immediately made sense to me due to the fact that ADSL has become a cheap technology to bridge larger distances than what is possible with other technologies. Have new long distance Ethernet technologies caught up in the meantime?

Whatever operators decide, I hope they decide quickly as HSDPA over 2 MBit/s E-1s is not going to make people happy.

It’s time for some mobile privacy!

I am sure that not even one person in a thousand has ever attempted to manage web browser cookies on the PC. I have to admit that I’ve been one of those 999 until recently. However, leaving the browser on its own to collect and send cookies as requested by web sites leaves the door wide open to advertisment companies and other institutions who love nothing more than to spy on where users are going in the web and what they are looking at. So I’ve set my cookie options in Firefox to only allow cookies from a few select web sites so I don’t have to log in everytime I go there. All other cookies are automatically deleted whenever I close the browser.

In the mobile world I would like to do the same thing. However, Opera for S60 has only very limited cookie privacy options. One can either delete all or none. Not good for me as I would like to keep some cookies like for example the one that keeps me logged into my mobile Flickr account.

Time for some action Opera!

French book on UMTS in its 3rd edition

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Silently, my fellow co-worker Pierre Lescuyer has updated his excellent book on UMTS called "Réseaux 3G" (3G networks) and the 3rd edition is now available in French. The new edition contains among other additions new chapters on HSDPA, HSUPA, IMS and MMS. Previous editions are also available in English and German.

Very well done, Pierre, congratulations!

Is Yahoo the end of Three’s Walled Garden?

A couple of days ago Yahoo and Three, a UMTS operator in a number of countries in Europe, Asia and Australia, announced a partnership to bring Yahoo services to Three’s customer base. Some news organizations like here, here and here are already speculating that this might mean the end for the walled garden strategy of Three.

I am a little bit more cautious in this regard as the original announcement just mentions that access to the Internet will be possible via a transcoding service for web pages delivered by Yahoo. Well, that’s a step forward but it’s still kind of a garden with a hedge around. As long as someone only wants to use the phone to browse the web via the mobile phone that’s probably o.k. but don’t dream that this offer will be useful in combination with a notebook.

I think this could be a win-win deal for both Three and Yahoo. Yahoo definitely needs such deals with operators in order to get their software pre-installed on mobile phones which is a precondition to reach an audience beyond early adopters who are willing and capable to install software on a mobile phone or type in URLs with the keypad in the mobile web browser to get to Yahoo’s services. Three on the other hand will surely welcome the attention the Yahoo brand will bring to its network.

For Yahoo, I think this is an important step in order to catch up with Google, who’s partnered with T-Mobile recently for its Web’n Walk mobile Internet access.

Great stuff, the mobile Internet is slowly tacking shape for the masses! In the next step the hedges and prices have to come down.

1% Makes or Breaks Usability – Especially in Mobile!

Logicam
A recent personal experience is yet another proof of how even small features can make or break usability in any product, no matter how good it is. I am away from home quite often so mobile technologies, the Internet and VoIP help me a lot to stay in touch. Since Skype has started to offer video telephony, things have improved even more. However, there was a catch.

We’ve had web cams for quite a while now but we didn’t use them a lot as my better half always felt uncomfortable with that "eye" (lens) staring at her even when not used. So the web cam was always unplugged and stowed away, usually not used again for a long time as it is just too much effort to position the camera and plug it in again before a call. Now Logitech has found a solution to the problem. One of their latest web cam models, the QuickCam Fusion features a lid that can be opened and closed to reveal or hide the lens. A small feature, but it makes Skype’s video service finally usable for us! No more camera positioning and plugging. After the call, the lid is closed and the "eye" is no longer staring at you! Strangely enough, Logitech doesn’t even mention this feature in their production description. Are they aware what they have done?

Now let’s take the lesson into the mobile domain: One of the small things that break the mobile Internet experience for most people is the fact that they have no idea how much it will cost them if they open their mobile phone’s web browser to go to the operator’s portal. Not a single person I asked who’s not regularly using the mobile web could answer this question. It’s unlikely this can be solved anytime soon, no matter how much mobile operators spend on advertising.

A different solution has to be found and actually, it is quite simple: How about having a button on the phone that automatically starts the web browser and directs the user to a pre-programmed page on the operator’s portal? Agreed, this already exists. However, most people hate this button because they feel it’s dangerous as they have no idea how much a press of that button will cost them. This is similar to the fear of the "eye" staring at you. So the only way to take that fear away is to make a subset of the portal free of charge. Sure, operators want to make money but to enter the shop (the portal) must be free and people must be made aware that entering the portal is free.

P.S.: Dear operators, once you do this, do this right! That means: Make the button free of charge for roamers as well!

Mobile Network VoIP capacity

One of my favorite topics is cellular network capacity. I posted an example a while back on the 1 kb/s 3G surfer. At the time I excluded VoIP as part of my application mix as it increases network traffic quite a bit. Today I found some interesting material which sheds some light on this part of the story:

Wireless Networks have a particular problem with Voice over IP. While traditional circuit switched traffic was optimized on all layers of the protocol stack to be transferred as efficiently over the air interface as possible, achieving the same effect for Voice over IP is very difficult due to the decoupling of the different network layers on the IP protocol stack. Thus, a VoIP call today consumes at least four times as much bandwidth on the air interface than a circuit switched voice call. In other words, if everybody started to use VoIP over wireless today, network capacity for voice calls would shrink to only a quarter of what it is today.

Now Ericsson has released an interesting slidepack on the topic which targets the non geek investment community but which nevertheless contains some interesting numbers on wireless network enhancements and optimization for VoIP in the future: As described above, Ericsson’s slide pack shows on page three that  UMTS networks today could only provide 20% of the voice capacity with VoIP compared to standard voice calls. So that’s close to my number above. With HSPA (I think they  refer to HSDPA + HSUPA) capacity increases to 70% if IP robust header compression (ROHC) is used. They then go on to claim that with efficient signaling (whatever that is…) and improved scheduler (what improvements?) and optional GRAKE2 (again what is that?) VoIP capacity can be pushed to 140% of today’s standard voice capacity. Finally the next evolution of UMTS called LTE (Long Term Evolution) targets 200% of current voice traffic for VoIP in the same bandwidth.

Not sure what the improvements are they are talking about as they don’t give any further explanations but it seems we are getting somewhere in due time. VoIP VoIP Hurray!

2006 – Year of the Quitter at MoJo

Debi a.k.a. Mobile Jones has discovered that a lot of people seem to quit one thing or the other this year. She wanted to join the pack and has quit smoking. Good idea 🙂 In a recent podcast recording she asked me what I would quit this year (has it become kind of an obsession with her)? Well, I might just quit blog reading…………… on the PC. My blog reader program (Resconews) on the mobile phone is almost good enough to let me do all my blog reading while on the go. Not much is missing in the software. So what will you quit this year?