It's proved very popular, yet we've always been aware that by only offering streaming, it misses out on one of the key use cases of mobile and portable devices - offline playback of programmes on planes, trains etc.

The Nokia N96 is the first device we've come across that really ticks all the boxes in terms of having all the features and capabilities we need to offer this: it's got a powerful browser, 3G and WLAN support and, crucially, it supports the OMA DRM 2 specification.

The BBC only has rights to make TV programmes available in iPlayer for a limited number of days after the original broadcast - so, when we provide downloadable programmes, we have to use DRM (Digital Rights Management) technology which ensures that the programme is only available to users on the phone for the allowed number of days.

OMA DRM 2 is such a DRM solution. It was designed a few years ago by the Open Mobile Alliance (the main mobile industry group that creates such things) and has been emerging in phones for the last year or so, now including the Nokia N96.

Until now, it's largely only the mobile operators that have been using it, but in order to provide the download experience we want to offer, we've decided to license the technology and build the server systems necessary to package and distribute our programmes in the OMA DRM 2 format.

As well as enabling us to provide downloadable programmes to the N96, the OMA DRM 2 system is available on a growing number of handsets, and so we expect our investment here to help enable us to provide mobile BBC iPlayer on a range of mobiles.

In order to build the necessary DRM servers, the BBC has taken licenses from three companies: CoreMedia, who provided us with a software development kit which allowed us to build the system in a few short weeks; Intertrust, which is a leading inventor and patent owner of technology in the OMA DRM 2 specification and CMLA (Content Management License Administrator), which is the leading Certificate Authority (CA) and "Root Of Trust" for the OMA DRM 2 system. I think this last one warrants a little more explanation.

On a technical level, the OMA DRM 2 system uses a certificate system similar to that used in SSL and other secure communication systems to identify the various parties involved in the download of DRM content to a phone (device model, device manufacturer, content distributor, CA etc).

The certificates provided by CMLA are preinstalled on the phones and integrated with our server system, and this allows each party to identify each other and confirm that the certificate is genuine and issued by CMLA - and, crucially, the server and phone are able to check the other party's certificates status with CMLA to determine whether the certificate is still trusted. This is the essence of "trust" in a DRM system.

The content creators and owners "trust" CMLA to manage the certificate status of devices and service providers like us so that, should a device implementation become compromised, or a service provider go "bad", they can be taken out of the system easily and without any explicit action by any other party (e.g. the BBC).

There is a lot more subtlety, complexity and technical detail underneath the surface in this topic. Interested readers will find more detail on the internet.

Matthew Postgate is Controller, BBC Mobile.

I can reassure andibeeb that this is not because the BBC has any kind of deal with Nokia to promote some types of phones over others. It is because we have not yet got the user experience on other devices to a point we are happy with.

While the mobile version of bbc.co.uk is a service that works across the broadest possible range of devices (even down to WML 1.0 browsers), Mobile BBC iPlayer is designed to be a much richer proposition. We have had to work very hard to get the level of user experience we are happy with and at the moment we have only been able to create that level of experience on the Nokia N96 and the Apple iPhone. The N96 improves on previous S60 devices in a number of ways like screen size and memory capacity, but one of the most important upgrades is with the way it integrates the browser and media player applications.

Photo of N96 advertising hoading courtsey of Jason DaPonte

Previous handsets do not automatically carry the browser's current network connection settings over to the phone's media player. As a result, you could select Wi-Fi on the browser, but without knowing it end up watching streams over 3G connections. This could lead to you getting bigger bills than you were expecting.

Looking at how we could support legacy devices is one of the things that the team is working on at the moment and was something we have been looking at for a while but we have not cracked it yet. As I said in my original post, we want to introduce support for other devices as soon as we can and I will post more when we have some news.

Mathew Postgate is Controller, Mobile, BBC Future Media & Technology

Lying in bed watching the latest episode of Strictly Come Dancing on a mobile phone will become possible from next month after a tie-up between the BBC and Nokia.
All BBC programmes transmitted in the past seven days will be available to download to the new Nokia N96 multimedia handset, in a first for the broadcaster and phone maker.

N.B. BBC News also has the story here (ed)

Mobile can be a complex environment and there is a great deal of fragmentation to contend with.

I have always wanted to take BBC iPlayer to mobile but we have been waiting for devices to arrive which mean we can create the kind of experience that audiences have come to expect from the service.

The iPhone and iPod Touch gave us something to work with and we launched a beta for those devices earlier in the year. Some aspects of the experience were fantastic but there were still compromises. The Nokia N96 was always gong to be a contender, as we knew it would be optimised for video and audio. The success of the N95 also meant there was a good chance of it becoming a mainstream device.

Nokia were keen to work with us on the project and together we looked into what it would take to launch something. It proved to be the first platform where we could fully realise the ambition that we had for mobile iPlayer. Naturally, we will want to introduce other devices as they become available - and we're already working on the next group.

It will be interesting to see how people use BBC iPlayer on mobile rather than over a set-top box or a computer. I think that the ratio of download to streams might be more, even compared to the PC; I also think that BBC radio programmes will perform well. No doubt there will be some surprises that we will be able to feed into the next version.

As ever, any launch is only the beginning of the journey and now we have the core functions of iPlayer available we will begin to see what the mobile version can do uniquely well. Social features seem an obvious choice but there is a possibility for something around location. Ultimately, we want the mobile version to make a contribution to a BBC iPlayer that is greater than the sum of its parts.

Matthew Postgate is Controller, Mobile, BBC Future Media & Technology.

For the BBC, supporting this type of event is really important to what we are trying to achieve on mobile. We wanted to help to create an environment where developers and designers who are passionate about mobile could exchange ideas. I think that - as grassroots development is beginning to scale and as the ideas it generates emerge - we will see some of the fragmentation that has dogged mobile for so long also begin to disappear. One of the most encouraging aspects for me was the tangible sense that mobile is happening right now, in front of us.

I gave a presentation at the beginning of the event which covered the "where we've been, where we are and where we are going" with mobile at the BBC. One of the themes I spoke about is the evolution of our mobile browser site. I think that our mobile site is great but I also think that it's in the process of fundamentally changing.

Increasingly, we need to understand how it relates to the fixed line version of bbc.co.uk. Bringing the web together is one of the real challenges that "mobile" becoming mainstream presents all of us, whether you maintain mobile versions of your website or not.

Audiences who are increasingly accessing the web on portable devices naturally have expectations that services will work and relate to the experiences they have become used to on their computers. The developers that were at OTA and the ideas they are coming up with are also increasingly creating an expectation that the mobile web will offer even more: an experience that plays to the strength of the medium, of an integration with other platforms that is more sophisticated than just straight repurposing.

The talks and the prototypes that were developed over the two days hinted at the opportunities being created. It was all stimulating but three of the category winners in particular pointed towards this future.

Best mobile widget was awarded not to a widget but to Auto Widget Configurator, which was an easy way of moving a widget from your PC browsing experience to your mobile - again a simple idea that brings the two situations together.

It was similar to the winner of Best mobile web application: Browser Sync. This prototype moved your history including the page you are currently browsing from you desktop to your mobile or vice versa. The judges could see the immediate benefits but there was also the potential to develop the idea so that there is some subtle optimisation as the page is "moved across", either in terms of formatting or even the content of the page. At their best, ideas that bring the web together change the way people use both the mobile web and the fixed line web by taking into account the audience's different situation.

While the mobile web was, quite rightly, an important theme of Over The Air, the breadth of talks and prototypes also reflected what a rich area it is for designers and technologists. Applications, Location, Accelerometer interfaces and even remote controlled robots all got a look in.

The event was a testament to all those involved in organising and running it, along with everybody who attended.

I want to extend a heartfelt thanks to the team from Momolondon, Imperial College, Mobile Monday and BBC Backstage who did a really good job pulling it all together, and to all the people from the BBC who toughed it out from the Thursday night to Saturday morning.

I hope that the connections people made will continue to be productive - the BBC will continue to work with Momolondon, so look out for future events.

Matthew Postgate is Controller, Mobile, BBC Future Media and Technology.

Today, the BBC's mobile team launched a significant release of the mobile version of bbc.co.uk.

We've been calling this the "refresh release" and the team has been working on it in earnest since November. It's the first of three major releases we are planning for 2008 and brings together a number of enhancements that are probably long overdue.

There are upgrades to the code base and to the hardware, the replacement of a critical piece of hardware that was seven years old. The team is currently petitioning for release of the relevant box from the server farm so we can display it like the Toyota Hilux that wouldn't die on Top Gear. These parts of the project mean that you should notice an improvement in the speed with which we are able to publish stories.

This release has been focussed on consolidating the existing mobile version, so there is not a great deal of new editorial material at this point, although there is more local content and Newsbeat has been included for the first time.

You'll also notice the new design. I believe a new design for the site is long overdue - but, like all design changes, I'm also sure it will divide opinion.

The BBC has had a presence on the mobile internet since 1999. There was a major overhaul of the mobile version of bbc.co.uk in 2003, when we moved from a black and white WML 1.0 service to one that used more colour and images. At the time, some people felt we had betrayed the simple elegance of the previous design.

In 2003, as new devices emerged and audiences began to grow, it was clear that this approach was going to restrict what we could achieve on the platform. Our philosophy evolved as we attempted to provide the richest possible experience based on the capabilities of the device with which you were accessing bbc.co.uk.

At that time, we knew that we would be signing up for a significantly more complicated challenge. The continued fragmentation of the mobile device market since then has only proved us right. Because the mobile internet is so important to the BBC, I feel that the extra effort is worth the return.

The 2003 design upgrade has been tweaked over the years. In reality, the capabilities of the devices accessing the service at the beginning of 2008 have outstripped the templates we were using. In addition, the launch of the new bbc.co.uk homepage - the beginning of a new design language we are trying to develop across all our platforms - presented a great opportunity to have another look at the design of bbc.co.uk on mobile and to create something that works well with the mobile devices accessing bbc.co.uk at the moment.

I see this as a foundation that positions us for the next release, which is focussed on supporting a number of major events over the summer like the Olympics. We have added over a million users in the last year alone and are still growing fast.

Your comments are welcome.

Matthew Postgate is Controller, Mobile, BBC Future Media & Technology.