 We're here today in the ITU TV studio with Stefano Rafini, who's from Ericsson and he's an ITU expert in synchronization. Welcome Stefano. Thank you. So the obvious first question is, what is synchronization? Yes, synchronization means, let's say, distribute the same notion of time or frequency to different nodes in the network. So that's something that is really important in telecom. It's a basic fundamental function to allow network to properly work. And I understand that the story is that synchronization up until now has been ignored in the development of the internet, which sounds extraordinary. Can you give us some background on that story? Yes, it's a quite interesting story. What has happened is that normally telecom networks used to be synchronized, let's say, on the fundamental of the physical layer. And that was required to allow networks to distribute data without losing data on the path. And what has happened is that when mobile technologies have been deployed, essentially they relied on a good synchronization from the physical layer to deliver the radio interface with accurate signals. So when the network has been moved from TDM to packet, what has happened is that the packet network was inherently asynchronous. I mean packet technologies does not need a synchronous operation. All the routers or Ethernet switches can exchange data without any accurate synchronization. So what has happened is that the radio base station remains without synchronization. And that's why most of the work has started in ITT a few years ago to define some technologies to allow the distribution of accurate frequency, synchronization towards base stations. So it's really synchronization in mobile that's a driving force for the work right now. It's not so much related to, let's say, VOIP, but it's related to mobile and mobile base stations. Indeed, the main client of the work we are currently doing. And a shell out that recently, in addition to have an accurate frequency synchronization to be distributed to the radio base stations, there is also a need in several cases to distribute an accurate time or an accurate phase, which means that the same time knowledge has to be delivered to the radio base stations distributed in the network. For various reasons, for instance, to support time division duplex technologies to avoid interferences between the radio base stations, but also in the new LTE standards, LTE advance. There are new features that rely on base stations that have the same knowledge of time when they deliver time, deliver the signal towards the mobile equipment. Why do we need standards here? Yeah, that's a good question. Of course, it's important to allow in building the network solutions from different vendors. Let's say you have an interworking possibility that can interoperate, and operators can build the network with solutions from different vendors. And one key point is that in the past to distribute an accurate time, for instance, to radio base stations, a very common solution was to have a GPS receiver from the satellite receiving the signals. What's happening now is that in many cases this is not possible, or at least it's not sufficient. You can imagine if you have a peak of base stations in an underground or in a shopping mall, so that's not feasible to have a visibility of the sky to receive the GPS signal. So there is an increased need to deliver time reference from the network to the base stations, and this is a much more challenging task than in the past was to deliver frequency. So it's really a difficult task, but it's where many people are really contributing to provide solutions for that. Yes, I've seen that a number of people, the number of contributions is going up. This is fascinating work. Thank you very, very much for joining us today, Steph Arnan. Thank you.