What ya working on?
Posted by stephen on Friday, 27th January, 2006 @ 15:47
It's been a little while since I had one of my geeky blog moments, so I thought I'd take the opportunity to blurt out a little bit about what's been happening with work lately.
As I've mentioned before, Richard and I will be off to Moffat in Scotland in the next couple of months to fit up a hotel with an IPTV system. Hotels and the commercial sector aren't really what we're about, so you might be asking yourself why we're doing it.
Our work is part of a project to examine what services can be delivered over wireless networks.
With all the buzz lately about triple play services, telephony, television and Internet access through a single IP connection, large parts of Scotland are missing out. Only very recently has the area we're going to received ADSL. And there's no LLU, no connections above 2Mb for the foreseeable future (the Scottish Executive gave BT money to set it up in the first place) and many homes are beyond the usual reach limits of DSL technology. Some don't even use copper pair cabling.
Costs of laying a wired network of any kind are enormous and commercially it's just not viable at the moment. There's near-zero chance a cable company is going to come along and fix the situation. So Scottish Enterprise has stepped in and decided to sponsor a project to find out what IPTV services can be made available wirelessly.
A local wireless broadband provider, working with Locust will be sorting out the wireless networking issues and adapting their mesh technology where possible to the kinds of traffic an IPTV service generates.
Our role is to provide a low-cost RegenTV head-end and Set Top Boxes. Two new developments to RegenTV are being made by us. First off, access to a full-featured web browser without the need to log in to a full desktop session. As you'll have seen from previous blog entries, this has been completed.
Secondly, our video content must be provided in MPEG4 format to reduce the bandwidth requirements as much as possible. For video on demand this is straightforward, the software we use is already capable of ingesting and delivered MPEG4 streams. For redistribution of free-to-air digital TV, it's a little more tricky.
My current challenge is taking the MPEG2 transmissions off the air, decode the video and re-encode it into H.264 format, all in realtime. A lot more complicated than simply pulling apart an MPEG2 transport stream and multicasting each channel onto our network as we do now.
H.264 is a fairly recent standard. As such, it's proving very difficult to get hold of encoding hardware at a reasonable price with decent software support. So I'm currently investigating with a full-featured DVB-S card that'll provide VLC with an already decoded video stream and then transcoding to H.264 and spitting out a multicast. My main concern is can we do it fast enough in software? I'll find out soon!
A rather unexpected surprise was the lack of vendors with H.264 capable set top boxes. What seems to have happened is that one vendor has produced a prototype and mentioned it to their marketing department. This has pushed all the other vendors to do the same. So far, only one company we've talked to has a proper commercially available box right now. All the others are three months off. We've got two months left to complete this project!
The aim of this project is not to produce a working IPTV solution for a hotel. It is a research and development exercise to find out what services can be offered over wireless. Which is definitely a good thing. We have huge reservations about realtime video transmission over wifi technology. A lot of online research has borne out this assumption. But we shall see!
I suspect that ultimately this project can deliver a meaningful service. But I suspect not in the form we'll be working with now.
I can imagine that for a proper rollout in peoples homes the best approach would be a set top box with hard disk and DVB-T tuner. This would be connected both to their TV aerial and to a wifi antenna. PVR functionality is offered for over-the-air broadcasts, Internet access is available wirelessly, potentially along with VoIP service.
And Video on Demand content would be trickle fed through the wifi connection so users would select in advance what local or premium content they wish to watch. This would then be available on their STB's disk at a later time.
It may not be ideal, but short of running fibre I think it's a reasonable and useful solution for the time being.
