UK TDD specialist IPWireless has been pushing the idea of using 3G allocated TDD spectrum for all manner of data delivery to a phone, for as long as we can remember. But more and more it is finally finding some key allies.
Recently it signed up Samsung as a handset vendor to support IMB, Integrated Mobile Broadcast, which is a way of broadcasting audio and video over existing cellular spectrum ‘ so mobile TV in TDD ‘ Now it says it has signed up ST-Ericsson. The two will work together to offer a pre-integrated IMB system to 3G device vendors.
If you are in cellular you know that most 3G licenses came with 5 MHz of TDD, one way, unpaired spectrum for data delivery and virtually no-one has ever used it. IPWireless tried to push this using the prior generation MBMS standard (Multimedia Broadcast Multicast Service), which could be implemented in either TDD or FDD spectrum. Ericsson in particular had a problem with its approach, and wanted to be enabled to build video delivery in a single platform ‘ 3GPP Unicast streaming and broadcasts in one integrated whole. This is because Ericsson is fairly dominant in offering 3GPP streaming technology to most European Cellcos.
The compromise was IMB, which although standardized in late 2008, has yet to have an implementation. The idea is that large TV services can be offered in a combination of VoD and linear broadcasts, with the broadcasts not using up spectrum set aside for voice or broadband usage.
Having got Ericsson onside via the agreed standard it makes a lot of sense that ST-Ericsson, it’s chip partner, should begin implementing it in existing 3G chipsets, so that handsets just arrive with this built in. We should expect USB 3G dongles to begin arriving relatively quickly.
As a first step in the partnership, IPWireless and ST-Ericsson are jointly developing a demonstration platform that device vendors can use to initiate IMB development. The demonstration platform will feature an IMB ASIC supplied by IPWireless and a 3G baseband radio platform from ST Ericsson. IP Wireless says that because of its integration with W-CDMA, IMB allows device vendors to reuse existing radio technology and antennas to create a lower overall bill of materials. It hopes this means that there will be commercial IMB network launches during 2011 and says some partners are already planning them.
Dr. Bill Jones, Chief Executive Officer, IPWireless said, ‘ST-Ericsson is one of the world’s leading providers of wireless platforms and chipsets. Their platforms combined with our key enabling IMB technology will enable our device vendor partners to shorten the time to market for IMB enabled handsets, boost worldwide IMB adoption, and enable operators to more efficiently use intelligent broadcast to address the looming capacity crunch driven by video and other multimedia applications.’
The big issue here is that Ericsson used to aggressively push MBMS, which was in 3GPP release 6, and had about three trials around the world, and never got any of them to deploy broadcast video.
There are always issues to be resolved. In DVB-H the issue was that broadcasters had to build a separate network and then found that handset vendors didn’t fancy adding DVB-H to their handsets. MBMS had some of the same issues, in that it needed some extra logic on the 3G chips, or an entire extra chip, in order to co-ordinate with base stations. IMB still requires that a set of new TDD transmitters are implemented in the system, but because they use virtually the same spectrum as the 3G signal, these can use cellular tower sites, something that DVB-H couldn’t do.
It’s anybody’s guess if this will lead to a major implementation, but it might, because the kinks have been ironed out and Ericsson is behind it. The problem is that the timeframe for all this is around 2012 which so happens to be when analog TV is switched off across Europe and more UHF spectrum would be available for things like DVB-H and MediaFLO (although we think these are dead now).
What IPWireless has done is create potential diversity inside its ASIC, making the deployment far cheaper, by being able to work from a weaker signal, so allowing only one in three cellular macro base station sites to need a transmitter. By combining Orange and T-Mobile’s TDD spectrum, where a trial is due in the UK, IP Wireless can implement it on one in 6 base stations for each of the two networks (yes we know Orange UK and T-Mobile UK are merging, but this would work even if they weren’t). This has the effect of using the transmitters over 10 MHz of spectrum instead of 5 MHz, enough for about 30 TV channels. As recently as last June Vodafone and O2 added themselves to this UK trial, effectively making 20 MHz of TDD spectrum available in a single multiplex. This trial, headlined for about two years, will finally start in the fourth quarter of 2010 and could offer 60 broadcast TV channels alongside unicast on demand content.
IMB was defined in the 3GPP release 8 standards, and was recently endorsed by the GSMA as its preferred method for the delivery of broadcast services.