Steve Roberts: Ever since digital television standards and services were developed for consumer home receivers (DTV to fixed antennas on the home), research and standards to enable digital television (DTV) services to mobile (moving) receivers has been evolving.
In New Zealand, when the first digital terrestrial television (DTT) trials were conducted by Kordia - way back in 1999 and 2000 - I witnessed the robustness of the early DVB-T standards on the Auckland Motorway.
At about 80kmph, safely strapped into our coverage vehicle, we noticed that the DVB-T receiver displayed a steady picture even as the receive antenna was ‘parked’ for travel. As a Wellingtonian struggling to get ghost free reception in Paramata, I was an instant DTV supporter.
In 2008, commercial free-to-air DTT was finally launched in New Zealand and by that time the DVB Group had released a standard that supported mobile broadcast services in the UHF broadcast TV bands called ‘DVB-H’ [“H” for handheld].
Trials, pilots and technology demonstrations were held all over the world of DVB-H systems plus many competing technologies evolved and they all vied to be ‘the standard of choice’. While the technologies clearly work, spectrum issues - such as the lack of International uniform allocations and the difficulties getting business cases agreed between broadcasters, transmission and infrastructure providers, and mobile operators - meant few commercial deployments eventuated.
One of the most ambitious deployments was undertaken by Qualcomm in the United States with their MediaFLO technology. However, in December 2010, Qualcomm announced they were suspending new sales to users, and that AT&T would purchase their 700MHz spectrum. Therefore, FLO TV would cease to operate from 27 March 2011. If a commercial service is not sustainable in the US, where might it be made to work?
While broadcasters and content aggregators were pursuing the ‘wide area UHF Broadcast’ deployment options, the GSM Association developed Integrated Mobile Broadcast (iMB) standards that were accepted as part of the Release 8 3GPP standards in 2008.
But it was only in June last year that trials were held in the UK with O2, Vodafone and Orange. iMB delivers mobile data broadcast services in the 3G TDD (Time Division Duplex) integrated with existing 3G technology and at the Base Station level.
This allows bandwidth intensive mobile data services to be offloaded from the Mobile unicast network (where the voice and data applications currently sit) and put onto the broadcast portion of the TDD spectrum. This helps address the growing mobile network capacity issues many operators are facing.
The key here is the integration of this second data channel into the handset/device such that end users don’t know how they are getting their streamed video and data services. It just works – and without congesting the voice and other data applications.
Here in New Zealand, Digital Switchover (DSO) is scheduled for completion in late 2013. At that time, the UHF broadcast band will be half what it is today and possibly limiting further DVB-H or MediaFLO opportunities for broadcast mobile services.
The released spectrum is to be allocated (by an as yet undefined auction process) to mobile users. Maybe by then there will be enough international cooperation, spectrum and device technology commonality to finally see mobile television services to mobile devices reach the market.
Keep watching this space.
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