One of the question marks over the future of mobile TV, has been just what kind of contribution MBMS can make either in competition with, or in co-operation with broadcast technologies like DVB-H, which already appear to be established.
There are still an enormous number of over the top players, and operators, which seem to be more comfortable with paid cellular streaming services ‘ albeit with farcically low customer penetration rates ‘ which would rather not bother with broadcast at all and may prefer a system based on MBMS.
Which is why we sought an audience with Ericsson, without whom MBMS would be unlikely to make any kind of dent in Broadcast mobile TV, being its biggest adherent, and very much thought of as its inventor, controlling as it does, so much of the modern UMTS base station market.
Miguel Blockstrand, Strategic Product Manager for Mobile TV at Ericsson walked us through the technology, ‘We had always thought of MBMS as an add on for Unicast, and it offers up to 7 TV channels in any of 64 kbps, 128 kbps, or 256 kbps per 5 MHz carrier, but it is really very flexible and can be configured however an operator likes. But you have to remember that there are two flavors of MBMS, point to multipoint broadcast, and enhanced broadcast.’
This enhanced broadcast mode, often referred to as multicast, is vital to understand the full capabilities of MBMS. When a phone requests a TV channel, the base station begins delivering it over the cellular network as a Unicast stream. When the base station software recognizes that the same stream has been called for, it allows a second stream to be set up. But at a threshold set by the operator, which might be as low as three identical channels, it shifts to broadcast. That means that the base station only has to send one copy of this TV channel, now shared by all three.
‘This is dynamically re-allocated, as people watching various TV channels, walk into and out of a cell,’ said Blockstrand. ‘An operator will be able to set up a service area based on a cell, a group of cells or the whole network and decide which are the popular channels based on what happens in this service area.’
A multicast of TV channels only has be taken to the radio network controller and then each one is sent to the base station when needed, cutting down on backhaul for TV services.
What most people don’t seem to understand is that by focusing the entire video multicast to the radio network controller, this means that each defined service area can have a ‘different’ set of 7 TV channels being delivered via multicast and at a maximum 256 kbps for each, that’s only 1.75 Mbps allocated to TV channels which are going to more than one person.
While most broadcast mobile TV suppliers have said that this is too small a bouquet to compete with broadcast, the quality of the video, at 256 kbps should be close to DVB-H standard, which means that this type of service can sit side by side with DVB-H without it dropping to a lower video quality when a different source of video is selected at the handset. Granted the DVB-H services will be multicast and will often begin with a 400 kbps or even 500 kbps stream, but the quality differential is not too vast.
‘MBMS video services are compliant with OMA BCAST so when the EPG for a DVB-H service sees an MBMS delivery, it looks exactly the same as if it was playing out a DVB-H service. This can be merged at the EPG so that all services look alike to the customer,’ said Blockstrand
‘Broadcasters are mostly responsible for setting up broadcast mobile TV services like DVB-H, and they have not accepted the idea that a single cellular operator can carry those broadcasts. So it is hard for a cellular operator to differentiate themselves, which is why they continue to push cellular streaming services.’
So just as Faultline has been suggesting that the MBMS part of the content might be the differentiating piece in a broadcast bouquet, so is Blockstrand. A common 16 to 20 TV channels across all of the cellular carriers in one country, delivered by MediaFLO or DVB-H, with either another 7 channels of material which is different for each cellco, or better still, another 7 channels per base station of differential material.
With a set up like that, installing MBMS becomes an easy decision. The 63 unicast channels that Orange boasts throughout its French cellular service would allow a huge amount more viewers if every one of the TV channels that had more than 3 people watching them, fell back to a broadcast signal. That would harvest a huge amount of existing backhaul and air interface capacity (since every repeated signal is backhauled separately pre-MBMS) for voice on its 3G network.
The most interesting aspect is just what this will cost cellcos ‘ which is nothing. A software upgrade is needed for the base station and a specialized handset is needed for MBMS reception.
‘Most chip makers are either ready with chipsets that carry the MBMS protocol stack pre-loaded or are preparing to offer it. Qualcomm and our own chip company EMP put the stack automatically into all HSDPA chips. Over time others will do the same, it’s just a matter of time. There is no increase in the bill of materials, and there’s no extra radio, and not much in the way of an increase in the use of battery. So there is no penalty for including it,’ said Blockstrand. However MBMS cannot download the protocol stack required he said and it has to be factory loaded. ‘The handset vendors then need to embrace it,’ he added.
But here Ericsson has some tricks up its sleeve. Most operators have found other compelling reasons to upgrade to Version 6.0 and even the subsequent Version 7.0 of the base station software, which both support MBMS. And the use of it is being sold not specifically for mobile TV, but for clipcast and podcast file delivery.
The idea is that in broadcast mode MBMS can send out all of this week’s soccer goals, or rugby tries or tennis passing shots or golf drives or American Football hits or baseball home runs, all in coded clipcasts, instead of sending them as unicast downloads. So for very small amounts of money, individuals can subscribe to services which rely on MBMS being installed on their handsets. This will drive the inevitable handset transition on devices which don’t actually cost any more, and since the software is already installed, the scene is set for zero cost addition of video services. With the advent of more and more devices with 8GB or 16GB of onboard storage, these types of clips can approach the quality of DVB-H delivered as downloads, when the network is least busy, and not as streams, and stored for later replay.
Do operators see all of this coming? ‘No I can’t say that operators fully grasp what MBMS can do for them, but they are starting to. When you are dealing with a company like Vodafone, getting the right marketing teams and the right technical teams in the same room at the same time presents enough of a challenge,’ said Blockstrand, ‘but we are seeing more trials and over the coming weeks there will be more trials announced, mostly in Europe and Asia and we should start to see MBMS moving.’
‘Services will emerge in the latter part of 2008 and early 2009,’ he said, which is not far behind DVB-H in many countries and in some spectrum starved countries, considerably ahead. ‘There are some companies that we know have hard plans to proceed, and there are others that are still not sure and who are trying to work out just who has what content rights.’
But where does Nokia stand on all of this, so often the arch-rival and nemesis of Ericsson, despite their dominating neighboring countries. ‘For Nokia it is a political decision. It doesn’t want to put MBMS into its handsets before DVB-H is established, but already Samsung and LG are pushing ahead, and we would expect Sony Ericsson to follow, and it is just a matter of time before Nokia accepts that MBMS is inevitable,’ said Blockstrand.
‘This all changes the moment an operator says he wants to use MBMS terminals, and suddenly they will appear.’
In our mind, the operators that best understand the idea of blending MBMS services with unicast, upgrading unicast to mostly file download, and merging the entire effort with any other common broadcast TV services, are those that will have a completely compelling video story, coming together towards the end of this year, early next.