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Read the blog post (with hyperlinks) here: https://communities.cisco.com/community/solutions/sp/mobility/blog/2014/01/06/cellular-broadcast-may-fail-again
1. Cellular Broadcast may fail again
Posted by Zahid Ghadialy
It’s happening again! The excitement, business cases, discussion on how the
technology has matured, lessons learnt from previous such rollouts, etc. Believe it or
not, it’s happening all over again. LTE Broadcast TV (a.k.a. eMBMS) is coming to an
operator near you, soon.
Back in 2006, when Release-6 of UMTS was released, MBMS (without the leading ‘e’)
was being hailed as a great technology that would solve many of the ills that had been
plaguing the Mobile TV rollout. For example, the biggest issue was additional spectrum
that was required with any of the other Mobile TV Broadcast technology, was not a
problem for MBMS. In case of MBMS (Multimedia Broadcast Multicast Service), the
spectrum of the UMTS channel (fixed 5MHz) could be dynamically partitioned to serve
the regular Voice(CS) + Data(PS) traffic and the broadcast data. None of the other
competing broadcast standards then like DVB-H, T-DMB, ISDB-T, CMMB and
MediaFLO could offer such an advantage. Another big advantage with having 3GPP
cellular broadcast standard (MBMS) in comparison to the competing technologies was
that no additional hardware/chipset was required and there was no necessity for
additional authentication and security mechanisms.
Even after many such advantages, MBMS never got off the ground. The simplest of
explanations revolved around the limitation that UMTS channels bandwidth is fixed to
5MHz, which means only limited number of channels could be supported for Mobile TV
transmission. Another reason was that the operators tried to do too much too soon and
as a result their business case fell flat. This was a result of using Multicast to sell
subscription services to the users who had very little or no experience of watching
TV/Video. Let’s look at the broadcast and multicast concept in detail.
Unicast, Broadcast and Multicast
2. In case of ‘Unicast’, the radio access network (RAN) has to setup a dedicated bearer
with the cellular device and then transmit the broadcast video. This would defeat the
purpose of broadcast as a dedicated bearer is set up with the device and the device is
effectively using the data. This is not a preferred approach and used in extreme cases
for the sake of continuity. If only a few users in the cell are watching the mobile TV then
there could be a saving of bandwidth by letting each of these users have a unicast
connection rather than sending all information using the broadcast. Unicast mode is
also known as ‘one-to-one’ or ‘point-to-point’ (ptp) transmission. Normal video streaming
(using Youtube, Netflix, etc.) is always using the Unicast mode.
In case of ‘Broadcast’ mode, the transmitted information is available for every device to
be able to view. Broadcast mode is also known as ‘one-to-many’ and ‘point-tomultipoint’ (ptm) transmission.
3. ‘Multicast’ mode is a special case of Broadcast mode where the information may be
available for all users but could only be decoded / deciphered by a device that belongs
to the multicast group. To belong to this group, the user would have to subscribe to the
service beforehand by calling the operator or using some online website, etc.
While in case of 3G MBMS, all the three modes were supported, in case of LTE eMBMS
(‘e’ stands for evolved), Multicast mode is not supported. To highlight the similarity with
3G MBMS, the abbreviation was not changed to eMBS.
High profile Mobile TV launches in the past
Over the last few years, many big players have tried their hands on Mobile TV. Here is a
summary of a few of them:
MediaFLO: A very ambitious and bold
Mobile TV attempt was made by
Qualcomm when it launched its
services back in June 2009. Initially it
was sold by AT&T and Verizon but the
users had to pay $15 for subscription
per month. This pricing was reduced
and there were also other discounts
available for users to sign up to the
service. Qualcomm also sold a
standalone device with subscription
and tried to partner for in-car
entertainment systems. The main
reason for failure was high subscription
prices for limited content and lack of
smartphone models supporting
MediaFLO. We have to remember that
this required additional spectrum and
hardware (chipset) which meant
additional subscription charges. This
service was eventually shut down in
early 2011.
NOTTV: Japan has always been a
trendsetter and a leader in technology.
No discussion on Mobile TV could be
complete without mentioning Japan or
their leading operator NTT Docomo.
Back in April last year, they
announced that they have 680K
subscribers to their NOTTV Mobile TV
service after a year of launch (though
they were expecting atleast 1 million).
Each subscriber pays 420JPY (roughly
4. $4/£2.5/€3) per month. One of the ways
NOTTV was made appealing to the end
subscibers was by providing original
content that was only available here and
was also archived so playback was
possible too. Subscribers can also
provide live feedback or answers to
what was being shown thereby
increasing participation and value over
the traditional television.
China Mobile TV Service: China
Mobile is another operator with clout
and loads of subscribers. It has been
pushing the Chinese mobile TV
standard (CMMB – China multimedia
mobile broadcasting), not only in China
but in other parts of the world as well.
Again, this requires an additional
hardware and spectrum for the
receivers to be able to receive the
content. A report back from
2010suggested that the number of
users of this service were much less
than expected and only a few of them
were actually paying subscribers. China
Mobile Hong Konglaunched mobile
TV services based on CMMB in Dec.
2011. CMMB based mobile TV is also
being launched in Philippines this year.
Many other operators and other television & media companies have launched mobile
TV services based on the streaming (unicast) model discussed above. While this may
work in the short term, in the long term this is going to congest the mobile networks
thereby impacting the traditional voice and data services. An easy option available with
the operators is reduce the priority of the mobile TV data but this would mean the quality
of experience (QoE) of the mobile TV subscribers would suffer and they may desert the
services.
‘eMBMS’ as the saviour
Back in March last year, a top Verizon executive confirmed that they will be launching
Mobile TV based on LTE broadcast technology, eMBMS, sometime in 2014. In June
last year, Verizon is reported to have agreed a multiyear $1 billion deal with NFL for the
rights to broadcast the games on smartphones. The deal though is only for the
smartphones, not for the tablets. My guess is that it’s for any device that has a SIM card
in it. eMBMS would make sense for broadcasting content such as live games to a wide
audience without overloading the network.
5. AT&T doesn’t want to be left behind and its building its own eMBMS network on the old
MediaFLO spectrumit bought off Qualcomm. In fact, if it reserves an entire 5MHz
spectrum available nationally for eMBMS, it can use the alternative eMBMS
configuration of 7.5KHz channels (rather than the regular 15Khz channels) which could
result in more channels being available and also better performance.
Finally, the Australian operator Telstra recently conducted LTE-Broadcast (eMBMS)
trials over its commercial 4G network, broadcasting several sport events and even a file
download to several mobile devices over the same wireless transmission. Qualcomm
and Ericsson, who partnered Telstra in these trials, believe that they have found the
right model to make broadcasting work.
Do users want Mobile TV
The short answer is, of course they do. I remember being told many years back about
this survey where the users were asked if they would want TV on their mobile and if
they would prefer to pay for that. The answer was a resounding yes. The only problem
with that survey was that nobody asked the respondents what they understood by
Mobile TV and how much would they prefer to pay. Over the last many years I
remember asking people I meet in various works of life the same questions. The most
common answers I get are; Mobile TV is like Youtube or iPlayer and the maximum
about anyone would prefer to pay is £2($3). I am sure this is not what the operators
expect. In fact in this day and age where the Freemium model is being used for Apps
and services, are the users not going to expect the same from any Mobile TV offering.
Maybe some users wouldn’t mind paying extra in a bundle offering.
6. The above picture from the Adobe’s digital Index team highlights the important point that
users still prefer watching video on tablets, rather than the small smartphone screens.
This picture above from Business Insider article early last year highlights the difference
in viewing habits with smartphone and other kind of devices. Frankly, I am surprised by
the number of users on the smartphone watching video longer than 10 minutes.
7. Another piece of statistics from an eMarketer article, also from early last year, shows
that the top three kinds of content for both smartphones and tablet users were movies,
user-generated content (such as YouTube videos) and TV shows. But the difference
lies in emphasis: Tablet viewers were much more likely than mobile phone viewers to
prefer feature-length movies and TV shows. Mobile phone viewers were more likely to
watch user-generated content.
It is important to highlight that the span of attention and the patience required watching
lengthy content on smartphone is a tricky job. Mobile TV is exactly what smartphone
users don’t want.
There’s still hope for eMBMS and Mobile TV
I have tried my best to reason why Mobile TV on smartphone may be difficult to
succeed. Tablets are becoming increasingly the main means of watching lengthy videos
but most of them are Wi-Fi only. Two simple ways in which Mobile TV uptake may get a
boost would be to have unique content, tailored for smaller screens and to have similar
content being broadcasted on other connected devices like tablets, regardless of
whether they are Wi-Fi only or support cellular access. Without allowing these
alternative devices to receive Mobile TV, eMBMS may suffer the same fate as those of
MBMS and MediaFLO.
About the Author
Read other blog posts by Zahid Ghadialy here
Follow Zahid on Twitter @zahidtg
For more discussions and topics around SP Mobility, please visit our Mobility Community:
http://cisco.com/go/mobilitycommunity