Evolved MBMS: Making Broadcasters Mighty Scared?

“Telstra just became a video broadcaster - for a short spell at least.” That was how GigaOM reported Telstra’s trial of Evolved Multimedia Broadcast Multicast Service (eMBMS), announced by Telstra yesterday in a blog post, and undertaken with network supplier Ericsson and chip maker Qualcomm.

An even more provocative comment on the potential of eMBMS technology was made by supplier Ericsson’s Kirsten Leins a couple of years ago when he told the ACMA's Radcomms 2011 conference that digital TV broadcasts, which in the US take up 300MHz of spectrum, could be delivered over LTE eMBMS technology in just 28 percent of this spectrum.

Liens played down his comments, adding, “This is just for a bit of fun. I am not advocating that the broadcasters would want to do this right now. This is more to illustrate the capability and the evolution through the R&D we put into telecom services year after year as an industry to show that we can do a lot more with spectrum than we do today…It is of course very much in the theoretical domain."

However, as I said at the time "Theoretical it may be … but its eventual adoption may be inevitable. … The ACMA's planning out to 2020 is forecasting mobile data volumes 1000 times greater those in 2007, and the need for an additional 300MHz of spectrum to carry it, notwithstanding expected increases in spectral efficiency that will come from LTE and, beyond that LTE Advanced.”

There’s clearly no prospect of broadcast transmissions being moved to cellular technologies and their spectrum being freed up for mobile usage anytime soon, but in the more distant future, who knows? That 1000 fold increase in mobile data volumes by 2020 has become almost a mantra in the industry, and what happens beyond 2020?

eMBMS requires handset support and the dedication of a portion of the LTE spectrum to services that are broadcast to all users. It can be cell-site specific or just used over a number of neighbouring cell sites and can be turned on and off at will, according to demand. Its big attraction is that, where the same content can be delivered simultaneously to multiple users, it requires much less spectrum than delivering a unique stream of that content to each user.

Ericsson Australia CEO Håkan Eriksson suggested that the first commercial eMBMS rollout could take place early next year. Of course he could not even hint that it might be Telstra, but Telstra has been up with the leaders in LTE deployments since day one. Meanwhile Verizon CEO Lowell McAdam has been reported saying that Verizon hopes to have the technology in place to broadcast the biggest US sporting event, the Super Bowl, in 2014.

Telstra’s acting director of wireless network engineering wrote when he announced the trial on Telstra’s blog:  “we are seeing a massive 23 percent growth in traffic on our 4G network – EACH MONTH!” That equates to a doubling every three months and at that rate the 1000 fold increase would be reached in just over two years!

So the incentive to deploy eMBMS is strong, assuming there is sufficient content suitable for broadcasting. As Eriksson explained, there’s been a bit of a chicken and egg situation to date. Operators have been reluctant to deploy eMBMS when there are no handsets to support it and handset manufacturers have reluctant to implement it without any services. Even if eMBMS were launched and handsets offered tomorrow it would take a few years to get sufficient penetration for the spectrum saving benefits to be realised.

So given the growth in demand, the sooner they start the better. But that’s assuming there is sufficient content suitable for broadcasting to achieve substantial spectrum savings. Fortunately we do have an estimate. It was published in January 2013 by iGR, a market strategy consultancy focused on the wireless and mobile communications industry.

And to show you just how quickly this market is evolving iGR reported that none of the operators interviewed for its white paper had firm eMBMS implementation plans. “MNOs appear to be currently preoccupied with deployment of their first LTE networks and optimising the operation of those networks and increasing the penetration of LTE devices in their subscriber bases,” it said. “[eMBMS] is seen therefore as a capability to be deployed after the initial LTE networks rather than part of any initial service.”

iGR admitted that estimating the impact of eMBMS on a mobile market was complicated by the fact that no trials had been conducted and that no specific user data was available. Nevertheless, it had a go, and this is what it came up with.

iGR‘s model shows that LTE broadcast can offload up to 11.5 percent of the total daily demand per subscriber and 14.7 percent during the peak hours. iGR forecast an overall reduction in busy hour bandwidth of 9.8 percent if LTE broadcast were deployed adding that “For the [US] mobile operators, this means the amount of network capacity built in 2016 could be reduced by 9.8 percent, equivalent to an overall potential saving of $4.21 billion.”

The figure for Telstra would clearly be much smaller, perhaps a few hundred million, but in parallel with the new service opportunities eMBMS opens up is surely sufficient incentive for early deployment.

And once deployed the iGR report points out that eMBMS could turn our phones and tablets into mobile DVRs. We could subscribe to particular programs, the LTE-broadcast network would schedule the download of the shows we wanted to watch and they would be stored on our tablets for later consumption. More competition fof the free-to-air broadcasters.