eMBMS or enhanced Multimedia Broadcast Multicast Service is a hybrid technology that tries to marry the traditional one-to-many broadcasting architecture used by Doordarshan and FM radios with the one-to-one architecture used by cellular service providers.
In other words, even though both TV broadcasting and cellphone towers use essentially the same kind of spectrum, TV and radio are one-way communication, while cellular services are two-way communication.
But the more relevant difference in this case is not in the direction of communication, but the scalability of the two models.
Using the traditional broadcasting model, a single tower can deliver several live TV or video channels to lakhs of users.
However, a single tower on 4G can only serve 100 or 200 users using the same amount of spectrum.
While scalability is plus point for the ‘broadcast’ or ‘multicast’ model, the key advantage of the 4G model is that each end user can watch any video from the Internet, and not just the handful of live TV channels made available.
eMBMS tries to combine the best of both worlds — the scale of one-to-many broadcast (multicast) with the choice of one-to-one streaming (unicast).
This is done by having some, popular content placed on ‘broadcast’ mode, while reserving some of the spectrum and capacity for those who want to watch something else.
In other words, when a cricket match is going on, the sports channel can be kept in the multicast mode. This will take up a part of the spectrum, while leaving most of it for one-to-one video streaming.
Anyone who is watching the cricket match on their JioTV app is hooked on to the single data stream without them realizing it.
If this is not done, JioTV would end up serving tens of thousands of live streams from its servers all carrying the same data, instead of just one stream that is ‘shared’ by many users.
The true extent of the deployment of the technology by Jio is not clear yet. In its quarterly update, Jio said it performed an “eMBMS broadcast stream across Pan-India.” Still, this alone would make it the largest eMBMS trial or deployment anywhere in the world.
The technology is still in its infancy and has not been reported to be under regular use by any 4G operator so far.
Besides, it requires some level of support from the chipset of the phone, and many of the lower-priced phone models do not support it yet.
Despite this, Jio seems to be serious about its ambition of combining TV and entertainment with its communication service and more action is likely on this front in coming months.