What is 5G Broadcast and what is it used for?
Updated: Jun 24, 2019
Despite the "5G" label, the only possibility to deliver data traffic in a broadcast mode currently relies on LTE eMBMS. How is it possible? The first releases of 5G (the novel 5G, the 5G everybody is talking about) have not yet developed capabilities to deliver the same data to multiple users.
This sounds reasonable as in terms of standardization priorities fix the schedule and, obviously, defining multicast or broadcast before having properly defined unicast, makes absolutely no sense. Therefore, it is normal that 5G Release 15 and Release 16 come only with unicast capabilities.
Due to this fact, 3GPP decided that if solutions based on LTE can already meet requirements established for broadcasting in 5G, then this can be referred to as part of 5G. Indeed a very sofisticated argument since technically LTE and 5G have significant differences but... this is where we are now.
The enhacements of LTE eMBMS that make possible to meet the requirements for broadcasting in 5G are already part of 5G.
The situation might change soon if the new "Study on Architectural enhancements for 5G multicast-broadcast services" gets approved in 3GPP in order to bring mutlicast/broadcast capabilities to 5G for Release 17 (the novel 5G, not the LTE-based 5G).
LTE-based 5G Terrestrial Broadcast, the most accurate name to the technology 3GPP is defining/refining to deliver TV and radio services
LTE eMBMS was evolved in Release 14 as a result of a study item called “EnTV” or Enhanced Television services. This is also known as FeMBMS (although this name is not officially used by 3GPP). We covered the main novelties here: https://www.free2air.info/post/5g-broadcast-using-3gpp-technology-to-receive-tv-and-radio-services
LTE-based 5G Terrestrial Broadcast (simplified as 5G Broadcast) is designed to make possible the delivery of TV and radio services using infrastructure and user equipment provided with only downlink capabilities (no uplink is used). 5G Broadcast is supposed to meet the needs of broadcasters, operators and users, but it is too early to make any statement about this without having tested in depth what this technology offers.
What is evident is that 5G Broadcast provides the most promissing means to be able to finally provide smartphones and tablets (integrating a 3GPP chipset) with TV and radio services without any additional dongle or chip. DVB-T, DVB-T2, DAB or even FM are not widely implemented in smartphones (and in some cases like FM, even disapearing). The only chip that is there is the 3GPP one and now ideally provides TV and radio capabilities.
With 5G Broadcast it is possible to address mobile devices with receive-only transmissions even free to air, and without the need of a SIM card. And, thanks to the lack of uplink, the transmission can be made from operator infrastructure where only the downlink coverage matters, opening the door to reusing traditional broadcast towers (as the ones used for DVB-T,/T2 or DAB).
5G Broadcast and its main applications
The 5G Broadcast technology, the LTE-based, or better said, the LTE-based 5G Terrestrial Broadcast, is meant for the provision of TV and radio services with an ad-hoc service layer, architecture and radio layer based on pre-existing eMBMS functionalities which have been enhaced to address broadcaster's requirements.
This is the main application, the delivery of TV and radio services to equipment implementing eMBMS-enabled chipsets in a very similar mode as other terrestrial broadcast systems.
Extremely high data rates, very low latency, the famous 5G KPIs... None of this is related to LTE-based 5G Terrestrial Broadcast. Massive IoT, dynamic traffic off-loading, V2X, PPDR... neither.
Mixing all together is one of the consequences of confusing the nature of eMBMS (broadcast as a service) with other emerging systems for integrating multicast/broadcast into 5G as network and service-agnostic optimization tools. This will come soon, but based on NR, not under LTE.