5G Broadcast, using 3GPP technology to receive TV and radio services
Updated: Jun 23, 2019
5G Broadcast, FeMBMS, EnTV, Release 14, LTE-based 5G Terrestrial Broadcast... all these are terms that are becoming more and more relevant. 5G Broadcast is becoming a reality and therefore we can start evaluating the technical details of the technology and its advantages and disadvantages. You can already find many information around 5G Broadcast but only very few sources present a rigorous approach to this technology.
So, keep an eye here because we will be publishing information about this from time to time. For the moment and to start, we are providing a short introduction to what today it is known as 5G Broadcast. This comes from an IEEE paper published here.
Also recommended is the article recently published by Dr. Roland Beutler in the 3GPP website "TV and radio services over 3GPP systems": https://www.3gpp.org/news-events/2008-broadcast and the one highlighting the main improvements in LTE MBMS Release 14 "Enhanced Television Services over 3GPP eMBMS": https://www.3gpp.org/news-events/3gpp-news/1905-embms_r14
With 5G Broadcast, TV and radio services can be tuned in the smartphone
Terrestrial Broadcast (or, let's say, the delivery of linear TV and radio services) was considered as a 3GPP use case in LTE Advanced Pro 3GPP Release 14. The Multimedia Broadcast Multicast Service (MBMS) system was enhanced to fulfil a wide set of requirements input by the broadcast industry.
The 3GPP study item on Enhancements for TV (EnTV) proposed several enhancements that resulted in an evolution of eMBMS (also known as FeMBMS). FeMBMS is based on the pre-existing LTE Advanced Pro specifications. At the radio layer the most significant enhancements are:
dedicated FeMBMS carriers that allocate up to 100% of the radio resources to Terrestrial Broadcast (i.e. with no frequency or time multiplexing with unicast resources in the same frame) with all required signaling in the so-called Cell Acquisition Subframe (CAS);
a reduced-overhead subframe containing no unicast control region; and
the support of larger inter-site distances in SFN (Single Frequency Networks) reaching higher spectral efficiency with a new numerology – 1.25 kHz subcarrier spacing (SCS) and 200 µs cyclic prefix (CP).
Enhancements made to the system architecture comprise:
xMB interface through which broadcasters can establish the control and data information of audio-visual services;
Application Programming Interface (API) for developers to simplify access to eMBMS procedures in the User Equipment (UE);
support of multiple media codecs and formats;
transparent delivery mode to support native content formats over IP without transcoding (e.g. reusing existing MPEG-2 Transport Streams and compatible equipment);
shared eMBMS broadcast by aggregating different eMBMS networks into a common distribution platform; and
receive-only mode (ROM), which enables devices to receive broadcast content with no need for uplink capabilities, SIM cards or network subscriptions – i.e. free-to-air reception.
These changes led to a system like other Digital Terrestrial Broadcast systems such as DVB-T/T2, ATSC 3.0 or DAB/DAB+. The introduction of a ROM and the new framing and numerology options may make FeMBMS suitable for use with conventional broadcast infrastructure (including high, medium and low power sites).
A further study item in 3GPP Rel-16 has evaluated the ability of FeMBMS to support SFN of cells with coverage radii of up to 100 km (implying even longer CP) and mobile reception with speeds up to 250 km/h (large SCS) but this will come in another post... :)