5G and broadcast technologies

Broadcasting technologies seem to be evolving at the same pace as other technologies around us. In Spain we are still using first-generation DVB-T (Digital Video Broadcasting – Terrestrial) Digital Terrestrial Television (DTT) technology, pending a migration to DVB-T2 technology (Digital Video Broadcasting – Terrestrial 2nd Generation), which has been on the market for more than 10 years. The switch to DVB-T2 technology will enable an increased spectral efficiency of DTT networks by more than 50%. That is, improve the ability to transmit information by more than 50%, which will result in an increase in the quality of the content being broadcast. For example, more high-definition and ultra-high-definition content.

Since the introduction of DTT by the end of the last century, we have gone through the mobile telephony standards 2G mobile telephony (digital telephony and SMS text messaging), 3G (beginning of the mobile internet and arrival of the first iPhone), 4G (mobile broadband and popularization of apps and social networks) and now 5G, which is much more than a new generation of mobile communications with higher connection

and Deputy Director

By David Gómez-Barquero, Professor at the Department of

speeds. 5G’s ambition is to provide wireless connectivity in the digital transformation of many industrial sectors. 5G also offers new possibilities for the broadcast industry.

On the one hand, 5G technology can facilitate the convergence of mobile, fixed and DTT networks, as it can now reach smartphones and tablets, which had not been possible by means of any DTT technology. In fact, the international digital television standardization body, DVB, (Digital Video Broadcasting) declared that there would be no new DTT standard, and that a possible new broadcasting standard would have to come from the 3GPP standardization forum, the one in charge of the standardization of mobile technologies.

On the other hand, the audiovisual production sector uses at present different wireless technologies and, therefore, will be among the first to take advantage of 5G. Thanks to 5G’s inherent compatibility with IP (Internet Protocol) and the use of cloud computing resources, it could also act as a catalyst to improve existing workflows or enable new ones in various scenarios.

The Institute of Telecommunications and Multimedia Applications (iTEAM) of Universitat Politècnica de València (UPV) in Spain is one of the landmark research centers in the application of 5G technology to broadcast technologies, both for the distribution side and for contribution (content production). From the mobile communications group of iTEAM-UPV, we have actively participated in standardization processes of broadcasting technologies, such as DVB-T2 (and its mobile profile T2-Lite), DVB-NGH (Next Generation Handheld) and ATSC 3.0, as well as in the optimization of 3G mobile broadcasting technologies (MBMSMultimedia Broadcast Multicast Service) and 4G (eMBMS, enhanced MBMS).

Much of the work on 5G and television has been done in research projects of the European Union’s Horizon 2020 programme by the partnership for public-private collaboration in 5G 5G-PPP (5G Infrastructure Public Private Partnership, www.5g-ppp.eu). Specifically, in the 5G-Xcast, 5G-TOURS, 5G-RECORDS and FUDGE-5G projects, three of which have been coordinated by iTEAM-UPV (5G-Xcast, 5G-RECORDS and FUDGE-5G). Domestically, it is also worth highlighting the Castilla La Mancha 5G project within the national 5G pilot plan of Red. Es, as well as the collaboration with Radiotelevisión Española (RTVE) within the framework of the Global 5G 2019 event, in which the first live broadcast for television was made using exclusively 5G technology in Spain. It was also the first worldwide broadcast carried out with a stand-alone 5G network.

Next, I will briefly explain the main innovations of the two main projects: 5G-Xcast for 5G content broadcasting and 5G-RECORDS for 5G content production, as well as highlighting the main results of the other projects.

The 5G-Xcast project: Broadcast and Multicast Communication Enablers for the Fifth-Generation of Wireless Systems (€8 M budget, 18 partners from 10 countries, run period June 2017 to July 2019, www.5g-xcast.eu) was the first international research project on 5G Broadcast, and became the flagship project on 5G content broadcasting worldwide. From the project’s much effort was devoted to the definition and analysis of the technology popularly known as 5G Broadcast, and also to the design of a native 5G solution for broadcast.

This technology -known as 5G Broadcast- allows broadcast services to be transmitted to 3GPP devices, and in some areas has come to be considered as a possible substitute for Digital Terrestrial Television. This technology meets essential requirements of DTT, among which we can highlight:

• Receive-only mode, in which having a SIM card is not required to receive the service. This allows free-to-air broadcasting, like in traditional DTT.

• Transmission mode in which all radio resources (spectrum) are dedicated to broadcast transmission.

• Ability to create singlefrequency networks, in which several transmitters broadcast the same content on the same frequency in a synchronized manner.

Although the technology is known as 5G Broadcast, it is based on 4G mobile phone technology referred to as LTE (Long Term Evolution). In fact, the technical name of the technology is none other than LTE-based 5G Terrestrial Broadcast. The 3GPP marketing move conceals the fact that 5G Broadcast does not feature the technological advances of 5G technology (which we will explain below). The 5G-Xcast project was the first to demonstrate that 5G Broadcast technology would have considerably lower spectral efficiency than secondgeneration DTT technologies

(such as DVB-T2 and ATSC 3.0). This work* received the award to the best article published in 2020 in the specialized journal IEEE Transactions on Broadcasting.

Despite its limitations, 5G Broadcast technology represents a milestone in the world of broadcasting, being the first 3GPP broadcast technology with a high potential to reach all smartphones and tablets. Although numerous pilots have already been conducted around the world, there is still no commercial rollout for 5G Broadcast. But don’t forget the fact that 5G Broadcast was designed for a purpose other than DTT standards. While, for example, DVB-T2 is highly optimized for the distribution of linear television services for fixed reception on rooftops, 5G Broadcast has the ability to reach portable and mobile 3GPP devices, and has a rich legacy of 4G LTE technology. In addition, 3GPP has recently included in Release-17 the possibility of using 5G Broadcast for bandwidths traditionally used by DTT (6, 7 and 8 MHz). Without making predictions about what may happen at the World Radiocommunication Conference (WRC) in terms of the spectrum currently dedicated to broadcasting technologies, 5G Broadcast technology is sure to play an important role at that conference.

In the Castilla La Mancha 5G project (budget €1.2 M, 6 collaborating companies for the broadcasting case of use, duration July 2020 to January 2023, https:// www.red.es/es/initiativas/ proyectos/proyectopiloto-5g-castilla-lamancha-2a-convocatoria) iTEAM-UPV developed a 5G Broadcast solution using a radio platform defined by open source software and generalpurpose processors. In collaboration with Telecom CLM and broadcast equipment manufacturer

BTESA, a pilot has been conducted on a network equipped with high-power infrastructure in the city of Toledo, with enough radio frequency power to cover the entire city. This was the first pilot using an SDR (Software Defined Radio) platform for both the transmitter and receiver on an infrastructure such as those traditionally used for DTT broadcasting. SDR solutions not only enable rapid testing of new functionalities for the standards, but also allow greater flexibility for software updates and decreasing costs. Major manufacturers of DTT equipment already have software-based solutions. This work has had a great impact on the 5G-MAG

(5G Media Action Group) industry association, where collaboration has been undertaken with other partners for the development and validation of the SDR platform and this group has provided an open source version of the code https://wwww.5g-mag. com/reference-tools.

On the other hand, the 5G-Xcast project was a pioneer in defining pointto-multipoint (multicast/ broadcast) components for native 5G networks -based on the new NR (New Radio) and 5GC (5G Core) technologies- which provide greater efficiency and flexibility as compared to LTE both at radio level and at the system architecture level.

The 5G-Xcast project proposed a paradigm shift in point-to-multipoint transmissions on 4G LTE (remember that 5G Broadcast technology is based on LTE), where pointto-multipoint transmissions were initially conceived as a complementary service with a predefined static configuration. The solution being proposed in 5G-Xcast integrates pointto-multipoint broadcasts into the overall system architecture as an internal network tool to optimize transmission when multiple devices consume the same content in the same cell. This allows dynamic and flexible use of point-tomultipoint transmissions by the network in a manner transparent to the user, in order to maximize the efficiency of network resources. Multicast/ broadcast components were designed with the aim of maximizing compatibility and interoperability with point-to-point broadcasts (unicast), to allow dynamic switching between different modes of operation, as well as their potential use in parallel. This approach leads to a simplified, unified service design across access networks. In addition, it not only enables the deployment of stand-alone 5G networks for distribution of radio and television services, but also encourages all network equipment and all devices to support pointto-multipoint broadcasts. The fact that 5G Broadcast requires specific equipment supporting the technology at network level and -mainly- at terminal level, is probably the main barrier that has slowed down the investment in this technology, which leads to the eternal chicken-egg dilemma the first mobile broadcasting technologies (DVB-H, MediaFLO, etc.) had to face.

In 5G-Xcast, point-tomultipoint components were designed for the radio interface, the Radio Access Network (RAN) and the network core (5GC). The work of 5G-Xcast has had a major impact on 3GPP in the third version of the 5G standard (Release-17), where 5G-MBS (Multicast Broadcast Services) has been specified with multicast/broadcast components for NR and 5GC. However, the requirements for DTT services are not being taken into account. The problem is that the first two versions of 5G do not support point-to-multipoint broadcasting, and therefore the opportunity to include this functionality from the outset so that all devices would support it was missed. Support for 5G-MBS technology will be optional, and the degree of deployment in future devices is yet to be seen when Release-17 hits the market (devices with the second version of the 5G standard (Release-16) are currently starting to arrive).

The 5G-RECORDS project: 5G key technology enableRs for Emerging media COntent pRoDuction Services (budget €7.5m, 18 partners from 11 countries, duration September 2020 to October 2022, www.5grecords.eu) addressed the design, development, integration, validation and demonstration of 5G components for professional production of multimedia content. The project was structured around three actual content production use cases: live audio production, multi-camera wireless studio, and immersive content production, each of them with a number of 5G-enabling technologies and innovative multimedia components.

In addition, the project focused on the use of private 5G networks, similar to a WiFi network but with the difference that the spectrum is not shared with any other network, thus ensuring greater performance without relying on the public network of a telecommunications operator. Another advantage lies in privacy, since all the information circulating on these networks is only accessible to their owners. These on-demand 5G networks, or private “super WiFi” networks with revolutionary features for the industry make a lot of sense for remote professional content production environments with higher reliability, lower latency and the ability to sync different devices. The project developed a complete 5G multi-camera production system that was used in a broadcast for the initial stage of the 2022 Tour de France in Copenhagen (Denmark), which was a total success and had great media impact.

The immersive content production use case focused on the use of 5G millimeter bands (26 GHz), which enables bandwidths of hundreds of MHz and Gigabit-per-second speeds comparable to downstream or download fiber optics. Upstream, current terminals have limitations in reaching those speeds. Despite these limitations, the project organized a live concert that was captured with multiple perspectives and shots in which the filmmaker could move the point of view of the image freely. And with an Edge Computing deployment to ensure low latency, it was possible to play content both live and in replays.

Last, the audio production use case focused on Ultra Reliable Low-Latency Communications (URLLC), as professional live audio production has very demanding requirements in terms of response time, availability, and synchronization. This use case was not demonstrated in a pilot, but the progress made in the testing and validation of 5G URLLC technology have been a great leap forward of the state of the art and have interested some major manufacturers of 5G chips.

I would not like to finish this article without mentioning the first 5G touring orchestra that was performed under the 5G-TOURS project (www.5gtours.eu), led by RAI and in collaboration with LiveU, which merged music and distributed content production with 5G on the streets of Turin in December 2020.

With all these advances, it can be said that, unlike content distribution, where there are still reasonable doubts about the use of 5G for broadcasting services… and a future new 6G Broadcast technology may be needed!, 5G will be widely used for content production in a not-toodistant future. 