It’s been hard to avoid 5G recently. The fifth generation of mobile telecom and broadband internet technology has been talked of as the next big thing, and now the major service providers are launching 5G networks this year. EE started its rollout in six UK cities during May, followed by Vodafone in July and Three in August, all of which has received considerable coverage on television and radio.
While the main focus has been on faster download speeds and streaming to smartphones and other mobile devices, 5G is also being positioned as a carrier and distribution technology for broadcasting that could complement, if not replace, established RF, satellite and fibre systems.
Ian Wagdin, senior technology transfer and partnerships manager with BBC R&D, says his department first starting thinking about how 5G could be used in production about a year ago: “We looked at the possibility of 5G and existing technologies and whether it could replace or enhance what we are already using. Spectrum is at a premium now and we may not be able to carry on using RF.”
Wagdin explains that either bonded cellular or WiFi would usually be used for single camera news contributions, carrying HD video and embedded audio. Cellan-Jones’ reports were passed through a WMT (wireless multiplex technology) encoder for distribution to the BBC Breakfast studios at MediaCityUK in Salford.
Wagdin admits he did not expect the link to work as well as it did, even though there were some problems in getting on air. “We’d been doing four days of testing and we thought the SIM card had been unloaded but it hadn’t and we ran out of data,” he says. “But we got on air and for a first trial it was extremely successful.” The sound- only contributions used the same infrastructure as the TV link, with the audio stripped off as a separate feed.
The emergence of 5G has brought about a change in attitude towards telecom technology for broadcast, largely due to its higher bandwidths and lower latency. Among the projects currently in progress to develop suitable network standards and broadcast/ entertainment related applications is 5G-MEDIA. This involves companies from the telecom, cloud, broadcast and academic sectors, including IBM, Spanish AV group RTVE, University College London (UCL) and German technology research institute, IRT. The IRT is also heading the 5G TODAY project in Germany, which is focusing on large-scale TV transmission in the FeMBMS (Further evolved Multimedia Broadcast Multicast Service) mode.
IRT spokesman Thomas Schierbaum says the main task of 5G TODAY is to evaluate the robustness of FeMBMS, with the first results expected to be published towards the end of this year. Schierbaum comments that 5G Broadcasting covers both production – mobile/ location contributions, wireless cameras/microphones and drones – and distribution for linear TV and on- demand services.
IRT is working on 5G TODAY with Bavarian regional broadcaster Bayerischer Rundfunk, transmitter manufacturer Rohde & Schwarz, communications specialist Kathrein and telecoms provider Telefonica. R&S is supplying two transmitters, which will operate in the 700MHz band currently being auctioned off for mobile and Internet of Things (IoT) applications.
Mohamed Aziz Taga, product manager for LTE/5G Broadcast transmitter systems at R&S, highlights the difference between 5G for mobile phone/broadband use and broadcasting as being the quality of service combined with the ability to reach multiple users simultaneously from a single source. “The approach with 4G was unicast, on a one-to-one basis,” he explains. “If you want to distribute a major event that lasts five to six hours, then it is better to broadcast it using a one-to-many format. Unicasting in small cells means that other people can be affected when there are a lot of others watching the same programme.”
The broadcast and multicast elements of 5G are being formalised by the 5G-Xcast project. The technology for this is designated 5G PPP (Public Private Partnership) Phase II and is being developed jointly by the European Commission along with information and communication technology (ICT) manufacturers, telecommunications operators, service providers and research bodies in Europe. It includes Next Generation Audio (NGA) and object-based production.
BBC R&D is part of 5G-Xcast and has been researching 5G Broadcast as a potential means of radio distribution. Lead research engineer Andrew Murphy says work is also taking in object-based media and personalisation, as well as coverage for remote areas. This last category is being investigated as part of an ongoing test on the island of Stronsay, part of the Orkneys off the northeastern coast of Scotland.
Because Stronsay has limited fixed broadband, little or no mobile coverage and poor digital radio transmission, Murphy says it was an ideal location for the tests. “The key point was to prove the possibilities of the technology,” he comments. “The project is divided into two parts: a public trial of broadcasting to mobile phones and a development from scratch of a 5G Broadcasting modem, which is taking place in Glasgow. We are using some 4G aspects but the test is free to air and SIM-free, which are features of 5G Broadcasting.”
Another broadcaster looking into a different aspect of 5G Broadcasting is BT Sport. In November 2018 it staged what was described as a world first when a live link from Wembley Stadium was beamed to a presentation theatre at the ExCel exhibition centre in London’s Docklands.
All vision and audio mixing on the transmission was handled from the broadcaster’s headquarters in Stratford, east London.
BT Sport had been looking for a means of performing remote productions at lower league football matches, with only a few cameras and microphones on site and the production team back in the main studio. In the past, it has used 4G, even though, as Matt Stagg, director of mobile strategy for BT Sport concedes, it was never designed for broadcast. “It does work,” he notes, “but it is only one network that is designed for downloading and streaming.”
The remote production set-up demonstrated by BT Sport encoded the output of the camera and passed it over Ethernet to a CPE dongle. The signal was 5G up to the cell, with the handshake done in 4G. After this the feed moved on to the EE 5G test network, using 3.4GHz spectrum from a 5G antenna in the stadium connected to a 10Gbps backhaul link for transmission to BT Sport’s broadcast centre. Audio from Sennheiser radio mics was embedded in the video signal, while a Comrex codec was plugged into the 5G cell for in-ear monitoring.
Stagg describes this new way of working as a mixture of TV and telecoms. “If there is fibre in a stadium we will always use that,” he says, “but a director might still want the freedom of 5G cameras and mic links. There are other use cases, including breaking news as well as standard OBs. We also see 5G as changing the way film or drama productions are edited, with footage sent directly to the edit suite.”
These are very early days for 5G and 5G Broadcasting in particular, but broadcasters and telecom companies are looking seriously at what it may offer in the future.