Telecom companies are pushing further into broadcast distribution through emerging 4G technology, with Ericsson trialing LTE video systems during a recent Australia-England cricket match. But is it a viable alternative to current digital radio and TV transmission?
Telecom companies have long provided many of the links and contribution circuits used by radio and television broadcasters. IT techniques have moved into broadcast over the last 20 years, even more so recently through the advent of audio and video over IP, but the next generation of telecommunications look set to take back some lost ground through new mobile networks.
Telecoms giants such as Ericsson and EE (owner of Orange and T-Mobile) see LTE (long term evolution), now being deployed as new 4G networks, as the basis for video and audio broadcasting as well as high quality telephony and super-fast broadband.
LTE Broadcast is based on three technologies: eMBMS (Evolved Multimedia Broadcast Multicast Service), which allows mobile networks to carry broadcast and multicast services; HEVC (High Efficiency Video Coding), a video compression format claimed to reduce the amount of bandwidth needed for video by half; and MPEG DASH (Dynamic Adaptive Streaming over HTTP, a carrier format that adapts the streams to fit the available bandwidth.
Ericsson is keen to promote the broadcast capability of the new platform. During January it collaborated with Australian telecom provider Telstra to test LTE Broadcast at Melbourne Cricket Ground. Coverage of Australia’s T20 game with England was transmitted to devices in three streams, providing highlights and statistics in addition to live video.
Telstra’s executive director for networks, Mike Wright, commented that the trial showed LTE Broadcast “worked effectively in a stadium environment” and was able to deliver three streams at approximately 6GB as opposed to the single stream of 2GB that would be produced by previous technologies.
Another advantage of LTE Broadcast is that the quality of the transmission is not dictated by the number of users in the cell area. Explaining Ericsson’s attitude towards the technology at last year’s Radio Academy TechCon, head of TV and media market development Frank Hermans called it an “efficient use of spectrum” able to deliver video, including TV and YouTube.
During the same session, Is Telephone Broadcasting a Long Term Evolution?, Andy Sutton, principal network architect at EE, said explained that LTE was an “evolved packet core data network” was based on IP and gave new voice capability compared to 3G systems.
While many broadcasters have been moving to IP operations, the BBC is faced with the dilemma of what to do in the short-term as ISDN is on the verge of being phased out and other OB circuits are now discontinued.
Colin Muir (pictured), a newsgathering technology lead with BBC Scotland, has been looking at how mobile networks can be used for broadcasting: “We started with 3G and although the quality was very good that has changed because the networks are now congested.”
Muir sees the benefits of LTE as its full IP nature with the capability for broadcast, lower latency and data rates of up to 150Mb/s. He added that the BBC has used LTE Broadcast for live radio work and was considering it for longer length OBs involving music as well as speech.
Andrew Murphy, a senior research engineer in the Distribution Core Technologies section of BBC R&D outlined LTE’s possibilities for transmission, saying that people were already streaming video and audio to mobile devices but that there were often problems with rebuffering due to connection speeds.
He continued that LTE can support broadcast due to the eMBMS mode (also known as LTE Broadcast) allocates parts of the signal for video and audio, giving one to many distribution and has the option for a single frequency network. He concluded that LTE Broadcast could be used as a hybrid and dynamic network for congested frequencies and busy times of day respectively and be deployed when necessary.
There seems little argument over LTE Broadcast’s potential for contributions and production but, at TechCon at least, there was scepticism over its usefulness for transmission.
BBC Distribution director Alix Pryde, announcing a new phase of DAB expansion, said that while multicast IP “will change things” radio transmission is the best way to reach large daytime audiences. “The breakfast peak of 17 million people, each listening for 15 minutes, at 128kbps would need 2Tbps per stream, which is the entire internet capacity of the UK,” she commented.
Rounding up the sessions, futurologist James Cridland pointed out the possible cost of that. Based on estimates from two streaming companies it could set listeners back either £145,824 or £28,031.51 a day.
That’s when you have to ask yourself how much you really like listening to Nick Grimshaw or Chris Evans.