BY THE MAGIC RAYS OF LIGHT [445]

The opening of BBC Two on Tuesday 21^st April 1964 marked the first time British audiences needed to update their televisions, to receive the more detailed 625-line pictures sent over the air by the new channel. Early adopters may have had a Baird mechanical set from the first experimental transmissions in the 1930s, but this was the first time that the regular TV standard changed. This switch happened at a glacial speed: 625-line versions of BBC One and ITV began later in 1969, two years after BBC Two became Europe’s first colour TV channel, but the old 405-line system used by them continued until 1985 as households and television rental firms slowly replaced their sets.

The television standard in the UK has arguably changed three times since then, in more rapid succession. The first came after digital television began in 1998, using the DVB-T standard, the switch-off of analogue signals was completed from 2008 to 2012 – this coincided with the introduction in 2009 of the updated DVB-T2 standard used mostly for high-definition channel, prompting a further push for new TVs. But perhaps the biggest change hardly involves the television, because the inexorable move to online streaming of programmes is really the end of the physical act of “broadcasting”, as sharing one channel from a transmitter is replaced by everyone having their own discrete link their device and a content provider’s server, known as “unicasting”. 

I then remembered that BBC Research & Development had carried out a trial of something named “5G Broadcast” in 2019 on Stronsay, one of the Orkney Isles. A 5G network was constructed that provided mobile internet to one of the most poorly-connected places in the UK, while also using that network to broadcast radio stations, including BBC Radio Orkney, to devices with the software capable of receiving the signals. By all accounts, the exercise proved successful, leaving the island with more reliable internet access after the trial ended.

The 4G and 5G mobile signal standards allow for broadcast capabilities, which is a naturally more efficient use of bandwidth in situations where many people are watching the same thing at the same moment, freeing up capacity on the mobile network. The computer chip manufacturer Qualcomm, which had a hand in developing the technology used for these mobile standards, explained on their website that no extra equipment is needed to receive 5G Broadcast, as mobile devices already have the necessary technology built into them, and existing television transmitters, more physically resilient than mobile signal masts, can broadcast the 5G signal too. Furthermore, if someone is outside the range of the 5G Broadcast signal, their device will seamlessly move to “unicast” mode.

However, that depends on the will of broadcasters to keep their own transmitters going at all. Switzerland is a country that already switched their TV transmitters off, in 2019, but most viewers already received their services via cable. This shift is perhaps inevitable: the cost of keeping networks of high-powered transmitters in working order would be avoidable if you can piggy-back on the internet, but relying on that network poses problems in binding one service, once available to all over the air, into another service that requires payment to access. Even Qualcomm’s article made clear that “In the unfortunate scenario that the cellular network becomes disabled from structural damages (e.g., in case of an earthquake), public authorities could still use the broadcast infrastructure to communicate with smartphones that support broadcast services” – the will has to be there.