In the previous issue of CT, we focused on the introduction of 5G to Norway’s cinema industry. Here, Jim Slater takes a deeper dive into the technologies behind the next generation of wireless communications. Do they really address our industry’s changing needs?
5G is the forthcoming generation of mobile technology. It is expected
to deliver faster and better mobile broadband, and to enable more revolutionary uses in sectors such
as manufacturing, transport and healthcare. How will it impact on our media industries and will 5G technology provide improved facilities for the cinema industry?
In the last issue of Cinema Technology, Patrick explained how our Norwegian cinema colleagues have already begun trialling 5G in cinemas, but we mustn’t get carried away with our technogical enthusiasm. It is sobering to remember just how far ahead of the world the Nordic cinema industry can be — they were using broadband distribution for about a decade before it became the norm in other countries. The rest of us continued to send DCPs on hard drives in vans.
During 2018, 5G made its first tentative steps into the US with Verizon providing 5G home internet services in a handful of cities. Together with AT&T they are now offering mobile 5G services to considerable populations. 5G rollout plans vary tremendously around the world, and the second half of 2019 has seen a start in the United Kingdom, where communications technologies are fairly strongly regulated, so it is interesting to look at how the rollout is likely to proceed.
Ofcom is the UK’s communications regulator. Among other things, it regulates the TV, radio and video-on- demand sectors. In 2018, Ofcom produced a discussion document “Enabling 5G in the UK” (available for download from ofcom.org.uk) which provides a good deal of the basic information about this new technology, and enables those of us involved in the media industries to consider and speculate on how our businesses might be affected. Much of the information here is gleaned from that Ofcom document. The UK’s well-established 3G networks don’t have the capacity to cope with modern mobile working demands, including video, but the 4G networks that have so far been rolled out to around 95% of the UK landmass have higher base speeds and more than enough capacity for core services, such as e-mail and web browsing.
Possible media industry applications
Data rates that 5G promises are more than adequate for most forms of video (HD content works well at a few tens of megabits per second). Whilst it could be extremely convenient to be able to send ‘rushes’ directly from the camera head to the production house, 5G will ostensibly provide little more than what existing and proven systems can do for HD pictures — but if the technology can be shown to work consistently and reliably, the convenience factor for TV companies could in fact be the key to the adoption of 5G in this area.
If news-gatherers and outside broadcast crews could avoid the logistical complications of having to employ expensive, cumbersome satellite uplink equipment, then direct-streaming from the camera to studio centre via a 5G link could be the obvious solution. Various video link products using 4G links are already available from companies, including JVC’s Connected Cam, so the move to 5G should be straightforward. Those with practical experience of the difficulties faced when jostling shoulder-to-shoulder with other camera operators will know that there can be other problems apart from ensuring you have a good clean radio link with no interference from the camera a few feet away when trying to get those all-important celebrity shots.
Virtual and augmented reality needs
Another area where 5G may come into its own in the media sector, however, is in the worlds of virtual and augmented reality. Those who have already tried the existing solutions will know that there is a real need for very high resolution video.
Current display (and transmission) technologies find it difficult or impossible to fill the VR user’s entire field of view with high-resolution (perhaps 4K) images. Products such as Google’s ‘daydream’ VR headsets are promising to use 5G-type communications to allow VR headset wearers to share experiences on large screens, without interconnecting wires. The Pimax VR headset (pimaxvr.com) moves video resolution forward, with 4K per eye, totalling a massive 16.6 million pixels. That will require wireless data rates only possible with 5G if the data from these headsets is to be transmitted to others.
The 8K implications
8K images have 16x the pixels of HD and four times the pixels of 4K: 8K resolution equates to 7,680 × 4,320, or 33 million pixels (33,117,600), compared with 3,840 × 2,160 (8,294,400 pixels). Although it is early days, 8K TV screens are available from several manufacturers, and 8K content is starting to become available. Japanese broadcaster NHK broadcasts 8K on a permanent basis, aiming to carry the 2020 Tokyo Olympic Games and the Paralympic Games live in 8K. NHK’s 8K broadcasts are available on a special satellite channel between 10am and 10pm daily. They are accompanied by 22.2 multi-channel sound, and broadcast at frame rates of 59.94, 60 and 120P.
Naturally, CT readers will be fascinated to hear that Stanley Kubrick’s “2001: A Space Odyssey” was used to launch the world’s first super-high definition 8K TV channel, NHK having arranged for Warner Bros. to scan the original film negatives in 8K. Currently, NHK is showing only a limited number of programs in 8K, which are shown repeatedly. For those not covered by the Japanese satellite footprints, several 8K streaming channels are available over the internet. YouTube can now stream 8K content, but it requires a broadband speed of around 50 Megabits per second, so 5G is likely to be essential for mobile users. Google has uploaded a few 8K videos, including a clip entitled ‘Ghost Town’ shot on Red EPIC Dragon 6K cameras. Vimeo also has a number of 8K video clips available on line.
Should all this 8K content gain traction in the market, then there is no doubt that 5G communications will become essential.
Although 8K on a phone handset screen seems a ridiculous idea, maybe phones driving VR displays will need to be 8K-capable, and one good thing about the mobile phone market (from the manufacturers’ view at least) is that people change their phones regularly — so it will be no great problem to change to a 5G-capable device. Even if VR doesn’t become ubiquitous, there is little doubt that camera resolutions will continue to increase, so with more and more pixels in use, and remote video processing becoming more popular, the demand for 5G will grow. Yet another warning, though — it is still early days for 5G, with coverage only available in parts of a few major towns, and towards the end of 2019 there are few 5G-capable phones available.
Cinema exhibition and 5G
For the cinema exhibition industry similar thoughts apply. An example of what will be possible can be gained from a Huawei estimate that the download time for an 8Gb HD movie will be just six seconds, compared with seven minutes over 4G and over an hour with 3G.
This would indicate that a 200GB DCP — typical for a standard 2K movie these days — could be delivered to a cinema in around 3 minutes. That’s quite an advance over current practices, where several hours are usually needed, and this could potentially provide enormous flexibility for last-minute changes of programming. 5G Could also be useful for carrying extra DCP ‘Version’ information such as subtitled or Audio Described versions which can be late arriving at cinemas. It would take only seconds to add the extra information to the Original Version files.
But just how practical is it to transmit DCPs to cinemas, and why would you want to?
Do cinemas actually demand such fast delivery, and would they be prepared to pay for it when cost-effective delivery systems are already in place?
A city centre cinema would be likely to have access to the wide bandwidth 5G signals, which could come from a base station on a nearby lamp post, but this could lead to bandwidth-sharing issues. Unless a dedicated 5G base station had been installed for the cinema, what would the effects be on other hopeful users of the data from a 5G public cell, whilst the cinema gobbled up the bandwidth, albeit only for a short period?
In fact, the 5G engineering planners have anticipated such problems and one of the most innovative aspects of the 5G architecture will be network slicing, which will enable telecoms operators to allocate portions of their networks for specific customer use cases whether for machine-to-machine IoT communications or for more data-intensive uses such as media delivery. Each user can be provided with a unique set of optimised resources and network topology allowing them to have Service Level Agreements relating to aspects such as connectivity, speed, and capacity, to suit the needs of any particular application.
And hasn’t all this come about too late to affect most cinemas, when most will have already made arrangements to use wired or fibre broadband signals or specialist satellite services (including highly targeted ka-band services using small dishes) which are readily available, and which will be at least as robust and reliable as anything 5G can offer?
Although Ivar Hastvedt of Norway Odeon Kino told CT that 5G can provide faster speeds than fibre, as an experienced engineer I doubt this (fibre capabilities are constantly improving) and anyone who suffers the vagaries of mobile phone connections (includng broadcasters like the BBC who take every technical precaution but still suffer frequent ‘lost lines’ when interviewing people over mobile links) must understand that a fixed fibre connection is likely to be significantly more robust and reliable than any radio link, especially one using millimetere wave frequencies.
So, with most cinemas already having access to fast-enough delivery services, it’s hard to make a case for DCP distribution to cinemas as a ‘killer app’ for 5G — but it would be interesting to hear the opinions of other knowledgeable distribution expert readers of Cinema Technology.
5G is available in a pre-standard form this year, with a wider rollout expected in 2020. The International Telecommunications Union (ITU) is working on benchmark 5G standards for future mobile broadband — the International Mobile Communications IMT-2020 standard. IMT-2020 is intended to develop the vision of ‘IMT for 2020 and beyond’ and it should be finalised in 2020.
According to IMT-2020 specifications 5G networks should theoretically be able to achieve data rates of 20Gb/s. The so-called “user-experienced data rate” is likely to be nearer a few hundred 100Mb/s in the early years.
5G networks will need to provide enhanced throughput and massive fast connectivity with improved spectral efficiency, so new modulation and multiple access schemes are being developed to meet the many different demands 5G systems will need to address. Getting a vending machine to contact its supplier to demand replacement supplies will need different modulation systems than those required for sending DCPs to a cinema!
Much as SMPTE carries out standardisation work in our industry, the 3rd Generation Partnership Project (3GPP) unites telecommunications standard development organisations and provides its membership with a stable environment to produce specifications that define technologies on which 5G will depend. In 2018 it completed “3GPP Release 15”, the first full set of 5G standards. It is readying 3GPP submissions towards IMT-2020.
Radio wave behaviour
Whatever ‘generation’ we consider, the rules of physics relating to radio transmission apply.
The higher the frequency of the radio waves, the more like rays of light they behave — buildings can cause shadow areas, making reception impossible.
Lower frequencies travel further (giving a greater coverage area). They penetrate buildings more effectively and are less obstructed by topography, but as available bandwidth is necessarily less, the amount of data these signals can carry is less.
As examples, the ‘700MHz band’ now cleared of UHF TV signals to allow future 5G coverage ranges from 790-862 MHz. The maximum available bandwidth is 72MHz. Another higher-frequency band proposed for 5G (3.4-3.8GHz) gives 400MHz.
The wider the available bandwidth, the greater the amount of digital data that can be carried in it.
Low-frequency spectrum will support improved coverage and user experience. Ofcom is expected to auction the 700MHz band in spring 2020, and is currently consulting on proposals for coverage obligations that could be attached to that process.
Mid-frequency spectrum will meet the capacity demand for mobile services, including 5G.
The 3.4-3.8GHz band has been identified as the primary band for 5G in Europe as it offers increased capacity for mobile broadband over wide areas.
The auction for 190MHz of the 2.3 GHz and 3.4 GHz 5G bands was completed by Ofcom in A2018, and Ofcom will auction the 3.6-3.8GHz band in 2020. High-frequency (mm Wave) spectrum has not yet been used to deliver mobile services, and is likely to be used to support new 5G applications, in particular those that require high capacity and low latency. Latency is time between a command and its corresponding action — 5G will make this delay unnoticeable, vital in applications such as in self-driving cars where any delay is unthinkable.
Operators will likely use the lower frequencies to provide more extensive coverage in rural areas (meaning highest data rates won’t be available there), but in cities — where there will be huge demands for data — they will use higher frequency bands. Since high frequencies don’t travel far and are easily obstructed, it will be necessary to have thousands of small transmitter sites in built-up areas to provide coverage. High frequency base stations could be mounted on lamp posts or fixed to buildings — large masts aren’t needed. Such base stations could also be installed in offices to provide good indoor coverage.
The 5G networks are not going to be a monolithic network entity and will be built around a combination of technologies designed to support a variety of applications such as the ‘Internet of Thing s’ (IoT), where machines talk to other machines, connected wearables, augmented reality and immersive gaming. For example, 5G will provide ultra-high-speed links for HD video streaming as well as low data rate speeds for sensor networks, so that automated vending machines could call for re-filling as needed and cars could ‘talk’ to each other and the road traffic network to reduce congestion. ‘Low’ and ‘mid’ frequencies shown in the diagram overleaf will be 5G frequencies used in the near future. 26GHz and higher are in the hands of the experimenters.