Next-Gen 5G Contribution: Part 1 - The Technology Of 5G
5G is a collection of standards that encompass a wide array of different use cases, across the entire spectrum of consumer and commercial users. Here we discuss the aspects of it that apply to live video contribution in broadcast production.
5G is another evolutionary step in cellular network technology. It is a journey which really began for the digital media world in 2001 when 3G arrived. 4G arrived in 2009 and it is believed 4G still accounts for around 60% of global cellular use. 5G began rolling out in 2019 and has around 12% of global use, but 5G is projected to rise to over 50% market share by 2030.
What is not so straightforward is that 5G is actually a fairly broad set of standards established by the 3GGP (3rd Generation Partnership Project) encompassing a number of different use cases. This guide is focused on using 5G cellular networks for live video contribution. We discuss ‘5G Broadcast’, which has significant ramifications for content delivery in our series on 5G Broadcast.
What is also not so straightforward is that 5G as a cellular service is effectively a two-stage roll out for telco service providers. For the vast majority of cell phone users who switch on and see that little 5G icon, what they are actually connected to is 5G NSA. The ‘NSA’ stands for Non-Stand Alone and what it means is that 5G base-stations have been installed but are connected to 4G core network technologies.
A cellular network divides a large geographical area into cells which are served by multiple antennae and several individual transceivers or ‘base-stations’ operating on different frequencies. When a device enters the cell, they are allocated an available frequency and served by one of the base-stations. As a device moves between these geographical cells, a collection of systems known as the network ‘core’ manage the identification of devices, dynamic allocation of frequencies, how they are passed from cell to cell, what services the user has access to and of course the passing of data to and from the device. With 4G this core network management infrastructure is typically run in dedicated hardware that is relatively local. This legacy 4G network core infrastructure can accommodate 5G NSA but it can’t handle 5G SA.
The ‘SA’ stands for Stand Alone. With 5G SA the network core functionality is handled by a VNF or Virtualized Network Function implementation where software is deployed on a series of virtual machines installed at a data center. This allows the separation of the cellular network control layer and the user data layer and brings massively increased flexibility, functionality and bandwidth. The system can be taken a step further with implementation of a CNF or Cloud-native Network Function where systems are deployed in an even more flexible and scalable cloud infrastructure. Telcos need to roll out VNF or CNF core technologies to enable the use of SA.
Frequencies & Coverage
One of the technical differences between 4G, 5G NSA and SA is the frequencies used. 4G uses low and mid band frequencies below 6 Ghz. 5G has two different frequency flavours; 5G FR1 which uses similar sub 6 Ghz frequencies to 4G, and 5G FR2 which uses ‘high-band’ frequencies between 24.25 Ghz and 52.6 Ghz. These high frequencies mean much shorter waves known as ‘mmWaves’. 5G NSA and SA can both use FR1, but SA is required for FR2.
The lower the frequency the wider the coverage. Both 4G and 5G can use low-band frequencies to cover rural areas but bandwidth and latency will suffer. They both more commonly use a range of mid-band frequencies which are deployed commercially to suit different areas and terrain.
Bandwidth and Latency will vary accordingly.
A 5G SA network using the higher frequency mmWaves can deliver significantly higher bandwidth but they don’t travel far and have poor structure penetration. Maximum reception distance is about 500m. This is probably sufficient to provide solid coverage within a sports stadium, but for a telco it means they need to deploy a dense base station network to achieve consumer coverage. Crucially, this inevitably means a completely new core network infrastructure to replace existing 4G infrastructure. It makes deploying networks in urban environments worthwhile with plentiful mounting structures and more potential users, but in rural areas more challenging and far less cost effective.
The timescales vary by country and telco but estimates range between 4 and 10 years from now before we see national coverage for 5G SA in Europe or the US and subsequent phasing out of 4G. However, critically for live remote production, the very first sites where 5G SA tends to get deployed is sports arenas, where the network capacity and number of simultaneously connected devices has historically proven challenging for 4G.
One of the potentially disruptive attributes of 5G is the vast numbers of devices that can be connected simultaneously to a 5G network (subject to bandwidth, coverage etc). This is a key factor fuelling development in other consumer applications.
Bandwidth & Latency
Of key importance to broadcasters is the significantly increased bandwidth and reduced latency of 5G. There are stated maximum bandwidth and minimum latency values for 4G and 5G. However, if you try to research average bitrate and latency for 4G and 5G you will find a diverse range of opinion across the world, with many sources trying to spin the data to suit their own sales agenda. There are many reasons for this and we are not going to digress into it in any technical detail but it is obvious that the bitrate and latency achieved by any network will be extremely variable according to location, the service and equipment being used. One reasonably reliable study of average consumer level data based on genuine field testing is the UK OFCOM Mobile Matters 2023 report. In Fig 1 we reflect the data from this alongside the theoretical maximums. Unfortunately, 5G SA is not widely rolled out in the UK so not included in the report. We also researched a range of international sources that included academic studies and commercial testing and reflect this in the ‘Collated Data’ row.
Private 5G
Private networks are nothing new. Private WiFi networks have been an integral part of most broadcast production systems for a very long time – but WiFi has a number of limitations and weaknesses. Achieving good coverage for a sports stadium for example, requires a substantial deployment of repeaters, bandwidth is limited and WiFi is vulnerable to interference from other systems competing for frequencies. WiFi frequency planning and control is an art and an integral part of the planning for any large-scale sports or major public event production. In a large-scale sports production most fixed camera positions remain wired wherever possible for good reason.
Wholly owned private 4G has been possible for some time. It is entirely feasible to deploy your own antennae & base stations, create your own cells, install and configure your own core infrastructure and source compatible devices to connect to your network. It is of course eye wateringly expensive and requires significant expertise – making it a non-viable option for broadcast production. It is done by the military and some of the world’s largest industrial complexes. It is technically possible to deploy a wholly owned private 5G network in the same way – but even more expensive.
However, the new generation of VNF and CNF core technology of 5G SA brings the same kind of substantial increase in flexibility we get from most new generation software-based systems. It enables a service provider to use ‘network slicing’ to offer managed services with controlled bandwidth and latency on different frequencies – to create private 5G networks within a stadium or other narrowly defined area. The system is controlled, stable and secure. The specific amount of bandwidth and latency performance however will be governed by whether the service provider has deployed mid-band or high-band mmWave infrastructure.
The ability for broadcasters to rent a private 5G network within a stadium opens up the potential to connect cameras and other equipment directly to a very high bandwidth, very low latency, controlled and very secure network. mmWave based infrastructure theoretically has the capacity and functionality to handle all of the cameras, audio and comms equipment deployed within a stadium fairly comfortably.
In part 2 we look at Multi Access Edge Computing and the potential disruptive impact of 5G and MEC on broadcast contribution and remote production.
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