PMSE

How spectrum is essential for an increasingly switched-on world

PMSE is a vital component for the creation of audio and video content so spectrum requirements must be met to make sure it thrives, writes Zeljko Tabakovic, spectrum expert at the ECO.

Considering recent experiences with adapting to the new normal, we are increasingly surrounded by a virtual reality environment and immersed by different kinds of connected devices such as cameras, screens, microphones and speakers. We are interacting with the world through these devices and our media habits are rapidly changing.

Recent research shows that screen time increased by more than 30% over the past year and led to almost a 60% increase in the amount of content we watch. With less social contact we are consuming more content but also creating and sharing audio and video streams with our friends, families and colleagues.

Leaving aside societal, environmental and health care aspects we can investigate what is going on behind the scenes of creating content and related technical context. Programme Making and Special Events (PMSE) is an enabler for the creation of audio and video content which is broadcast and consumed globally using a variety of platforms.

The PMSE industry is one of the crucial pillars behind professional equipment for the culture and creative industry, and is looking for solutions to the availability of radio frequency spectrum for advanced wireless applications. PMSE content capture is at the start of the supply and value chains for a wide range of products, consequently expected to provide the highest quality possible - see Figure 1. Producers and programme makers take steps to ensure the quality and robustness of content capture and delivery.

PMSE encapsulates a multitude of different services such as services ancillary to programme-making, services ancillary to broadcasting; electronic news gathering, and outside broadcasting and applications. These services are used in meetings, conferences, cultural and education activities, trade fairs, local entertainment, sport, religious and other public or private events. There are three main groups of PMSE equipment:

• audio PMSE – the most commonly used audio PMSE applications are wireless microphones (handheld and body worn) and in-ear monitors;
• video PMSE;
• PMSE service links – PMSE equipment that is used for transmission for production.

Figure 1: From capture to consumption, ECC Report 323

In recent years, available spectrum for PMSE applications has been reduced. This is because some parts of the spectrum, previously used by PMSE, have been allocated to other services. Sharing frequency spectrum between different services has been more demanding due to ever emerging new wireless applications.

During two past ITU World Radiocommunication Conference cycles, UHF radiofrequency spectrum primarily used for television broadcasting distribution and audio PMSE applications changed frequency allocation and were re-purposed to other services. On the other hand, new bands for audio PMSE were identified by CEPT and are now included in ERC Recommendation 25-10 and ERC Recommendation 70-03, Annex 10. These include 1350-1400 MHz and 1518-1525 MHz. Currently, WRC-23 Agenda item 1.5 is reviewing the spectrum use and spectrum needs of existing services in 470-960 MHz which also considers PMSE frequency use in this band.

On the other hand, there is a trend of increasing demand for content production and consumption. There is greater need for higher quality, much more connected and synchronised devices and interactive content.

Availability of PMSE equipment is making production more affordable and reachable not just to the professional users – widespread use of mobile devices and unmanned aircraft systems enable new user applications. There is also diversification of services and new forms of media and applications, including streaming services, rich content sporting events, user generated content, social networks, and sharing and exchange of audiovisual content. We are also seeing developments which will possibly increase future spectrum needs for PMSE. These include different augmented reality applications, co-operative media production, distributed performance, new mobile applications, interactive video games, and so on.

In assessing regular spectrum requirements for PMSE, it must be borne in mind that PMSE demand is either at permanent sites or is time and location specific. A number of PMSE uses, in particular those of news gathering, happen at unpredictable times and locations and necessitate a very rapid response time. In such cases, it is very important that the delay and the procedures for frequency co-ordination and licensing are limited to the minimum.

On the other hand, some of the PMSE uses, such as outside broadcasting, are normally planned in advance of an event. In that aspect availability of sufficient and adequate frequency spectrum for PMSE applications should be ensured, taking into account future needs and fundamental impact of the PMSE to the creative industry. These aspects are reflected in ECC Strategic Plan for the period 2020-2025 where two of the major topics address PMSE. They are also reflected at the EU level with several documents adopting harmonisation legislation and opinion on a long-term strategy on PMSE spectrum requirements facing future needs.

In February 2021, ECC Report 323 on spectrum use and future spectrum requirements for PMSE was published. It was developed within Project Team FM 51, and includes recent advances and trends in PMSE, and provides updated information, accompanying analysis and conclusions of ECC Report 204.

Frequency ranges for the use of terrestrial audio and video PMSE are available in ERC Recommendation 25-10. The ECO Frequency Information System (EFIS) tool provides harmonised information relating to spectrum use in Europe and information on national conditions for audio and video PMSE applications as illustrated in Figure 2.

The use of PMSE equipment may not be fully harmonised across the CEPT countries due to divergent national frequency plans and differing PMSE requirements. Within the tuning range, the use of PMSE radio equipment is limited to the range of frequencies identified nationally within that country and will be operated in accordance with the related national regulatory conditions and requirements. Within each tuning range, CEPT countries may assign specific sub-bands or particular frequencies for PMSE links subject to availability, actual demand and sharing arrangements with primary services using those bands.

Figure 2: Extract from EFIS illustrating national conditions for video PMSE in ERC/Rec 25-10

The Project Team FM51 has been tasked with preparing the update of ERC Recommendation 25-10 which will include recent technological advances and changes in frequency ranges and national conditions for audio and video PMSE applications.

Requirements of the PMSE applications

There are many totally different use cases and a wide range of PMSE equipment use, making it difficult to find a common denominator for determining requirements for different applications. Quality, adequate data rate, low latency synchronicity, mobility and reliability of the radio link are fundamental to PMSE users. For PMSE productions the commercial pressures on users are significant as there is no opportunity for recovery, and so the tolerance for disturbance to the quality of service is extremely low. Peak demand for PMSE is usually temporarily and locally limited, such as big music festivals or sporting events or where several events are co-located at the same time. However, peak demand may also appear in various permeant locations where there is a high density of longer-term PMSE in use, such as cultural districts, sporting arenas, broadcasting facilities and studio complexes. Figure 3 illustrates requirements needed for some of the audio and video applications using PMSE equipment. Note that requirements can vary a lot depending on the specific application and event considered.

Figure 3: Illustration of technical requirements for different PMSE applications

Audio: Audio PMSE applications require very low latency and system delay, moderate data rates, high communication service availability and system reliability. Live audio production requires high level of synchronicity of all mobile devices service area, and there could be large number of links needed. For PMSE equipment there is demand by wireless microphone and IEM users for more audio channels and clean, interference-free spectrum, as well as for higher audio quality. Wireless microphone and IEM use enables artists at live music events to move freely around a large stage unencumbered by trailing wires.

Video: For video PMSE applications there are requirements for high quality of service and data rates. Very high communication service availability and system reliability, low to moderate latency and system delay, high data rates, high communication service availability and system reliability are also needed. For video productions and sporting events there are requirements for high level of mobility and high level of synchronicity of all mobile devices service area. There could be a large number of links needed. Developments in wireless camera technology have also greatly improved portability allowing a multitude of cameras to be spread around a stage or studio, providing the producer with multiple views to switch between or from which to edit and compile footage. In live televised sport, small cameras are placed right in the middle of the action to offer audiences and production teams immersive point-of view camera angles, for example, on racing cars in F1 and the World Rally Championship, or on bicycle seat posts in the Tour de France.

PMSE is an essential component for the creation of audio and video content, which is broadcast, distributed, exchanged and consumed globally using a variety of platforms. Looking at current trends we are more and more surrounded by different connected wireless devices, we are consuming more content but also creating and sharing between our peers, while new applications and forms are constantly emerging leaving new technical challenges to PMSE. Currently there are several projects developing and investigating technologies for different PMSE applications. It is important for the PMSE industry to address all of these technical challenges and for regulators to ensure enough frequency resources, sharing conditions and adequate licensing regimes for addressing current and future needs of PMSE applications.