Presented at UK Spectrum Policy Forum – Cluster 2 meeting 'DTG DSA Forum and discussions on PMSE' held on Thursday 9th July 2015 at DTG offices Presented by Martyn Lee, Senior Technologist, BSkyB

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PMSE – Programme Making and Special Events
• PMSE equipment is used for video and audio capture
• Inside and outside: studios, theatres, stadiums, OBs (outside broadcasts)
• Spectrum is mostly shared on a secondary basis with other primary users such as DTT (audio) and
MoD (video)
• Request for spectrum is made to Ofcom (formerly to JFMG / Arqiva)
• Request can be frequency specific, will be location and time specific (to ensure security of primary
services)
• Pressure on all spectrum, is PMSE at risk?
– PSSR (Public Sector Spectrum Release) putting pressure on video (camera) spectrum
– DSO and 700 MHz clearance impacting audio spectrum
• Pro-active involvement from Ofcom in terms of finding alternative spectrum
– Video spectrum tight but currently thought to be just OK
– Audio spectrum post 700 MHz clearance presents issues
CONFIDENTIAL – NOT FOR PUBLICATION

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PMSE audio equipment
• Sky currently uses 26 UHF channels at Osterley (not including c38)
– … for >200 analogue microphones and IEM devices
– … whereas post 700 Mhz clearance there will only be 27 UHF channels in total
– Some analogue equipment is not (very) frequency agile
– Meaning some kit purchased to cope with 800 MHz clearance won’t be suitable after 700 MHz clearance (2020-22)
• Is “digital” the answer?
– Digital compression is not feasible for audio (too much latency when used with monitoring such as IEM)
– Digital modulation will help through more efficient use of spectrum (carriers can be more tightly packed because
there is much greater immunity to cross modulation) but …
CONFIDENTIAL – NOT FOR PUBLICATION

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Digitally modulated PMSE audio equipment
• The extra 3 to 4 milliseconds processing delay sounds small but might still mean that audio systems
need to be totally re-engineered;
• Studio operations typically need 8 hours battery life (not an issue on analogue devices) whereas many
digital products offer 5 to 6 hours with a new battery and that will degrade to 3.5 to 4 as the batteries
age;
• Will there be new artefacts caused by the various extra processing stages?
• What can be done about RF fading ?
– Fading is gradual with analogue equipment, gives notice of failure through a hiss or crackle;
– Will digital equipment take on “cliff effect" properties?
• What about cost? Product is typically 50 to 100% more expensive;
– … some of which was only purchased for 800 Mhz clearance and uses channels 39 – 60!
• Are there digital versions of all products?
– IEM? Mix and match analogue with digital prolongs spectrum planning issues;
• Not clear that a switch to digital provides a comprehensive answer for loss of 700 MHz!
CONFIDENTIAL – NOT FOR PUBLICATION

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Any questions?