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[pdf] Coexistence of new services in the 700 MHz band with digital terrestrial television (May 9, 2017)
Via Cyprien De Cosson

Explicitly frame analysis in terms of risk, and risk mitigation.

Exec Summary

1.6 Our projections based on data from the current 800 MHz mitigation scheme indicate that there will be between 25,000 and 36,000 confirmed interference cases by the end of 800 MHz network roll-out. This is less than 0.2% of DTT households in the UK. We expect that the number of 700 MHz interference cases will be broadly similar.

1.9 Households with television receivers that perform poorly1 and that are in an area of relatively high handset activity might experience a single transient picture interruption on average around once every 100 hours of viewing standard definition TV. For high definition (HD), the equivalent figure would be just one interruption in 10,000 hours of viewing.
Ofcom  DTV  700MHz  risk-assessment  DTT  television 
january 2018 by pierredv
Ofcom leaves DTT interference mitigation to UK government — PolicyTracker: the spectrum management newsletter
"The UK regulator has published a technical analysis of the interference risks to digital terrestrial television (DTT) services following their 2020 move out of the 700 MHz band and into the 470-694 MHz band."

"The regulator said it intends to work with the UK government in the coming months to consider policy options for managing the coexistence risks it identified in its analysis and to “explore the potential for early use of 700 MHz filters instead of 800 MHz filters where appropriate, to future-proof households against any future interference issues”.
"However, it said that it expects receiver filters will be the most technically effective way to mitigate interference for the 700 MHz band."
Ofcom  DTT  700MHz  receivers  filters  800MHz  PolicyTracker 
may 2017 by pierredv
Coexistence of new services in the 700 MHz band with digital terrestrial television - Ofcom May 2017
"This consultation presents our technical analysis of coexistence issues between future mobile services in the 700 MHz band and digital terrestrial television (DTT) in the adjacent band.

The 700 MHz spectrum band currently houses DTT and wireless microphones used for programme making and special events (PMSE). In November 2014, Ofcom decided that the 700 MHz spectrum band would be repurposed for mobile data services. At that time we also presented results of our initial work on coexistence issues.

We have now completed more detailed work to investigate the nature and scale of potential interference risks. We also discuss technical aspects of some potential solutions to mitigate the risks."
Ofcom  consultation  DTT  700MHz  cellular 
may 2017 by pierredv
More LTE-DTT interference reported in France than UK - PolicyTracker Jan 2015
"Ben Roome, the chief executive of At800, explains why the UK’s 800 MHz interference problem is less significant than expected and how the majority of interference cases the organisation deals with have nothing to do with LTE." "Of the 2.3 million households that could be affected by LTE, only forty per cent of them (900,000) relied on DTT for TV. In 2013, the figure for the households that could be affected was revised down from 900,000 to 90,000." "In the first 18 months of operating there were 200,000 phone calls and 12,000 home visits to deal with complaints of interference. In three quarters of these cases, a separate cause – usually badly installed equipment – is found to be the main cause of poor reception." "On a per base station basis, there are 10 times fewer cases of interference in the UK than in France. France’s spectrum agency ANFR sees 10-12 cases per mast, while At800 sees a cumulative average of 0.9 cases per mast."
PolicyTracker  LTE  DTT  DTV  At800  interference  UK  France  800MHz 
january 2015 by pierredv
Reports cast doubt on expanded role for MNOs - PolicyTracker January 2015
"Plum and Farncombe completed a study in December on the possible convergence of the DTT and mobile platforms. The consultants found that an economic case for convergence cannot yet be made. They said that even though the potential benefits are substantial (such as the release of 110–175 MHz), these benefits are uncertain and come with costs that are undoubtedly high, such as the need to roll out low-power low-tower networks on single frequency networks."
PolicyTracker  DTT  TV  cellular  convergence  Plum 
january 2015 by pierredv
Ofcom | TV white spaces: DTT coexistence tests - Dec 2014
"This document contains the data from Ofcom’s tests to examine to what extent a new class of devices - white space devices (WSDs) - could cause interference resulting in video and audio quality degradation of Digital Terrestrial Television (DTT)." Bottom line seems to be: "measurements suggest that some adjustments will need to be made to theparameters used in the model as assumed in the TVWS consultation" Notes cases where UK Planning Model predicted higher DTT field strengths than measured; and cases where it did not correctly identify the DTT transmitter in use "Observed protection ratios were broadly in line with those measured in the laboratory. Different DTT receivers have very different adjacent channel protection ratios from signals from different WSDs. In particular, some DTT receivers have significantly worse performances than others when presented with bursty waveforms"
Ofcom  TVWS  coexistence  television  DTT  data  measurement  UKPM  UK-Planning-Model  interference 
january 2015 by pierredv
When it comes to interference, you can't beat real world experience - PolicyTracker Mar 2014
"... the organisation's initial estimates suggested that up to 900,000 TV households could be affected by the UK rollout of LTE. At800 notified 8.5 million households of possible disruption and sent out a million filters. ... The estimate of how many households could be affected has been revised down drastically, to 90,000. At800 says even that is “a conservative upper limit” of the potential scale of the problem. At current rates, the upper limit is likely to be more like 50,000." "At800 did some research in December into about 600 households that received a filter, and found that only 10 had noticed some disruption, inserted a filter and found that had improved the situation. “We found a further seven who had noticed some disruption, inserted a filter and there was no change to their TV,” Roome says."
Ofcom  At800  interference  DTV  LTE  DTT  PolicyTracker 
march 2014 by pierredv
at800 unveils accredited installer scheme - Land Mobile
"at800, the company working to address possible disruption of Freeview services by 4G at 800MHz, has announced its accredited installer scheme. The installers will help householders resolve disruption to Freeview services on their primary TV set."
Freeview  at800  DTV  DTT  professional-installation  UK  interference  800MHz  LTE 
july 2013 by pierredv
Ofcom | Reducing interference between digital TV and future mobile services
"Ofcom today set out proposals to ensure that digital TV delivered through a roof top aerial can function alongside the next generation of mobile services to be rolled out from 2013.

On 22 March, Ofcom set out plans to auction 800 MHz spectrum for 4G mobile services next year.

The 800 MHz spectrum is adjacent to the frequencies used for digital terrestrial television (DTT) broadcasting. Due to its proximity, in a small number of cases this could cause the signals from mobile base stations to interfere with set top boxes and digital televisions in the future. This could potentially affect up to 3% of DTT viewers if no measures were put in place to solve the problem."
filters  receivers  interference  800MHz  cellular  UK  Ofcom  DTV  DTT 
october 2012 by pierredv

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