TV white spaces: DTT coexistence tests

17 December 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).

All wireless equipment transmits signals using radio waves, making use of electromagnetic spectrum. We are currently piloting a new method of spectrum access called dynamic spectrum access. Use of dynamic spectrum access potentially allows WSDs to use the same spectrum that is currently used for Digital Terrestrial Television and Programme Making and Special Events (PMSE). Different locations, frequencies or times can be selected such that those DTT or PMSE services will not be adversely affected by WSDs.

In this way, WSDs can use valuable spectrum that would otherwise lie fallow, and provide useful new wireless services, while ensuring a low probability of harmful interference into other services. The tests described in this report are one component of our dynamic spectrum access pilot, which also includes:

  • similar tests in relation to the potential of interference from WSDs into PMSE;
  • tests of processes, software and databases required to make the technology work, and
  • trials of services using WSDs.

We will use the information in this report, along with any other relevant evidence from the pilot, responses to our previous consultations and any other relevant stakeholder input or further evidence to inform our approach to co-existence and our decisions on the rules for authorising WSD operation, which we intend to set out in a forthcoming statement. We currently anticipate that this statement will be published in early 2015.

Full report

TV white spaces: DTT coexistence tests (PDF, 2.9 MB)
Full print version

Lab Measurements of WSD-DTT Protection Ratios (PDF, 5.7 MB)
A report for Ofcom by DTG Testing Ltd