The World Radiocommunication Conference (WRC-12) commenced this week in Geneva, Switzerland, after lengthy preparations in all corners of the world. The International Telecommunication Union (ITU) organizes the event, which will run for four weeks. WRC-12 is designed to amend the ITU radio regulations, adopt resolutions and recommendations, and generally set the rules for international use of radio frequencies.
The ITU has sponsored a series of presentations by different industry sectors that use spectrum to summarize their position at WRC-12. Broadcasters were represented by an article posted just before the conference began, by Christoph Dosch, Institut für Rundfunktechnik (the German institute IRT) and David Wood, European Broadcasting Union (the EBU, also based in Geneva). Their presentation is entitled “Broadcast: Radio spectrum needs for changing lives.”
The major issue they sought to flag is spectrum sharing in the upper part of the UHF broadcast band between broadcasting and international mobile telecommunications (IMT) in Region 1 (Europe and Africa) in the range 790 to 862 MHz, which will take effect at the time of the transition to digital. Technical studies on this sharing will be considered by WRC-12 under agenda item 1.17. The authors identify the following problems (which we paraphrase):
• Mobile systems using “Long Term Evolution” (LTE) links affect the broadcasting service below 790 MHz; LTE handsets operating near a television receiver can block television reception.
• Because of the 1 MHz guard band between the broadcasting and the mobile services (from 790 MHz to 791 MHz), there are no adequate, economically viable filters to provide sufficient attenuation of out-of-band emissions of mobile service IMT signals, which blocks use of channel 60 for mobile television services.
• Strong LTE downlink signals near a mobile service IMT base station may cause a severe degradation of the television picture quality in areas where the DVB-T signal is relatively weak in comparison to the LTE signal.
• Thousands of licence-exempt wireless microphones in the hands of the public operate in the range 790-862 MHz on a secondary (that is, non-interfering) basis, and must be relocated in other frequency bands. The proposed relocation of these wireless microphones to frequencies below 790 MHz is problematic as this band is already used for professional applications ancillary to broadcast production – the so-called programme-making special event systems – that also operate on a secondary basis.
The authors put in a plug for more studies to be conducted before additional UHF broadcasting spectrum is considered for allocation to the mobile service. The WRC-12 will normally include potential future allocations under its agenda item 8.2. The broadcasters want these studies to consider capacity issues, service concepts “and, especially, the complete compatibility considerations with the existing broadcasting service (and the secondary usage of the band).”
In a provocative ending, the authors argue that the case for more wireless broadband use of spectrum that broadcasters consider to be their own “appears to be based more on short-term profit than on long-term public interest. It does not take into account the quality evolution of television, the increasing public demand for Internet data capacity, or the latest thinking in wireless broadband delivery technology.”