LPFM consultation 2010 - Questions & answers

The questions and answers included below have been modified from the actual questions received and the answers sent to the questionnaire, to provide a more complete or generalised answer.
References used in the answers refer to the Low Power FM General User licence Requirements Consultation Paper March 2010.

Question 1 – The effect of changes on individual broadcasters

“What are the main effects of proposals contained in the consultation document for LPFM broadcasters?”

Answer 1

The effect on individual users of the present licence will vary depending on the frequency they are using and their transmit location. It is expected that the new licence will cover all existing users, and that some users will need to change frequency to comply with the new licence. Each user will need to assess their own compliance with the new licence
If the draft licence is confirmed as currently proposed there will be more frequencies available overall, but some existing frequencies will no longer be available. Some specific restrictions in particular defined areas are also intended.
Details of frequencies that will not to be available in particular locations and areas are identified in the Attachments to the consultation document.
Maps will be placed on the RSM web site prior to 1 June 2010 that show the LPFM exclusion zones associated with;

• landmobile services protection required from 1 June to 30 September 2010;
• VHF-FM broadcasting sites; and,
• other locations as detailed in Section (b) of Schedule 2 of GURL to be published prior to 1 June 2010.
   

Samples of the maps are now available at http://www.rsm.govt.nz/cms/policy-and-planning/current-projects/broadcasting/lpfm-gul-consultation-2010/lpfm-consultation-2010-maps-of-proposed-lpfm-exclusion-zones, and others will be added progressively until 31 May 2010.

Question 2 – Consultation document complexity

“Why is the consultation document so complex?”

Answer 2

The complexity exists to ensure adequate protection for licensed services from interference. Aeronautical radio navigation and voice services that are used constantly by aircraft throughout NZ need increased protection due to an increasing number of reported interference incidents caused by LPFM operations. Some incidents had the potential to contributed to safety of life issues.
The complexity is also a result of the need to coordinate the LPFM frequency band changes with the relocation of landmobile services in the band 87.5 - 88.0 MHz and VHF-FM broadcasting services being relocated to the 88.4 - 88.8 MHz band.

Question 3 – Use of modulation enhancement equipment

“What is modulation enhancement equipment?”
 

Answer 3

Modulation enhancement equipment can alter the spectral shape (spread of frequencies components and their amplitudes) of a broadcast transmitter to provide improved quality of broadcast signal reception by preconditioning the transmitter input (baseband) signal in way that compensates for transmitter nonlinearities, or changes the dynamic range¹ of the transmitted signal to allow improved reception in low signal areas. Such devices can use both software and hardware techniques.

High quality modulation enhancement equipment does this without the resulting transmissions exceeding the permitted bandwidth and transmit power levels. Poor quality modulation enhancement equipment does the same thing but results in signals where bandwidth and power exceed the permitted levels for extended time periods.

In the VHF-FM broadcasting band, regulation of frequency use and separation can mean that short term increases in occupied bandwidth and band edge spectral density do not cause significant interference issues. With LPFM services those short term increases can have a much greater impact on reception due to the common use of more closely spaced transmit frequencies (200 kHz instead of 800 kHz), and reduced frequency re-use due to transmit level enhancement.

The use of poorly designed modulation enhancement equipment can therefore significantly impact LPFM usage and some LPFM operators may have already had to change frequency or abandon their transmissions because of such equipment operated by others.

The inclusion of the prohibition of modulation enhancement in the draft GURL and GUSL attached to the consultation document was initially proposed as a possible solution to allow the LPFM regime to be used as widely as possible and by all users on an equal basis. However, it is evident that there is also a need to enable LPFM operations currently using good quality modulation enhancement to continue operation.

An alternative option is to include a new clause in the GUL ‘Terms conditions and restriction’ that is similar to a European requirement for frequency deviation to be limited to 75 kHz except for very small periods of time. MED will consider the suitability of this along with and other solutions, including those suggested by submitters.

Question 4 – Use of 88.4 MHz for LPFM

“Why is 88.4 MHz identified as a usable LPFM frequency when is at the limit of the LPFM band and part of the signal extends into the VHF-FM management right?”

Answer 4

It is not uncommon for licensed spectrum to continue over the boundary of a management right where there is agreement between the adjacent management right holder (managers) and the management right conditions of use permit. In the case of 88.4 MHz, MED is the manager of both the radio licensing band below 88.4 MHz and, on behalf of the Crown, the manager of the VHF-FM band management right above that frequency, and will establish the appropriate management right boundary conditions.

The real issue is the prevention of harmful interference to licensed high power broadcast services. To meet this requirement it is proposed that the GURL will identify that “Use of the frequencies in schedule 1 (a) is not permitted where those frequencies are within 400 kHz and within 50 km of the location of any individually licensed broadcasting transmitter. This requirement applies to any LPFM frequency closer than 400 kHz to both the 88.4 MHz and 106.63 MHz edges of the VHF-FM management right.

This condition is being reconsidered because a 400 kHz spacing would reduce the frequencies available for LPFM and experience suggests that a 300 kHz spacing could be used without resulting in interference issues. This matter will be discussed with representatives of licensed broadcasters before finalising the clause.

Question 5 – Will 88.7 MHz be available for LPFM

“Can I still use 88.70 MHz until April 2011? The graph shows 88.7 MHz as being able to be used yet wording beside it (vertical wording) says that 'Frequencies 88.7 MHz...must not be used for LPFM services". Is 88.7 MHz usable until April 2011?

Answer 5

88.7 MHz is likely to be usable at Napier until 2 April 2011. However, the use of 88.7 MHz may not be available in all areas. Please refer to Attachment A – Available LPFM Frequencies during the Transition Period, of the LPFM GUL Consultation Document, to identify LPFM frequencies expected to be available/prohibited based on the current proposals.

The correct vertical wording in table two on page 27 of the consultation paper is “Frequencies 88.8 MHz to 106.3 MHz must not to be used for LPFM services”.

Question 6 – Use of 88.1 MHz for LPFM

“We are currently broadcasting on 88.1 MHz and would like to find out any information on how this will affect us and whether we require any other licences.

Answer 6

Attachment A in the consultation document identifies 88.1 MHz as a frequency that will not change as a result of the LPFM band changes it should be available unless the installation is located within the LPFM exclusion zones. Use of all LPFM frequencies is proposed to be prohibited in those areas.
LPFM use is expected to continue to operate under General User Licences. No other licences are required while those GULs are current.

Question 7 – Identifying the location of other services

“The requirement for use of isolation devices to prevent the transmitter intermodulation requires us to locate other radio services close to us. How can we locate those other services?

Answer 7

To identify these locations you can:

• Identify all licensed transmitters via access to the Radio Spectrum database (SMART) web site. Details on how to use SMART are available here.
• Ask the owner of your transmitting site or your local LPFM user group. The person who maintains your equipment may also be able help identify other local radio services:
• Identify other local LPFM users by searching the LPFM user web sites and by listening for local LPFM broadcast programmes (which are required to identify contact details every three hours).

Footnote

¹ Dynamic range is the difference between the highest and lowest levels of a signal, and is usually accomplished by raising the level of the low level signals without changing the level of the high signal levels.