Summary of comments and feedback

Submitter: Airways New Zealand

Section 2.1 of the draft document – covering technical compatibility

This section quotes Article 3.3 of the Radio Regulations and gives the meaning of the term technical compatibility as used in the Radiocommunications Act 1989 in relation to the certification of licences. Notes that attention is also drawn to the definition in the Act of interference and further that harmful interference is defined under the Act as meaning ‘interference which endangers the functioning of a radionavigation service, or other safety services, or seriously degrades, obstructs or repeatedly interrupts radio communications’. While agreeing that these references to specific provisions in the Radio Regulations and the Act are necessary, notes there are additional important provisions within ITU and ICAO documentation that also need to be drawn to the attention of Approved Persons.

Additional references to ITU provisions and ICAO have been added to PIB 38.

Section 2.3

Agrees with the requirements that are set out for a methodology of assessment requirements that must be followed by Approved Persons considering a licence certification.  Notes that Sub-sections 2.3.1 to 2.3.6 detail the analyses which must be included and specify the responsibilities of Approved Persons to ensure compatibility, to conduct whatever compatibility analyses that may be required and to obtain written agreements if necessary.

However, considers the section deficient in that it does not explicitly require Approved Persons to ensure the principles and requirements contained in Section 2.1 are satisfied by the proposed service. In view of the importance of ensuring compatibility with safety services, considers that the text must make it clear what the responsibilities of Approved Persons are in regard to Section 2.1.

PIB 38 as a whole sets out the requirements to be followed by Approved Persons.  This has been set out in section 1.1 ‘Purpose’.

Section 2.3

Suggests adding to the introductory text the following new wording: ‘Approved Persons in considering a licence certification must ensure that the principles and requirements contained in Section 2.1 are satisfied by the proposed service.’

PIB 38 as a whole sets out the requirements to be followed by Approved Persons. This has been set out in section 1.1 ‘Purpose’.

Sub-section 2.3.6 on Distress and Safety Communications

Considers the sub-section to be both incomplete and inadequate.

The current provisions only contain a partial list of Distress and Safety frequencies and do not address compatibility with safety services that are concerned with safety-of-life radiocommunications.

The current text is also misleading since it implies that the specific Distress and Safety Frequencies listed in the table in Sub-section 2.3.6 are the only frequencies that Approved Persons are required to take into consideration when considering compatibility and impact on safety services.

This may lead to interpretations and actions by Approved Persons that are inconsistent with the principles espoused in Section 2.1.

Distress and Safety covers special consideration required for ‘Frequencies for Distress and Safety Communications for the Global Maritime Distress and Safety System’ (GMDSS). The frequencies listed in this table are derived Appendix 15 of the international Radio Regulations. A new section has been added to cover consideration for Safety Services (aeronautical) recognised in the international Radio Regulations and ITU-R Recommendations.

Sub-section 2.3.6

Suggests adding a new table of the full list of frequency bands that have been identified by the ITU-R as being used for safety services. This list is contained in Annex 4 to Recommendation ITU-R SM.1535, ‘The protection of safety services from unwanted emissions’.

Reference to SM.1535 has been included in the document with specific references to Annex 4.

General

Under No. 191 of the ITU Constitution, international telecommunications must give absolute priority to all telecommunications concerning safety of life.

This provision refers to the type of traffic, not to particular frequencies or radio systems. Radiocommunications Act 1989 s137: 'Nothing in this Act shall prohibit any person in distress from using any means at that person's disposal to attract attention, indicate the person's position, and obtain assistance.'

General

No. 1.59 of the international Radio Regulations states that any radiocommunication service used permanently or temporarily for the safeguarding of human life and property is a safety service.

This needs to be read in conjunction with other parts of the international Radio Regulations to fully understand the context. The international Radio Regulations are referenced in PIB 38 and Approved Persons must have regard to them when signing a certificate.

Sub-section 2.3.6 on Distress and Safety Communications

Add this text in a new sub-section: Article 1 definitions of Aeronautical Services AM(R)S, AMS(R)S and ARNS together with the body of ITU-R recommendations (for example, Recommendations ITU-R SM.1535 and ITU-R SM.1757) make it clear that these services are safety services since they are concerned with safety-of-life radiocommunications.

Reference to ITU-R Recommendation SM.1535 has been made. A new section on Safety Services has been created.

Sub-section 2.3.6 on Distress and Safety Communications

In line with Recommendation ITU-R SM.1757, compatibility with existing safety services should be determined on a case-by-case basis in the form of a safety assessment analysis. This analysis would assess the specific safety service(s) that potentially may be affected by the proposed service and demonstrate that the integrity, continuity and availability of the safety service(s) are maintained under all operational conditions.

ITU-R Recommendation SM.1757 ‘Impact of devices using ultra-wideband technology on systems operating within radiocommunication services’ is not relevant at this stage as Approved Persons cannot certify licences for ultra-wideband technology.

Sub-section 2.3.6 on Distress and Safety Communications

‘that the provisions made by the ICAO should be considered as adequate for the planning and protection of Aeronautical Mobile (R) Service frequencies above 30 MHz; the provisions are contained in Annex 10, Volume 1, Part II, § 4.1.5, to the Convention on International Civil Aviation.’

Annex 10 to the Convention on International Civil Aviation is already referenced in PIB 38. An additional reference to ITU-R Recommendation M.441 is not required.

To assist Approved Persons in assessing protection requirements for safety services including aeronautical safety services and radionavigation services, reference should be made to: Recommendation ITU-R SM.1535, Recommendation ITU-R M.1477 (especially Annex 5), and Recommendation ITU-R SM.1757 (example of the use of aeronautical safety service margin in compatibility studies).

Reference to ITU-R Recommendation SM.1535 has been included (as above).

ITU-R Recommendation M.1477 is related to band planning issues and is considered by the Ministry when planning at the allotment stage not the assignment of licences (certification).

ITU-R Recommendation SM.1757 is not relevant at this stage (for reasons as above).

Submitter: Bill Jacob, Downer New Zealand

Paragraph 1.6, page 11 of draft – Records of Certification and their Retention

Second bullet point requires ‘modulation’ to be recorded by AREs / ARCs for auditing purposes. Mention is also made of ‘modulation mode’ in paragraph 2.2. RSM has not accepted previous suggestions that modulation be included as a mandatory field in SMART, and yet it is a vital part of spectrum calculations.  The transmitter's modulation is needed to adequately assess interference issues for licence certification. Examination of the SMART database does not yield what modulation is used on every transmitter and therefore interference analyses are at best generalistic.

Approved persons must specify the correct emission designator on any licence that they certify. PIB 38 specifies the following two methods for assessing for interference [band specific]:

• Interfering signals must be below a fixed threshold; or
• Interfering signals must be less than a  fixed amount below the receiver noise floor (eg 6 dB below the noise floor).

Neither method requires knowledge of modulation type. Modulation type would be required in a C/I interference calculation method, however C/I interference calculation methods are not used in New Zealand at this stage (except TS800 band).

Paragraph 2.2, page 16 – Antenna Beamwidth and Discrimination

Notes it is not clear that ‘discrimination’ refers to both the off-beam skirt selectivity of the antenna as well as the cross-polar discrimination, both of which are essential to improve spectrum use density. This paragraph also omits any reference to diversity techniques which can significantly affect spectrum density. Space and angle diversity techniques should be used before frequency diversity techniques are used where improvement to the non-diversity link is necessary for customer service performance.

This has been clarified as antenna discrimination.

Paragraph 2.4 – Signal Strength Calculations

Notes the statement is made: ‘The Ministry uses...a conservative approach for the determination of field strengths’, and on page 26, under the heading of ‘For all other services’, a K factor of 2 is used for unwanted signal strength analysis.  

Does not agree that K=2 is conservative for determining an interference assessment. It is barely different from ‘Normal’ at K=1.33. The most conservative approach is to rely entirely on free space loss and antenna discrimination (generally achievable in high capacity route design with parabolas – not so easy at I-band).  The least conservative approach is to assume that all obstruction losses occur at K=1.33. Recommends that interference assessments be done at K=10 and preferably K=1000.

The Ministry considers K=2 is appropriate for unwanted paths.  This has been supported in previous consultation with Approved Persons and other interested parties. PIB 38 has been amended to permit that Approved Persons to use higher K values at their discretion.

Paragraph 2.7 – Geographic Co-ordinates

Considers that obtaining grid co-ordinates for every actual antenna location to a resolution of 1 m is a practical impossibility. GPS-sourced location data can be inaccurate to say 10 m resolution unless expensive survey techniques are employed. Reliance on Google Earth photos can be equally inaccurate.

Approved Persons need to ensure that the geographic co-ordinate data is as accurate as practicable. Resolution refers to the level of specificity of the location data; i.e, the number of digits the location must be supplied to the Ministry for recording. In practice the accuracy may not be as good as the resolution.

Para 2.4 – Signal Strength Calculations

Notes the statement is made: ‘for all services...signal strength calculations shall all be done in dBm’. From page 53: ‘Pr = RF signal power at the input to the receiver (dBm or dBW)’, and also on the next line for Pt.

Considers it is inconsistent to introduce a receive power measured in dBW when it ‘shall all be done in dBm’.

This has been rationalised where possible. Generally dBW is used to specify transmit EIRP and dBm is used for expressing received signal levels and other low power signals.

Paragraph 4.7 – Polarisation

Does not agree that the term ‘Other’ should be used where both Vertical and Horizontal polarisations are used on a fixed link (exampled where XPIC is used). A more accurate description of both V & H usage to be ‘Mixed’ polarisation. Cites extract from http://www.mds975.co.uk/txmaps/manchester.html in which FM broadcast antenna arrays are discussed: ‘The original aerial system was a stacked pair of aerials, each individual aerial consisting of a crossed pair of multi element yagis. The crossed arrangement provides mixed polarisation, i.e. power is transmitted in both the horizontal plane (best for horizontally fixed rooftop FM aerials) and the vertical plane (better for car and portable radios using rod aerials).’

Suggests the term ‘Other’ should be used where it is plainly not linear Vertical and/or Horizontal polarisation nor fits into any alternative category.

Where XPIC is used, the practice is that the polarisation is specified on the licence as ‘Other’. ‘Mixed’ implies a single polarisation such as slant with one stream of information. The polarisation 'Other' is intended to indicate that more than polarisation is used carrying more than one stream of information. The Ministry does not propose any change.

Paragraph 4.10, page 56

Notes the entries for ‘Receive level bandwidth’ seem to be meaningless.

This has been corrected.

Para 4.10 – Propagation Availability, page 57

Considers a broad simplistic objective propagation availability of 99.995% pa is unworkable. 99.995% availability represents 1578 seconds or 26 minutes outage per year just for propagation. Wanted path availability objectives can vary between 99.9% and 99.9999% (network objective) depending on the customer service required and propagation availability objectives being greater, as one also has to consider Equipment and Power availabilities. By considering link availability in the absence of any diversity applicable to the hop is ignoring the real-world case.  Recommends against adopting an arbitrary one-size-fits-all approach.

This section has been clarified and changed to a multipath reliability of 99.999% for worst month – Approved Person must refer to ITU‑R  Recommendation P.530.

Rain Rate Data

Noted that a search of NIWA website and Google yielded nil results for TRIPS rain rate data. Actual rainfall data is downloadable from: http://cliflo.niwa.co.nz/, covering about nine years of data. Found this data to be similar to historical data previously in use (in the days of the Post Office) and considers that it provides what appears to be realistic rain rates for the specific locations available. This provides a much more targeted data set than a general ‘All New Zealand' set and is in line with spectrum conservation.

The reference has been changed to the suggested link. In addition, a note has been added that ITU-R Recommendation P.837 can be used as a minimum.

Paragraph 4.14 – Passive repeaters

Re the second paragraph and last bullet point, the statement ‘transmit power of the second fixed link being the receive power of the first and vice-versa’ is contradicted by ‘must be ‑76 dBW’. It is not difficult to determine the receive power at a Passive (at least for back-to-back antennas) and therefore to obtain an effective transmit power for the second hop starting at the Passive.  Considers it unnecessary to require ‘‑76 dBW’ in all cases for the EIRP of a Passive, noting that it also presents a false impression for interference protection purposes.

-76 dBW is used as a flag so that SMART recognises it as a passive repeater and therefore does not charge generate an invoice for fees. The Ministry does not consider that it gives a false impression for interference because passive repeaters do not require protection, and the receivers at each end of the fixed link are protected.

The abbreviation of Equivalent Isotropic Radiated Power

Notes that this term is not abbreviated consistently in the document; it is sometimes abbreviated as ‘e.i.r.p.’ and sometimes as ‘eirp’. Suggests abbreviating as EIRP as this is a modern style of abbreviation.

Abbreviation EIRP as been adopted.

Appendix B, note below Table 1

This note states, ‘The “Types” of antennas as defined are differentiated on the basis of their F/B ratio. Essentially, standard (STD) antennas are Type 1 and high performance (HP) antennas are Type 2.’

Notes that the values used in Table 1 for F/B ratio do not match with the note, as for many of the bands there is no difference between Types 1 and 2, and by reference to the manufacturers data sheets there is usually a significant difference between STD and HP antenna performance.

Table 1 in Appendix B has been updated to clarify the minimum antenna requirements.

Appendix B: Links Crossing DMA areas

Considers this paragraph to be incorrect and in contradiction with paragraph 4.1.1 footnote 5.

Notes that the purpose of a DMA is to increase the density of links by requiring a tighter specification on antennas. What this does in effect is to limit the spillover of RF from the intended azimuth. Considers that there is no reason to relax this requirement for ANY link that even partially crosses this zone even if both terminals are outside the DMA, as any antenna pointing even vaguely at the DMA has the possibility of limiting usage within the zone.

This may be an item for future review if demand begins to lead to spectrum denial. The current DMA restrictions are a simple methodology for Approved Persons to assess if DMA restrictions apply to a proposed licence.

Submitter: Doug Ingham, New Zealand Association of Radio Transmitters

Page 12, Licensing Agency Table: Amateur Beacons Policy

Notes that currently all AREs and ARCs can certify Amateur Beacons.

This has been corrected.

Submitter: Greg Smith, Tait Radiocommunications

Page 23

Section 2.4 covers Signal Strength Calculations, not Section 2.3 as stated.

This has been corrected.

Mixing of dBW and dBm

Suggests that the document could usefully be standardised by using one or the other.

This has been rationalised where possible. Generally dBW is used to specify transmit EIRP and dBm is used for expressing received signal levels and other low power signals.

Em Designators

The relevant Em Designators for APCO C4FM are F1EDN, and F1DDN, not EJN and DXN as stated. The fourth symbol should be a D representing ‘a 4-condition code in which each condition represents a signal element’.  J is ‘sound of commercial quality’ and X is ‘cases not otherwise covered’.

This has been corrected.

TD band allocations, page 41

Considers the fact that the block channel separations are an exact sub-multiple of the Tx-Rx spacing is unfortunate from an intermodulation (IM) point of view. Notes that it could be argued that it is the responsibility of the equipment user to ensure that hardware is of sufficiently high quality to ensure that IM products are not produced, but this can be extremely demanding in duplexed systems using a common antenna for Rx and Tx.  Also, the user may not have control of the mechanical design of all antennas on the mast he is using.

This has been noted but is outside the scope of PIB 38 and may be an item for future consideration.

Trunking licences in the TD band

The Tait trunking licences in the TD band do not comply with the block allocations (with Ministry approval).  Appreciates that, for historical reasons, it would be difficult to change these allocations, but considers that a note in the new document, outlining the possible problems and potential solutions, would be useful.

This has been noted but is outside the scope of PIB 38 and may be an item for future consideration.

Page 83

At the bottom of the page, there is a reference to Appendix D. Is this meant to be Appendix B?

This has been corrected.

Submitter: Kordia

2.3.5 Off-site compatibility: Determining signal level from a transmitter to a receiver

Suggests clarification of antenna discrimination.

This has been clarified.

3.5.1 Interference Thresholds Coverage: Adjacent channel criteria

Suggests providing clarity on what an adjacent channel is.

This has been clarified.

4.4 Calculation of receive signal levels

Suggests changing Lb to Lp (Loss Path) to be consistent with the rest of the document.

This change has been made.

Various non-substantive editorial suggestions

These have been reviewed and changes made where required.

Submitter: Larry Purchas, Purchas Communications Ltd

3.6.4 paragraph on First Adjacent Channel.

Notes this paragraph is not clear. Suggests it be reworded to ensure the meaning is conveyed.

This has been corrected.

#5 introduction, first paragraph

Points out that the second sentence,  ‘Satellites are permitted…’ needs a grammatical correction.

This has been corrected.

Submitter: Radio Broadcasters Association

Section Four: Fixed Linking

Various brief sub-sections are included in this section. These deal with planning rules specific to individual Fixed Linking technologies and/or bands.  Notes however that there is no sub-section on studio-to-transmitter linking.  Considers that PIB 38 would be significantly improved if such a section was included.   The sub-section should as a minimum include information relating to the planned band changes [841-849 MHz, 915-921 MHz, 928-929 MHz], including that in the longer term adherence to an agreed channel plan is likely to become mandatory.

A sub-section has been created to cover STLs in the fixed link section. Work is currently underway to finalise changes to the STL bands including engineering rules and policy rules. Once this work is completed the STL section will be updated and a new edition of PIB 38 will be published.

Submitter: Spectrum Engineering Australia

Para 2.3.3 – Assess the site sense

Notes that the discussion about how to manage site sense between overlapping contiguous bands (see bottom of page 19) could be strengthened. Where there are no constraints imposed by the far end on the site sense of the new service, i.e. where the choice of site sense is arbitrary, it should be mandatory to adopt a site sense that is consistent with adjacent band services at the site. Where it is not possible to avoid an ‘incorrect’ site sense, assignments should be made on channels as far away from the band edge as possible so as to maximise separation between Tx and Rx that are in the incorrect site sense.

The wording is this section has been strengthened.

Paragraph 2.3.5 – Determine a signal level from transmitter to receiver

Considers that the use of the word minimum (‘minimum loss’ – see page 23) is probably not quite correct – though the general intent of the statement is understood. The propagation loss that should be used for the interference path should not be the absolute minimum, rather a level that occurs for some small defined percentage of time. The subsequent specification of a ‘k’-value of 2.0 (appropriately) for the unwanted signal calculation (see comments on #2.4 below) implies a small finite time percentage. Higher k-values would give lower losses, so k=2 does not produce the ‘minimum loss’ value.

The bullet-point reference to ‘Total aggregate power’ also seems inappropriate. Loss is loss – how you deal with aggregation is a separate matter. This also applies to ‘Channel offset losses’.

Changed the wording from ‘minimum’ to ‘conservative’.

Paragraph 2.4

Suggests that ITU-R Recommendation P.452 be included in the references here (contrary to initial advice). This Recommendation is specifically a ‘Prediction procedure for the evaluation of microwave interference between stations on the surface of the Earth…’ and it is probably therefore more appropriate than P.526 for assessing loss on the unwanted path.  Has implemented and tested the method contained in P.452 and notes that it is quite feasible to use and quite fast in execution. A free spreadsheet version can be found at http://www.itu.int/oth/R0A0400005F/en. P.452 requires the input of explicit time percentage parameters (whereas P.526 uses k-factor as a surrogate). If using P.452 the wanted signal should be calculated for 50% of time, and the unwanted signal for 20% of time.

This has been noted for future consideration.  The Ministry notes that ITU-R Recommendations P.525 and P.526 are widely used by industry and considers continuing the use of these appropriate.

2.4.1 – Total interfering power

Strongly disagrees with the proposed approach here. Whilst it is practical to sum the interferers into a new link, it is not practical to do so when assessing the effect of the new link on the existing links. That would require the full re-coordination of every existing link against all of its existing neighbours every time a new link is added to the neighbourhood. Suggests that RSM would not do this at present and would not want to do it in the future. States that Spectrum Engineering Australia certainly would not want to do it and that if the PIB require this, they would require an exemption.  Suggests that a realistic compromise is needed to produce a workable situation.

This requirement has been amended to be a guideline.

Paragraph 2.4.2

Notes that where the noise figure of the receiver is not available a simplified approach is needed, and that they had previously suggested a figure of 3 dB across the board. The ‘error’ caused by using a simple approximation will be acceptable considering the uncertainty in many other components of the process.

This suggestion has been included.

Paragraph 4.3

Queries whether the reference to Appendix A (last line in this section) is relevant here.

Appendix A is providing additional information on the co- and adjacent channel relationship. The Ministry believes this is the most relevant place to reference it.

Paragraph 4.5 – Use of a k-value of ‘2’

This assumes the calculation method is as contained in ITU‑R P.526. But if other methods are used, time percentages will need to be added here – see earlier comments on Paragraph 2.4.

At this stage there are no plans to change from ITU-R Recommendation P.526.

Paragraph 4.10

Does not understand the intent of the first entry in the table (receive level bandwidth). Notes that the values don’t seem relevant.

This has been corrected.

A performance standard of 99.995% annually has been nominated. Notes that for Spectrum Engineering Australia’s work in New Zealand, to date they have been using 99.999% (under a standing arrangement with RSM).  Even that figure requires levels of back-off that are often questioned by clients. Considers that it is difficult to know what a ‘reasonable’ figure is here (and is not arguing for any particular value), but that whatever is nominated will need to be acceptable to the majority of users. Adds that there is little point in providing a very high level of protection from interference (which PIB 38 does) if at the same time the base level of performance is limited by a low wanted signal level.

This section has been clarified and changed to a multipath reliability of 99.999% for worst month – Approved Person must refer to ITU‑R Recommendation P.530.

Rain rate data

Notes that the proposed use of the TRIPS data is consistent with their original suggestion. Queries whether the data is readily available (particularly for use in an automated system), and the cost of the data.

The reference has been changed to free database CliFlo http://cliflo.niwa.co.nz/ and a note has also been added that ITU-R Recommendation P.837 can be used as a minimum. Power limiting above 10 GHz is not currently mandatory. 

Paragraph 4.14

Notes that the Ministry’s reason for recording the passive Tx power as -76 dBm is to put it below the power threshold for licence fee. However, does not understand the rationale for not charging for both legs of the system – even though only one channel is involved. Notes that where the same channel is used back-to-back at an active repeater there are two fees. Suggests that the consistent solution would be to record the actual powers and charge for both legs.

At this stage the Ministry does not see a justification to charge fees as passive repeaters are not afforded protection nor do they have an active transmitter. This may be considered in the next fees review.