Restack channel planning
Melbourne
ENGINEERING REPORT TPS2012/06
sEPTEMBER 2012
Canberra
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© Commonwealth of Australia 2012
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acma | 1
Contents (Continued)
Executive summary
Proposed channel allotments
1Introduction
1.1Scope
1.2Channel planning principles
1.3Channel block identifications for the Melbourne licence area
1.4Consultation
1.5Terminology
1.6Transmitter specifications
2Block identification and channel allotment proposals
2.1Background
2.2High-power sites
2.3Melbourne licence area repeater sites
3Implementation/sequencing considerations
3.1TLAP timing windows
3.2Constraints on the restacking of sites
Appendix A1—Planning principles
Appendix A2—Proposed channel plan
Appendix A3—Maps
Appendix A4—Service-by-service constraint list
acma | 1Executive summary
This engineering report accompanies, and is intended to read with, documentation related to the draft Television Licence Area Plan (TLAP) for the Melbourne TV1 Licence Area. It provides background explanations for the proposed channel block identifications and channel allotments for broadcast sites and other relevant types of sites such as retransmission sites within the Melbourne TV1 Licence Area.
The proposed channel allotments are discussed in detail in section 2 of the report, and are summarised in the table following this executive summary.The proposed block identifications and channel allotments follow the restack planning principles unless specifically noted.
Section 3 of the report discusses implementation sequencing constraints that may need to be captured as events or circumstances in the draft TLAP or as licence conditions.However, the determination of restack ‘timing windows’ is not covered in this report.It is considered separately in the discussion paper for metropolitan licence area draft TLAPs that is being released together with this engineering report.
Proposed channel allotments
The table below summarises the channel allotments proposed in this engineering report. These allotments will be included in the related draft TLAP instrument.
Sites shown in rows with grey shading have all retransmission services.These services are not expected to be included in the TLAP instrument.However, they have been taken into account in channel planning for the TLAP.
Channels that are allotted in the TLAP for currently operating services that will be restacked are identified by ( ).
General area served / Block / SBS / ABC / HSV / GTV / ATV / UAMelbourne[1] / A / (29) 7 / 12 / 6 / 8 / 11 / 10
Marysville / C / (57) 34 / (60) 35 / (63) 36 / (51) 37 / (54) 38 / 39
Warburton (VIC) / C / (57) 34 / (60) 35 / (63) 36 / (51) 37 / (54) 38 / 39
Healesville / C / 34 / 35 / 36 / 37 / 38 / 39
Monbulk / E / 50 / (52) 49 / 46 / 47 / (53) 48 / 51
Selby / C / (50) 34 / (47) 35 / (41) 36 / (44) 37 / (54) 38 / 39
Upwey / C / (50) 34 / (47) 35 / (41) 36 / (44) 37 / (54) 38 / 39
Ferntree Gully / D / (50) 40 / (47) 43 / 41 / 44 / (54) 45 / 42
South Yarra1 / D / (57) 40 / (60) 43 / (63) 41 / (51) 44 / (54) 45 / 42
Melbourne Inner Suburbs / D / (57) 40 / (60) 43 / (63) 41 / (51) 44 / (54) 45 / 42
Safety Beach / D / (57) 40 / (60) 43 / (63) 41 / (51) 44 / (54) 45 / 42
Rosebud / D / (57) 40 / (60) 43 / (63) 41 / (51) 44 / (54) 45 / 42
Ocean Grove / D / (57) 40 / (60) 43 / (63) 41 / (51) 44 / (54) 45 / 42
Geelong / E / (53) 50 / (64) 49 / (66) 46 / (67) 47 / (69) 48 / 51
Anglesea/Aireys Inlet / B / (39) 28 / (56) 29 / (42) 30 / 31 / 33 / 32
Wye River / C / 34 / 35 / (55) 36 / 37 / 38 / 39
acma | 1
1Introduction
1.1Scope
This report should be read in conjunction with the draft TLAP for Melbourne, the associated discussion/explanatory papers and the related planning documents. These contain the detailed transmitter specifications consistent with the parameters assumed in conducting predictions of signal levels as part of the planning process.
The legislative and regulatory background of the Melbourne TLAP is discussed in the metropolitan draftTLAP discussion paper.
The Melbourne TV1 licence area covers the greater metropolitan Melbourne area as well as Geelong.The main high-power transmission site in this area is Mt Dandenong.This report also includes Wye River, which although being located in the Regional Victoria licence area is expected to be fed with input signals from Mt Dandenong.
The digital switchover timetable has set the Melbourne TV1 licence area to switchover on 10 December 2013.Surrounding areas in the Regional Victoria TV1 licence area completed switchover on 5 May 2011.
This engineering report provides supporting engineering information to explain the choice of channels at sites to be included in the Melbourne TLAP.To provide a complete view of the constraints influencing channel block selection, the scope of this engineering report also includes sites used to provide retransmission services (both those operated by TX Australia, and those operated by councils or other community organisations).
The report also analyses the constraints affecting the sequencing of the move to final restack channels but the determination of the timing window within which the transition to final digital channels must occur, is coveredin the Discussion Paper for metropolitan licence area draft TLAPs.
1.2Channel planning principles
The planning principles that underpin the identification of blocks and allotment of channels have been the subject of extensive consultation/discussion at the Restack Planning Advisory Group (RPAG) and then a formal public consultation.Feedback on the proposed restack objectives was broadly positive and supportive of the proposed planning objectives.In its analyses that led to the decision to incorporate the Block planning approach in its planning principles, the ACMA undertook an extensive comparative analysis of two alternative planning approaches and eventually adopted the block approach over the alternative Minimum Moves approach.
The development of the overall restack channel plan has followed a top-down approach.That is to say, high-power sites and other sites serving large populations were considered first and the most suitable channel blocks for those key sites were identified.After that, more detailed region-by-region analyses were performed to identify channel blocks for the repeater sites in each region.
1.3Channel block identifications for the Melbourne licence area
The identified channel block for the high-power Melbourne services was fixed as BlockA by the ministerial direction to the ACMA.
Within the RPAG a collaborative process was undertaken to develop an indicative channel plan for ‘key sites’ around Australia.That process concluded that the block identifications for major surrounding regional transmitter sites around Melbourne should be: Bendigo (Block B), Latrobe Valley (Block B), Ballarat (Block C), and Goulburn Valley (Block C).Those block allocations strongly influence the block identifications of several of the repeater sites in the Melbourne licence area.Further details of the block identification and channel allotment for all sites in the Melbourne licence area are discussed in detail in section 2.
In addition, channel blocks for other lower-power sites in Regional Victoria have been identified in an earlier engineering report, which has been the subject of industry consultation, both through a formal public consultation and through informal consultation at RPAG Working Group meetings.During the process of developing channel plans for Regional Victorian sites, Melbourne licence area sites were considered and channel planning for these sites was undertaken so that the planning principles for both regional and metropolitan area sites were applied simultaneously).Notwithstanding, the engineering report for the Melbourne TV1 licence area was developed after the consultation of the Regional Victoria engineering report, and therefore in this report the blocks identified for Regional Victoria sites are presented as fixed.
Section 3 uses the proposed Block identifications, and knowledge of interference compatibility constraints to determine limitations or conditions that could apply to the sequence in which the restack is implemented.
Appendix A1 provides the ACMA’s planning principles.
Appendix A2 provides a channel chart that summarises the proposed channel allotments as well as current analog (where applicable) and digital channels at each site.
Appendix A3 provides colour-coded maps that illustrate the channel blocks identified for each transmitter site together with an indication of its expected coverage.
Appendix A4 provides a service-by-service listing of constraints on restacking each service.
1.4Consultation
The ACMA distributed a draft of this engineering report prior to the RPAG Working Group meeting on 30 May 2012 and discussed the channel planning proposals contained in the draft at that meeting.
1.5Terminology
Block identification and channel allotments
To align with terminology being adopted in TLAP instruments, this report uses the terms ‘identify’ or identification’ when referring to the proposed block of channels to be used to serve a particular area.The channels of the identified channel block are specified in TLAP.The term ‘allotment’ is used in the TLAP and in this engineering report in relation to which channel is to be used by which broadcaster.Some channels will remain unallotted in TLAP and may be available for future allotment to a new service or be made available for retransmission services operated by third parties.
Call sign for ABC services
The ABC has traditionally been given a unique call sign for services from main sites and off-air fed translators and a generic state-based call sign for the main metropolitan service and satellite fed services.For example, the ABC service at Melbourne has the call sign ABV.This convention has not been rigorously applied over the years and this can lead to confusion.For the purposes of consistency, in this engineering report and draft TLAP documents, the call sign ABC has been used for all ABC services.
1.6Transmitter specifications
Detailed transmitter specifications for each service at each site are included in separate planning data.The planning data will become a ‘living document’ that should quite closely reflect the actual operating conditions of all services within the planning area covered by the TLAP.It is intended that the planning data will be revised from time to time as better information, or changes to transmitter specifications, are advised to the ACMA.Generally those specifications follow existing DCP technical specifications (except for channel changes).Research background and methodology
2Block identification and channel allotment proposals
2.1Background
This section of the engineering report explainshow the proposed channel blocks were identified for each area and describes the proposed channel allotments within each identified block.In addition to the normal consideration of avoiding or minimising predicted interference between services, channel allotments have been made in accordance with the ACMA’s planning principles unless specifically noted in the discussion in this section.The planning principles are reproduced in Appendix A1.
Selection of channel blocks and channel allotments has been done in accordance with planning principles 4 and 5 in all cases.In the selection of channel blocks the ACMA has been guided by the need to avoid interference between services and by Planning Principle 7.Discussion on the rationale for particular block selections is included on a site-by-site basis in sections 2.2 and 2.3.Similarly the channel allotments within each identified block generally follow Planning Principle 6, but individual issues are discussed in sections 2.2 and 2.3.
In addition to the site-by-site discussion in this section, the channel allocation proposals have also been summarised in a consolidated channel chart (that also shows current analog and digital channels) in Appendix A2.
2.2High-powersites
2.2.1Melbourne(MtDandenong)Block A
Melbourne (Mt Dandenong) is the main high-power transmission site serving the Melbourne Switchover Area.At Mt Dandenong three transmission sites may transmit digital services; however, those sites are considered to be effectively co-sited for the purpose of this report.
The identified channel block for the high-power metropolitan services in Melbourne is Block A.Proposed channel allotments for Melbourne follow Planning Principle 6 and are shown in Table 2.1.
The Melbourne MGV32 community service may be licensed to operate until 31December 2013.Arrangements beyond that date are subject to future government decisions
2.3Melbourne licence area repeater sites
Table 2.1 shows the proposed block identifications and channel allotments for repeater sites in the Melbourne switchover region.In addition the Wye River retransmission site has been included in this analysis as, even though it is located in the Regional Victoria TV1 licence area, it is expected that it will be off-air fed with Melbourne TV1 licence area services.
Block identifications have been made for sites listed in Table 2.1.If channels for additional sites are required in future, they should fit within the framework provided in Table 2.1.
The ACMA is aware of potential proposals for additional council funded retransmission sites at Kalorama (South) and/or Kalorama North.However, those potential sites were not providing operating services at the time of the restack planning and were therefore considered to be outside the scope of the restack planning activity.As noted above, should finalised, funded proposals be submitted in future they could be considered provided they can be accommodated within the channel plan framework shown below.Pending detailed engineering analysis of actual proposals it appears that Blocks B or E may be potentially available.
Table 2.1Proposed channel allotments for the Melbourne region2.3.1Overview discussion
Due to the interactions between Melbourne area repeaters it is not possible to identify independent channel blocks for all repeater sites.Therefore some use of Single Frequency Networks (SFNs) is essential if all broadcast sites and proposed retransmission site conversions and gap fillers are to be accommodated.Wherever possible it is highly desirable to maintain existing SFN arrangements to avoid creating new potential interference situations.Therefore the starting point for Melbourne TV1 licence area channel planning studies was:
Safety Beach and Rosebud operating in a SFN;
Selby, Upwey and Ferntree Gully operating in a SFN;
Melbourne Inner Suburbs and South Yarra operating in a SFN.This is because of their geographic proximity, and to avoid inefficient spectrum use (which would likely prevent channel blocks being found for other sites in the Melbourne area).
However, as detailed planning progressed it was found necessary to break Ferntree Gully away from Selby and Upwey due to potential interference from Ballarat to Ferntree Gully.This is discussed in sections 2.3.5 and 2.3.6.
Because of their mutual interactions, and the large populations potentially covered by the Melbourne Inner Suburbs/South Yarra, Geelong and Safety Beach/Rosebud sites, Melbourne area channel planning was performed by first identifying the most suitable channel blocks for those sites.
2.3.2Melbourne Inner Suburbs and South YarraBlock D
The Melbourne Inner Suburbs services have been planned on the basis of protection of locations where the received field strength exceeds the ‘suburban’ level and where locations receive their best signals from the (proposed) Melbourne Inner Suburbs site.
South Yarra services have been planned on the basis of protection of locations where the received field strength exceeds the ‘suburban’ level.
Melbourne Inner Suburbs and South Yarra services (operating in SFN) need to avoid Bendigo and Latrobe Valley services on Block B and Ballarat services on Block C.Healesville and Selby/Upwey services and Mt Cowley IBL (near Lorne) also need to be avoided.Therefore it is proposed that the identified channel block for Melbourne Inner Suburbs and South Yarra should be Block D.
The channel allotment for Melbourne Inner Suburbs and South Yarra should follow that for Safety Beach and Rosebud, and are explained in section 2.3.4.
The MGV South Yarra service can be accommodated on the unallotted channel (channel 42) on an interim basis until 31 December 2013.
2.3.3GeelongBlock E
The Geelong services have been planned on the basis of protection of locations where the received field strength exceeds the ‘suburban’ level.
A medium-power Geelong service transmitting 4 kW ERP has been proposed to replace the existing, much lower-power, analog services.The proposed new service has been planned to provide suburban grade signal to known poor coverage areas of Drysdale/Clifton Springs and Barwon Heads/Ocean Grove.An incidental benefit of establishing the new services with significantly increased power is that they are predicted to provide a stronger and alternative source of signals to most of Geelong, Corio and Leopold than the signals currently provided by Mt Dandenong.
Geelong services need to avoid Latrobe Valley and Bendigo services on Block B, Ballarat, Lorne services on Block C and Melbourne Inner Suburbs/South Yarra services on Block D.Selby/Upwey, Safety Beach (national services), Ocean Grove and Wye River services also need to be avoided.Therefore it is proposed that Geelong should operate on Block E.
To optimise compatibility with surrounding Block E sites the polarisation of this service is proposed to be horizontal.This differs from the polarisation of the co-sited low-power Geelong (Newtown) analog retransmission service; however, given the high field strengths that the new Geelong service will provide within the coverage area of the Geelong (Newtown) analog service it is expected that in that area vertical antennas will provide adequate performance and should not require modification.
The proposed channel allotments for Geelong are HSV46, GTV47, ATV48, ABC49, SBS50 and UA51.This follows the channel allotment order requested by TX Australia (which will hold the licences of all these services).
2.3.4Safety Beach and RosebudBlock D
The Safety Beach services have been planned on the basis of protection of locations where the received field strength exceeds the ‘suburban’ level and where locations receive their best signals from the Safety Beach site.
The Rosebud services have been planned on the basis of protection of locations where the received field strength exceeds the ‘suburban’ level.
Safety Beach and Rosebud currently operate in a SFN, and this arrangement is proposed to continue.It should be noted that at Arthurs Seat (the Safety Beach transmitter site) commercial services are transmitted using a panel antenna pointing north-east (currently operating at 25 W maximum ERP), while national services are transmitted using a slot antenna pointing south-west (nominally 400 W maximum ERP).