The Manager
National Infrastructure, Government and Space Section
Spectrum Infrastructure Branch
Australian Communications and Media Authority
PO Box 78
Belconnen ACT 2616
Comments on IFC27-2011 Earth Station Siting
Dear Sir/Madam,
I thank ACMA for the opportunity to provide constructive comment on its discussion paper concerning the siting of Earth Stations. As an ACMA accredited person, I recognize the challenges facing ACMA in development of spectrum policy for co-shared bands or where an adjacent band services may cause harmful interference from unwanted emissions from a transmitter or receiver susceptibility. I note that the paper particularly focuses on the C Band and issues surrounding s-E FSS compatibility with P-MP/FWA FS, an issue that created political concerns for Australia in the lead up to WRC-07.
While the CBand issue presents complex policy and political issues for ACMA, it is important that other Bands and Services that rely on Earth Stations for either receive or transmit (EESS,BSS, MSS, GPS, RAS etc) be considered to develop a consistent regulatory framework. It is also worth noting that the same coordination issues that affect Earth Stations, also effect terrestrial services and that such issues are usually dealt with in a RALI.
My comments were recorded during my review of IFC27, and accordingly I have included these not in any editorial manner, but rather as part of a holistic response. Should you have any queries on my submission, please contact me.
PMcGill
BE, MEng
ACMA Accredited Person
5 October 2011
Comments on IFC27-2011
Executive. Summary section
Para1 should also state that Satcom is also a high value use!
Para 2 noted
Para 3 earth stations, whereever located ,will compete with any adjacent or cochannel service, however they will not compete for spectrum with Fibre optic (FO) such as the NBN! NBN FO will cover all high density areas.
Para 4 All services have interference protection ratios, there is no service that will not suffer from itinerant mobile services. It seems that the satellite terminal is being blamed for the interference
Para 5 noted
Para 6 but should not the issue be focused on the interference rather than try to justify a particular proposed solution? I wonder if the IFC is addressing the right question?
Para6 noted
Intro duction
Para 1 also worth noting that domestic users have no choice but to install earth stations on their house. National building regulations permit installation of “ small” satellite earth stations in high density areas.
Para 2 Mobile services will always try for more spectrum ,rather than install smaller cells- this is simple economics. Spectrum demand may actually decrease when NBN rolls out in high density areas. It is against Government stated public t policy for P-MP/FWA to “cherry pick” the NBN broadband : as well as being potentially wasteful of spectrum. It appears more logical that the FWA terrestrial services would provide more benefit in rural low density areas,where the FO cannot be economically rolled out.
Para 3 noted that paper is for discussion only
Para 4 noted
Para 5 but domestic earth stations (dishes) are installed where people live!
Para 6 Public benefit is best served by maximizing use of NBNFO where it exists, this includes use of local femtocells etc.
Legislative Framework
Para 1 total welfare standard, principles spectrum management are noted. I am pleased these criteria are being used to address this issue but note that like all paradigms, they may need to be reviewed from time to time to ensure they reflect good policy.
1.1.1 noted I note that public services etc included elderly Australians of ethnic backgrounds who wish to receive overseas TV broadcasts by satellite just as they woulda short wave broadcast, in the past.
1.1.2 regretfully the principles do not allow for consideration of laws of physics that effectively limit moderate bandwidth overseas/ remote isolated area circuits to satellite links. Nor do they encourage use of alternative communications mechanism eg as an accredited person I usually set up for clients VPN over ADSL (NBN?) rather than use scarce FS/MS spectrum. Spectrum principles need to be integrated into a holistic systems wide approach to the ACMA regulatory paradigm.
1.1.3 decision framework is noted , however as above ,it is a closed system and does not consider any options outside of the box. It appears that the decision making paradigm is skewed towards a particular solution?
1.1.4 noted but the paper does not mention anywhere the needs of (generally) elderly citizens of ethnic background who wish to receive free to air TV broadcasts. In a similar way as they would, in the past, listen to short wave broadcasts from overseas , on their unlicensed radios, yet still were afforded “protection” from the local radio inspector..ACMA should consider the convergence in media content and recognize that media what was once predominately sound content has moved to AV multimedia.
1.2 Comment.
It seems that the estimated 10.000 domestic earth stations(ES)in each major Capital city will need to be included in the analysis.
The objectives should consider non spectrum solutions to the customers spectrum demands eg force FWA to use FO, provide free ethnic TV on other channels(siphon to other bands)/media (IPTV/ etc) : but then siphoning and rebroadcasting the same content on other frequencies covering the same area would also be wasteful of spectrum (note currently most Australian satellites do this multibroadcast of siphoned content!)
1.3 structure noted
1.4 submissions : thanks for the opportunity.
2. Pressures
2.1 growth
Actually satellites are a long term investment of more than 15 years, as the orbital slot/ assignment continues with replacement satellites.
Note trend towards higher bands now -even Ka, however cannot overcome basic physics of rain high attenuation in tropical areas at the higher bands. Also no comments aremade regarding mobile satcom. These MSS services are currently very expensive and more spectrum could force down prices . MSS is usually lower band (L,S or C) For emergency communications , MSS and C band VSAT are preferred.
2.2
2.2.1 the growth curves certainly look impressive, however are they sustainable? We can look back at previous forecasts for FS growth (eg the ACA Trends paper of a decade ago where, not only did it contain calculation errors, but it also did not predict the last dotcom bust). The graph does not indicate how much of this so called mobile traffic is actually mobile traffic and not just use of mobile service being used as a pseudo fixed service. The solution to this unsustainable growth is to move mobile onto fixed circuits, especially FO. Also, has there been any analysis of spectrum waste caused by completion ie how much MS spectrum is not used at any point of time (especially at night)? Other utility regulator s adopt demand side management schemas to dampen unsustainable demand.
1.2.2 wireless data I thought the paper was on satellites? ACMA should produce a similar forecast for satellite earth stations into the future. If every person in a town has access to a FO link then there is effectively unlimited “spectrum”.
Comment 4 but domestic earth stations would follow a demographic model/ analysis also, perhaps with reference to the ABS population data for citizens not born in Australia..
3. Tools also need to consider social/ marketing tools ie current domestic earth station users may be encouraged to give up their dish if the desired service was provided by other means .
3.1 economic tools
Para 1 Spectrum pricing does not guarantee efficient spectrum usage eg one competitor may have many customers accessing the spectrum in a given area, while another competitoroperator has spare underused capacity
Para 2 the increasing use of FO in high density areas means that wireless FWA is no longer justified on economic grounds. I understand that it is Government policy to prevent (FWA etc)from “cherry picking” NBN FO links and hence, it could be argued that FWA no longer has a role, where NBN FO services are provided. True mobile usage is a legitimate use of spectrum where there is no alternative. It is noted that widespread use of WLAN in many public spaces will reduce need for mobile spectrum,
Spectrum increases in value by monetary or intrinsic reasons. In a very remote area or on an island -not connected by undersea cable (possibly troppo-scatter/HAPS)-, the value of satellite spectrum may literally be a matter of life or death or of economic survival.
Fig 3.1 is very graphic and prima-facia, proves the claim of spectrum denial. However, as the picture is intended for comment by non technical/non Engineering types, it could lead them to form an incorrect opinion on spectrum coordination. Some specific comments on the picture may illustrate the dangers in this type of presentation: The picture shows a coordination trigger-area it does not mean that a competent accredited person could not coordinate a FS within the colored area ie by means of cross polar discrimination, directive antennas (a FS link not aiming at the Ref ES may not interfere) and other Engineering solutions. I would expect that ACMA would charge a apparatus license fee for any successfully coordinated FS link within the colored area? Or is this spectrum space free of charge at the discretion of the earth station license holder?
I observe that a P-MP FWA sited at Ultimo would produce a coordination area of a similar size: similarly denying rollout of ES.
The graph does not indicate any of the parameters concerning the particular reference license;( in fact the earth station license at Ultimo shows the Dish azimuth aiming south! -157degree S –some type of advanced “Molniya” orbit?. Also, the spectrum denied is obviously reflected in the license fee paid by the ES based on ACMA spectrum space apparatus fee schedules. It is worth noting that within the Fig 3.1 area of spectrum denial, that there could be as many as 10,000 domestic earth stations used by elderly, citizens of ethnic origin who also view signals from this and other satellites (and they are effectively protected from interference by courtesy of the existing earth station license holder). Even so, these domestic earth stations should be licensed: ACMA may wish to consider adding domestic C Band to the class license Schedule. The economic worth of this use of spectrum by all users must be considered.
Comment 6 What is current basis for satellite earth station fees? How can we put an opportunity cost on an elderly consumer who wishes to view satellite TV? Opportunity cost must consider all alternative means of media transport. Consideration should be given to payment for actual erlangs used; this would allow licensing for a single bouquet’s PID.
3.2 Planning and Tech tools
Para 1-4 noted, but note that sensible spectrum planning such as the allocation of FDD downlinks adjacent to FSS s-E rather than allowing say Radars or TDD links to operate in adjacent bands to s-E bands.
Para5 200m site management is fine on rural mountain tops , but is not practical in urban areas eg adjacent high-rise buildings, domestic earth stations and ubiquitous/anonymous FWA installations
Para 6 agree and also should include reciprocal mixing effects and blocking etc..
Para 7 spurious emission may come from the interfering Tx or occur in the Rx earth Station. It is thus for the regulator to balance the burden on both receiver and Tx , including mandating/enforcing equipment standards where appropriate.
I note that there is no mention of regulated codes ( eg ACMA/ACIF C564) or National standards (eg AS5070/3516) that pertain to the siting of radio facilities. These apply both to the earth station as well as any P-MP etc service.
3.2.1 geographic
This is clearly not a solution for domestic earth station s and VSATS (On one of my recent deployments, secure communications was provided by a DFAT C Band VSAT terminal, obviously for security reasons this had to be collocated with the crypto/modems etc). Domestic FTA TV receiving dishes are installed on a viewer’s house. Local Government planning usually allows for <2.5m mesh or < 1M solid antenna to be installed in residential areas-except for heritage listed properties.
The concept of satellite parks may be attractive to some satellite users (this is a good case for the Market to work out coordination/compensation etc), however it could also be argued that the fact that a broadband backhaul infrastructure is needed, that the use of the satellite link may be better served by use of broadband links end to end rather than space links where this is possible. This backhaul link also causes concern for network reliability (what back up/ redundant links are available) and infrastructure security sand resilience (climate change/CT attack etc). I can say that targeting (for kinetic shaping purposes ) usually places a high value on communication infrastructure nodes.
It is noted that the satellite parks are in rural areas, the very areas that NBN plans to use more economic FWA links rather than FO. Restricting ES to a few parks will have the effect of reducing growth in the satellite industry, especially impacting on innovative solutions or future NGSO DTH systems .
A policy of restricting earth stations to a few geographic sites will impact on the financial opportunity and restrict the business model of ACMA accredited persons: compensation may be warranted.
Any geographic siting of Earth Stations should be left up to market forces or Engineering Value analysis. I would welcome an opportunity to participate in any planning work for potential park sites.
3.2.2
Agree, wherever possible for any spectrum planning, including FS links, terrain shielding should be exploited.
3.2.3 Filters
Filters add extra cost to an earth station. Where both RX and TX use a common feed, TX reject (often with Rx BPF)is essential. Earth receive station, especially domestic earth stations, may have adjacent band FWA subscriber units virtually next door, or worse in an overlooking multistory building. While filters (such as the ACMA 15dB filtering requirement) will improve interference rejection, the effect can be similarly obtained by :
- Reducing the FWA subscriber TX levels by 15dB (and if needed by say adding 15dB gain to base station):
- Increasing the ES LNB Spurious Free Dynamic Range eg input intercept point (3IIP)by 5dB ( assuming spdr is intermodulation limited)
The filter approach and increased LNB performance places all burden on the incumbent satellite spectrum user. Even with these measures, intermodulation will at best be reduced,: high user loadon FWA networks will result in generation of vast quantities of spurious responses that ,in broadband design principles , are treated as increase in the systems noise floor. It must be noted that just by placing a filter in front of the LNB will not overcome poor systems design where high gain elsewhere in the Receiver system (say by use of too high a gain line amp) causes intermodulation. It is the total receive systems spurious free dynamic range that is important. ACMA has not mandated any Receive system performance regulations- apart from the filter requirement.
Effective Filtering should be mandatory in both base stations and Subscriber units of adjacent band FS systems as part of a license condition- in like manner to that applying for earth stations. The emission masks used in the ETSI FWA standards should not be accepted without detailed engineering analysis.
3.2.4 Guardband
The efficacy of a guard band is contingent on sound spectrum planning. It is obvious that making a radar allocation next to a Radio astronomy allocation will require a large guard band! ACMA must consider the guard band as part of the economic cost benefit analysis if they wish to allocate nomadic Tx stations, radars etc next to s-E allocations.
3.2.5 Antenna
Noted
3.2.6 Tx Power
This would require consideration by a WRC, perhaps ACMA could raise it as a possible agenda item for WRC-16? Many DTH satellite beams are already above 40dBW @CBand and above 50dBW EIRP @Ku. During coordination of these beams, Australia has never placed any limits on their use: apart from the need for licensing. I would expect that any satellite successfully coordinated with Australia would expect to be able to beam into ES located within the coordinated footprint.
3.3 Site protection
Para1 Not possible for domestic earth stations, VSAT terminals.
Para 2 noted
Para 3 License holders expect protection in accordance with their license conditions.
4. Analysis of pressures.
Para 1 noted
Para 2 the broadcast bands and fixed service bands also get /require significant levels of interference and spectrum denial buffer zones protection! Only a secondary service gets less protection.
Para 3,4 Agree, this is where license precedence dictates who is causing the spectrum denial, it is not always the FSS.
Para 5 TWS analysis must be cognizant of the Government Policy, NBN policies and the spectrum that is wasted when the traffic could go via Fibre optic. Also TWS needs to consider the needs of elderly Citizens who want to watch satellite TV