SUMMARY OF COMMENTS DOCUMENT FOR THE

EUROPEAN ORGANISATION FOR THE SAFETY OF AIR NAVIGATION EUROCONTROL SUMMARY OF COMMENTS DOCUMENT FOR THE DRAFT REGULATORY APPROACH FOR Mode S Interrogator Code Allocation (MSI) Written Informal Consultation 26 October – 17 November 2006 18 December 2006 Edition 1.0 DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 DOCUMENT CONTROL DOCUMENT CHANGE RECORD The following table records the complete history of the successive editions of the present document. Edition Number 0.1 0.2 0.3 1.0 Pages Affected All All All All Edition Date 27-11-06 30-11-06 13-12-06 18-12-06 Creation Reason for Change Inclusions of remarks and corrections Update after 1st workshop Review Status: Released Edition No: 1.0 Date: 18 December 2006 Document No: SES/IOP/MSI/INFORMAL/SOC/1.0 Authors: Nicolas Eertmans Pierre Loubières Reviewed by: Jean-Luc Garnier Lilian White Approved by: Jean-Luc Garnier Approval Date: 14 December 2006 - ii - DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 TABLE OF CONTENTS DOCUMENT CONTROL ..................................................................................................... II TABLE OF CONTENTS ..................................................................................................... III 1. INTRODUCTION .......................................................................................................... 1 1.1 General .....................................................................................................................1 1.2 Scope of Consultation...............................................................................................1 1.3 Purpose and Structure of Document.........................................................................1 OUTCOME OF THE INFORMAL CONSULTATION ................................................... 2 2.1 General Response and Preferred Option .................................................................2 2.2 Consolidated Comments...........................................................................................4 2.2.1 Introduction ........................................................................................................ 4 2.2.2 Scope of the IR .................................................................................................. 4 2.2.3 Criteria for Code Allocation................................................................................ 5 2.2.4 Specific Cluster Prescriptions ............................................................................ 5 2.2.5 Conflict Reporting and Monitoring ..................................................................... 6 2.2.6 Contingency Requirements, Fallback Mode & SLO .......................................... 6 2.2.7 Detailed procedures........................................................................................... 7 2.2.8 SI Codes and II/SI Mode.................................................................................... 7 2.2.9 EMS Coverage Map Compliance ...................................................................... 7 2.2.10 Impact Assessment ........................................................................................... 7 2. ANNEX ................................................................................................................................ 8 ANNEX A .........................................................................................................................8 - iii - DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 1. 1.1 INTRODUCTION General The draft Regulatory Approach for the Mode S Interrogator Code Allocation implementing rule was circulated for written consultation from 26 October to 17 November 2006. The informal consultation was achieved through the focal points nominated by stakeholders. 1.2 Scope of Consultation As required by the European Commission’s mandate, the consultation aimed at collecting views and opinions of the stakeholders on the draft Regulatory Approach. The Regulatory Approach document outlines the headlines of the regulatory provisions, identifies and analyses the subjects to be covered by the draft implementing rule in order to ensure the desired interoperability. It also proposes several options that might be followed for the development of the draft implementing rule. The stakeholders were requested to indicate their preferred option, among three options proposed in the document, and/or to provide any other proposal or comments on the content of the draft Regulatory Approach. 1.3 Purpose and Structure of Document The purpose of this document is to provide a consolidation of the main comments, relevant to the draft Regulatory Approach in general and to the proposed options in particular, received as part of the written informal consultation activity. The responses section (Section 2) of the document is structured as follows: • General Response – providing a general analysis of the comments received and the results concerning the Preferred Option to be followed for the development of the draft implementing rule. Consolidated Comments – summarising the comments made on the draft Regulatory Approach in general and providing proposed responses. • -1- DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 2. 2.1 OUTCOME OF THE INFORMAL CONSULTATION General Response and Preferred Option The consultation provided comments from 15 Stakeholders and showed a significant support (66%) for the Preferred Option of the Regulatory Approach (RA), namely the Minimum Prescriptions Package, augmented by the support to SI codes as one of the proposed Specific System Prescription Options. The following table illustrates the distribution of the comments: Informal Consultation on the Draft Regulatory Approach for Mode S Interrogator Code Allocation Comments received by Stakeholders Authority (Civil & Military) Service Providers (ANSPs) Airspace Users Airport Operator Industry Other Total Received Comments by Category Percentage (%) Prefer Agree with Propose Detailed the another Procedure Preferred alternative Prescriptions Option 5,0% 0,0% 5,0% 15,0% 2,5% 5,0% 0,0% 0,0% 0,0% 0,0% 0,0% 0,0% 0,0% 0,0% 0,0% 5,0% 0,0% 0,0% 25,0% 66,7% 2,5% 6,7% 10,0% 26,7% None of the above responses 0,0% 0,0% 0,0% 0,0% 0,0% 0,0% 0,0% 0,0% Total by Stakeholder 10,0% 22,5% 0,0% 0,0% 0,0% 5,0% 37,5% 100% % 26,7% 60,0% 0,0% 0,0% 0,0% 13,3% 100% However, one stakeholder proposed to add to the Preferred Option, the full set of Detailed Procedure Prescriptions (also proposed in the RA) whilst 2 Authorities and 2 Stakeholders proposed different alternatives. Those alternatives were based mainly on additional systems and/or procedures prescriptions in addition to the Preferred Option -2- DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 The distribution of the comments received from the different Stakeholders is shown in the chart below. Informal Consultation on the draft Regulatory Approach for Mode S Interrogator Code Allocation Comments received by Stakeholders Service Providers (ANSPs) 60% Authority (Civil & Military) 27% Airspace Users 0% Other 13% Airport Operator 0% Industry 0% Concerning the categories of comments the distribution of the preferences was as follows: Informal Consultation on the Draft Regulatory Approach for Mode S Interrogator Code Allocation Comments by Category Agree with the Preferred Option 66% Prefer Detailed Procedure Prescriptions 7% Propose another alternativ 27% None of the above responses 0% -3- DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 2.2 Consolidated Comments 2.2.1 Introduction This section reflects the main comments arising from the consultation, including the proposed response to the comments. Other comments, including those of an editorial nature and those correcting minor spelling or grammatical errors, have not been included for the sake of brevity. However, all comments submitted are included in the table in Annex A. 2.2.2 Scope of the IR A need was expressed for further discussion on whether or not the IR would apply to systems using II=15 and/or II=0 and to what extent (including or not requirements such as SI code capability for radars using these codes, IC Reporting and Monitoring). However, the intention to have special (while possibly limited) prescriptions for the use of II=0, in relation to its stipulation by ICAO Annex 10, was nevertheless seen as a clear requirement. Proposed response: It is intended to define, in the IR, those radars for which a coordinated code allocation is not practical (typically, mobile radars). The IR will indicate that the mode of operation on II=0, as stipulated in ICAO Annex 10, is foreseen for such radars. No coordination is required at the European level for radars operating on that mode. It is intended to acknowledge the fact that II = 15 has been exclusively allocated to NATO for an undetermined period. The possibility to review this allocation should be maintained, should an alternative become more effective. Given the above, mobile radars operating on II = 0 could be exempted from all systems prescriptions (SI code…) conflict reporting and monitoring. Following the Essential Requirement on Civil-Military Co-ordination, contained in Annex II to the Interoperability Regulation 1 , requirements regarding military airborne and ground equipment can be addressed to Member States of the European Union as long as these are within the scope of the Interoperability Regulation. The MSI IR can thus include requirements applicable to military radars. However it will not be possible to address some of the issues in the rule, notably taking into account the fact that military operations and training are excluded from the Single European Sky. EUROCONTROL would endeavour to discuss, in particular with NATO, practical issues related to operational usage of mobile radars, so as to prevent any harmful consequence on Mode S stations used for ATM. The special arrangements for the allocation of codes (currently II code 14) to Test, Research & Development (TRD) systems would not be detailed in the IR. TRD operators are required to follow the regular code allocation process. This is currently defined in the EATM Process document and could eventually be detailed in a CS. Systems operating on II code 14 or 15 would not benefit from a blanket exemption from the general IC prescriptions, although some special considerations and transition periods could be developed for specific systems (in particular AEW aircraft). Indeed, it is desirable that all systems relying on All Call or capable of performing Mode S lockout are part of the conflict monitoring and reporting scheme. 1 A copy of the Interoperability Regulation can be downloaded from: http://www.eurocontrol.int/ses/public/standard_page/sk_mandates.html -4- DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 2.2.3 Criteria for Code Allocation A number of comments related to the introduction of levels of priority to the radars requiring code allocation. A service provider and an authority proposed that, in a given controlled airspace, priority should be given to radars associated with the operator controlling that airspace when optimising radar coverage. Another proposal, common to two service providers and an authority, was to give priority, when allocating codes, to radars operating in a cluster. Proposed response: The IC Allocation Process takes operational coverage requirements into account when optimising coverage maps. This needs to be acknowledged in the IR. The IR could state that a number of mitigation options (without providing an exhaustive list) will be considered by the central coordination function when meeting a code shortage. Clustering (based on a voluntary decision by the radar operator) is judged to be the most efficient option. Alternatively, the central coordination function may have to propose more constraining measures (coverage reductions, and in exceptional cases: SLO…). This would indirectly favour operators choosing the clustering approach. 2.2.4 Specific Cluster Prescriptions Whilst clusters were generally recognised as the best way to efficiently reduce the volume of the interrogator codes needed, there was no support for an unconditional prescription, by the allocation process, of specific clusters. A service provider suggested that the central IC allocation function could propose cluster prescriptions only as an alternative and beside less demanding (but possibly more penalising) alternative(s), including for instance significant reductions of coverage. Proposed response: It is planned to take into account these remarks for the IR (See above 2.2.3), as the proposal of alternatives would be a practical way to give priority to those radar operators implementing clusters, without prescription. Consequently, in order to give priority to radars participating in a cluster while avoiding unconditional cluster prescription, alternative proposals would have to be designed, in ca se of code shortage, for radar operators when they choose not to operate in a proposed cluster. These alternative proposals would likely be more constraining in terms of coverage or RF impact. -5- DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 2.2.5 Conflict Reporting and Monitoring Conflict reporting was generally well accepted by the contributors, some suggesting the need to impose a requirement for timely reporting. However there was a clear requirement from NATO to exempt ship-borne and airborne interrogators using II=15 or II=0 from conflict monitoring and reporting. Proposed response: The intention is confirmed to address conflict reporting and monitoring in the IR with minimum requirements so as to guarantee interoperability. The IR will thus include prescriptions ensuring timely IC conflict reporting. Some higher level, general provisions for IC conflict monitoring are required to ensure proper detection of these conflicts, but it is also acknowledged that there is no support requested from stakeholders to prescribe specific or detailed monitoring requirements. Conflict monitoring is not applicable to II = 0, since radars operating on that code are working on a non interference basis. Hence mobile radar operators could be exempted from such prescriptions. Still, it is important that procedures are in place to prevent such radars operating inadvertently on a wrong code, and contact points should be available to report/investigate possible conflicts impacting other, fixed radars. 2.2.6 Contingency Requirements, Fallback Mode & SLO There were different views about the promulgation of contingency requirements: some supported it while others considered that it must remain the responsibility of the States and that the diversity of the complementary surveillance equipments did not favour a general rule in this matter. There was a general agreement with the proposal to avoid prescribing SLO as the only possible fallback mode. However, one radar operator and one authority considered that SLO, even if it was not mandated as a fallback mode, could also be used as part of the normal allocation process, to complement coverage reduction. Proposed response: We would propose to maintain the need for a contingency plan, without prescribing which approach to take. Doing nothing could be acceptable if it was demonstrated that there was sufficient redundancy in the system. But this should be supported by a safety analysis and endorsed by States. Even if an operator had no contingency measures in place, he would have to respect a minimum set of monitoring requirements as possible conflicts might not only affect him but could also affect other operators. It should be noted that an ad-hoc working group has recently been set-up to address the technical aspects of conflict monitoring and fallback modes. The group could come up with a global solution but it is unlikely to happen before the end of 2007. Using SLO in the normal allocation process, could be done exceptionally, with due justifications and with explicit consent from the NSA concerned (see above 2.2.3). Regarding the RF environment, it is not within the scope of the mandate to determine which options would be more or less detrimental to it. -6- DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 2.2.7 Detailed procedures There was only one radar operator that defended the totality of the Detailed Procedures Prescriptions. Another radar operator supported detailed Application procedures and IC allocation Promulgation and Review. But in general the detailed procedures were perceived as too constraining and seen as falling within the remit of the States, with possible support of means of compliance. Proposed response: Adoption of the Preferred Option, but the level of detail of the IR may be adapted for specific issues. 2.2.8 SI Codes and II/SI Mode There seemed to be a general support for SI Codes, but many contributors indicated that such a requirement could not be efficiently separated from a requirement to support II/SI Mode of operation. NATO indicated that they wished AEW systems operating on II=15 to be exempted from the SI codes prescription. Proposed response: We could include the II/SI Mode in the scope of the IR drafting (with a transition period). When we have more results from the various SI modes (II/SI mode, mixed modes MIP…) testing (end of Q1 2007), we will be able to make a more informed decision, which could result in dropping the system requirement for II/SI mode. 2.2.9 EMS Coverage Map Compliance Most of the contributors agreed in recommending radar compliance with the EMS Coverage Map Interface Control Document, but there was no consensus to make it a mandatory prescription within the IR. Proposed response: We propose not to include a system requirement for maps, but also to indicate that lack of that technical capability may lead to further reduced sectored coverages. 2.2.10 Impact Assessment Special circumstances applicable to military ship-borne and airborne interrogators and past experience led NATO to express reservations on possible increase of the cost impact of this IR requiring system upgrades: in circumstances where competition was not practical, the amount charged for upgrades reflected the quasi-monopoly position of the supplier and bore little or no relation to the actual software development costs. Proposed response: This reservation could have more or less consequences depending upon the number of the radars needing upgrades. If this need is limited to the 5 most ancient ones, the impact would be limited. -7- DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 ANNEX A ANNEX ANNEX A Annex A provides a table containing all the comments provided by Stakeholders. -8- DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 ANNEX A INFORMAL CONSULTATION ON THE DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION Reason(s) for Comment Title wrong § No 2.2 2.2.7.2 Comment ‘Mode’ Missing from title of section. Proposed Change/Text Should read ‘2.2 SSR Mode S and Interrogator Code…’ It is proposed to remove § 2.2.7.2 from the section “Technical options to avoid using a co-ordinated IC” and to insert a new section, immediately after § 2.2.7, which would read as follows: 2.2.7.4 Conclusion on technical alternatives to coordinated IC allocation. Considering their impact on the RF environment, the three two aforementioned options cannot be considered as long term alternatives to coordinated IC allocation. The stochastic lockout override technique, described in the next section, may also have some impact on the RF environment but not at the extent of those two options. 2.2.8 Stochastic Llockout override Alternatively, SSR Mode S interrogators can override the lockout status of Mode S transponders. This forces transponders to reply and allows target acquisition, irrespective of their lockout status. However, this has the same detrimental effect on the RF environment as not locking out targets. Lockout override can be combined with stochastic acquisition, resulting in the mode of acquisition known as stochastic lockout override (SLO) acquisition. Such a mode of operation is recommended as a fallback mode in case of an IC conflict, to maintain target acquisition. Nevertheless, as a low probability of lockout override is required to limit the RF interference to sustainable levels, the acquisition performances may be degraded. 2.2.7.2 Lockout Override: this technique deserves more Various RF studies have been conducted and their credit as long as it has not be proven that it affects the RF results are sometimes contradictory. For DSNA, it is not environment. proven that lockout override deteriorates drastically the RF environment. The latest RF study conducted on the 1090 MHz link, with updated scenarios, indeed concluded that the situation was much better than expected and that ADS-B applications could be performed on that link up to 2015-2020 without any congestion on that link. For that reason, DSNA would like that the Lockout Override technique be considered as a solution to mitigate the IC code shortage issue. -9- DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 ANNEX A INFORMAL CONSULTATION ON THE DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION Reason(s) for Comment § No Comment Proposed Change/Text However, the evaluations performed on the use of that technique are encouraging. Consequently, while tThe use of SLO is therefore considered suitable for the fallback mode of SSR Mode S interrogators, it is not recommended for normal operationsand could also be used as the normal mode of operation if no other solution is foreseeable in the considered timeframe. 22.7.2 2.2.7.2 Lockout Override: this technique deserves more Various RF studies have been conducted and their credit as long as it has not be proven that it affects the RF results are sometimes contradictory. It is not proven that environment. lockout override deteriorates drastically the RF environment. The latest RF study conducted on the 1090 MHz link, with updated scenarios, indeed concluded that the situation was much better than expected and that ADS-B applications could be performed on that link up to 2015-2020 without any congestion on that link. For that reason, we would like that the Lockout Override technique be considered as a solution to mitigate the IC code shortage issue. It is proposed to remove § 2.2.7.2 from the section “Technical options to avoid using a co-ordinated IC”, to renumber §§ 2.2.7.3 and 2.2.7.4 as, resp., 2.2.7.2 and 2.2.7.3, and to insert a new section, immediately after § 2.2.7, which would read as follows: “2.2.7.3 Conclusion on technical alternatives to coordinated IC allocation. Considering their impact on the RF environment, the three two aforementioned options cannot be considered as long term alternatives to coordinated IC allocation. The stochastic lockout override technique, described in the next section, may also have some impact on the RF environment but not at the extent of those two options. - 10 - DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 ANNEX A INFORMAL CONSULTATION ON THE DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION Reason(s) for Comment § No Comment Proposed Change/Text 2.2.8 Stochastic lockout override. Alternatively, SSR Mode S interrogators can override the lockout status of Mode S transponders. This forces transponders to reply and allows target acquisition, irrespective of their lockout status. However, this has the same detrimental effect on the RF environment as not locking out targets. Lockout override can be combined with stochastic acquisition, resulting in the mode of acquisition known as stochastic lockout override (SLO) acquisition. Such a mode of operation is recommended as a fallback mode in case of an IC conflict, to maintain target acquisition. Nevertheless, as a low probability of lockout override is required to limit the RF interference to sustainable levels, the acquisition performances may be degraded. However, the evaluations performed on the use of that technique are encouraging. The use of SLO is therefore considered suitable for the fallback mode of SSR Mode S interrogators, and could also be used as the normal mode of operation if no other solution is foreseeable in the considered timeframe.” The use of SLO is therefore considered suitable for the fallback mode of SSR Mode S interrogators, and could also be used as the normal mode of operation if no other solution is foreseeable in the considered timeframe.” 2.3.2 Capitalization of Standards and Recommendations Title wrong Should read ‘2.3.2 ICAO Standards and Recommended Practices’ - 11 - DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 ANNEX A INFORMAL CONSULTATION ON THE DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION Reason(s) for Comment Even though II code 0’s use is stipulated within ICAO Annex 10, inclusion in the rule would reinforce its correct application. II codes 14 & 15 are currently allocated to TRD & NATO, although it is not foreseen that these allocations should be withdrawn, it may be deemed necessary to change the specific allocation for these purposes, for example to SI codes. Therefore they should be included in the IR, with the supporting specifications or other appropriate documents specifying that they are currently allocated to TRD & NATO. DSNA is in favour of prescribing the management of coverage maps using cells. This will allow (compare to maps based on sectors) a better optimisation and a larger radar coverage (a better operational service is then provided) whilst mitigating the IC code shortage issue. The standard developed by Eurocontrol for the coverage maps of Mode S radar (well described in § 2.2.5) should therefore be prescribed as part of the preferred option. This will also mitigate risk 8 of §2.5.1. § No 3.3.1 c) Comment Proposed Change/Text UK supports inclusion of II codes 0, 14 & 15 within the IR 3.3.3.1; According to DSNA, there is some of inconsistencies 3.3.3.2 & between those paragraphs: options §4 · Paragraph 3.3.3.1 states the current requirements for Mode S radars and that “it is a requirement of the SES mandate that the draft IR takes into account existing requirements for Mode S radars”. It further continues stating that “prescriptions in the rule concerning SSR Mode S interrogator capabilities will need to support and enhance the existing requirements for Mode S radars”. These requirements actually include that the coverage maps be based on cells (approximately 5x5 NM cells). DSNA agrees with the above mentioned statements. · Paragraph 3.3.3.2 states that “the nature of the prescriptions could vary” and it includes its bullet d on “Mode S Responsibility or Coverage Maps”. It is therefore not really required any more… - 12 - DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 ANNEX A INFORMAL CONSULTATION ON THE DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION Reason(s) for Comment § No Comment Proposed Change/Text · Paragraph 4 does not include in the minimum prescriptions package the management of these coverage maps. It is only mentioned in § 4.4 when focusing on the specific system prescriptions option. 3.3.3.2 d) Unclear what definition of coverage map is? In current MICA Process, allocation includes an IC, Surveillance Coverage Map and Lockout Coverage Map. Definition of ‘Coverage Map’ should be included to indicate that it is the Surveillance and Lockout Map, or should be broken-out explicitly. 3.3.3.2. e) 4.2 b) Do not understand relationship between Sectored Lockout Do not understand relationship between Sectored Range reduction and fallback mode. Lockout Range reduction and fallback mode. Needs clarification or deletion. The following comment has been received from the UK MOD regarding the use of II Codes 15 and 0 and further development of Community Specifications as MoC: The EUROCONTROL EATM IC Allocation Process Document states II=15 is currently reserved for NATO use. Suggest rewording last section to “…this would include all II codes (apart from II=15 which is currently reserved for NATO use) and all SI codes, with special prescriptions for the use of II=0.” - 13 - DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 ANNEX A INFORMAL CONSULTATION ON THE DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION Reason(s) for Comment § No 4.2 e) Comment Proposed Change/Text Add the following sentence to bullet e of 4.2: e) Scope of the output from the centrally coordinated European IC allocation process. The output of the central allocation process could be either an II or an SI code, possibly associated with coverage restrictions. With appropriate justification, the process could also result in proposals for specific clusters. This would rely on pre-existing technical capabilities of the radars involved, to support clustering. This assumes a full knowledge, at central co-ordination function level, of the technical capabilities of Mode S stations with regard to clustering, that will have to be declared by the radars operators. In addition, in case of conflict in a particular controlled airspace, priority (with respect to the coverage of that airspace) will be given to radars of the operator in charge of that airspace. In the current IC allocation process, coverage maps are To ensure that in a given controlled airspace, radars sometimes provided to an operator with a range which from the operator providing services for that airspace goes far beyond its controlled airspace. This is done are given priority to cover that airspace. systematically when there is no IC code allocation issue. The problem is that at the next cycle, a second operator (providing services in that extended coverage) ask a code for its own radar and can experience problems to get the appropriate coverage to satisfy its operational needs because of the coverage allocated to that first radar of the other operator. A solution is usually found but it would therefore be better to have stated in the IR that in a given controlled airspace priority will be given (for the coverage of that airspace) to radars from the operator controlling that airspace. - 14 - DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 ANNEX A INFORMAL CONSULTATION ON THE DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION Reason(s) for Comment Whenever the clustering function will be fully validated and a cluster controller available on the market (in case the central mode is the one to be used from a safety point of view), the use of the cluster techniques to mitigate the IC code shortage issue will be foreseeable (if the State is willing to do so) in case other implemented solutions are not fully satisfying so far. § No 4.2 e) & 4.4 Comment Proposed Change/Text It is proposed to amend 4.4 as follows: Clustering capability requirements, for all or part of the SSR Mode S interrogators was initially considered as a potential option, but the elements available (in particular those stated within the Impact Assessment Section) led to the conclusion that there is for the moment no strong evidence to impose the technical clustering capability neither in terms of time horizon nor in terms of geographical area. The consequence was to withdraw the option proposal, by considering that any potential cluster proposal as considered within the minimum prescription package would be based on cluster-capable Mode S interrogators. Operators are nevertheless encouraged to acquire radars with clustering capabilities. It is proposed to amend 4.2 bullet e as follows: The output of the central allocation process could be either an II or an SI code, possibly associated with coverage restrictions. With appropriate justification, the process could also result in proposals for specific clusters. On a voluntary basis a State may also propose to use specific cluster in order to alleviate the IC code issue in some geographical area. [The proposal will nevertheless need to be approved by the concerned States.] This would also rely on pre-existing technical capabilities of the radars involved, to support clustering. If accepted, the same amendment is needed in 4.5. About § 4.4: It is recognised that it is difficult at that stage to impose in an IR the clustering capability requirements. There is a lack of evidence that all safety cases have been covered in the evaluation exercises conducted so far. In addition, if it is proved that the central mode of the cluster operation is the safest one, it would require a new ATC component, a central controller, which is not yet available in all countries. A prototype has been developed by Eurocontrol but the industrialisation of this prototype still needs to be performed. Nevertheless, the clustering solution, when validated, is certainly the best one on a technical point of view. For this reason, the IR should at least encourage States to acquire Mode S stations with that capability without prescribing it at this stage. About 4.2 bullet e: it is stated that “The output of the central allocation process could be either an II or an SI code, possibly associated with coverage restrictions. With appropriate justification, the process could also result in proposals for specific clusters. This would rely on preexisting technical capabilities of the radars involved, to support clustering.” An inconsistency may be pointed out with 4.4. Even if “pre-existing technical capabilities” are mentioned, this could lead for an operator having such radars to be forced to cluster its radars and support the associated costs (communication links, the acquisition of cluster controllers and its inclusion in the ATC system) for the benefit of other operators which have not made the effort to acquire such radars. - 15 - DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 ANNEX A INFORMAL CONSULTATION ON THE DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION Reason(s) for Comment It would be of very little use for a conflict to be reported days/weeks after the event. Immediacy is key. § No 4.2 i) Comment Proposed Change/Text The rule would require the Mode S operators to report conflicts to Member States and to the central function coordinating the European IC allocation process in a timely manner. Need to add text to ensure conflicts are reported in a timely manner. 4.3 UK believes these Detailed prescriptions should be contained within supporting specifications and not within the IR. Additionally, it is considered that no specific method for fallback mode should be mandated. This would be inherent in the IR under the minimum prescriptions package. States should be required to endorse and promulgate IC contingency measures The UK would support the inclusion of the following Specific System prescriptions in the IR: a) Support of SI codes b) Support of II/SI special mode of operation c) Compliance with EMS Coverage Map ICD The UK would not support the inclusion of the following Specific System prescription in the IR: d) Support of SLO or any other effective fallback mode. The UK agrees with the statement regarding Clustering. The UK agrees with and supports the Preferred Option. Paragraph 4.5: “a proposal of cluster when the technical capabilities of the radars already exists” => please note, as commented above, that implementation of a cluster implies much more than only the technical capabilities of a radar!!! The UK supports systems measures a-c, as they would assist in the efficient allocation of all ICs. Notwithstanding, there appears to be some overlap with the Surveillance Performance IR, and the relationship between the two must be managed carefully. The UK does not support systems measure d, as it believes this should be included in a supporting specification and that it may not be necessary to mandate a single form of fallback mode. States would be required to endorse and promulgate these contingency measures. 4.3 d) 4.4 4.5 4.5 - 16 - DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 ANNEX A INFORMAL CONSULTATION ON THE DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION Reason(s) for Comment The reason why this mode of operation is required is that there will always be a small percentage of transponders which will not be retrofitted to manage SI codes. This option enables to detect those transponders. It can therefore not be proposed to support the SI codes without this mode of operation being available in radars. § No 4.5 Comment Proposed Change/Text It is proposed to amend 4.5 to read: The recommended option is therefore to retain the “minimum package”, however complemented by the support of the SI codes and the implementation in radars of the II/SI mode of operation to allow the detection of non-retrofitted transponders. Paragraph 7.2.1: The references to the several items of paragraph 4.2 do not match. For instance civil military coordination is referenced to 4.2 (h), which is not correct. DSNA / DGAC/DAST agrees with the support to SI codes. It would indeed be awkward not to support those given the fact that their support is required in the mandatory carriage for Mode S transponders. But the usage of SI code is not foreseeable without the specific II/SI mode of operation described in 4.4 b. 7.2.1 7.2.3.1 Would this include remote or automatic switch to fallback mode in the event of a conflict? Will this require changes to the EMS functional specification? What about independent/airfield SSRs? This cannot be monitored centrally, nor would they necessarily be able to afford to implement and maintain expensive monitoring systems. Although the 400-600KEuro software development cost in Special circumstances applicable to military shipborne Table 1 “IC Conflict Monitoring and Reporting Costs” is and airborne interrogators and past experience of cost not disputed, it is considered highly unlikely that a impact of new legislation requiring system upgrades. manufacturer would make the software available to military users at a price of 560-840KEuro, representing a mark-up of only 40%. For most military applications the military user does not own the IPR for the software in the Mode S interrogator, which prevents competition for upgrades. Also the Mode S interrogator is usually integrated with other sensors that are much more expensive than the Mode S interrogator itself. The “lowest cost compliant bid” procurement approach that is normally used for military sensors tends to force down the initial acquisition costs but tends to force up the costs of any later upgrades – especially for upgrades which are required by new legislation and where the supplier knows that the end user has no option but to go ahead with the upgrade or replace the integrated suite of sensors. Insert in para. 7.2.3.1. “IC conflict monitoring and reporting to a central monitoring system is not envisaged for military shipborne and airborne interrogators using II=15 or II=0.” after the end of the existing sentence beginning “Such a system would be typically installed at a technical maintenance site … “ 7.2.3.1 and 4.2 item i - 17 - DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION SUMMARY OF COMMENTS DOCUMENT / Edition 1.0 ANNEX A INFORMAL CONSULTATION ON THE DRAFT REGULATORY APPROACH FOR MODE S INTERROGATOR CODE ALLOCATION Reason(s) for Comment § No Comment Proposed Change/Text In these circumstances where competition is not practical, the amount charged for upgrades reflects the quasi-monopoly position of the supplier and bears little or no relation to the actual software development costs. For ground based Mode S interrogators a stand-alone system for “IC Conflict Monitoring and Reporting” can be envisaged, which could be subject to competition to ensure acceptable value for money. However a standalone system is not considered practical for shipborne or airborne interrogators. Moreover the existing military data links to shipborne and airborne platforms do not make provision for “IC Conflict Monitoring and Reporting” messages and would themselves require expensive upgrades. For the above reasons it is requested that military shipborne and airborne interrogators using II=15 or II=0 should be exempted from the IC Conflict Monitoring and Reporting requirements in item i) of the Minimum Prescriptions package. Page 17, last paragraph:“the aggregation of airborne and ground-based constituents …” The NATO understanding is, the term Ground-based should be treated more globally, as Surface-based, i.e. to include ship-born Mode S sensors/interrogators. - 18 -