ICAO ACP Working Group C-7 meeting Montreal, 19-23 April 2004 REPORT Introduction: The seventh Meeting of the ACP-WG C was held from 19-23 April 2004 at ICAO HQ in Montreal, Canada. The meeting expressed its gratitude to the ICAO secretary for the preparations. The participants (see attachment A) in attendance introduced themselves and agreed on the Agenda (see attachment B). The list of working papers is contained in Attachment C. Agenda Item 1: Results from Toulouse meeting 1.1 Those action items from the Toulouse meeting were discussed which were not on the Agenda of the meeting with the following results; The secretary didn’t receive any comments on the new text for the AMS(R)S SARPs to be submitted to WG-C. No feedback has been received from WG-F on the proposed role of WG-C in the preparation for WRC 2007 by WG-F. Agenda Item 2: Update related ICAO, ITU and Industry Activities; 1.2 The panel received an update on the following activities: WG-F met recently in Nairobi and has developed a draft ICAO position for WRC 2007. Of particular interest to WG-C is the position on Agenda 1.6, which is discussed under Agenda Item 4. It is expected that WG-F will finalize the draft ICAO
Transcript
ICAO ACP Working Group C-7 meeting
Montreal, 19-23 April 2004
REPORT
Introduction: The seventh Meeting of the ACP-WG C was held from 19-23 April 2004 at ICAO HQ in Montreal, Canada. The meeting expressed its gratitude to the ICAO secretary for the preparations. The participants (see attachment A) in attendance introduced themselves and agreed on the Agenda (see attachment B). The list of working papers is contained in Attachment C.
Agenda Item 1: Results from Toulouse meeting
1.1 Those action items from the Toulouse meeting were discussed which were not on the Agenda of the meeting with the following results;
The secretary didn’t receive any comments on the new text for the AMS(R)S SARPs to be submitted to WG-C.
No feedback has been received from WG-F on the proposed role of WG-C in the preparation for WRC 2007 by WG-F.
Agenda Item 2: Update related ICAO, ITU and Industry Activities;
1.2 The panel received an update on the following activities: WG-F met recently in Nairobi and has developed a draft ICAO position
for WRC 2007. Of particular interest to WG-C is the position on Agenda 1.6, which is discussed under Agenda Item 4. It is expected that WG-F will finalize the draft ICAO position at its next meeting in August of this year.
WGC7/WP14 contained the memorandum sent by WG-N, initiating a survey on the use of TCP/IP internetworking for aeronautical communications.
The secretary of the OPLINK panel provided an update on the Panel’s work on RCP and ADS-B requirements. He explained that the RCP work is mainly directed to the aspect of aircraft separation and therefore there won’t be many if any detailed communications requirements resulting from this work. For WG-C to obtain more detailed communication system requirements he advised to consider the work of RTCA SC189 and EUROCAE WG53
WGC7/WP21 informed the meeting on a draft IATA position seeking exemption from the ICAO Annex 6 requirements for data link recording in relation to Link 2000+.
2.2 WGC7/WP 25 was presented by the Secretariat as a report of the 2nd meeting of ITU-R Task Group 1/8 (Geneva, 27 – 31 October 2003) dealing with Ultra Wide Band (UWB) issues. UWB technology could potentially integrate into very many applications and therefore in certain areas a high density of UWB devices may be expected in the future. UWB devices are intended to operate across numerous frequency bands and may affect existing and future aeronautical radio services. TG 1/8 is addressing, inter alia, compatibility issues between UWB devices and different radio services. The developments in that area need to be monitored since it may also affect future aeronautical communications systems.
2.3 WGC7/WP24 reviews the output of ITU-R Working Party 8B (WP8B) which was held in Geneva from 25 November to 2 December 2003. WP8B is responsible for radio determination, maritime and aeronautical radio services. The meeting was informed that no contributions were made to WP8B concerning WRC-07 Agenda Item 1.6 and hence no work was progressed in that area.
2.4 The meeting was also provided with a brief oral report on the output of the ITU-R Working Party 8D meeting held in Geneva from 25 November to 3 December 2003.
2.5 The meeting was informed of recent RTCA activities concerning ADS-B. RTCA Special Committee 186 (ADS-B) had met in Plenary session on April 8, 2004 and had approved a new revision of the UAT Minimum Operational Performance Standards (MOPS), to be designated, subsequent to approval of the document by the RTCA Program Management Committee, as RTCA DO-282A. RTCA DO-282A was reported to have been developed because of 1) feedback from the work of the ICAO UAT Subgroup; 2) feedback from manufacturers, particularly from the certification process for UAT equipment; 3) feedback from further operational use of ADS-B in Alaska and pre-operational use in Australia; and 4) further requirements inputs from the operational community. For example, DO-282A included a requirement for the transmission of Mode 3/A (“4096”) codes in UAT Mode/Status messages (alternating with the Aircraft Call Sign) at the request of FAA Air Traffic.
2.6 The meeting was further informed of activities of the joint FAA/RTCA/Eurocontrol Requirements Focus Group (RFG) in developing harmonized requirements for initial ADS-B applications (e.g., Package 1). The RFG had held working group and plenary sessions in early April 2004 and continued to make progress in its task.
Agenda Item 3: VHF spectrum congestion
3.1 Since the VHF spectrum congestion is likely to be the driving force behind the implementation for a new air-ground communication system the FAA and Eurocontrol were requested to keep WG-C informed on the future date that requirements for a new frequency couldn’t be satisfied.
3.2 WGC7/WP19 and WGC7/WP 26 provided an update of the situation in the European and US airspace, respectively. Both papers indicated that by 2015, there would be a real congestion problem if no alternatives to the already identified measures were to be found. To have a better understanding of the parameters being used to determine the saturation date for the European Region, the meeting invited Eurocontrol to provide a presentation of the SENSI software.
3.3 WGC7/WP17 presented the status of the study on the CLIMAX/8.33 kHz operation. The study has started and is scheduled for completion in November 2004. In case the CLIMAX operation on 8.33 kHz channels is feasible it could provide some relief to the VHF channel congestion in the European core area Action: 1 Provide regular updates on the VHF radio spectrum congestion.2 Provide a presentation on the SENSI at WG-C8.
Agenda Item 4: WRC 2007 AM(R) S and AMS(R)S
4.1 The Secretary introduced WGC7/WP 4 containing the draft ICAO position on WRC 2007 Agenda 1.6. In its discussion it was agreed that there is no direct role for WG-C in relation to resolution 415. With respect to the MSS requirements it was noted that this would be addressed through the assessment of the candidate technologies.
4.2 Resulting from an Action of WG-C6, WGC7/WP 3 introduced an initial approach of the WG-C strategy to address WRC 2007 Agenda Item 1.6. It was agreed not to look for a separate document but basically to address the strategy as an integral part of the technology assessment, including the plan of action for a new communication systems deployment. WGC7/WP20 provided specific considerations in the usage of the target bands. It was stressed that it would not be necessary to finalize the selection of candidate technologies before WRC 2007, in order to provide appropriate contribution in the WRC preparation process, as the communication operating concept and the traffic volume would be more of a determining factor.
4.3 In conclusion of this Agenda Item the agreement of the Toulouse meeting on the role for WG-C regarding resolution 414 was confirmed as follows:
WG-C will be the focal point for the establishment of the operational scenarios, the identification of the ATM services/applications and the resulting traffic of communication. It shall also identify a limited number of most appropriate technologies, which are directly related to the band selection and are dimensioned for the quantity of spectrum to be required. Identification of the upper layer mechanisms is not relevant in this process. The signal form, including the modulation type is essential for spectrum capacity and radio compatibility with a focus on the WG-F recommended bands 960-1164 MHz and 5091-5150 MHz. Based on proposals from ACP WG-F, the WG C has to consider which spectrum
allocation seems the most appropriate to comply with the identified scenario (considering issues such as coverage, capacity, and propagation characteristics). Based on evaluation of traffic WG-C shall define the volume of spectrum within the bands identified by WG-F.
4.4 The reason why WG-C is looking at new technologies i.e. to cater for traffic growth and new applications should be the general approach to justify an additional AM(R)S allocation.
4.5 In discussing the ICAO position on WRC Agenda 2007, the meeting noted some discrepancy in the official WRC 2007 Agenda Title with the draft ICAO position. Also the desire was expressed to bring two specific matters to the attention of WG-F with regard to the studies to take into account the capacity available in the existing AM(R)S allocation. It was decided to write a liaison statement from ACP WG-C to WG-F, which is contained in Attachment D..Action:3 To compile WGC7/WP 20 and WGC7/3 into one document for inclusion in the
report of the Technology Assessment Group.4 Secretary to send the liaison statement in Attachment D to ACP-WG-F
Agenda Item 5: UAT
5.1 The Rapporteur of the UAT Subgroup provided the meeting an overview of recent activities of the Subgroup. The fifth meeting of the Subgroup was held March 1-4, 2004 at ICAO Headquarters in Montreal. The draft RF SARPs, UAT Technical Manual, Validation Cross Reference Index (VCRI), and UAT Implementation Manual were reviewed, with a small number of changes incorporated into the draft RF SARPs and Technical Manual. The VCRI was updated to include use of Flight Tests as a validation technique, per the action set at WG-C6 in Toulouse. Finally, a significant portion of the Implementation Manual was reviewed in detail.
5.2 The UAT Subgroup Rapporteur further briefed the meeting on coordinative activities of the Subgroup with the OPLINKP, SCRSP, and NSP. It was reported that the OPLINKP had provided detailed comments on the UAT Requirements and Desirable Features document that had been reviewed at AMCP/8. An updated draft of this document, reflecting the OPLINKP comments, would be provided to the UAT Subgroup at its next meeting and, subsequently, to WG-C8. Coordination with SCRSP on UAT compatibility with SSR and TCAS had occurred on two occasions, with a third briefing to be provided to the SCRSP Technical Subgroup and WG-B later in April 2004. Compatibility testing of the sharing of transponder antennas using a passive diplexer had been completed, and the UAT Subgroup had formed the view that such antenna sharing could be employed in a manner compatible with the operation of the UAT and SSR/TCAS systems. A draft input for April 2004 meetings prepared by the leadership of the SCRSP Technical Subgroup reflected agreement with this view. With regard to
coordination with NSP, the meeting was informed that UAT/DME compatibility had been assessed. At the suggestion of DFS, in an additional terminal/approach scenario in future high density airspace was added, presuming that a full complement of DME assignments at 979 MHz (the first adjacent channel to the proposed UAT frequency of 978 MHz) would be operational. Mike Biggs reported that this compatibility assessment had yielded favorable results and was in the process of being coordinated with the DFS, Eurocontrol, and the NSP Spectrum Subgroup.
5.3 TSO-certificated UAT equipment was anticipated to be available by mid-May 2004, with production UAT ground stations undergoing factory test in early May and an air-transport class UAT transmitter being ready for bench testing at the FAA William J. Hughes Technical Center (WJHTC) and at DFS by the end of August. Further meetings of the UAT Subgroup had been scheduled for 15-17 September in Madrid, Spain (hosted by AENA), November 16-18 at ICAO Headquarters in Montreal, and 25-27 January 2005 at a location yet to be determined. The Subgroup’s schedule remained targeted toward presentation of a completed validation of the draft UAT SARPs and Technical Manual at WG-C9 in 2005.
5.4 The meeting then reviewed the draft RF SARPs, Revision 2.2, dated March 3, 2004 (WGC7/WP10). Changes to the draft SARPs since WG-C6 were highlighted in the draft, and the meeting reviewed each such change. The Rapporteur of the UAT Subgroup informed the meeting that one change reflected in the recently updated RTCA UAT MOPS (RTCA DO-282A) that would affect Figure 2 of the draft SARPs had not yet been reviewed by the Subgroup, and that this change, after such review, would be brought to WG-C8 in Munich. The meeting approved the designation of the draft RF SARPs as Revision 3.0.
5.5 The meeting subsequently reviewed the updated draft UAT Technical Manual, Revision 1.2, dated March 3, 2004 (WGC7/WP11). Again, changes to the Technical Manual made since WG-C6 were highlighted in the draft, and the meeting reviewed each such change, approving each one. Additionally, the Subgroup accepted an action, to be designated “Action 4” in the draft Technical Manual, to consider what codings should be used for transmitted accuracy and integrity parameters to reflect RNP-5. An additional correction to the nomenclature of the “CDTI Traffic Display Capability” was made in Table 3-1 of the draft. Moreover, the Rapporteur of the UAT Subgroup informed the meeting that one changed reflected in RTCA DO-282A concerning the duration of suppression pulses output by the UAT equipment had not yet been reviewed by the UAT Subgroup, and that this change, after such review, would be brought to WG-C8 in Munich. The meeting approved the designation of the draft Technical Manual, with reflection of these comments, as Revision 2.0.
5.6 The meeting was informed that the UAT Validation Plan had not changed since WG-C6.
5.7 The meeting then reviewed the VCRI for the UAT draft SARPs and Technical Manual, Revision 1.2, dated 2 March 2004 (WGC7/WP12). Changes to the VCRI made
since WG-C6 were highlighted in the draft, and the meeting reviewed in particular the changes associated with the use of Flight Tests as a Validation Method, asking the Subgroup to add Flight Testing to the validation of requirement 2.1.5.6.1. A validation method was added for requirement 2.1.4.2, the Subgroup accepted an action to fill in validation methods for requirements 2.1.5.1.3.3 through 2.1.5.1.3.6, and corrections were made to validation methods incorrectly specified in three places as being “I”. The meeting was informed that the WJHTC was currently reviewing certification test results from a manufacturer of UAT equipment to determine which of such results could be used, with the manufacturer’s permission, in the validation. The meeting approved the designation of the VCRI, with reflection of the comments provided by the meeting, as Revision 2.0.
5.8 A brief discussion was subsequently held of the draft Implementation Manual for the UAT, Revision 0.3, 4 March 2004, which without its Appendices was paper WGC7/WP13. The meeting was informed that further review of this document by the UAT Subgroup was necessary before WG-C would be asked to designate a draft as Revision 1.0. The Subgroup accepted an action to post the entire draft Manual, including Appendices, on the ACP website. The Subgroup was also requested to add material to the Manual on how UAT fits into the ATM environment, as well as further informative material on aircraft L-band suppression circuitry.
5.9 The UAT Subgroup was asked to provide a 30-minute overview of UAT under the UAT agenda item at WG-C8.
Action:5 Prepare presentation on UAT at WG-C8.
Agenda Item 6: New Technologies
6.1 WGC7/WP7 introduced the work on the concept of a Self-synchronized ADS using satellite, which has the potential to improve significantly the ADS satellite-based performance. The ADS service is likely to become a significant application to be supported by a new communication system. An introduction of this concept, if appropriate, could be beneficial.
6.2 WGC7/WP27 provided a status overview of the FAA NEXCOM programme. From the original program some elements will be finalized, including the certification of the vocoder. Since it is likely that digital voice will be an integral part of a future aeronautical communication systems and considering the long and costly qualification and certification the use of this vocoder should be taken into consideration
6.3 WGC7/WP8 and WGC7/WP9 introduced a new concept in air traffic voice communications taking advantage of the inherent packet nature of push-to-talk two-way voice communications to significantly improve the efficiency of network bandwidth. The present voice operation was characterized in comparison with the proposed packet voice
concept. In its discussion on this paper the meeting agreed on the need to develop a concept of voice operation before considering new voice communication techniques. Operational experts should then validate this concept and whether it will satisfy their needs. WGC7/WP 8 contained some elements that should be taken into consideration in this concept.
6.4 WGC7/WP5 and WGC7/WP6 provided an overview with an emphasis on the technology being used for the B-VHF concept. The question was raised whether the additional capacity obtained in a highly congested VHF band would justify a possible implementation. It was noted that this specific issue was an integral part of the study. It was agreed that the system should be included in the technology assessment report as a candidate technology.
6.5 WGC7/WP2 informed the meeting on a project initiated to study the DS-CDMA technique, which is the underlying technology in both the UMTS and IS-95 system. The project has started in November 2003 and is expected to be finished in December 2005. The author of the paper was requested to coordinate with Eurocontrol the submission of the necessary information for the technology to be considered in the assessment.
6.6 WGC7/WP15 contained an inventory of the candidate technologies identified thus far. It was noted that for some of the candidates the information was not complete enough to make a full assessment of the technology concerned. The meeting agreed that there is a need of a closure date for the submission of new candidates, but that it is premature to agree on a specific date. The updated version of WGC7/WP 15 is contained in Attachment E.
6.7 Before WG-C can initiate the assessment, not only the communication requirements have to be established but also higher level ‘Assessment Parameters” to categorize the candidate technologies.
6.8 In its discussion the meeting made a preliminary inventory of potential parameters and identified the following:
Modulation technique Cellular Structure Scalability Terrestrial/ Satellite Narrow- / wide- /broad-band Operating band Industry standards Aircraft Integration Cost
Action:6 Develop a draft concept of voice operation
7 Comments on assessment parameters8 Send formal request to proponents of specific technology for additional information
Agenda Item 7: Communication requirements
7.1 WGC7/WP18 introduced proposed high-level requirements for a future aeronautical mobile satellite (R) service. These requirements were developed to support a safety and regularity of flight communication service in high-density airspace such as in Europe. This work has been carried out as part of the EUROCONTROL NexSAT activity and draws on work underway in Europe, which may be typical of high-density airspace throughout the world. WG-C is requested to review the attached document, confirm that its content is consistent with requirements in other similar airspace types, and consider the proposed next steps. WG-C is also requested to consider providing expertise, which is outside Eurocontrol's mandate, related to AOC requirements.
7.2 WGC7/WP 28 introduced preliminary requirements, being a compilation of various existing documents. It was noted that the requirements were mainly directed to terrestrial systems and also largely based on the traditional concept of operation. The meeting agreed that it would be useful to merge the requirements in WGC7/WP 18 and WGC7/WP 28 as the first step towards a full set of requirements in the to be developed new concept of communication.
Action:9 Merge WP 18 and 28 communication requirements.10 Challenge questionable or archaic requirements. 11 Provide comments to ensure global applicability of communication requirements12 Provide information on AOC traffic
Agenda Item 8: Institutional considerations
8.1 WGC7/WP22 was a first draft addressing the institutional elements, which are of important weight in the implementation process for a new system. It was noted that the security element was missing and that input is required on pending security requirements, which might have a bearing on a new communication concept above the already being in progress development of ATN security. Since the paper was submitted during the meeting, more comments are invited before the end of June in order to timely circulate a new version before WG-8C. The majority of the elements will be related to the assessment parameters, therefore it was agreed that the new version should form an integral part with the “Assessment Parameters”.Action:
13 Comments on WGC7/WP 22, institutional elements by the end of June 14 Circulate new version of institutional element before WG-8C15 Investigate the source to obtain the relevant security requirements.
Agenda Item 9: WG-C8 workplan
9.1 WGC7/WP 16 presented a FAA/NASA/Eurocontrol common action plan to progress the investigation of new Air/Ground Communication systems in support of the ICAO ACP work. The tasks are divided in two main streams, the technical and business aspects. It is expected that the work is completed at the third quarter of 2007
9.2 WGC7/WP 23 introduced a road map for consideration by WG-C to use as a guide for the implementation of a new communication concept. The suggestions made during WG-C7 were included and it was agreed to invite further comment on the draft, which is contained in Attachment F
9.3 In summary of the meeting the following task were identified which need completion before WG-C8
Number Task Date LeadWGCT_1 Provide regular updates on the VHF
radio spectrum congestionWG-C8 Eurocontrol/FAA
WGCT_2 Provide a presentation on the SENSI WG-C8 Philippe RenaudWGCT_3 To compile WGC7/WP 20 and WGC7/3
into one document for inclusion in the report of the Technology Assessment Group
31/05/04 Mike Biggs
WGCT_4 Secretary to send the liaison statement in Attachment D to ACP-WG-F
31/05/04 ICAO Secretary
WGCT_5 Prepare presentation on UAT. WG-C8 George LiglerWGCT_7 Comments on assessment parameters 31/07/04 AllWGCT_6 Develop a draft concept of voice
operation31/08/04 FAA/Eurocontrol
WGCT_7 Comments on assessment parameters 31/07/04 AllWGCT_8 Send formal request to proponents of
specific technology for additional information
30/06/04 Philippe Renaud
WGCT_9 Merge WGC7/WP 18 and WGC7/28 communication requirements
31/05/04 Gregg Anderson
WGCT_10 Challenge questionable or archaic requirements
31/08/04 All
WGCT_11 Provide comments to ensure global applicability of communication requirements
31/08/04 All
WGCT_12 Provide information on AOC traffic WG-C8 Van den Boogaard
WGCT_13 Comments on WGC7/WP 22, institutional elements
31/06/04 All
WGCT_14 Circulate new version of institutional element
31/07/04 Van den Boogaard
WGCT_15 Investigate the sources to obtain the relevant security requirements
WG-C8 Van den Boogaard
WGCT_16 Comments on Attachment F 31/07/04 All
9.4 Meeting schedule: 20-24 Sept 2004, Munich11-15 April 2005, Montreal (tentative, relate to ACP/1 date)3 or 4 Quarter 2005, TBD
Agenda Item 2: Update related ICAO, ITU and Industry Activities
Agenda Item 3: VHF spectrum congestion
Agenda Item 4: ICAO guidelines on standardization
Agenda Item 5: UAT
Agenda Item 6: New Technologies
Agenda Item 7: Communication Requirements
Agenda Item 8: Institutional Considerations
Agenda Item 9: WG-C workplan
Attachment C
LIST OF WORKING PAPERS
WP’S AGENDA ITEM
TITLE PRESENTED BY
1 Draft Agenda
2 6 Research on future Aeronautical Communication Systems based on DS-CDMA
Eleuterio Esteban
3 4 ACP WGC Strategy for Addressing WRC-07 Mike Biggs
4 4 Draft ICAO position on WRC 2007 Secretary
5 6 Overview on B-VHF Michael Schnell
6 6 B-VHF System Concept Michael Schnell
7 6 Concept of self-synchronized automatic dependent surveillance using satellite
Yasuto Sumiya
8 6 Packetized Voice: A new communications concept for air traffic control
Alvin Burgemeister
9 6 Packet Voice Radio Alvin Burgemeister
10 5 Draft RF SARPs for UAT (Revision 2.2) George Ligler
11 5 Technical Manual on the UAT (Revision 1.2) George Ligler
12 5 Draft validation cross reference index for the UAT SARPs and Technical Manual (Revision 1.2)
George Ligler
13 5 Implementation manual for the UAT (Revision 0.3) George Ligler
14 2 Survey about the use of TCP/IP internetworking for aeronautical communications
Rapporteur
15 Rev.1
6 Report of the Technology assessment Group Philippe Renaud
15Rev.1Adden.
6 Report of the Technology assessment Group Diane Revell
16 9, 10 Common FAA/NASA/EUROCONTROL action plan for investigating new communication systems
Brent Philips &Philippe Renaud
17 3 Information paper on CLIMAX/8.33 Study performed by EUROCONTROL
Philippe Renaud
18 6, 7 Requirements for a world-wide Aeronautical Mobile Satellite (R) Service
Philippe Renaud
19 3 VHF AM (R) S spectrum evolution in Europe Philippe Renaud
Attachment C
20 4 Some considerations regarding the future WRC-2007, agenda point 1.6 and specially its first part dealing with the need for additional spectrum allocations to the aeronautical mobile service (route)
Alain Delrieu
21 2 Data communication recording requirements Kors van den Boogaaard
22 8 An inventory of institutional elements Kors van den Boogaaard
23 10 The Road Map Kors van den Boogaaard
24 2 Results of ITU-R WP 8B meeting 25 November - 2 December 2003
Secretary
25 2 Report of the Second Meeting of Task Group 1/8 Secretary
26 3 Assessment of radio spectrum depletion in the U.S. in the VHF Comm Band
Mike Biggs
27 6 Status NEXCOM James Eck
28 7 Communications requirements Brent Philips
Attachment D
LIAISON STATEMENT FROM ACP/WGC TO WGF
Re :Draft ICAO position on WRC 2007 Agenda Item 1.6
Working Group C, in their 7th meeting reviewed the draft "ICAO position for WRC-2007" as elaborated by the Working Group F, 11th meeting in Nairobi, 19-27 February. As the result WGC have the following comments to offer on the Agenda Item 1.6 element of that position , specifically on the textual part preceding the boxed position:
a) editorial : insert words "additional" and "satellite" in the Agenda Title To consider additional allocations for the aeronautical mobile (R) service in parts
of the bands between 108 MHz to 6 GHz, in accordance with Resolution 414 (see Appendix E), and to study current satellite frequency allocations that will support the modernization of civil aviation telecommunication systems, taking into account Resolution 415 (WRC-03)
b) matter of substance with respect to Res 414 part: Same paragraph : .." Further studies will take into account the capacity available
in the existing AM(R)S allocation " Question : 1) Will those studies concern only the aeronautical HF and the
118-137 MHz bands?2) Would it be beneficial to make the band 108-118 MHz more generic (currently AM(R)S limited to ICAO-standard NAV + surveillance )?.
Clarification is requested regarding “the additional AM(R)S allocations” in the last paragraph of section entitled "Res 414 which can be interpreted possibly as:
o a) “Preliminary studies indicate that additional frequency allocations to AM(R)S to meet the above requirement may be considered available in the bands with existing aeronautical allocations, including, but not limited to the 960 – 1164 MHz and 5091 – 5150 MHz”or,
o b)” that additional AM(R)S allocations, other than the afore-mentioned, may be available to meet the above requirement, …....
At the moment the draft position may be interpreted as restricting itself to supporting studies needed to assess new systems’ communication capacity and to protect aeronautical systems already operating, solely within current aeronautical allocations . Is this intent of Working Group F?
Note: the band 5091-5150 MHz, as part of the band 5000-5150 MHz is also allocated under R.R. 5.367 to the AMS(R)S on a primary basis…
Attachment E
Report of the Technology assessment Group
Change Record:
Ed Localisation Modifications Reason for change1.0 All Original N/A2.0 New section
3.4Addition of “Connexion By Boeing” information
The information provided by the Author was lost by the document co-ordinator
2.0 New section 3.6 and 3.7
Modification of “Max. number of simultaneously supported users per sector/cell” (UMTS), andRemarks in “Standardisation” (CDMA2000)(identified in red highlighted yellow in Ed 2.0
Editorial
2.1 Section 3.4 Information on Connexion by Boeing Correction and addition
Introduction
As resulting from ANC11 7/4 recommendation, ACP WG C has started the investigation of future mobile communication systems which could be integrated in the communication infrastructure circa 2015 to support the aeronautical traffic evolution and the ATM system enhancement.
To progress this work, WG C has formed during its 6th meeting four groups of interest in charge of dedicated items i.e.:
This paper is related to the second item, i.e. Technology assessment.It is a co-operative contribution whereby volunteer organisations are describing the main characteristics of potential candidates according to a pre-agreed form.
Section 2 summarises the technologies which have been felt valuable to be evaluated in the view of enhancing the future mobile communication infrastructure.
Section 3 provides a description of each of these proposed technologies.
Attachment E
Attachment E
Potential technologies
Technology organisation contributing to the assessment
B-VHF German Aerospace Center (DLR) (M Schnell)
B-VHF Consortium represented by DLR
ADL (Advanced Airport Data Link), i.e. data link especially designed for the use in the high density airport environment including arrival and take-off
German Aerospace Center (DLR) (M Schnell)
SDLS ESA (C Loisy)Connexion By Boeing Boeing (W Estermann)Aero B-GAN Inmarsat (G Colledge)3GPP UMTS (FDD) Eurocontrol (L Lommaert)CDMA2000 1xRTT Eurocontrol (L Lommaert)
Table 1 – Technologies considered as potential candidate for the future aeronautical mobile communication infrastructure
Technology description
Attachment E
B-VHF
Development and design of B-VHF has started on January, 1st 2004, within the FP6 European research project B-VHF (“Broadband VHF Aeronautical Communications System Based on MC-CDMA”). Since the system design of B-VHF is not yet finalized, the system description is preliminary and subject to changes.
B-VHFAuthor: B-VHF Consortium
ITEMS DESCRIPTIONAIR INTERFACE TECHNOLOGY Duplexing scheme FDD or TDD (T.B.D within B-VHF project)Multiple-access scheme CDMA, FDMAModulation types QPSK and QAM, adjustable to channel conditionsFEC Coding Separate FEC schemes for each service type (voice, different data
service classes). Details on FEC schemes T.B.D within the B-VHF project.
Diversity techniques Yes, inherent frequency diversity due to spread-spectrum transmission based on multi-carrier technology.
System bandwidth About 1 MHz (T.B.D within the B-VHF project)Supported data rates per user Up to 128 kbps. In addition, channel aggregation possible.Max. number of simultaneously supported users per sector/cell
Up to 128
Remarks B-VHF is based on the multi-carrier technology and, therefore, highly flexible with respect to exchanging data rate per user and user capacity. Moreover, the multi-carrier technology enables to realize B-VHF as an overlay system in the VHF band, since frequency gaps can be easily utilized.
GENERIC COMMUNICATION SERVICEService 1
Types Voice User throughput 4800bpsUser interface PTT + analogue voice interface to vocoder.Connection topology Air/Ground, Air-airType of QoS Real-time voice operation, 250 ms max. end-to-end delay, FEC as
provided by the 4,8 kbps vocoder.Service 2
Types Addressed data linkUser throughput Up to 128 kbps, dependent on the transition phase.User interface IP, option for integration as an ATN subnetworkConnection topology Point-to-pointType of QoS Time-critical data operation, estimated 10 s typical 95% end-to-end
transmission delay, detailed integrity mechanisms (e.g. FEC) T.B.D within the B-VHF project.
Service 3Types Broadcast (T.B.D. within B-VHF project)
Attachment E
Remarks
TOPOLOGYGeographical coverage Cellular terrestrialRange 200 NM from the ground station
Remarks
SPECTRUMCurrent spectrum status Spectrum occupied by the legacy narrowband VHF systems (or a
dedicated sub-band of the VHF spectrum)Propagation Degradation due to broadband channel effectsFrequency Band VHF band, alternatively also MLS bandAvailable spectrum bandwidth Currently, no spectrum is assigned to B-VHF
Remarks VHF spectrum is intended to be used by B-VHF together with legacy VHF systems. Compatibility between B-VHF and legacy VHF systems is guaranteed due to overlay concept.
AIRBORNE INTEGRATIONAvionics Anticipated as a replacement of -/ extension to the VDR 750 radio.
ATN compatibility also requires CMU modifications.Mutual spectrum compatibility Co-location problems with other VHF radios
Remarks
GROUND INTEGRATIONInfrastructure evolution Anticipated as a replacement of ground voice and VDL2 radios, with
external interfaces similar as today.Remarks
SERVICE PROVISIONPossible model Voice part could remain in the ANSP domain, data link part may be
delegated to communications service providers. Remarks
MIGRATION/TRANSITIONIdentified issue Target is an overlay concept, where B-VHF system would locally re-
use – without interference - spectrum ressources that are currently used by the distant narrowband VHF systems. As a fallback, sub-banding may be used.
Allow incremental deployment With an overlay option, incremental per-sector deployment would be possible.
Inband transition Yes, due to overlay concept.Remarks
SECURITYSecurity function supported B-VHF system will be designed to support encryption and other
security applications. Multi-carrier technology combined with CDMA offers a robust physical layer.
Jammer suppression Narrowband jammers are suppressed due to the CDMA transmission (several narrowband multicarriers are used for the transmission of a single bit of information).
Remarks
INDUSTRIAL MATURITY
Attachment E
Status of development of the necessary components by the industry
B-VHF underlying MC-CDMA technology is being developed for the telecommunication industry (4G)
Remarks
STANDARDISATIONStandardisation status No standards available yet.
Remarks
OTHER IMPORTANTS ASPECT
High level description
Attachment E
ADL
The system design for the ADL is not yet finalized, thus, the system description is preliminary and subject to changes.
ADL (Advanced Airport Data Link)Author: DLR
ITEMS DESCRIPTIONAIR INTERFACE TECHNOLOGY Duplexing scheme FDD / TDDMultiple-access scheme CDMA (Ground/Air) and FDMA (Air/Ground)Modulation types QPSK, QAMFEC Coding Adaptable FEC depending on data or voice service. FEC based on
convolutional coding. Additionally, CRC check for data.Diversity techniques Yes, inherent frequency diversity due to spread-spectrum transmission
based on multi-carrier technology.System bandwidth 8,192 MHzSupported data rates per user From 128 kBit/s to 2 MBit/sMax. number of simultaneously supported users per sector/cell
128
Remarks ADL is based on the multi-carrier technology and, therefore, highly flexible. Data rate per user and user capacity can be exchanged in a simple way allowing to easily adopt transmission to the current requirements.
GENERIC COMMUNICATION SERVICEService 1
Types Data (connection-oriented and connection-less)User throughput Up to 2 MBit/sUser interface IP, option for integration as an ATN subnetworkConnection topology Point-to-point, point-to-multipointType of QoS Different priority levels, guaranteed assigned user data rates
Service 2Types VoiceUser throughput Configurable, e.g. 4800 bpsUser interface PTT + analogue voice interface to vocoderConnection topology Air/Ground, Ground/AirType of QoS Real-time voice operation, 250ms max. end-to-end delay
Remarks
TOPOLOGYGeographical coverage Cellular terrestrialRange 30 NM from the ground station
Remarks
SPECTRUMCurrent spectrum status Shared spectrum with microwave landing system (MLS)Propagation Degradation due to multipath propagation mitigated by frequency and
time diversity with propagation channel estimation and equalizationFrequency Band 5 GHz (MLS band)
Attachment E
Available spectrum bandwidth 56 MHzRemarks
AIRBORNE INTEGRATIONAvionics 5 GHz antenna and new radio equipment necessaryMutual spectrum compatibility Shared with MLS
Remarks
GROUND INTEGRATIONInfrastructure evolution 5 GHz antenna and new radio equipment necessary
Remarks
SERVICE PROVISIONPossible model Future ATC/ATM, A-SMGCS, airport/airline data link services
Remarks
MIGRATION/TRANSITIONIdentified issue Part of the MLS spectrum has to be migrated to ADLAllow incremental deployment Yes, airport-basedInband transition Yes, use unoccupied part of the MLS spectrum
Remarks
SECURITYSecurity function supported EncryptionJammer suppression Narrowband jammers are suppressed due to CDMA transmission
Remarks
INDUSTRIAL MATURITYStatus of development of the necessary components by the industry
Ground/Air link designed, evaluated and implemented in demonstratorAir/Ground link under development
Remarks
STANDARDISATIONStandardisation status Standardisation planned
Remarks
OTHER IMPORTANTS ASPECT
High level description
Attachment E
SDLS
SDLSAuthor: ESA
ITEMS DESCRIPTIONAIR INTERFACE TECHNOLOGY Duplexing scheme FDDMultiple-access scheme CDMA (Synchronous and quasi-synchronous)Modulation types QPSK.FEC Coding YesDiversity techniques AES receives from two satellites and transmit through the one it
receives best. Two AESs per aircraft would likely be required.System bandwidth 900 KHzSupported data rates per user From 6.4 Kb/s in global beam to 30 Kb/s in narrower beamsMax. number of simultaneously supported users per sector/cell
Remarks
GENERIC COMMUNICATION SERVICEService 1
Types Voice User throughput 4800bps or 2400bps (oceanic)User interfaceConnection topology Air/GroundType of QoS Communication establishment < 5 s
Voice latency < 400msResidual error rate 10-3
Service 2Types ATS and AOC Data services User throughput Up to 20KbpsUser interface Packet serviceConnection topology Point-to-pointType of QoS
Remark Short Data Service is to be used for down-linking of on-board parameters
. . .
Remarks
TOPOLOGYGeographical coverage Geosynchronous satellite: global beam (ocean), regional beams (cont)
Attachment E
Range from GES Determined by satellite coverageRemarks
SPECTRUMCurrent spectrum status AMS(R)S Allocation (priority access)Propagation Line of sight. Less than 1dB attenuation by rain in service bandFrequency Band L-Band 1.5 and 1.6 GHz.Available spectrum bandwidth Up to 10 MHz ?
Remarks
AIRBORNE INTEGRATIONAvionics Antenna and RF building blocks currently available. Modem to be
developed Mutual spectrum compatibility Compatible with AMSS
Remarks
GROUND INTEGRATIONInfrastructure evolution Existing compatible satellite and GES RF front end infrastructure
Remarks Dedicated infrastructure to be deployed in a longer term on continents as traffic builds up.
SERVICE PROVISIONPossible model Investment in AESs (# 20.000 $ per unit) is the dominating cost item
Remarks Low capacity system dedicated to safety communicationsOnly limited capacity transponders are needed for ATS and AOC data traffic. Voice usage is expected to diminish with time
MIGRATION/TRANSITIONIdentified issue Status of the AMS(R)S L-Band to be improved in the futureAllow incremental deployment Geosynchronous satellites are ideal for incremental deploymentInband transition Only sharing with non priority users in MSS is an issue.
Remarks
SECURITYSecurity function supported Could be addedJammer suppression CDMA techniques are naturally protected from narrow band
interference in particular for non fully loaded systems. Satellite diversity also provides protection
Remarks
INDUSTRIAL MATURITYStatus of development of the necessary components by the industry
Synchronized and quasi synchronized CDMA are commonly used in military tactical communication systems
Remarks
STANDARDISATIONStandardisation status
Remarks
OTHER IMPORTANTS ASPECT
Attachment E
Connexion By Boeing
Connexion By BoeingAuthor: Boeing
ITEMS DESCRIPTIONAIR INTERFACE TECHNOLOGY Duplexing scheme FDDMultiple-access scheme CDMAModulation types O-QPSKFEC Coding Turbo codingDiversity techniques NoneSystem bandwidth Less than or equal to 32.4 MHzSupported data rates per user Forward link - up to 5 Mbps per receiver card (up to 4 receiver cards),
Return link up to 1 Mbps; assumes a "user" is an airplaneMax. number of simultaneously supported users per sector/cell
Aggregated users to remain below regulatory limits on return link. Typical maximum would be 25 airplanes.
Remarks
GENERIC COMMUNICATION SERVICEService
Types voice and dataUser throughput Forward Link (E-s) up to 20 Mbit/s (with 4 receiver cards) –
Return Link (s-E) up to 1 Mbit/sUser interface IPConnection topology Air/Ground, Point-to-pointType of QoS BER > 10-6
Remark Availability > 99.9%
TOPOLOGYGeographical coverage GSO satellite regional beamsRange from GESRemarks Up to 75o N & S and oceanic major air routes
SPECTRUMCurrent spectrum status Shared spectrum, currently secondaryPropagation Possible degradation due to rain effects below 10,000 feet which
includes rain effects in equatorial regions.Frequency Band Ku – band 14-14.5 GHz (E-s) 11/12 GHz (s-E) Available spectrum bandwidthRemarks Propagation Delay: > 250 milliseconds for GSO satellites
AIRBORNE INTEGRATIONAvionics No issues envisaged with integrationMutual spectrum compatibility N/ARemarks
GROUND INTEGRATIONInfrastructure evolution Evolution of ground infrastructure to accommodate IP protocols is
requiredRemarks
Attachment E
SERVICE PROVISIONPossible modelRemarks
MIGRATION/TRANSITIONIdentified issue NoneAllow incremental deployment Considered to be the most practical solutionInband transitionRemarks
SECURITYSecurity function supported EncryptionJammer suppressionRemarks
INDUSTRIAL MATURITYStatus of development of the necessary components by the industry
Technology was initially developed for the telecommunication industry but has been adapted successfully for the AMSS
Remarks
STANDARDISATIONStandardisation status Compliant with ETSI and ARIBRemarks
OTHER IMPORTANTS ASPECT
High level description
Attachment E
Aero-BGAN
Aero-BGANAuthor: INMARSAT
ITEMS DESCRIPTIONAIR INTERFACE TECHNOLOGY Duplexing scheme FDDMultiple-access scheme FDMA/TDMAMultiple-access interference N/AIntersymbol interference Yes (an appropriate allowance is made in the Link Budget design)Modulation types O-QPSK, π/4-QPSK, 16-QAM; FEC Coding Yes – turbo codingDiversity techniques NoSymbol duration 60, 30, 15, 6.7μs (16.8, 33.6, 67.2, 151.2 kbps)Frame duration 5, 10, 20, and 80 msSupported data rates per user Up to 432 kbps (average data throughput) per channelMax. number of simultaneously supported users per sector/cell
Aggregated up to maximum capacity per spot beam. (Approximate maximum of 10% of satellite capacity to a spot beam.)
Remarks
GENERIC COMMUNICATION SERVICEService 1
Types Voice User throughput 4800bps AMBE voice codecUser interface 4 wire analogue, and CEPT E1Connection topology Point to point (and Point to Multipoint capability)Type of QoS (target GoS of 4% for APC) Priority and Pre-emption for non-APC
Service 2Types ISDN Connection basedUser throughput 64 kb/sUser interface H.323Connection topology Point-to-pointType of QoS (target GoS of 4% for APC)
Service 3Types IP based Connectionless dataUser throughput User defined up to 432 kb/sUser interface IETF standard (Ethernet based)Connection topology Point-to-point, Unicast, MulticastType of QoS User request
TOPOLOGYGeographical coverage GEO Satellite global, regional and spot beamsRange N/A
Remarks
SPECTRUMCurrent spectrum status Shared L band MS(R)S spectrumPropagation Line of sight down to 5 degrees elevation to satelliteFrequency Band L band (1525MHz-1559MHz RX and 1626.5MHz – 1660.5MHz TX)
Attachment E
Bandwidth Shared co-ordinated Inmarsat Spectrum Remarks For BGAN the spectrum is subdivided in 200kHz channels
AIRBORNE INTEGRATIONAvionics Integration with Aero-H/H+ using common RF infrastructure (HPA
and antenna)Mutual spectrum compatibility As per ICAO AMSS SARPs and RTCA DO-210D
Remarks
GROUND INTEGRATIONInfrastructure evolution Ground infrastructure for Aero-H/H+ is independent from Aero-
BGAN. Inmarsat is procuring and deploying BGAN ground infrastructure. (Infrastructure operational mid-2005)
Remarks
SERVICE PROVISIONPossible model TBD
Remarks
MIGRATION/TRANSITIONIdentified issue Parallel integrated operation of Aero-H/H+ services and Aero-BGAN
Spreading : QPSK up and downlinkFEC Coding Low data rate (<32kbps) : 1/3 or ½ Convolution coding K=9
High data rate : 1/3 Turbo coding (PCCC) Diversity techniques Space : Base station antenna diversity standardisedSystem bandwidth 2 x 5MHz Occupied Bandwidth / 3,84 Mcps (FDD/Down and Uplink)Supported data rates per user 12,2 - 64 - 144 - 384 kbps typical with test scenario for BER in
standard. Any data rate can be used as long as the rate is pre-defined (multi rate puncturing-repetition).
Max. number of simultaneously supported users per sector/cell
Pole capacity = 98 users/cell (voice channels) within an omni directional cell.
Remarks CDMA/FDD uses down/uplink isolation in the frequency domain. Relative FDD frequency separation should be at least 10% preferable 15%.
CDMA is an interference limited system. Its cell capacity limit is sooner reached by its interference level limit rather than by its code availability.limit. Hence CDMA is said to have a SOFT capacity.
All commercial telecom service providers base their next generation cellular coms on CDMA as this technology provides the largest user capacity and greatest flexibility vis-à-vis data rates and QoS.
CDMA radios normally transmit at much lower power levels compared to narrow band and/or TDD radios. While analogue (digital) narrow band radios need a SINAD of +12 dB (C/I of +9 up to +11 dB ) a wideband radio operates on negative SIR levels of around -15 dB! The actual SIR value being determined by CDMA processing gain which is function of spreading factor.
UMTS FEC is best on the market today. Turbo coding gets very close to theoretical SHANNON limit.
GENERIC COMMUNICATION SERVICEService 1
Types voiceUser throughput 12,2 kbps max when using variable rate vocoder ( rate is variable and
decreases in function of speech activity). User interface Microphone – Earpiece Connection topology Air/Ground. Point-to-point. Connection oriented – often circuit
switched. VOIP also available.
Attachment E
Type of QoS Real Time Conversational class (stringent & low delay).A BER of 1.10-3 is sufficient to provide normal speech quality
Service 2Types Data on dedicated channel (connection oriented at air interface)User throughput 12,2 - 64 - 144 - 384 kb/s or any other pre-defined data rateUser interface TBDConnection topology Point-to-point. Circuit switched standardised - ATM standardised - IP
standardised. Type of QoS Real Time Conversational – Real Time Streaming Class
Service 3 Types Packet data (connectionless at air interface)
User throughput 12,2 - 64 - 144 - 384 kb/s or any other pre-defined data rateUser interface TBDConnection topology Point-to-point – Point to Multipoint – Limited Broadcast
Packet switched standardised - ATM standardised - IP in standardisation process
Type of QoS Interactive and background class / best effortRemarks Throughout this whole document ATM stands for Asynchronous
Transfer Mode.
As UMTS incorporates a multi-rate adapter any data rate can be transmitted as long as the rate is predefined for puncturing/repetition.
UMTS FDD allows a change in data rate every 10 ms as each frame carries a transport format combination indicator (TFCI). UMTS also allows asymmetric data transfer (downlink data rate being different from uplink one). However the amount of asymmetry is having an impact on the user capacity of both down/uplink (interference limit and/or code usage). Therefore amount of asymmetry will be limited.
TOPOLOGYGeographical coverage Cellular terrestrial Range Function of frequency band to be allocated. VHF band 160-200 NM
expected with omni and TX of 3W only. MLS C band 25 NM with omni and TX of 2W – 50 to 70 NM with High gain (10dB).
Remarks Besides transmit power and frequency band allocation the cell range is also function of cell loading and spreading factor employed.
SPECTRUMCurrent spectrum status Request for new spectrum assignment to be forwarded at WRC07Propagation C band : 0,133 dB / Vert Pol (D3 Crane Model) : degradation due to
rain effectsFrequency Band Optimal spectrum allocation would be VHF-UHF bandAvailable spectrum bandwidth 5MHz needed for Downlink – another 5 MHz needed for Uplink(FDD)
Remarks As CDMA has a frequency reuse factor = 1 (all cells operate on the same frequency) a second frequency pair will be needed for aviation due to the existence of the radio horizon. The radio horizon induces between large adjacent cells a silence area. In case a TMA / airport would be located within such a silence area a second set of frequency pairs is needed to serve this unit.
AIRBORNE INTEGRATION
Attachment E
Avionics A guard band is to be foreseen between any analogue narrow band and a digital wideband radio.
Mutual spectrum compatibility CDMA signals behave as additional white Gaussian Noise ( AWGN ) and has as effect to decrease the sensitivity of other receivers in case they would be located in the guard bands
Remarks CDMA in general emits with low power and does in general not create energy bursts (except during compressed, DTX and packet data mode).
Note: the 5 MHz channels spacing foreseen in UMTS is not the 3 dB bandwidth!
GROUND INTEGRATIONInfrastructure evolution Ground infrastructure exists but is mostly ATM based. Full IP
infrastructure has been standardised end 2002 (Release 5).
Ground infrastructure consists of BTS/RNC and CN. CN might be circuit switched/ packet switched or both.
The RF Front end of a BTS needs to be converted from auctioned RF spectrum towards ICAO COM spectrum.
UMTS does not need GPS synchronised BTS but can use it. Remarks UMTS RAN deployment and implementation should be part of other
ground infrastructure projects such as iPAX (IPV6 based).
RAN infrastructure as standardized contains lots of functions which are inherited from previous 2G systems such as GSM. It is obvious that UMTS RAN for ATC should not carry the burden of this backward compatibility. Therefore some effort is needed for optimizing the ground infrastructure for ATC operation. Also the UMTS RAN standardized security functions are to heavy for ATC use. Parts such as SIM, HLR, VLR should be carefully investigated and probably deleted from the reference network.
SERVICE PROVISIONPossible model UMTS could not only supply safety-of-life services but AOC and APC
as well. APC service will however consume scarce spectrum resources. In addition a connection to a public network and the installation of an expensive billing system is needed.
Remarks Prime service should be ATC. AOC could be supported but with low priority.
MIGRATION/TRANSITIONIdentified issue Implementation phase can only take place when additional spectrum is
granted. Seen the large UMTS bandwidth and the heavily used VHF band no big bang operation can ever work out.
Allow incremental deployment Only possible with green field spectrum.Inband transition Not possible
Remarks WRC07 spectrum allocation process is determining all future com systems for ATC. States are requested their full support in order to obtain enough spectrum at WRC03.
SECURITYSecurity function supported UMTS includes many security functions. Part of it is inherent
embedded in the CDMA technology through the assignment of codes.
Attachment E
Additional security functions are provided at network access, network domain, user domain and application domain levels such as : User authentication through SIM/HLR/VLR.Data Encryption is standardized not only over the air interface but includes also Node B – RNC interface.End to end node data encryption using IPSec
Jammer suppression Yes, narrowband signals are spontaneous suppressed by the CDMA despreading.
Remarks Any Jammer signal is seen as interference and hence has an impact on cell capacity. CDMA copes extremely well with self interference.
An overlay on spectrum occupied by high power narrow band users should be excluded in order to preserve CDMA high user capacity.
INDUSTRIAL MATURITYStatus of development of the necessary components by the industry
Many UMTS components are available on the market ( e.g. MSM 5000-6000 series from Qualcomm). The RF components cannot be used for ATC as the frequency band will different. Depending the new spectrum allocation for a future Terrestrial Com System some components may be used ( function of Doppler compensation ).
Remarks During ANC-11 the request was made that any new radio system must be backward compatible with existing radio com format. Therefore the future terrestrial com radio will be software defined (SDR).
STANDARDISATIONStandardisation status Standardisation process is done through the 3GPP forum.
The Air interface standard is known as R99. Release 5 contains new air interface for HS-DSCH which is not relevant for ATC as it provides a very high data rate in downlink only.
However Release 5 is very important for the All IP based ground infrastructure definition know as Internet Multimedia Subsystem (IMS)
Remarks Though work on standardisation is still evolving to include higher data rates these new releases have no useful impact on the air interface as specified in R99 when ATC functionality is considered only. A larger downlink data rate can only be useful for APC which is not Eurocontrol’s priority.
OTHER IMPORTANTS ASPECTUsing existing standards has large benefits :
ICAO standardisation procedure can rely on existing standards. UMTS standard modification for ATC operation is believed to remain limited to adaptation of frequency bands, power classes, X-tal accuracy at air interface level.
Telecom equipment manufacturers such as Qualcomm, Alcatel, Siemens, Motorola, Ericsson have spent an estimated 50.000 man years on developing 3GPP(2) standard compliant equipment. Therefore it may be assumed that UMTS technology is technology wise the most advanced at this moment. As newer standards such as 4G, UWB all concentrate on higher data rates this has as consequence that modulation schemes (64 -256 QAM) are more efficient but can only serve users in smaller cell areas.
Attachment E
In Europe the EC has spent more than 6 billion euro in R&D funding on 3GPP over the last 15 years ( on programmes such as RACE I, ACTS( FRAMES), CODIT, ATDMA, SIG5).
High level description
Attachment E
CDMA MAIN ADVANTAGE IS ITS HIGH USERS CAPACITY. This high capacity is obtained through two main factors :
1. CDMA is a cellular based communication system2. CDMA is the only cellular system that operates with a frequency re-use factor of 1 (or cluster size = 1)
MOBILE CELLULAR COMMUNICATION SYSTEM: A mobile cellular communications system strength lies in its radio interference behaviour. Many analogue radios transmit continuously at full power often resulting in signal quality levels which are not needed but at the same time creating large RF interference levels. A cellular mobile system handles a large number of low-power wireless transmitters. By controlling the transmit power, cells can be sized according to the user density and demand within a certain geographical area. Each user’s transmit power is controlled in such a way that signal integrity at the receive side is sufficient for the service to be provided to that particular user. Hence RF interference levels are optimised leading spontaneously to an optimised cellular user capacity. CELLULAR SYSTEM CELL SIZE: Reduction of cell size increases the spectral efficiency within a geographical area. When the traffic demand in a cell increases and reaches a point so that the existing spectral allocation in that cell could not support any longer a good grade of service, the cell could be subdivided in a number of smaller cells (cell splitting). Or cells could be split up into sectors. Smaller and/or sectorized cells will dictate users to transmit with lower transmitter power levels compared to the full-sized cell while at the same time increasing cell capacity by a multiple of the original cell capacity. For example the CDMA cell capacity is increased by a factor of 2,5 for a 3 sector cell and a factor 5 for a 6 sector cell. CDMA/FDD FREQUENCY RE-USE: The most important feature of CDMA/FDD is that its cell frequency reuse factor is equal to one, meaning that all adjacent cells use the same frequencies. Hence the large user capacity a CDMA cell can cater for. All other cellular FDD systems (non-CDMA such as GSM) have a lower capacity because the frequency reuse factor is at least 3 (most technologies have an N= between 3 and 7). CDMA BASICS: CDMA stands for Code Division Multiple Access. CDMA makes use of a spread spectrum technology. The information signal bandwidth is expanded (spread) by a hundred fold or more by multiplying the data with a code. This large increase of bandwidth (also called spreading gain) provides a corresponding increase in interference rejection. A large number of CDMA signals share the same frequency channel, and if viewed either in the time or frequency domain, CDMA signals appear to be on top of each other. CDMA users are uniquely identified by a code sequence, embedded as an address, within the carrier waveform.SPREADING-DESPREADING-JAMMER REJECTION: Applying a pseudo random noise source (PN code sequence) to a data signal spreads the energy of the original data signal over a much wider bandwidth. This combination of data and code sequence is put onto the air. Besides the transmitted signal, the receive antenna also picks up background noise, external interference, interference from other cell sites, and interference from other users within the same cell. By applying at the receive side to the overall received signal an identical PNnoise source (=code) the data can be recovered (despreading or code correlation) leading again to the original narrowband signal. During the same process background noise and other sources of interference will be spread out. The interference, now being wide band while the information being narrow band, can be greatly reduced by low pass filtering.CDMA’s PROCESSING GAIN: CDMA’s processing gain is a function of the bandwidth of the data signal versus the bandwidth of the spread signal. The wider the spreading, the higher the gain. In UMTS a 12,2 kbps data rate has a spreading factor of SF=128 resulting in a processing gain of 24,9 dB ( 10xlog(3,84M/12,2K). CDMA is the only technology where such processing gain exists. This processing gain is added in the link budget calculation. (While link budget is improved with 24,9 dB it is deteriorated by 3 (6) dB due to cell loading of 50% (75%). CDMA POWER CONTOL: Adaptive control of power level settings is one of the cornerstones of cellular communications, in particular CDMA. CDMA’s working concept is based on the principle that the power of all mobile units is controlled so as to arrive at the base station at an equal level, regardless if a user would be very close or very far from the BTS (near far effect). This implicitly requires the simultaneous existence of both a down and uplink channel and operate always in duplex. UMTS power control takes place 1500 times per second. CDMA SECURITY FEATURES: for ATC purposes the standardised UMTS security features are too far fetched. CDMA has already inherently some basic security features integrated in its concepts. For the user part (A/C) several million codes are available for assignment together with up to 256 OVSF codes. For the BTS 512 scrambling codes combined with up to 512 OVSF codes are available. Many other security features are part of the standard – from authentication up to data encryption in various stages. Security features have been set up in such a way that real time eavesdropping is impossible and deciphering is only possible in delayed time (depending computing performance). Security can also be implemented at end nodes at application level through e.g IPSec.
Attachment E
CDMA2000 1xRTT
CDMA2000 1xRTTAuthor: EUROCONTROL
ITEMS DESCRIPTIONAIR INTERFACE TECHNOLOGY Duplexing scheme FDDMultiple-access scheme CDMA : CODE DIVISION MULTIPLE ACCESSModulation types Forward Link data QPSK | Reverse Link data BPSK
Forward Link spreading QPSK | Reverse Link spreading HPSK FEC Coding Forward link : Convolutional code ¼ (RS1-RC3) or ¼ (RS2-RC5)
Reverse Link : Convolutional code ½ ( RS1-RC3) or ¼ (RS2-RC4)Both convolutional coders operate with constraint length K=9.
Note1: for data rates > 14,4 kbps a turbo coder ( ½ -1/3 – ¼ ) has been specified for the supplemental channel SCH.
Note2: A forward link RS1/RC4 exists also with other data rates and for convolutional encoder R=1/2 and K=9
Diversity techniques Yes : BTS transmit diversity on 2 antennas(TD). Space diversity. System bandwidth 1,25 MHz (3dB) 1,2288Mcps ( Associated spreading Rate 1)Supported data rates per user RS1/RC3 : 1,2-2,4-4,8-9,6kbps (EVRC-QCELP) for voice
Data : as per voice + 19,2-38,4-76,8-153,6kbps with R=1/4
RS2/RC5(F)4(R) : 1,8-3,6-7,2-14,4kbps(ACELP) for voiceData : as per voice + 28,8-57,6-115,2-230,4kbps with R=1/4
Max. number of simultaneously supported users per sector/cell
Pole capacity = 27 users/cell (voice channels) within an omni directional cell.
Remarks Within this doc only CDMA20001xRTT has been considered as it is the only FDD narrow band CDMA version available. This is important as during WRC07 not enough spectrum may be allocated for a future terrestrial ATC com system based on UMTS.
RC = radio configuration as specified in 3GPP2 (C.S0002-C) and is f (data rate, channel encoding & modulation parameters supported on traffic channel).
RS = Rate Set and determines voice vocoder basic data rate.
SR = Spreading Rate : 1 means 1,228 Mcps / 3 means 3,6864 Mcps
CDMA2000 has in some Forward RC as option CCSH (Code Combining Soft Handover) together with TD.
The traffic channel can have any data rate from 750 bps up to 14,4 kbps.
In case higher data rates are needed 1 or 2 supplemental channels can be added with data rates as defined above and in function of RC.
Attachment E
CDMA2000 1xRTT standard uses the same word “MULTIRATE” for indicating the use of variable data rates. However CDMA2000 does not allow the transmission of ANY data rate as in UMTS but only allows the insertion of 1-2 supplementary channels in addition to the fundamental one.
All CDMA2000 BTS need to be synchronised by GPS in order to be able to make a soft handover.
CDMA is an interference limited system. Its cell capacity limit is sooner reached by its interference level limit rather than by its code availability limit. Hence CDMA is said to have a SOFT capacity.CDMA radios normally transmit at much lower power levels compared to narrow band and/or TDD radios. While analogue (digital) narrow band radios need a SINAD of +12 dB (C/I of +9 up to +11 dB ) a wideband radio operates on negative SIR levels of around -15 dB! The actual SIR value being determined by CDMA processing gain which is function of spreading factor.
GENERIC COMMUNICATION SERVICEService 1
Types voice on traffic channelUser throughput Vocoder either based on 9,6 or 14,4 kbps depending Rate Set
RS2/RC5(F)4(R) : 1,8-3,6-7,2-14,4-{ 28,8-57,6-115,2-230,4}kbpsUser interface TBDConnection topology Point-to-point : Circuit or Packet switched (PDSN)Type of QoS Real Time Conversational class , Real Time streaming class
Service 3Types Packet Data - Connectionless on traffic {and supplemental channel}User throughput RS1/RC3 : 1,2-2,4-4,8-9,6-{ 19,2-38,4-76,8-153,6}kbps
RS2/RC5(F)4(R) : 1,8-3,6-7,2-14,4-{ 28,8-57,6-115,2-230,4}kbpsUser interface TBDConnection topology Point to Point – Point to multipoint – Broadcast / Packet switched
(PDSN) / IP ( simple IP or mobile IP )Type of QoS Interactive and background class / best effort
TOPOLOGYGeographical coverage Cellular terrestrialRange 150-200 NM from the ground station but pilot modification needed.
Remarks CDMA2000 uses a single unique PN code as PILOT which is always broadcast by each BTS. BTS differentiation (needed for soft handover) is enabled by providing a different time offsets (PILOT_INC) to the PILOT of each individual BTS. This concept leads to serious cell range limitations. E.g. Cell ranges of 100 km result in the deployment
Attachment E
of maximum 8 cells/sectors only. To avoid this problem and be able to deploy a large amount of large CDMA2000 cells L1 has to be modified.
Eurocontrol has studied this issue already and can propose a simple way with minimum modifications to the standard.
SPECTRUMCurrent spectrum status Spectrum allocation to be requested at WRC07.
Preference given to VHF/UHF bandPropagation VHF/UHF is not degraded due to rain effectsFrequency Band TBDAvailable spectrum bandwidth At least 2x (1,25 MHz + guard band) should be allocated for a single
forward/backward link. Note : No guard band is needed in between 2 or more forward / backward links.
Remarks CDMA2000 is an FDD system so forward/backward links need to be isolated in the frequency domain. Relative FDD frequency separation should be at least 10% preferable 15%.
In order to avoid silence areas in between large cells a second forward/backward frequency pair is needed (see UMTS).
Eurocontrol proved in 2001 that 18 simultaneous channels could be set up with a prototype. This should allow the simultaneous connection of at least 12 voice channels within a cell dealing with approach, tower, ground, upper airspace, vhf2,….etc within that cell.
AIRBORNE INTEGRATIONAvionics As CDMA always operates in FDD mode the TX is always on.
Fortunately CDMA emits far less power (< 3W) than any existing airborne radio. Existing radios emit > 15 W but all have a small duty cycle. CDMA TX and RX simultaneously on the same antenna. Hence the need of a duplexer behind the antenna.
Mutual spectrum compatibility Because CDMA behaves as AWGN any interference on narrow band systems would lead to a RX sensitivity increase. A guard band must be foreseen between any narrowband analogue and digital radio.
Remarks CDMA needs an ultra linear amplifier. The concept of e.g pre-distortion amplifiers is that linearity increases dramatically while at the same time the amplifier size decreases dramatically as well ( less cooling needed and PA operation in class AB). However within a 3MCU unit the duplexer should be integrated as well.
GROUND INTEGRATIONInfrastructure evolution CDMA 1xRTT ground infrastructure evolves to an all-IP network.
Remarks Mainly ANSI-IS-41 or GSM-MAP or all-IP connectivity
Ground infrastructure consists of BTS/BSC and MTSO. MTSO might be circuit switched/ packet switched based or a combination of both.
The RF Front end of a BTS needs to be converted from auctioned RF spectrum towards ICAO COM spectrum.
CDMA2000 1xRTT needs GPS synchronised BTS.
Attachment E
SERVICE PROVISIONPossible model CDMA2000 could not only supply safety-of-life services but AOC and
APC as well. APC service will however consume scarce spectrum resources. In addition a connection to a public network and the installation of an expensive billing system is needed.Pls note that the CDMA capacity is only 1/3 of UMTS
Remarks Prime service should be ATC. AOC could be supported but with low priority.
MIGRATION/TRANSITIONIdentified issue Implementation phase can only take place when additional spectrum is
granted. Seen the CDMA20001xRTT bandwidth and the heavily used VHF band no big bang operation can ever work out.
Allow incremental deploymentInband transition Only possible with green field spectrum.
Remarks WRC07 spectrum allocation process is determining all future com systems for ATC. States are requested their full support in order to obtain enough spectrum at WRC07.
SECURITYSecurity function supported CDMA is already secured natively by its 2^42 PN Long code
(Backward link) and Walsh code + 2^15scrambling code( forward link) for data and voice.
CDMA uses standardized CAVE to generate 128 bit SSD. The 64 bit A-Key, ESN and network supplied RANDSSD are input to CAVE generating the SSD.
Jammer suppression Yes inherently linked to CDMA systems. Narrow band jammers are suppressed at the RX side after dispreading.
Remarks See UMTS : Security functions are overdone and should be simplified for ATC.
INDUSTRIAL MATURITYStatus of development of the necessary components by the industry
Standard is evolving continuously due to pressure from service providers having deployed IS95A/B.
Remarks CDMA2000 standards are not obvious to read due to the many radio configurations and 2 different vocoders. Its origin is linked with the use of CDMA at 2G (IS95A&B) level in the USA. The backward compatibility needed is leading to a lot of overhead in the standards.
STANDARDISATIONStandardisation status Standard approved by 3GPP2 committee & ANSI/TIA/EIA
Remarks Standards as EV-DO and EV-VD are recently developed but are not to be considered for ATC as in our case high data rate forward ( BTS-A/C) are not needed. Within ATC the backward link (A/C-BTS) is expected to carry most of the data volume.
Last in the row of standards is CDMA2000 1xRTT. The 3xRTT has not been finalised yet.
OTHER IMPORTANTS ASPECTUsing existing standards has large benefits :
Attachment E
ICAO standardisation procedure can rely on existing standards. CDMA2000 standard modification for ATC operation needs adaptation of frequency bands, power classes, X-tal accuracy and MODIFICATION OF LAYER ONE FOR PILOT AND PILOT ACQUISTION ISSUES
CDMA 2000 is mainly driven by Qualcomm who owns most of the patents (even on wave shape). As it is based on 2G communications IS95 A and B many intermediate standards exist.
As newer standards such as 4G, UWB all concentrate on higher data rates this has as consequence that modulation schemes (64 -256 QAM) become more complex. Because these complex modulation schemes have smaller Eucledian distances between symbol constellation points - leading to a very efficient spectrum use- this has as a consequence that only small cell areas ( 0,5-2 km) can be covered..
High level descriptionThe reader is requested to read all info provided in the UMTS proposal because it is also applicable to this “narrowband” CDMA version.
In case WRC07 assigns enough spectrum to ATC, UMTS CDMA should be preferred. The wider a signal can be spread the better it is protected against jamming , the higher the processing gain and the larger the eventual user capacity will be.
In case ACP would opt for CDMA2000 1xRTT than the audience should be aware that some additional standardisation is needed at layer 1 level in order to be able to support large cell ranges. In addition to the outcome of a study let by Eurocontrol some more simulation work is needed. After a positive outcome a more detailed acquisition procedure should be investigated and standardised.
Attachment E
DS-CDMA
DS-CDMAAuthor: AENA
ITEMS DESCRIPTIONAIR INTERFACE TECHNOLOGY Duplexing schemeMultiple-access schemeModulation typesFEC CodingDiversity techniquesSystem bandwidthSupported data rates per userMax. number of simultaneously supported users per sector/cell
Remarks
GENERIC COMMUNICATION SERVICEService 1
Types User throughputUser interfaceConnection topologyType of QoS
Service 2Types User throughputUser interfaceConnection topologyType of QoS
Research to Research to Prove FeasibilityProve Feasibility
Technology DevelopmentTechnology Development & Demonstration& Demonstration
Basic TechnologyBasic Technology ResearchResearch
Timeline Towards 2020 Communication system
11stst Quarter 2005 Inventory of Alternatives Quarter 2005 Inventory of Alternatives Inventory of assessment parametersInventory of assessment parameters
22ndnd Quarter 2005 Selection from Alternatives Quarter 2005 Selection from Alternatives Established communication requirementsEstablished communication requirements
