1. direction générale de lAviation civile direction de la Technique et de lInnovation direction des services de la Navigation aérienne AGCFG meeting Brussels 18/09/2006 ETDMA Study results: Integration of ETDMA sub- network within an ATN/IP network Sous-titre facultatif de la diapositive Luc Deneufchatel] Présented by

2. - 2 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation Agenda 1. End-to-end connectivity i.VDL/ETDMA architecture ii.Protocols stack model iii.Mobility management iv.Addressing requirements v.QoS management 2. Guaranteed QoS i.At ATM services level ii.At ETDMA network level iii.End-to-end iv.In the Internet 3. Conclusion

3. - 3 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation End-to-end connectivity Objectives –Definition of protocols stack model for end-to-end connectivity (without using ISO 8208, identification of ETDMA users) –Clarify the role of each protocols stack layer –Describe service primitives –Define addressing requirements –Describe QoS management (soft guaranteed QoS)

4. - 4 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation End-to-end connectivity ETDMA architecture ETDMA Sub-Network ETDMA Network Users

5. - 5 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation End-to-end connectivity Protocols stack model

6. - 6 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation End-to-end connectivity First contact

7. - 7 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation End-to-end connectivity Data transfer –LREF compression: specific to CLNP and thus provided in Frame Mode SNDCF proper (refer to ATN specifications) –Deflate compression: part of ETDMA network layer and it requires a low probability of re-ordering! Problem: ETDMA Data Link layer provides a high probability of re-ordering (use of ETDMA Classes of Service). Adaptations are thus necessary: Frame Mode SNDCF proper should handle ETDMA QoS to request appropriate ETDMA QoS before compression One Deflate compressor should be used for each ETDMA QoS (one channel should be established for each ETDMA QoS) Deflate function has to be implemented at the link layer level ETDMA network should transit data using the requested ETDMA QoS –Priorities: priorities should not be used after Deflate compression => priorities should not be used at ETDMA Data Link level

8. - 8 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation End-to-end connectivity Data transfer –Delivery reliability: at Data Link level, ETDMA should implement acknowledgements and a CRC –Service primitives: description of parameters and behaviour (uplink)

9. - 9 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation End-to-end connectivity Handoff –Handoff between Ground Stations in same cluster has only a minor impact on air and ground: On ground side, it will be handled by the GNI On airborne side, the ETDMA radio should recognize that it is still connected to the same ETDMA sub-network, using first part of the address of ground ETDMA users (A/G Routers) advertised using the GSC. –Handoff between Ground Stations in different clusters has more impact on air and ground: On ground side, it will be handled by the previous GNI (leading to Leave Event) and the next GNI (leading to Join Event) On airborne side, the ETDMA radio should recognize that it is no longer connected to the same ETDMA sub-network, using first part of the address of ground ETDMA users (A/G Routers) advertised using the GSC. This will lead to Join and Leave Events.

10. - 10 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation End-to-end connectivity Addressing requirements Ground-based ETDMA User address Mobile ETDMA User address

11. - 11 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation End-to-end connectivity QoS management –ETDMA Classes of Service Frame Mode SNDCF proper should have capability to handle ETDMA Classes of Service to request appropriate ETDMA Class of Service ETDMA link layer should use one Deflate compressor for each ETDMA Class of Service (one logical channel for each ETDMA CoS). ETDMA Ground Stations and radio should transmit data using the requested ETDMA Class of Service. –Priorities Priorities should be used before and not after compression i.e. at the level of the Frame Mode SNDCF and not at the level of ETDMA. Some mechanisms should be implemented to allow the ETDMA network layer to know status of sending queues within lower layers. –Integrity ETDMA should implement an acknowledged service between an ETDMA Ground Station and an ETDMA radio. A CRC should be used.

12. - 12 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation Guaranteed QoS Objectives –Investigate the implementation of guaranteed QoS (hard guaranteed QoS) at ATM services level using ETDMA capabilities –Methodology: Analyse the gap between guaranteed QoS at ATM services level and guaranteed QoS at ETDMA network service level Review solutions implemented in the Internet to provide a guaranteed QoS

13. - 13 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation Guaranteed QoS At ATM Services level –Operational requirement for a hard guaranteed QoS –Several possible solutions for guaranteed QoS implementation: Time stamps could be added in messages sent by the ATM service. Main drawback: sending of additional information (time stamps) Timers could be implemented at ATM services level (current solution with ATN). Main drawback: lack of responsiveness and requires a reply at ATM service level Network service could support the provision of compulsory and guaranteed QoS. Main drawback: additional mechanisms must be implemented –ATN Classes of Communications should be re-defined as they are not adapted to the implementation of guaranteed QoS to meet operational requirements –Guaranteed QoS applicability: A flag is required to indicate whether the ATM service requests best-effort, compulsory or guaranteed service Operational context may need to be considered to set this flag!

14. - 14 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation Guaranteed QoS At ETDMA network level –QoS provided in an ETDMA cell from a user viewpoint: Guarantee of a minimum QoS (maximum transit delay and minimum throughput), which essentially depends on the size of slots, the size of families and ETDMA frame duration. Actual QoS, which depends on the current traffic load conditions (number of aircraft inserted into the ETDMA cell). –QoS provided in a multi-cells environment: Minimum QoS (maximum transit delay and minimum throughput) that ETDMA can guarantee to an aircraft is expected to change when moving from one cell to another one. –QoS provided at ETDMA network level: Integrity using CRC Priorities before compression (at ETDMA network layer) QoS parameters in SN-UnitData.Request service primitive: QoS category, ETDMA QoS, Max Transit Delay

15. - 15 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation Guaranteed QoS End-to-end –Main issue is to implement the guarantee of a maximum transit delay: Need to estimate the maximum one-way ATN mobile sub-network transit delay Need to estimate the maximum one-way ATN end-to-end transit delay Need to provide this information to end users Need to report anomalies

16. - 16 - AGCFG meeting Brussels 18/09/2006 direction générale de lAviation civile direction des services de la Navigation aérienne direction de la Technique et de lInnovation Guaranteed QoS In the Internet –Initial development to provide a best-effort service: not adapted to carry real time traffic that requires a guaranteed transit delay and minimum throughput –Integrated Services (IntServ) model –Differentiated Services (DiffServ) model –None of those models really provide a « guaranteed » QoS –No real benefit to be taken from the IP world and there is a strong need to further investigate the issue and to address the necessary evolutions required at transport layer level