Ioannis Tomkos AIT

1. WP-JP-E on mitigation of optical transmission impairments by electronic meansFirst Review MeetingBrussels, 23-24 May 2007 Ioannis Tomkos AIT

2. WP-JPE: mitigation of optical transmission impairments by electronic means • Scope • to study and further develop techniques and schemes for next-generation Core, Metro and Access networks that are based on advanced electronics and be able to enhance the transmission efficiency when applied at the physical transport layer. • Leader: • Ioannis Tomkos, AIT, Greece • Advisory Board • Pierluigi Poggiolini (PoliTO) • Izzat Darwazeh (UCL) • Josep Prat (UPC) • Antonio Teixeira (IT) • Ronald Freund (Fraunhofer) • Partners involved • 9 active partners • PoliTO, UPC, IT, GET, UCL, FT, UoA, AIT, Fraunhofer

3. JP-E Organization • Topics of research • Equalization techniques, FFE,DFE, MLSE • Equalization in WDM systems, for CD, PMD, NL • Coherent multi-level systems + equalization • Impairment tolerant formats • Signal pre-distortion, pre-shaping • DML pre-/post-equalization • MMF equalization • Focus on various network segments: • Access, Metro, Core

4. JP-E Organization

5. JP-E Task 1 – on access Studies in access networks focus on: • electronic processing techniques to compensate multimodal dispersion in multimode fibres. • Studies include: • FFE/DFE equalization in MMF • DML transmitter equalization • special modulation formats with cost effective pre-processing schemes that may be proven efficient in this type of networks. • Studies include: • Multilevel formats • Pre-processing in DMLs The general goal is to increase the access network capacity and/or reach at a cost effective manner.

6. JP-E Task 2 – on metro Studies in metro networks focus on: • 10 Gbit/s metro/access or higher with single mode fibres • Studies include: • Mitigation of chromatic dispersion in ring based topologies. • Non-linear effects and PMD compensation (at higher rates). • The effects of ROADMs when these are cascaded in a ring configuration. • Special transmitters/receivers for cost effective and high capacity metro and extended access networks • Studies include: • Multilevel coherent detection systems with equalization • DML with extended reach capabilities The goal is to use electronics only at the end nodes and achieve transparent transmission in the metro reducing the overall cost. The efficiency improvement that is offered by electronics when these are combined with special modulation formats, which are more appropriate to metro networks, is also part of this task

7. JP-E Task 3 – on core Studies in core and long haul networks focus on: • The mitigation of impairments due to non-linearities, dispersion and PMD • Studies include: • Simple equalizations schemes (FFE/DFE) • Advance equalization schemes (MLSE receiver) • Comparison studies combining modulation formats and equalization • Effects of equalizers in WDM networks The goal here is to enhance the system reach and additionally provide efficient adaptive solutions for time varying effects. In transparent networks the performance efficiency by the use of electronics may assist towards the reduction of regenerators in the network offering better economics.

8. JP-E Objectives An outline of objectives… • Design of electronic channel equalization schemes. • Design of electronic pre-/post-coding schemes • Examination of the performance limitations and the benefits of different schemes at different network segments. • Examination of the performance of available transceivers (modulation schemes).

9. JP-E Work plan FFE/DFE Equalization + Modulation formats MLSE Pre-Equalization Designs Coding FEC Combinations In access MMF Longer distances In metro Studies Performance Dispersion/OSNR Higher capacity In core Non-Linearities Comparisons

10. JP-E Activities per partner Research fields per partner poliTO MLSE receivers – Algorithm, design optimization Coherent systems + equalization. Optical PLL to increase receiver sensitivity FT WDM system equalization (CD, PMD) MLSE receiver FEC + equalization (comparative studies) ENST PMD equalization studies (1st and 2nd order PMD) Modulation Format (MOTS) to reduce SPM-induced chirp – Signal Pre-shaping

11. JP-E Activities per partner HHI Coherent systems (optical 16QAM) + Equalization IT Modulation Formats (OSSB) dispersion tolerant – Signal pre-shaping AIT WDM system equalization (CD) – DFE/FFE optimization DML – equalization UPC Coherent systems – Homodyne receivers (for ultra-DWDM in PONs) DML – Frequency modulation + pre-/post-equalization UoA MMF, plastic fibre equalization for Access, Home networks

12. Main Achievements • N° meetings and workshops • 3 meetings, • 3 workshops • N° Joint papers • 4 published, 2 pending, 1 under preparation • Public deliverables • 2 • Shared infrastructures • - • N° mobility actions • 4 mobility actions, • (2 more under preparation)

13. Meetings and Workshops

14. Joint Papers P. Poggiolini (PoliTO), G. Bosco (PoliTO), J. Prat (UPC), R. Killey (UCL), S. Savory (UCL), Branch Metrics for Effective Long-Haul MLSE IMDD Receivers, ECOC 2006 - paper We2.5.4, September 2006.J. Prat (UPC), M. C. Santos (UPC), M. Omella (UPC), A. Napoli (PoliTO), Electronic Distortion Equalization for Dispersion-Limited Radio-over-Fiber Systems, 13th International Conference on Telecommunications – ICT’06-, ., Vol. 1, No. 1, pp. 4, Madeira, May 2006. P. Poggiolini (PoliTO), R. Killey (UCL), J. Prat (UPC), 1,040 km uncompensated IMDD transmission over G.652 fiber at 10 Gbit/s using a reduced- state SQRT-metric MLSE receiver, ECOC 2006 - PD paper Th4.4.6, September 2006., Vol. 5, No. 1, pp. 3, Cannes, September 2006

15. Mobility Actions • PoliTO, UCL, UPC: • On the development and testing of MLSE equalization technique • PoliTO, UPC, IT: • Plans for further investigations and realization of MLSE • UPC, IT: • On the performance increase of low cost receivers with the use of SQRT equalizer. • UoA, PoliTO: • On electronic dispersion compensation for multimode and plastic optical fibers

16. JP Budget Allocation Criteria • The criteria on which the distribution will be based are:  the partners’ activity indicators of the first year, according to the point-score system  the general responsivity of the partners to VD initiatives  whether partners actively contributed to surveys and deliverables  whether they served in the Advisory Board or other VD-managing entities • A common scoring (point) system has been introduced among VDT, JPE and JPT: • According to this: Each MOBILITY ACTION is awarded: • 1 point per 5 working days of staff/post-doc mobility • 1 point per two calendar weeks of PhD student mobility Joint papers are awarded • 3 points: long-paper major-journal publications and post-deadline • 2 points: OFC and ECOC, and short-paper major-journal publications • 1 point: other journal publications (in English, refereed) • 0.5 points: other conference publications (international, in English) Participation in Meetings workshops • 0.5 points per meeting participation and • 0.5 points for each workshop presentation

17. Resources employed: Effort 90% Permanent staff (AC): 2 m/m

18. Resources employed: Budget 86%

19. Plan for Second Year Following the developed techniques and studies within the first year the following activities have been identified for the second year: • Extended research activities for the second year • Optimization of the MLSE equalization technique and further studies lead by PoliTo • Implementation of the SQRT receiver lead by UPC • Combinations of modulation formats with equalization techniques studied by various partners. Main focus is on coherent and multi-level systems • Investigation of equalization in WDM systems • Implementation and experimentation on equalization techniques for access networks incorporating MMF • New research activities planed for the second year • Experimental investigation of pre- and post- equalization in DMLs in order to extend their reach • Joint publication • Preparation of a tutorial paper on the topic “Electronics for the mitigation of physical impairments”

20. Scientific and Technical Impact JP-E addresses a new scientific topic that gained a lot of interest within the last few years only. Results may appear limited in number but are of great significance and uniqueness: • MLSE equalization method • Holds the world record in uncompensated transmission distance (>1000km)! • The only work that reported in post deadline paper • SQRT receiver • A unique device that can significantly increase the receiver sensitivity • Joint activity focuses on the realization of this device • a. Cheap Tx or modulation formats + equalization b. Equalization in MMFs • Investigated methods are of great importance to industry as the can provide extended reach for access and metro at a very low cost per user.

21. Final Comments Within the first year the JP-E partners have investigated and developed a number of equalization techniques. It is our purpose to extend these knowledge and where applicable implement the proposed schemes as well as optimize the techniques within the second year. Significant research innovations are investigated or already been reported with impact in European industry ranging from access to metro and core applications.