Technical Solutions on Interferences to GSM-R Philippe BRANLY GSM-R Product Line Manager

1. Technical Solutions on Interferences to GSM-R Philippe BRANLY GSM-R Product Line Manager Sierra Wireless www.gsm-rail.com

2. Interferences are an increasing and recognized concern for Railway Operators Radio communication quality of service of all railway safety related applications between on-board and track-side is an investment  it must be protected Different solutions considered so far Enhancements at receiver side Insertion of protective filters in cab radio or between the cab radio and the roof antenna Increased coverage level Improved spectrum availability Protection from Mobile Network Operators (MNO) radio sites Crossover frequency coordination Technical Solutions on Interferences to GSM-R 07.09.2014

3. Influence of out of UIC GSM-R Band Interferer coming from public mobile operator interferer Blocking and intermodulation creating extra noise inside receiver Blocking mechanism  1 interferer adding noise inside usefull channel Intermodulation  2 interferer signals combining into an Intermodulation product over wanted signal Spurious emissions inside GSM-R band coming from out of band interferers 3 main solutions Enhancements at receiver side: signal processing, received diversity, new antennas for cab radio Protection against out of band interferers: BTS filters at MNO side, coordination Increased coverage level: higher output power, Dual TDMA, radio site densification Short reminder on interferences 07.09.2014

4. Better receivers already available on the market Improvement against blocking caused by Intermodulation Tests organised by UIC in England have proven recently that improved receiver can support very hard LTE, 3G, 2G blocking environments without any quality degradation New radio modules designed to be easily integrated in existing cab radios Receive Diversity Simple principle: two receive paths improving radio reception Gain increased by 3 dB towards serving site, gain lowered in interferer direction Need of two antennas on roof top of train, signal processing in radio module Potentially applicable to 2 cab radio locos Cab radio antenna improvement Typical antenna radiation pattern not adapted in interfered scenarios Alternative antenna Enhancements at receiver side 07.09.2014

5. Agenda • Network solutions • Train additional filter solution • Improved radio solution

6. Network solutions Train additional filter solution Improved radio solution Agenda 6

7. Filters in public operators' BTS UMTS, LTE and GSM MultiCarrier BTS can cause more emissions in the GSM-R Downlink band than single carrier GSM External filters installed on public sites can minimize those emissions A rejection of around 20 dB can be expected (however upper frequencies of R-GSM band might not be protected) Negotiation with public operators so that such filters can be installed Improved GSM-R coverage Interferences mitigated by improved radio coverage / improvement of the C/I New radio sites to be inserted in addition to existing ones Higher output power to be used on existing radio sites, or Dual TDMA (3 dB coverage gain) Improved antenna (e.g. narrower beam / higher gain) Redesign of existing radio coverage Network solutions 07.09.2014

8. Fine tuning on engineering parameters For geographically located interferences, possibility to advance/delay the HO Modification of some radio parameters at the network side is achievable by all network suppliers Simple solution after thorough study of the interference case Frequency band management Re-allocation of carriers onto other frequencies Simple software-based action, remotely controlled, applicable to railway or public networks But available R-GSM frequencies are limited (19 frequencies) Re-allocation of broadband systems (UMTS/LTE) frequency is more complex (5MHz carrier) Network solutions 07.09.2014

9. Network solutions Train additional filter solution Improved radio solution Agenda 9

10. Produce a small economical filter that can be retrofitted on trains Fit either adjacent to the radio equipment or insert in the antenna cable Accept that the very worst cases may still require some negotiation with network operators (e.g. channel change) For voice applications Include ability to disable filter for when coverage of public bands is required Can be retrofitted to existing GSM-R installations A Possible way Forward for On-Train Filtering

11. Network solutions Train additional filter solution Improved radio solution Agenda 11

12. IMPROVED RECEIVERS • Keep the whole frequency range compliant to ETSI including the new ER band • Upward compatible with existing Radio Modules • Equivalent to an external filter • No extra-cost requested by filter installation between the rooftop antenna and the GSM-R MS SIERRA WIRELESS FUNKWERK Sierra Wireless Proprietary and Confidential www.gsm-rail.com

13. CAB RADIO and EDOR using improved receivers ALSTOM FUNKWERK KAPSCH SIEMENS

14. CONCLUSION • INDUSTRY HAS DEVELOPPED SOLUTIONS THAT ARE AVAILABLE. • INDUSTRY HAS DEVELOPPED SOLUTIONS THAT ARE COMPATIBLE WITH EXISTING EQUIPMENTS IN THE TRAINS. • INDUSTRY HAS PARTICIPATED ACTIVELY TO OFFICIAL AND PRIVATE TESTS THAT PROVED THE PERFECT EFFICIENCY OF THE SOLUTIONS. WE ARE READY FOR SOLVING EXISTING ISSUES RIGHT NOW Sierra Wireless Proprietary and Confidential www.gsm-rail.com

15. Thank you www.gsm-rail.com