1. GERAN update on ER-GSM band 11. 04. 2013
UIC RF WS
GERAN update on ER-GSM band

2. Introduction
Standardisation work progressing to include ER-GSM band into relevant Standards
ETSI TC RT activities closed
3GPP GERAN activities ongoing...
...ETSI MSG activities pending
873
918
876
921
880
925
890
935
P-GSM
E-GSM
R-GSM
ER-GSM
915
960 UL DL

3. Frequency ecosystem in the Standards
3GPP
1st step
ETSI
TC RT
GSM railway
TSG GERAN
GSM GPRS EDGE
EN defining
R-GSM band
Change Request needed to refer to ER-GSM band
New version of TS mentioning ER-GSM band TS
TS (RF parameters) TS
TS (conformance testing)
MSG
European
Harmonized
Standards
EN defining
R-GSM band
TSG CT
CN Function
(VGCS, billing)
TS (signalling capabilities)
Harmonized Standard
= applicable at EU level
2 phases approach: need to update 3GPP TS first

4. 3GPP GERAN activities 1/2
During 3GPP GERAN # 57 a Liaison Statement from 3GPP RAN4 was received
Reminder: RAN4 is responsible for UTRA/E-UTRA specifications (UMTS and LTE experts)
The LS answers the GERAN question on UMTS and LTE BS sensitivity and blocking performances not explicitly defined in RAN4 specifications  RAN4 recommends to set mitigation techniques (e.g. power reduction), so that Minimum Coupling Loss of 104/106 dB is ensured between ER-GSM BTS emission and UTRA/E-UTRA reception
Based on this answer NSN proposed a further proceeding
No question about RAN4 assumptions, but a segmentation approach of the ER-GSM band into different sub- bands, with power levels for each sub-band left to be defined in the co-existence study  Mechanism allowing to minimize the power reduction required by RAN4 (see slide 6)
Kapsch CarrierCom disagreed with the conclusions from RAN4
Assumptions on sensitivity of UTRA/E-UTRA equipments seem to be under evaluated, estimated blocking requirements at 918 MHz very conservative  Critics rejected as RAN4 recommendations on their specifications prevail
Limitations of the emissions of ER-GSM equipments should be subject to regulatory rules and not 3GPP specifications  Public operators and Industry firmly in favour of a mandatory requirement in TS

5. 3GPP GERAN activities 2/2 Kapsch CarrierCom presented 4 contributions
Update of the co-existence analysis  further parameters refined to take into consideration inputs from Public Industry and RAN4
Set of Change Requests to include ER-GSM in GERAN specifications
TS , and (see slide 3)
TR "RF scenarios"  Proposal to have no mandatory requirement in the main specifications and informative part in the TR
Proposal was discarded by Public operators and Industry and they would prefer to have a direct reference to the obligation of non-impact of ER-GSM equipments in the main specifications
Offline discussion was held where Kapsch CarrierCom proposed a way forward
See next slides for details
Generally Public operators and Industry ok with it
Way forward not officially communicated, waiting for Railway Operators opinion

6. Simulation of impact: NSN proposal
In their Proposed Further Proceeding NSN
Retained ER-GSM BTS power level of 6/8 dB for coexistence with UTRA/E-UTRA from RAN4 assumptions
Highlighted that power level at MHz can be up to dBm without restriction
Proposed segmentation of ER-GSM band to allow for different carrier output power levels depending on the frequency offset to the GSM 900 UL band
Assuming the 40 dB are equally distributed on 3 segments of 1MHz each power limits would be
Power limit C ( MHz) = 6/8 dBm  coverage distance divided by 8
Power limit B ( MHz) = 19/21 dBm coverage distance divided by 4-5
Power limit A ( MHz) = 32/34 dBm  coverage distance divided by 2-3

7. Offline session: proposed way forward
Participants and goal
Kapsch CarrierCom, NSN, Ericsson, Telecom Italia, Vodafone
Attempt to find a compromise solution based on all comments expressed during the official ER-GSM session
Main result: it is proposed to add the following paragraph in TS

8. Analysis of the proposed way forward 1/2
Preliminary remarks
The proposed way forward is a drastic change from RAN4 and NSN proposals:
No limitation of emission power at ER-GSM BTS side
Instead it considers emission levels received at victim system
In practice the proposed way forward is not directly binding ER-GSM emission, but will require analysis from a regulatory body to assess if victim system is indeed receiving exceeding levels
Would a regulator require ER-GSM BTS to minimize the levels at victim side this could be done either by power reduction or engineering modification (antenna gain, tilt, ...)
Explanations about figures in the proposed way forward
Reappraisal of RAN4 inputs would lead to considerable delays with jeopardized success
Values of -40.4, and dBm and slope of 13 dB/MHz are taken from Kapsch CarrierCom co-existence study on ER-GSM introduction (including RAN4 inputs)

9. Analysis of the proposed way forward 2/2
Graphic representation of the proposed way forward

10. Simulation of impact Goal and Working assumptions
The following analysis derives the worst case scenarios (e.g. 104/106 dB of MCL as assumed by RAN4) to simulate the distance at which a ER-GSM BTS should be placed from a victim system to ensure safe operation of UTRA/E-UTRA equipments  Kapsch CarrierCom is of the opinion that MCL is over estimated and that real cases interferences are likely to be lower than in the simulations
The following working assumptions are taken
ER-GSM BTS: output RF power = 45 dBm, antenna gain = 17 dB, no tilt, coupling losses = 5dB
Victim system: antenna gain = 13 dB, cable losses = 3 dB, tilt effect = 4 dB
3 aiming configuration considered: 0 dB (ER-GSM antenna pointing directly to UMTS site), -3 dB (30° from UMTS site direction), -10 dB (60° from UMTS site direction)
Propagation models: Free space model (only valid for distance < 5 km), Hata Urban & Sub-Urban (valid for distance > 1 km)

11. Simulation of impact: victim considered = MCBTS

12. Simulation of impact: victim considered = UTRA

13. Simulation of impact: victim considered = E-UTRA

14. Conclusions Pros of the way forward Cons of the way forward
Balance power at 3GPP GERAN level not in favour of the railways
Inductive limitation (received signals at victim system): implication of regulatory bodies
Different methods to implement mitigation if required
Limited impact on deployment scenarios provided RAN4 assumptions are unrealistic
Fastest way to finalize ER-GSM band introduction in 3GPP GERAN specifications
Cons of the way forward
Some channels will not be available in dense urban areas
Could jeopardize deployment scenarios of ER-GSM sites even years after  unless a precedence rule is established stating that the way forward is not applicable to UMTS/LTE sites activated after ER-GSM BTS deployment

15. Next steps RTEGSM-R #14 meeting on 23-24 April in Munich
Drafting of Change Requests / Liaison Statement towards 3GPP GERAN
3GPP GERAN #58 meeting on May in Xiamen
Continued discussion on impact from ER-GSM band introduction onto existing systems
Approval of Change Requests?

16. Thank you for your attention.
Thomas Chatelet Railways Regulatory Affairs Railways Customer Solutions Management
Kapsch CarrierCom France SAS SITE DE IMMONTIGNY | 1 RUE JEAN PIERRE TIMBAUD | CS | SAINT QUENTIN EN YVELINES CEDEX Phone +33 (0) | Mobile +33 (0) |
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