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INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 1
Radio bearer capacity and planning for ETCS
Solutions for BSS redundancy
Eric SAUTHIERLaurent POUTAS
10th December 2003
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 2
AgendaAgenda
IntroductionØ Targets of BSS redundancy
Single coverage architecturesØ Definition, Pros & Cons
Double coverage architecturesØ Definition, Pros & Cons
Capacity aspectsØ Theoretical capacities vs. terrain realities
Border issuesØ Illustration through Basel city
Conclusion
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 3
IntroductionIntroductionTarget of BSS redundancyTarget of BSS redundancy
• The very purpose of GSM-R is to ensure safe and reliable communicationsfor railways environment
è ETCS level 2/3 maximum non-availability times:
• The RF interface is a key point for reliability aspects:– Open interface exposed to external perturbations– Lots of on-field equipments prone to disturbances (BTS, transmissions; antennas)– Accomodating small spectrum allocations (4 MHz for standard GSM-R)
è Redundancy is aimed at improving system overall availability
ETCS 2/3
Other voice/data services
4 hours per 10 years (i.e. 99.995 % availability)
8 hours per year (i.e. 99.91 % availability)
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 4
Single coverage architecturesSingle coverage architecturesLow overlap sitesLow overlap sites
• Single layer, normal cell overlapPROS
– Low cost– Easier to parameter– Most efficient spectrum use for capacity– Fewer sites acquisition
CONS– Loss of service if a BTS is down
BSC A MSC A
Safety first!If the ETCS service isdown, trains will stop
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 5
Single coverage architecturesSingle coverage architecturesHigh overlap sitesHigh overlap sites
• Single layer, high cell overlap (if a cell is missing, service is still ensured)PROS
– BTS redundancy– Medium cost
CONS– No redundancy in case of any BSS element failure, except for a single BTS– Some impact on QoS (high number of HO)– Less efficient spectrum usage (large cell overlap)– Numerous site acquisitions– Medium parameter settings complexity (definition & maintenance)
BSC A MSC A
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 6
Double coverage architecturesDouble coverage architecturesCo-located sitesCo-located sites
• Dual layers, co-located BTSPROS
– Full system redundancy available– Low number of site acquisition (if site/mast sharing)
CONS– Higher cost– Parameter settings more complex– Loss of service if a physical site is blown
BSC B MSC B
BSC A MSC A
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 7
Double coverage architecturesDouble coverage architecturesInterleaved sitesInterleaved sites
• Dual layers, interleaved BTSPROS
– Full system redundancy available– Service is still ensured if a site is blown
CONS– Higher cost– Less efficient spectrum usage (multi-server effect)– Parameter settings more difficult– Lots of site acquisition
BSC BMSC B
BSC A MSC A
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 8
Capacity AspectsCapacity Aspects
Theoretical capacities– Planning in ideal conditions:
• single straight track,• flat & homogenous terrain
– The ratio of available frequencies to the distance remains the sameè Only minor capacity differences among the different architectures.
Real world– Complex topology– Crossings, nodes negative impact over C/I– Obstacles, Tunnels
• Need to manage mobility (High speed, HO, ..) highly depends on C/I
è Although practically achievable values are lower,the flexibility of GSM-R redundant architectures allowsto offer good capacity even with strong terrain constraints
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 9
ETCS solution in a difficult case:ETCS solution in a difficult case:Spectrum sharing in BaselSpectrum sharing in Basel
Case studyImplementation of ETCS facing terrain constraints
Basel, Switzerland gathers difficulties:– Complex spectrum sharing at border– Unfavourable topology: 3 countries, many tracks
Rhein
Railways
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 10
ETCS solution in a difficult case:ETCS solution in a difficult case:Spectrum sharing in BaselSpectrum sharing in Basel
DFF973DDSUI972
SUISUISUI971DDSUI970DDF969
SUISUISUI968DDSUI967DDF966
SUISUISUI965DFF964DDF963
SUISUISUI962SUIFF961DFF960
SUISUISUI959SUIFF958SUISUISUI957SUIFF956
D-SUIF-D-SUIF-SUIARFCH
European spectrum sharingagreement (1999)
• 9 channels for F-SUI bordersituation
• Only 6 channels for F-D-SUIborder situation !
• 9 channels for D-SUI bordersituation
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 11
ETCS solution in a difficult case:ETCS solution in a difficult case:Spectrum sharing in BaselSpectrum sharing in Basel
Frequency reuse policy
• 9 channels to use for F-SUI and D-SUI situation
– Redundant architecture on trackspossible
– Redundant architecture for clusterplanning not possible
• Only 6 channels to use forF-D-SUI situation !
– Redundant architecture on tracks onlypossible under ideal conditions
– No complete cluster 7 planningpossible
13
45
6
2
13
45
6
2
1/25
67
8
3/49
1/25
67
8
3/49
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 12
ETCS solution in a difficult case:ETCS solution in a difficult case:Spectrum sharing in BaselSpectrum sharing in Basel
• Frequency planning of this high traffic area with only 6 possible channels !
D-SUIF-D-SUIF-SUI
69
9
Solution: Cross border agreement between the three operatorsè common planning of Basel area (F/D/SUI)
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 13
Meeting ETCS challenges with GSMRMeeting ETCS challenges with GSMRReliability and capacityReliability and capacity
• GSMR meets ERTMS reliability targets thanks to redundancysolutions available at each BSS level (TRX, BTS, BSC, MSC,transmissions).
• Flexible redundant coverage solutions: they can be mixed to tightlymeet terrain constraints and customer requirements.
• Very good integration of GSMR track coverage with tunnel and indoorcoverage solutions.
• GSM-R has a high spectrum efficiency in traffic hot spots thanks tothe reuse of public GSM experience.
• One active TRX per site solutions available to fit ERTMS over tightspectrum allocations.
• GSM-R redundancy solutions offer the best answer toERTMS requirements, meeting expectations in a wide rangeof operational situations.
INDUSTRY GROUP
ALSTOM HÖRMANN FUNKWERK KÖLLEDA KAPSCH MARCONI MOBILE ACCESS NORTEL NETWORKS SAGEMSIEMENS INFORMATION & COMMUNICATION SIEMENS TRANSPORTATION SYSTEMS 14
Meeting ETCS challenges with GSMRMeeting ETCS challenges with GSMRConclusionConclusion
GSM-R flexible architectures can fulfil ETCS needs,from a low cost, single coverage solution to a higher cost, fullyredundant solution guaranteeing ETCS service.
CapacityReliability
Cost
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