ERTMS level in stations A look at the ERTMS operational conditions in larger station areas Presentation at Banebranchen 07, Signalling Programme Chief Engineer Jens Holst Møller
Kastrup Tog til/fra Kastrup Tog til/fra Ny Ellebjerg Tog til/fra Valby 8 8 Ny Ellebjerg Station areas 5 5 5 5 8 8 7 8 8 4 5 Operational capacity 5 4 7 Valby 7 8. Data transmission capacity shall be sufficient to allow systems communications as well as voice communication. o Optimised network design required and migration to package switched communication essentially best option for the entire network.. The operational concept and track layout in areas where trains start their mission shall be optimised. o Trains shall be able to start in the system without written orders etc. Cold Movement Detection is neccesary to enable start (in OS or FS) o Movements in controlled area shall be planned and supervised Avoid shunting moves outside possessions. o Entry/exit areas for stations shall be block-optimised (low speed require short block sections to allow high train density)
Data transmission capacity GSM-R cellular basis The data transmission for ERTMS is based on GSM-R. The available bandwith is 4 MHz which equates frequency slots (0 00 khz slots including guard band). A slot can provide 7 communication channels (two can provide 5 and three ) o Voice calls occupies channel each for the duration of a call. For a larger node around -4 channels will be needed to serve voice calls. o In circuit switched mode each mobile station (train) permanently occupies channel (like a non-stop voice call), in handover between RBC areas channels are used by the mobile station(both modems active). o In packet switched mode each channel can be shared between -5 trains and RBC handover can even be done without modems active.
Data transmission capacity GSM-R base stations typically cover an area of 5-8 km and carry or frequency pairs (TRX s). o To achieve sufficient reliability a redundant A/B base station network is established which traditionally doubles the operated frequencies in an area. o In dense areas the coverage area is reduced and the number of TRX es can be increased to to improve capacity. But less than 000 m cells will require special measures, and obviously increases the cost. The frequency plan for an area will have to take interference into consideration. o Minimum distance between reuse of same frequency (,,,,, priciple) o Measures to control out of band interference from other systems (like 4G/LTE) o In border zones or special geographic conditions the usage of some frequencies can be blocked(due to interference risk) 4
Example: Traffic model for Copenhagen (0) A: Tunnel section, trains A: Platform tracks, 8 trains A: Station access, trains A4: Depot area, 0 trains+0 shunting moves(~5 calls) 5
Example: Cell planning for Copenhagen Frequencies shared with Sweden so repeat pattern must be based on max frequencies BTS distances between 00 m and, km. Sites 404 and 04 have TRX allowing simultaneous CSD trains with 4 channels allocated for voice calls. 40 has TRX allowing 5 CS connections Conventional A/B redundancy clearly not feasible Hot standby principles will instead be used
Data transmission capacity Station areas with more than 0 concurrent train movements within an area of 000 m will require packet switched data (ETCS over GPRS/EDGE) o ETCS over GPRS is specified in B Release (TSI 0/ set #). Changes affect: the ETCS onboard systems (SRS..0, implementing IP stack, QoS parameters and PS SoM/handover procedures) The trackside fixed transmission (new enhanced ERTMS DNS service) The GSM-R network (Eirene 8.0 to implement QoS requirements) 7
Station areas -processes Operational concept and rules (how w/o colour light signals) Shunting will be restricted to areas outside the operational ERTMS system, in track possessions (TSA & PSAs using ERTMS mode SH). SH will predominantly be used by freight trains and yellow fleet. o Shunting in TSAs(Interlocked area) will be performed on shunting routes set by Shunter(through Handheld Terminal using GPRS) All remaining movements inside the ERTMS area will be performed from leading cab, supervised on a MA (ERTMS modes FS or OS). This increases speed of operations and reduces the risk of passing signals at danger, overspeeding, damaging points etc. Train data is neccesary: Default traindata available in Onboard or transmitted from train computer(depending on train type) 8
Joining, splitting & Start of Mission In a total of 5 stations, relevant tracks will be equipped for effective splitting and joining of trainsets Tracks with short detection sections and extra odometry correction balises Only short drive in ERTMS mode OS At all entries to ERTMS area, position balises ensure that the SoM happens with a valid position All trains entering the system will be able to start with a real movement authority (MA OS or FS)
Station areas Migration deployment principles Deployment is done in sections, typical boundary at the existing block-interface to avoid transitions in stations. The majority of equipment is installed in parallel to the operational railway. Point machines and level crossing protection systems are migrated through a combination of over and back on central point machines and migration+blocking before, respectively after commissioning Interfaces between migrated lines and lines with legacy signalling are divided in two classes: o Temporary interfaces where trains shall stop and switch over (max two weeks) o Interfaces where trains can transition automatically (no limit) 0