Activities in CEPT ECC/WGFM/ Project Team FM54
3rd Interferences Workshop - European Commission (DG Move) and the European Railway Agency
(ERA), 25 November 2014
Thomas Weber, ECO, Spectrum Management
Content
•
On-going work in Project Team FM54
•
Development of draft ECC Report 229
•
Interference Mechanisms
•
Draft Conclusions in ECC Report 229
•
Coordination/cooperation process
Where does the action take place?
Interference Mechanisms (1)
Interference Mechanisms (1)
A
925 MHz
GSM-R
channel
Unwanted emissions from UMTS/LTE in the GSM-R
channel
f
Interference Mechanisms (2)
A
Max. mixer power
Min. S/N
f
Receiver blocking due to high input powers
Interference Mechanisms (3)
A
GSM-R
channel
f
fIM

f1
f2
fIM = 2*f1-f2
Receiver intermodulation (2 narrowband signals)
Interference Mechanisms (4)
924.8MHz
UMTS
921.2MHz
GSM
UMTS signal
IM products (all)
IM frequencies involved when GSM-R frequency is 921.2 MHz
IM frequencies involved when GSM-R frequency is 924.8 MHz
Receiver intermodulation (1 wideband signal)
Draft ECC Report 229
•
It is planned to submit the draft ECC Report to the next WGFM meeting in February 2015
for public consultation approval.
•
Draft conclusions recognise:
•
EIRENE specifies requirements for a digital radio standard for the European railways
•
Both GSM-R and MFCN (Mobile Fixed Communications Network) licensees use the radio
spectrum in compliance with the relevant European and national regulations
•
Realistic UMTS and LTE signals have lower unwanted emission levels (10 to 20dB) than
specified
•
Measurement campaigns performed in 2013-2014 concluded that intermodulation products due
to UMTS/LTE intra-signal intermodulation and also inter-signal intermodulation with GSM are
generated within the current cab radio receivers and affects their operation
•
Wideband signals impact the whole GSM-R frequency range. UMTS, LTE/5 MHz and LTE/10
MHz have the same interference potential
Draft ECC Report 229
•
In order to successfully mitigate interferences due to blocking and intermodulation, the
standard relevant for GSM-R radios (ETSI TS 102 933) was improved with respect to the
receiver characteristics and published in August 2014. Field test clearly showed the
improvements achieved by the radio module vendors. Nevertheless, improved receivers
will still be impacted by unwanted emissions from nearby mobile/fixed communications
networks
•
A coordination/cooperation process should be used before, during and after the transition
period towards improved GSM-R receivers
•
The process may also be used to prevent interference from MFCN OOB emissions
before, during and after the transition period taking into account the predicted GSM-R
signal level then confirmed by measurement. Visibility and exchange of information shall
remain to prevent any further issues
Draft ECC Report 229
•
A formula is included in draft ECC Report 229 to provide the maximum MFCN OOB level
that should be fulfilled at 4m above the rail tracks by MFCN operators, which provide a
trigger to start the coordination process
•
The proposed generic coordination/cooperation process can be adapted to meet national
needs and remain a national decision, noting that existing processes are already in use
•
To support the technical analysis, a single agree electronic tool could be developed,
based on SEAMCAT; this is currently under investigation.
Coordination/cooperation process
Roadmap Approval ECC Report 229
•
9-13 FEB 2015: WGFM#82 approves draft ECC Report 229 for public consultation
•
Beginning of March – mid April 2015: public consultation process
•
18-22 May 2015: WGFM#83 approves ECC Report 229 for publication
•
25 May 2015: publication
Using Seamcat as a potential tool for GSM-R-MFCN in support of national
coordination/cooperation, please note the workshop on 5-6 March 2015 that is especially
covering EPP (Event Processing Plugin) customisation.
http://www.cept.org/ecc/tools-and-services/cept-workshops
Thank you for you attention
Questions??
Thomas.Weber@eco.cept.org
www.cept.org/eco
www.cept.org/ecc