RADIO COMMUNICATIONS SYSTEMS

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Jubilee 2000 Rome Simulcast Network
Fire Brigades requirements scenarius at
beginning of 1999

• 20 million people are expected during year 2000
• Fire Brigades need reliable radio communications
  in order to cover their urban and provincial Rome
  area (5300 km2) as well as their subway
• Speech and new data transmission services
• Re-use of existing VHF analog fleet and
  comunication protocol (CTCSS based)
• Only 2 broadcasting channels available 1 VHF and
  1 UHF
• Mobile-Dispatcher and mobile-mobile
  communications
• New dedicated backbone, open to future
  enlargements
• Network and fleet management services required by
  Rome Fire Brigades Headquarters

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Jubilee 2000 Rome Simulcast Network
Network diagram
S
S
S
CST
I Nesting Level
S
A2T
II Nesting Level
LIN
III Nesting Level
Rome Firebrigades Headquarter
Subway Segment
microwave link (PCM) UHF monochannel
link land line (4WEM)
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Jubilee 2000 Rome Simulcast Network
Synchronisation
A2T RBS

• GPS frequency (and time) synchronisation
• Synchronisation back-up from master in case of
  GPS failure

CST RBS

• Reference extracted directly from UHF link
  carrier coming from the sub master RBS

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Jubilee 2000 Rome Simulcast Network
Equalisation

• General characteristics
• DSP based
• 300?3400 Hz 1dB (amplitude), 10 (phase)
• Uplink and Downlink RBS equalisation
• - Upl from broadcast Rxs to voter (mainly
  for data transmission)
• - Dwl from voter output to broadcast Txs

Non equalised signal quality in the overlapping
area
Equalised signal quality in the overlapping area
TX2
TX1

• A2T (autoadaptive) technology
• a pattern is periodically sent to all RBSs which
  is compared with memorised pattern
• differences are used by DSP to calculate new
  equalisation parameters
• GPS provide necessary timing reference
• audio paths are automatically recovered

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Jubilee 2000 Rome Simulcast Network
ECOS simulcast equipment
CST RBS
A2T RBS
ECOS RBS have a modular structure, developed from
the same RD program (RF receivers and
transmitters, DSP base band and simulcast
devices) and are manufactured and tested on the
same premises
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Jubilee 2000 Rome Simulcast Network
What we learned from the application

• ECOS simulcast solutions are able to warranty
  very good voice quality and effective data
  transmission even if many RBSs are placed at
  different nesting levels and are connected by
  time variant links
• Analog simulcast is the right solution for wide
  area applications for emergency services, when
  few frequencies are available, low traffic is
  required, open channel communications and data
  based services are requested