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KOALATYAUSTRALIA

Band-selective BDA coverage for underground rail

Radio coverage carried into running tunnels and onto platforms from a donor link to the serving base station site, amplified band-selectively so only the nominated services are re-radiated.

RFI's BDA range suits structures close to a host site where the signal is obstructed rather than absent. The donor antenna, the amplifier and the platform antennas are all specified on the same band, so the system is coherent end to end.

DONOR LINK
698 – 890 MHz
AMPLIFIER
800 – 890 MHz, band selective
PLATFORM
806 – 870 MHz
DISTRIBUTION
Radiating cable and antennas
PIM
−150 dBc, platform antennas

PRINCIPAL PARTS

System schematic

LONGITUDINAL SECTION — NOT TO SCALE

Select a numbered callout to see the equipment at that position and its published specification. Keyboard: tab to a callout, press Enter.

Underground rail BDA coverage systemLongitudinal schematic showing a donor antenna and band-selective amplifier at the portal, feeding a radiating cable through the running tunnel to platform antennas at the station.GROUND LEVELPLATFORMRUNNING TUNNEL — 1 600 mTECHNICAL ROOMRADIATING CABLE — SHARED, 7/8"TO RAIL OPERATIONS CENTRECallout 1 — Off-air donor antennaFifteen-element yagi on a mast at the portal, aimed at the serving base station site.1Callout 2 — Band-selective headendBand-selective bi-directional amplifier and filtering in the portal technical room.2Callout 3 — Low-PIM power dividerFour-way low-PIM divider splitting the amplified output between the tunnel feeder and the platform.3Callout 4 — Shared radiating cableLeaky feeder run at crown height along the running tunnel and over the platform.4Callout 5 — In-line amplifier stationBi-directional amplifier in a tunnel-mounted enclosure between portals.5Callout 6 — Platform antennasLow-PIM meander collinears covering the station platform.6Callout 7 — Monitoring and alarmsLevel and fault monitoring reported to the rail operations centre.7
CALLOUT 01DON-01

Off-air donor antenna

Fifteen-element yagi on the portal mast, aimed at the serving base station site. Front-to-back ratio is what isolates the donor from the antennas inside the structure.

SUPPLIED PRODUCT
YW15-6989
15 Element Yagi, 698–890 MHz
FREQUENCY
698 – 890 MHz
ELEMENTS
15
POWER
100 W
VSWR
< 1.8 : 1
SYSTEM
Rail
VIEW
LONGITUDINAL SECTION
CALLOUTS
7 positions
PARTS CITED
7 of 7

Where this applies

  • 01Underground and covered rail where the serving base station site is close but the signal is severely obstructed.
  • 02Station platforms, concourses and running tunnels served from one shared distribution run.
  • 03Networks where only nominated services may be re-radiated, requiring band-selective rather than broadband amplification.
  • 04Retrofit into an operating railway, staged in engineering possessions.

Equipment in this system

Every numbered callout on the schematic names a real RFI part. Select a callout to open its published specification, or browse the full range in the catalogue.

Browse the product catalogue

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Send the part numbers and quantities you need. If you are working from a specification or a bill of materials, attach it in your reply to our acknowledgement and we will price it as listed.

TERRITORY
Asia and EMEA
BRANDS
RFI · ANDREW · RFS

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