User Manual

MDR2400/5800-SR, Orion2410/5810-SRi and Orion 5825-SR
862-01881 Issue 12c Page 12
2 Technical Description
2.1 System Overview
A digital radio link (DRL) consists of a pair of MDR / Orion radio stations.
The radio stations consists of two main parts:
• An RF Unit operating in the 2.4GHz or 5.8 GHz ISM frequency bands. The RF
Unit provides the radio transceiver functionality by accepting radio link data from
the Digital Indoor Unit and converting it to the 2.4GHz or 5.8 GHz ISM frequency
band using spread spectrum or QAM modulation. The received signal is de-
modulated and transmitted to the Digital Indoor Unit in a digital format.
• An Digital Indoor Unit, available with 1, 2, 4 or 8 T1 and 1, 2, 4 or 8 E1 data
interfaces (choice of T1 or E1 is software selectable). The Digital Indoor Unit
combines nT1 or nE1 data with Wayside Service Channel serial data and link IP
data to be transmitted across the radio link. The Digital Indoor Unit also provides
power to the RF Unit.
Interconnection between RF Unit and Digital Indoor Unit is achieved using low cost
data and power cables.
2.2 RF Unit
The MDR2400, MDR5800, Orion2410i and Orion5810i RF Units make use of Spread
Spectrum modulation technology for license-free operation in the 2.4GHz and 5.8 GHz
ISM bands. The Orion5850 RF Unit uses three software selectable bandwidths for
license-free operation in the 5.8 GHz ISM band.
The Orion2410i and Orion5810i RFUs are MDR2400 and MDR5800 RFUs
respectively, that have been repackaged into 1U units that should be used in indoor
unit applications only. Please refer to Appendix K for more detail.
For operation, the ISM bands are divided into upper and lower frequency sub-bands.
A ‘High Band’ RF Unit transmits in the higher frequency sub-band and receives in the
lower frequency sub-band, while a ‘Low Band’ RF Unit transmits in the lower sub-band
and receives in the higher sub-band. An MDR / Orion radio link will use a ‘Low Band’
RF Unit on one end of the link to communicate with a ‘High Band’ RF Unit on the other
end.
The RF Units use a Type-N RF output connector for connection to suitable 2.4GHz
and 5.8GHz antennas for applications where long range is required.
The system is available for use in FCC regulated countries.
User Data
MDR2400, MDR5800 or
Orion 5850 OU
MDR / Orion IU
User Data
MDR2400, MDR5800 or
Orion 5850 OU
MDR / Orion IU